TABLE 1. ASSESSMENT SUMMARY SHEET FOR UKAB MEETING ON 24th APRIL 2013 Total Risk A Risk B Risk C Risk D Risk E 14 1 1 10 1 1

Remaining Ineffecti Barrier Not Barriers ve Applicable

Barriers Controller Aircrew Barriers Barriers

board board Risk - No Reporting Reported Airspace Cause Cat

Controller Action Action Controller tech by prompt Rules Procedures& Sighting Visual SART from SA from on Rules Procedures& Action Controller systems SAfrom ACAS ACAS RA Score

2012154 DHC8 A319 D/A The Air Controller did not ensure C 1 (CAT) (CAT) (Gatwick separation before transferring the CTR/LTMA) aircraft.

2012164 AW139 C150 G In the absence of TI the AW139 C 10 (CAT) (CIV) (London FIR) crew was concerned by the proximity of the C150.

Recommendation: The current RDP design for the Anglia Radar sector highlights the coastline in white, which is the same colour as radar tracks. NATS Ltd is recommended to amend the RDP to provide greater clarity between radar tracks and map features.

1

2012167 JS41 T ucano G In the absence of an agreement C 50 (CAT) T MK 1 (London FIR) with the Tucano pilot, the (MIL) controller did not take further action to achieve deconfliction minima.

2012171 ASK13 Hughes G The MD500 pilot flew close C 10 (CIV) MD500 (London FIR) enough to a promulgated and (CIV) active glider site to cause the launch party concern.

2012173 AS332L EC135 D The AS332 crew did not take C 50 (CAT) (CIV) (Aberdeen timely action to give way to the ATZ/CTR) EC135.

2012175 B777-200 2 U ntraced D A sighting report on final D X (CAT) Objects (NK) (Gatwick approach. CTR)

2013002 PA28 NANCHANG G The CJ6 pilot flew into conflict C 4 (CIV) CJ6 (White with the PA28 on final approach, (CIV) Waltham ATZ) which he did not see.

2013003 PA18 NANCHANG G The CJ6 pilot did not conform to B 20 (CIV) CJ6 (White the pattern of traffic formed and (CIV) Waltham ATZ) flew into conflict with the PA18 on final, which he had not seen.

2

2013004 2 X Hawk Hawk G Hawk B crew deviated from the C 2 T MK2(A) T MK2(B) (LFIR/Valley Mona-Valley transit procedure (MIL) (MIL) AIAA) without informing ATC and turned in front of Hawk (A) No2, which he did not see.

2013006 Wildcat Wildcat G A conflict resolved by Wildcat (A) C 21 AH1(A) AH1(B) (London FIR) pilot. (JHC) (CIV) Contributory Factor: Wildcat (B) pilot utilised an inappropriate ATS while conducting an air test.

2013007 Hawk Hawk G Effectively non-sightings by the A 100 T MK 2 T MK 1 (Valley AIAA) crews of both ac. (MIL) (MIL)

2013008 DA42 FA20 G FA20 crew flew close enough to C 1 TwinStar Falcon (SFIR/OTA E) cause the TAY controller and (CIV) (CIV) DA42 crew concern. Recommendation: The FA20 operator is recommended to comply with Leuchars ASA requirements when operating in OTA E.

2013012 Cessna F86A G Controller perceived conflict. E 1 C510 (CIV) (London FIR) (CIV)

3

2013013 Viking T1 PA28 G The PA28 pilot flew close enough C 4 (CIV) (CIV) (London FIR) to cause concern to the Viking pilot downwind in the Wethersfield circuit.

NB. Event Risk Barriers: It is important to note that the assessment records only whether a barrier failed to achieve what it is designed to do in terms of safety mitigation or still remained as an actual or possible safety mitigation. The ineffectiveness of a barrier does not imply failure or blame on the part of the pilot or controller responsible for implementing it.

4

ANNEX A TO APRIL BOARD REPORT DATED 03 MAY 2013

EVENT RISK CLASSIFICATION TRIAL

Question 1 Question 2

If this event had escalated into an What was the effectiveness of the remaining barriers accident outcome, what would between this event and the most credible accident have been the most credible scenario? outcome? No Effective Limited/ Minimal Not credible Partial effective accident scenario Catastrophic Multiple 1 50 102 502 2500 Accident passenger fatalities on ac with >19 seats or MTOW >5700kg or significant 3rd party risk. Major Multiple 10 21 101 500 Accident passenger fatalities on ac with 5-19 seats or >5 crew fatalities. Serious <6 fatalities or 2 4 20 100 Accident multiple injuries or ac damage

No accident May be outcome operational implications (eg diversion)

5

AIRPROX REPORT No 2012154

Date/Time: 3 Oct 2012 1719Z Position: 5108N 00017W (3·5nm W Gatwick - elev 203ft)

Airspace: CTR/LTMA (Class: D/A) GATWICK CTR SFC-2500ft LTMA 2500ft+ Reporter: LTC SW DEPS 19:30 A47 1st Ac 2nd Ac 1718:12 1718:00 Gatwick A28 A22 Type: DHC8 A319 19:12 Elev 203ft A42 18:48 A319 19:06 A35 A3919:00 Operator: CAT CAT A33 A37 A17 A34  DHC8  A21 Alt/FL: 2000ft NK 19:00 1718:12 19:12 A29 18:48 A12 (QNH) (NK) 19:30 A32 A25 A37 19:06 A31 Weather: IMC KLWD NK NR 0 1 ATZ Visibility: NR NM Radar derived Levels show Reported Separation: altitudes as Axx LON QNH 1005hPa NR NR SW DEPS 400ft V/1nm H Recorded Separation: 800ft V/1·5nm H

CONTROLLER REPORTED

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE LTC SW DEPS reports that the DHC8 flight called on departure from Gatwick following a SAM SID. Without identifying the flight formally she observed the ac to be 400ft, she thought, and approximately 1nm from the previous departing A319 on a DVR SID which was in a R turn. She gave the DHC8 flight an avoiding action L turn onto heading 240° and the ac were seen to pull apart. She asked the DHC8 crew whether they had been visual with the ac ahead and they replied negative.

THE GATWICK AIR CONTROLLER reports the A319 departed on a R turn DVR SID and the DHC8 was departed behind on a SAM SID. The A319 flight was transferred early passing 2300ft with the DHC8 just getting airborne. He noted the A319 GS was slow so he ensured that it was established in the R turn before looking to transfer the DHC8 flight noting that there was 1000ft separation. Shortly afterwards he noted the DHC8 had been turned L off the SID but the next departure was a R turn so would not be affected.

THE DHC8 PILOT reports on departure from Gatwick, IFR and in communication with Gatwick Tower and then London on 134·12MHz, squawking an assigned code with Modes S and C. Gatwick cleared them for departure from the full length of RW26L after having just cleared an A319 for take- off and its wheels had just left the RW. Heading 259° climbing through 2000ft they lost sight of the A319 in cloud but thought nothing of it as it was normal at Gatwick for departures to be close. They started to accelerate to 210kt in the climb to 4000ft on the SAM2M departure as Gatwick handed them over to London. As soon as they selected the London frequency they were given avoiding action onto heading 230° by the controller. They had not received a TCAS warning but the ac ahead was displayed on their TCAS screen. The avoiding action was carried out and then the controller said they would be filing a report owing to Gatwick ATC departing their ac so soon after another ac. He assessed the risk as low.

1 THE A319 PILOT reports being unaware of an Airprox during their departure from Gatwick so they were unable to provide any detailed information about the incident.

ATSI reports that the Airprox was reported by the LTC SW (Deps) controller in Class A airspace, when avoiding action was given to the DHC8 after departure from London Gatwick Airport, due to the DHC8 having less than the required radar separation (3nm/1000ft) against a previous departing A319.

The A319 was operating IFR on a flight from Gatwick to Frankfurt and was in receipt of a RCS from LTC BIG on frequency 120·525MHz.

The DHC8 was operating IFR on a flight from Gatwick to Nantes and was in receipt of a RCS from LTC SW (Deps) on frequency 134·125MHz.

CAA ATSI had access to written reports from both pilots, the Gatwick AIR controller, the LTC SW (Deps) controller, area radar recordings, RT recordings and transcripts of the Gatwick Tower frequency and the SW (Deps) frequency together with the unit investigation report from London Terminal Control.

The Gatwick METARs are provided for 1650 and 1720 UTC:

EGKK 231650Z 21008KT 180V240 9999 FEW024 13/09 Q1006= and EGKK 231720Z 22007KT 9999 FEW022 BKN046 13/09 Q1006=

At 1717:15 UTC the A319 became airborne on a DVR8M SID, which requires a climb to altitude 4000ft with a R turn at 2·3DME from I-WW at Gatwick.

At 1717:42 (27sec after the A319 was airborne) the DHC8 became airborne on a SAM2M SID climbing to altitude 4000ft, initially straight ahead before a slight L turn at 8DME from MID. The AIR controller was using reduced separation in the vicinity of the aerodrome. CAP493 Section 1, Chapter 3, Page 1, Paragraph 3.2 states:

‘In the vicinity of aerodromes, the standard separation minima may be reduced if:

a) adequate separation can be provided by the aerodrome controller when each aircraft is continuously visible to this controller;’ or

b) each aircraft is continuously visible to the pilots of other aircraft concerned and the pilots report that they can maintain their own separation; or

c) when one aircraft is following another, the pilot of the succeeding aircraft reports that he has the other aircraft in sight and can maintain own separation.’

At 1718:00 the A319 was transferred to LTC BIG. At 1718:39 the Mode S SFL changed to indicate that the A319 was climbing to 6000ft. The climb rate of the A319 was 896fpm while the climb rate of the DHC8 was 1856fpm.

[UKAB Note (1): The DHC8 first appears on radar at 1718:18 climbing through altitude 1200ft QNH with the A319 1·7nm ahead climbing through 2800ft QNH.]

At 1718:50 the DHC8 was transferred to LTC SW (Deps). The radar recording indicates that the A319 had just started the R turn and was passing altitude 3600ft with the DHC8 1·6nm behind passing altitude 2500ft.

At 1719:05 the DHC8 contacted LTC SW (Deps), “London (DHC8 c/s) Southampton two mike passing altitude three thousand three hundred climbing four thousand”. The A319 was in the R turn

2 passing altitude 3700ft with a climb rate of 960fpm with the DHC8 1·5nm behind passing altitude 2900ft with a climb rate of 1696fpm. Low level STCA activated at 1719:10.

The LTC SW (Deps) controller transmitted, “(DHC8 c/s) avoiding action turn left heading two four zero degrees there’s traffic in your one o’clock range of one mile”. This was correctly read back by the crew of the DHC8 at 1719:20. The controller then asked, “(DHC8 c/s) were you visual with the one ahead” and the crew replied, “negative (DHC8 c/s)”.

[UKAB Note (2): The CPA (800ft /1·5nm) occurs during the 2 radar sweeps at 1719:00 and 1719:06, before separation increases to 1000ft/1·6nm at 1719:12 with the A319 turning R through a NW’ly heading, climbing through 4200ft, with the DHC8 climbing through 3200ft. The DHC8’s avoiding action L turn is evident on the radar recording at 1719:30.]

The written report from the Gatwick AIR controller stated that the DHC8 was transferred when the A319 was in the R turn and the DHC8 was 1000ft below the A319.

Prior to transferring the A319 and the DHC8, the Gatwick AIR controller was providing reduced separation in the vicinity of the aerodrome. The Gatwick Manual of Air Traffic Services Part 2, Air section, Chapter 3, states that:

‘departing aircraft are not to be transferred to TC until suitable separation exists.’

There is no specific guidance as to what constitutes ‘suitable’ separation. The use of the term ‘suitable separation’ is less prescriptive than the instructions contained in some other MATS Part 2 of airfields that transfer traffic to LTC. ADCs at Gatwick are expected to use their own judgement and experience to determine an appropriate point for transfer of communication and control to the radar controller. In this case the DHC8 was transferred to LTC when the separation provided was not acceptable to the LTC SW (Deps) controller.

At the point of transfer to LTC SW (Deps) the Gatwick AIR controller was content that adequate separation had been provided between the 2 departures, which the controller believed was confirmed by the information displayed on the ATM – the A319 was in the R turn and the DHC8 was 1000ft below. However, the AIR controller may not have given due consideration to the climb rate of the DHC8 relative to that of the A319 and transferred the DHC8 when vertical separation was eroding. When the DHC8 flight contacted the LTC SW (Deps) controller the 2 ac were 1·5nm and 800ft apart and the LTC SW (Deps) controller took avoiding action.

In sum, an Airprox was reported when the LTC SW (Deps) controller became concerned about the relative distance and positions between an A319 and a DHC8 on departure from Gatwick such that avoiding action was issued to the DHC8. The Gatwick AIR controller had been using reduced separation in the vicinity of the aerodrome but transferred the DHC8 before separation against a preceding A319 was acceptable to the LTC SW (Deps) controller.

Recommendation

It is recommended that both Gatwick and LTC review the wording of the Gatwick MATS Part 2, Air Section, Chapter 3 - ‘departing aircraft are not to be transferred to TC until suitable separation exists’ - to ensure that either both units have an understanding and acceptance of the term ‘suitable’ or alternative wording is used to clarify the conditions under which traffic will be transferred to TC.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequencies, radar video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC authorities.

3 Controller Members agreed that the spacing was tight when AIR cleared the DHC8 for take-off behind the A319 but the situation was manageable utilising ‘reduced separation in the vicinity of an aerodrome’ (RSITVOAA). A CAT pilot Member commented that controllers exercising this visual separation should not assume ac performance as crews do have options to adjust their flight profile to suit the conditions at the time. When he saw the A319 commence its R turn, and he transferred the DHC8 to LTC SW Deps, AIR was content that 1000ft vertical separation existed. However, the DHC8 was climbing at a higher rate than the preceding A319. This had led to the DHC8 flight calling on the SW Deps frequency with only 800ft vertical separation, which triggered STCA low-severity alert, and caused the radar controller sufficient concern that she felt that an avoiding action L turn was required. Had the AIR controller retained the DHC8 on his frequency for a short while longer, applying RSITVOAA until radar separation (1000ft/3nm) was ensured after transfer, the LTC controller would not have been placed in that invidious position. Members noted the comment and recommendation made by ATSI with respect to the MATS Part 2 guidance dealing with transfer of ac to LTC with ‘suitable’ separation existing. This guidance was very much down to individual controller judgement and experience; on this occasion AIR had not ensured separation before transferring the DHC8 to LTC and this had caused the Airprox.

Neither the A319 nor DHC8 crews were concerned with the situation. The early transfer of the DHC8 led to a momentary (~10sec) loss of radar separation (800ft/1·5nm) - the SW Deps controller perceiving 400ft/1nm – before separation was restored. The avoiding action L turn issued to the DHC8 flight does not become evident until after the CPA. Once the A319 had commenced its R turn, the DHC8’s straight-ahead track profile required of the SAM SID meant that the ac were not on converging/conflicting tracks, which allowed the Board to conclude that any risk of collision had been quickly and effectively removed.

The NATS Advisor informed Members that the ATSI recommendation had been received recently and this would be addressed following a Safety Survey to be undertaken later in 2013.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The Gatwick AIR controller did not ensure separation before transferring the DHC8 to LTC SW Deps.

Degree of Risk: C.

4 AIRPROX REPORT No 2012164

Date/Time: 15 Nov 2012 1510Z Diagram based on radar data Position: 5245N 00139E (8nm and pilot reports NNE of North Denes) AW139 1500ft alt Airspace: (Class: G) (Class: G) 014 Reporting Ac Reported Ac 3 Type: AW139 C150 1511:42 Operator: CAT Civ Trg 1511:58 2 014 1512:12 Alt/FL: 1500ft 2000ft NM 1512:28 RPS (1017hPa) QNH (1021hPa) 1512:43 1 Weather: VMC/CAVOK VMC/NR 014 Visibility: 20km 0 Reported Separation: CPA 1512:54 N/R V 0.3nm H 150ft V/0.75nm H C150 Recorded Separation: 2000ft alt Norwich CTA 0.3nm H 1500ft-FL50

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE AW139 PILOT reports returning to North Denes from an off-shore gas installation, cruising at 1500ft on the RPS of 1017hPa, heading 170° at 140 kt. The helicopter was red, white and blue with HISLs, navigation lights and two landing lights on and a serviceable TCAS1 system fitted. The pilot reports flying IFR in VMC, clear of cloud with 20km visibility. Anglia Radar was providing a TS on 125.275MHz; the ac was squawking A0263 with Modes S and C turned on.

The pilot reports seeing a high wing, single engine aircraft that he thought to be a small Cessna in his 1130 position, slightly above and on a reciprocal heading. The Airprox occurred 8nm N of North Denes and he reports that he initiated a 90° R turn, following which the other ac started to turn L towards him and he lost sight of it as it passed behind his helicopter. The pilot reports first sighting the C150 at a range of 1-2nm and estimated the minimum separation distance as 0.75nm horizontally and 150ft vertically; no contact was shown on TCAS.

THE C150 PILOT reports flying a blue and white ac on a training sortie from Beccles with a passenger/student who wished to take some photographs during the flight. He was flying VFR in VMC receiving a BS from Norwich APP on 119.35MHz; the ac was not equipped with a transponder.

The pilot reports that he had no recollection of the Airprox.

THE NORWICH APPROACH CONTROLLER reports that he was providing a BS to the C150 on 119.35MHz but he has no recollection of the event and he was unaware of the Airprox at the time.

NORWICH ATC INVESTIGATION reports that due to a complex traffic situation in Class D airspace and the need to monitor airways joining instructions and co-ordination with other ATC agencies, the pilot of the C150 was told to standby following his first call at 1502:02. APP only responded when the pilot called again at 1511:00, during which time the aircraft had progressed north along the coast. APP made an assumed identification of the C150 based on a position report. Notwithstanding this, APP twice issued timely and accurate traffic information to the C150 pilot on the AW139’s position.

APP was correct to issue a traffic warning to the C150 pilot in accordance with ‘safety of life’ requirements under BS. The correct phrase of ‘traffic believed to be you’ was not used and the

1 presumed identification was later reinforced when APP issued a joining clearance to the C150 pilot. Nonetheless based on the C150 pilot’s reported information, track progress, speed and headings there is little doubt that APP had identified the correct aircraft.

THE ANGLIA RADAR CONTROLLER reports that he was controlling the AW139 on 125.275MHz, 9nm NNW of North Denes under a TS, when the pilot reported taking avoiding action against a light ac. He recalls that the pilot filed an Airprox on his frequency and reported that the conflicting ac was 200ft above him tracking from S to N.

The controller reports that he did not observe any primary radar contact until approximately a minute after the Airprox when he observed a contact 2nm N of the reported Airprox position tracking N.

ATSI reports that the Airprox was reported by the pilot of an AW139 against a C150 in Class G airspace, 8nm N of North Denes Airport.

The AW139 was operating IFR, returning to North Denes from an offshore gas installation and was in receipt of a TS from Anglia Radar on frequency 125.275MHz.

Another helicopter, an EC155, which was conflicting with the AW139, was in receipt of an Offshore DS from Anglia Radar on frequency 125.275MHz.

The C150 was operating VFR on a flight to and from Beccles Airfield and was in receipt of a BS from Norwich Radar 119.350MHz.

CAA ATSI had access to written reports from the pilots of the AW139 and the C150, the Anglia Radar and Norwich Radar controllers, area radar recordings, Anglia Radar recordings, RTF recordings of both Anglia Radar and Norwich Radar frequencies and also the unit investigation report from Aberdeen (where Anglia Radar is based).

The North Denes METARs are provided for 1450 and 1520 UTC:

EGSD 151450Z VRB02KT 9000 NSC 10/08 Q1021 NOSIG= and EGSD 151520Z VRB03KT 8000 NSC 10/08 Q1021 NOSIG=

At 1433:45 UTC the pilot of the AW139 contacted Anglia Radar. The AW139 was identified and informed that the service was being provided using SSR only. The Aberdeen Manual of Air Traffic Services Part 2, Section GEN, Annex A states:

‘In the Anglia Radar Area of Responsibility only, when the controller informs a signatory helicopter in surveillance cover that it is identified, this is notification that the default FIS (in this case Offshore Deconfliction Service) will be provided, unless the controller states otherwise. When the default FIS is provided, the controller will not state the service. The Offshore Deconfliction Service will commence from the time the pilot is informed that the helicopter is identified and will continue until:

i. The pilot is advised of a change of service, or ii. The aircraft leaves the Anglia Radar Area of Responsibility, or iii. The aircraft leaves the frequency.’

At 1502:10 the pilot of the C150 contacted Norwich Radar and was instructed to standby.

At 1506:45 the Anglia Radar controller called the pilot of the AW139 to advise that there was an EC155 inbound to Norwich that might affect the descent of the AW139 and asked if the pilot of the AW139 was happy to expedite descent to 500ft. The pilot of the AW139 replied that they would be using RW09 at North Denes and would like 1500ft. The Anglia Radar controller replied that the

2 AW139 should maintain 2500ft until they had crossed the EC155 and the pilot of the AW139 replied that they were maintaining 2500ft.

At 1508:50 (Figure 1) the AW139 was tracking SSE at 2500ft with the EC155 at 1500ft on its LHS. The primary return from the C150 can be seen on the coast as indicated.

At 1509:45 the Anglia Radar controller established that the EC155 had the AW139 in sight and gave the AW139 descent to 1500ft. C150 PSR At 1510:50 the C150 pilot called Norwich Radar again and return was instructed, “pass your message”. The C150 pilot advised that they were out of Beccles and flying northbound Figure 1 Anglia Radar 1508:50 around the coast abeam Hickling at 2000ft on QNH 1022hPa and requesting a BS. The Norwich Radar controller replied that there was a helicopter inbound to North Denes in the C150’s, “...twelve o’clock five miles reciprocal same level, is a helicopter inbound to North Denes.” The C150 pilot replied that he was looking and a BS was agreed.

At 1511:40 the Norwich Radar controller instructed the C150 pilot to squawk A7370 if he was transponder equipped; to which the pilot replied that the C150 was negative transponder. The Norwich Radar controller updated the TI on the helicopter stating that it was “twelve o’clock three miles has descended 1600ft”. The C150 pilot acknowledged the transmission and stated that he was at 2000ft. Figure 2 shows the Anglia Radar display at 1511:40 highlighting the lack of conspicuity between the C150 primary return and the coastline map.

Figure 2 Anglia Radar display at 1511:40

On Figure 3, also at 1511:40, the Primary return of the C150 has been highlighted. C150 PSR return

Figure 3 Anglia Radar display at 1511:40

At 1511:45 the AW139 crew reported visual with the EC155 and the service was changed to a TS. [UKAB Note (1): ANGLIA RADAR was providing an Offshore DS until this point.]

At 1512:40 the Norwich Radar controller advised the pilot of the C150 that the AW139 was about to fly underneath the C150 and that the AW139 was believed to be 400ft below.

3 At 1513:00 the AW139 pilot advised the Anglia Radar controller that they were taking evasive action from a fixed wing ac a couple of hundred feet above, which was travelling S to N. The Anglia Radar controller acknowledged the transmission and advised that nothing was seen on radar.

[UKAB Note (2): The CPA measured on the radar recording at 1512:54 is 0.3nm H, but the primary return of the C150 is lost for one radar sweep immediately after that point so it may be marginally closer. The Mode C of the AW139 is FL014 and the C150 reported level at 2000ft on QNH 1021hPa giving a calculated vertical separation at the CPA of 360ft.]

At 1513:15 the AW139 crew advised Anglia Radar that the traffic was just behind them and that they had lost visual contact. At 1514:00 the Anglia Radar controller advised the pilot of the AW139 that he could see a primary contact tracking NW that was probably the traffic.

The incident took place in Class G airspace where both pilots were ultimately responsible for their own collision avoidance.

The unit investigation stated that the Anglia Radar controller did not see the primary return of the C150 at any time prior to the incident. When the AW139 reported taking evasive action the controller replied that nothing was seen on radar. Although the white primary return from the C150 could be seen on the Anglia replay it followed the coastline (also in white on the video map) very closely and is somewhat indistinct (see Figures 1, 2, and 3) particularly in comparison to other primary returns and secondary returns on the situation display. According to the unit report PSR clutter over the sea caused by both wave tops and wind turbines is not uncommon on the Anglia Radar sector. It is also possible that the controller may have subconsciously filtered out the target. Before the Airprox occurred the Anglia Radar controller’s focus was on the confliction between the EC155 and the AW139, which may have reduced the possibility of seeing the primary return from the C150.

The Norwich Radar controller gave TI on the AW139 to the C150 pilot. The Norwich Radar controller noticed the confliction after the C150 pilot called for a BS and described their position and level. The squawks of all Anglia Radar helicopters are converted in the Norwich RDP so the Norwich Radar controller was aware of the identity and level of the AW139 from the Mode C of the AW139 before passing TI. Conversely, the Anglia Radar controller was not aware of the presence of the C150 and an indistinct primary return with no associated secondary information was the only indication available to the Anglia Radar controller that there was conflicting traffic.

An Airprox occurred when an AW139 and a C150 came into proximity with each other 8nm N of North Denes Airport. The Norwich Radar controller passed TI on the AW139 to the C150 pilot. The Anglia Radar controller was not aware of the presence of the C150 and therefore was not able to provide TI to the AW139 crew.

PART B: SUMMARY OF THE BOARD’S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequencies, radar video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC and operating authorities.

Whilst the Board noted that there was a considerable delay between the C150 pilot’s first call and the provision of a BS by Norwich APP they also noted that the controller had been busy with other tasks. There was some discussion about the provision of TI by Norwich APP under a BS; the Board agreed that the TI provided was accurate, timely and appropriate under the ‘safety of life’ requirements of a BS and that Norwich APP had acted correctly in choosing to pass TI. Given the TI provided, the weather conditions and the CPA, some members of the Board expressed surprise that the pilot of the C150 did not achieve visual contact with the AW139.

The Members felt that the initial sighting distance of 1-2nm reported by the AW139 pilot was quite normal in Class G airspace given the geometry of the encounter and that if the AW139 crew had received TI on the C150 it was possible that they may have adjusted their course to prevent the

4 encounter becoming so close. The Board noted that the Anglia Radar controller was controlling a large area of airspace and was also focussing on deconflicting the AW139 from another helicopter. Members were clear that the colour of the coastline on the Anglia Radar display would have made it very difficult for the Anglia Radar controller to spot the primary return of the C150, especially so given that the Anglia Radar controller had to divide his attention at the time. The Board concluded that the Anglia Radar map was a significant factor contributing to the lack of TI provided to the AW139 crew and the display design should be reviewed.

There was some discussion about the circumstances when a controller should limit radar services but it was concluded that the level of clutter reported and observed on the radar recordings would not warrant Anglia Radar imposing a limitation.

In assessing the Risk, Members noted that the C150 pilot did not see the A319, at any stage. However, based on his reported altitude and QNH, the C150 pilot was some 400ft higher than the A319. Moreover, the helicopter crew had spotted the C150 early enough to take effective avoiding action that resulted in a minimum recorded horizontal separation of 0.3nm. The Board was satisfied, therefore, that A319 crew had removed any risk of a collision.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: In the absence of TI the AW139 crew was concerned by the proximity of the C150.

Degree of Risk: C

Recommendation: The current RDP design for the Anglia Radar sector highlights the coastline in white, which is the same colour as radar tracks. NATS Ltd is recommended to amend the RDP to provide greater clarity between radar tracks and map features.

Post UKAB Note: Following further investigation, NATS Ltd report that the media used for the AIRPROX investigation shows the radar map and the ac returns to be coloured white; this is not the case with radar display that the controller actually sees. The coastline, as displayed to the controller, is shown in beige but there is also a cyan coloured line along this section of the coast which denotes the boundary of the Anglia Offshore Safety Area (OSA); this combination of colours created the impression of white on the media used for the Board. NATS Ltd have concluded that the removal of the cyan line from the coastal boundary (whilst retaining it in the offshore areas) would not reduce the ATCOs’ knowledge of the extent of the OSA, and may increase the possibility of the ATCO identifying a slow moving aircraft following the coastline. Consequently, NATS Ltd have accepted the recommendation and will take appropriate action to amend the way the maps on the radar displays.

5 AIRPROX REPORT No 2012167

Date/Time: 4 Dec 2012 1202Z Diagram based on radar data Position: 5514N 00133W (12.5nm NNE Newcastle A/D) JS41 Airspace: Scot FIR (Class: G) F060 Reporting Ac Reported Ac Type: JS41 Tucano T Mk 1 F053 1200:04 Operator: CAT Mil Trg 5 00:27 Alt/FL: 3800ft 5000ft F047 QNH (999hPa) RPS (NR) 00:51

F044 Weather: VMC NR VMC NR NM 01:14 Visibility: >10km NR F047 F080 F080 Reported Separation: F041 F056 F080 NR NR V/2nm H Tucano 0 Recorded Separation: Newcastle CTA 600ft V/1.3nm H CPA 1201:38 600ft V 1.3nm H 0ft V/2.7nm H

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE JS41 PILOT reports flying the final descent into Newcastle A/D. She was operating under IFR in VMC with a RCS from Newcastle APP, she thought [124.375MHz]. The white and blue ac had navigation, conspicuity and strobe lights selected on, as was the SSR transponder with Modes A, C and S. The ac was fitted with TCAS II. When 9nm NE of Newcastle A/D, heading 165° at 220kt and descending through altitude 3800ft, she was informed by Newcastle APP of a ‘light ac’ turning away from her. She saw the ac about 4nm to the E, which appeared to both crew to be doing aerobatics. A short while later she received a TCAS TA and then RA ‘monitor vertical speed’, indicating a 2900fpm RoD, followed by ‘climb climb’. She reported the Airprox to Newcastle APP.

She assessed the risk of collision as ‘Low’.

THE TUCANO PILOT reports commencing his descent into low level after a medium level transit from his home base. He was operating under VFR in VMC with a TS from Newcastle RAD [284.600MHz]. The black and yellow striped ac had navigation, landing and strobe lights selected on, as was the SSR transponder with Modes A and C. The ac was fitted with TCAS I. He had been cleared to descend from FL110 with descent stopped at FL80 due to Jetstream traffic in his 1 o'clock position at ‘about 6nm and 5000ft’. He was approaching his low level entry point and, content that there were sufficient large gaps in the cloud below him to descend through, he informed Newcastle RAD that he ‘was VMC’ and was continuing en-route. The controller asked him to remain on frequency in order to update him on the previously notified traffic. As he had informed the controller that he was VMC and continuing en-route, he believed he was now in receipt of a BS and that the controller was ‘just keeping [him] on frequency to provide updates on the Jetstream’. He did not believe the Jetstream to be a factor, as his SA put the ac several miles to the NW, and he descended rapidly through a gap in the cloud in order to set up for entry to low level, a high workload part of the sortie. He remained VMC throughout the descent, but with some of his attention focused on ‘the navigational aspects’ of the sortie. He then overheard an RT exchange between the Jetstream pilot and Newcastle RAD from which he understood that the Jetstream pilot was 'going to have to file an Airprox’ because she had ‘received a TCAS TA’ as he passed through her level at 5000ft. He did not

1 see the Jetstream but noticed on TCAS that it was just inside 2nm range; he did not receive a TA throughout the incident.

He assessed the risk of collision as ‘Low’.

THE NEWCASTLE APPROACH CONTROLLER reports the JS41 pilot was inbound to Newcastle on a DS, heading 160° and descending to altitude 3500ft. The Tucano pilot was on a TS, requesting to go low level to the N and cleared to descend to FL80 until clear of the JS41. When the Tucano pilot requested to go en-route he gave him an update on the JS41 and passed the Tyne RPS. He requested the Tucano pilot to advise him when going en-route, which he acknowledged, replying, “wilco”. He observed the Tucano descending and immediately gave TI to the JS41 pilot on the Tucano who then advised him of the TCAS RA. He acknowledged this and confirmed that the Tucano pilot was still on frequency. The JS41 pilot confirmed that she had the Tucano in sight during the descent.

ATSI reports that an Airprox was reported by the pilot of a British Aerospace Jetstream 41 (JS41) when it received a TCAS RA against a Tucano T1 (Tucano) at 1201:30 in Class G airspace, 12.6nm NNE of Newcastle A/D.

Background

The JS41 pilot was operating IFR on a flight from Aberdeen to Newcastle and was in receipt of a DS from Newcastle APP on frequency 124.375MHz, which was cross-coupled with frequency 284.600MHz. The Tucano pilot was on a flight operating from RAF Linton-on-Ouse and was in receipt of a TS from Newcastle APP on frequency 284.600MHz.

CAA ATSI had access to written reports from the JS41 and Tucano pilots and the Newcastle Approach controller together with area radar recordings and RTF recordings from Newcastle APP.

The Newcastle weather was recorded as follows:

METAR EGNT 041150Z 28007KT 9999 FEW035 03/02 Q0999= METAR EGNT 041220Z 28005KT 9999 FEW015 03/02 Q0999=

Factual History

At 1148:10, the Tucano pilot, level at FL110, contacted Newcastle APP requesting a TS. Newcastle APP replied that he was identified on transfer and agreed a TS, instructing the pilot to report ready for descent. At 1155:30, the JS41 pilot, descending to FL120, contacted Newcastle APP requesting a DS. This was agreed and the JS41 pilot was subsequently given descent to FL70.

At 1157:20, the Tucano pilot informed Newcastle APP that he would be ready for descent in one minute’s time. The controller replied, “Roger report ready”.

At 1157:30, the JS41 pilot was instructed to fly heading 160° and given descent to altitude 5000ft [QNH 999hPa].

At 1158:00, the Tucano pilot reported ready for descent and the controller instructed him to descend to FL80, which was read back correctly.

At 1158:22, the JS41 was 24.6nm N of Newcastle, tracking 160°, and the Tucano was 19.9nm NE of Newcastle tracking W.

At 1159:00, the JS41 pilot was instructed to descend to altitude 3500ft.

At 1159:30, the Tucano pilot was instructed to maintain FL80 on reaching and was given TI on the JS41. The Tucano pilot read back, “maintaining eigh- fli-er flight level eight zero”.

2

At 1200:10, the Tucano pilot reported to the controller that he was, “VMC and continuing en-route er thanks for the service”. The controller updated the TI on the JS41 and passed the Tyne pressure setting, stating, “taking your own terrain clearance”. The Tucano pilot replied that he had copied the traffic and read back the new pressure setting. The controller instructed the Tucano pilot to squawk 7000 and report when going en-route. The Tucano pilot replied, “-service squawking seven thousand er wilco [C/S]”.

At 1200:36, the Tucano was indicating FL079 tracking W with the JS41 6nm NW, descending through FL051 on a converging track.

At 1201:00, the Tucano was indicating FL067, descending. The controller transmitted to the JS41 pilot, “Tucano ac just to the er southeast of you by about two and a half miles manoeuvring he’s turning left to go eastbound descending through your level very shortly er he’s indicating five thousand two hundred feet”.

At 1201:20, the Tucano pilot had turned L and was at FL056 at a range of 2.9nm from the JS41; he appeared to be turning away. The JS41 pilot acknowledged the TI and the controller advised that, “he’s just clearing your left hand side he’s in your eleven o’clock range of three miles”.

At 1201:30 the Tucano pilot was in a RH turn, 1.8nm ESE of the JS41, descending through FL052, while the JS41 pilot was descending through FL042. At 1201:35 the JS41 pilot advised the controller that she had received a TCAS RA.

The controller acknowledged the TCAS RA by replying, “roger”. At the end of that transmission the Tucano pilot was tracking N and passed down the LH side of the JS41 at a range of 1.3nm. The controller asked the Tucano pilot if he was still on frequency. The Tucano pilot replied that he was but that he was going en-route. The controller requested the Tucano pilot to remain on frequency due to the TCAS RA reported by the JS41 pilot.

The screenshots below, using the Great Dun Fell radar, show the sequence of events between 1201:20 and 1201:40.

At 1202:00, the JS41 pilot reported clear of conflict.

During a telephone interview with ATSI, Newcastle APP stated that when the Tucano pilot requested to go en-route and the controller updated the TI on the JS41, he had expected that the Tucano pilot would avoid the JS41. When the Tucano pilot descended and turned L, the controller believed that he was in the process of doing so. The controller expected the Tucano to then continue E-bound and turn L towards the Amble lighthouse, which would have taken him behind the JS41. When the Tucano pilot turned R the controller was not sure if he was still on frequency and decided that passing TI to the JS41 pilot on the Tucano position was the best course of action.

3

The written report from the JS41 pilot stated that ATC advised her of a light ac turning away to the E. When the crew saw the traffic it appeared to be conducting aerobatics. After watching the ac ‘for a minute’ the crew observed the Tucano making a series of tight turns. They subsequently received a TCAS RA.

The written report from the Tucano pilot stated that he was in receipt of a TS from Newcastle APP outside CAS and had been given descent to FL80 from FL110. He was aware that the descent had been restricted due to a Jetstream 6nm away at 5000ft. He was approaching his low level entry point and was content that there were sufficient gaps in the cloud to descend through, so he informed the controller that he was VMC and going en-route. He believed that the controller asked him to stay on frequency to update the TI on the JS41. The Tucano pilot believed in retrospect that he and the controller had different ideas of the service being provided; the pilot believed that the service had changed to a BS as he had informed the controller that he was VMC and going en-route. The Tucano pilot descended in a gap to set up for the low level entry, whilst remaining VMC. He noticed on TCAS that the JS41 was just inside 2nm but he did not receive a TA.

Analysis

Both ac were operating in Class G airspace where, regardless of the service being provided, pilots are ultimately responsible for their own collision avoidance.

The Newcastle Radar controller had previously instructed the Tucano pilot to stop descent at FL80, due to the inbound JS41, which the Tucano pilot was aware of. The controller was providing a Deconfliction Minima of 3nm or 1000ft between the 2 ac. CAP493, the Manual of Air Traffic Services, Section 1, Chapter 5, Page 10, Paragraph 10.1.5 states:

‘Aircraft under Deconfliction Service. If the intentions of the Mode C transponding aircraft are not known, the vertical deconfliction minima must be increased to 3000ft ...’

When the Tucano pilot stated he was going en-route the controller passed updated TI on the JS41 and had an expectation that the Tucano pilot would avoid it. However, the 2 ac were converging and the controller did not further agree co-ordination with the Tucano pilot. CAP 774 Chapter 1, Page 2, Paragraph 6, states:

‘Agreements can be established between a controller (not a FISO due to limits of the licence) and a pilot on a short-term tactical basis, such that the operation of an aircraft is laterally or vertically restricted beyond the core terms of the Basic Service or Traffic Service. This is for the purposes of co-ordination and to facilitate the safe use of airspace, particularly those airspace users with more stringent deconfliction requirements. In agreeing to a course of action, pilots must take into account their responsibilities as defined under the Rules of the Air, including that for terrain clearance. Unless safety is likely to be compromised, a pilot shall not deviate from an agreement without first advising and obtaining a response from the controller. Controllers shall remove restrictions as soon as it is safe to do so.

Agreements may be made which restrict aircraft to a specific level, level band, heading, route, or operating area. Controllers should be aware that not all requests for an agreement will be accepted and they should try to take account of the pilot’s operating requirements whenever possible. Consequently, controllers should avoid excessive or unnecessary use of agreements and be prepared to act accordingly if an agreement is not met.’

When the Tucano pilot turned L and descended the controller passed TI to the JS41 pilot but believed that the Tucano was turning away from the JS41. The controller was not expecting the Tucano pilot to then turn R, towards the JS41, and was unable to take any action to assist the JS41 pilot in discharging her collision avoidance responsibility due to the limited time available.

Conclusion

4

The Airprox occurred when the controller allowed the 2 ac to continue on converging tracks, without agreeing co-ordination with the Tucano pilot, which resulted in loss of the deconfliction minima and prompted a TCAS RA.

[UKAB Note(1): A TCAS Performance Assessment of the incident was provided by NATS Ltd. Note that as no TCAS RA events were downlinked, there are none included in the simulation.

Date: 04/12/2012 12:02 Mode A code for A/C 1: 3764 Mode A code for A/C 2: 3754, then 7000

Mode S Downlink

No TCAS RAs were recorded via Mode S downlink.

InCAS Simulation

InCAS Alert Statistics

Mode A: 3764 Alert Time Alert Altitude (FL) Intruder Range Vertical Sep. (ft) Description (Nm) 12:00:59 TRAFFIC ALERT 45 3.39 2063 12:01:25 TRAFFIC ALERT 42 2.19 731

Mode A: 3754 Alert Time Alert Altitude (FL) Intruder Range Vertical Sep. (ft) Description (Nm) This aircraft was not TCAS II equipped

5 Closest Point of Approach (CPA) CPA Time Horizontal Sep. Vertical Sep. (ft) (NM) 12:01:38 1.21 638

Minimum Lateral Separation Min. Latsep Time Horizontal Sep. Vertical Sep. (ft) (NM) 12:01:38 1.21 637.93

Minimum Vertical Separation Min. Vertsep Time Horizontal Sep. Vertical Sep. (ft) (NM) 12:01:56 2.66 11.15

Assessment of TCAS Performance

Eurocontrol’s automatic safety monitoring tool (ASMT) did not record any RAs relating to this encounter. The encounter was modelled in InCAS using MRT data (Multi Radar Track) in order to capture both sections of the Tucano track before and after its SSR code change.

As no TCAS RAs were recorded via Mode S downlink it was assumed that at least one aircraft was not TCAS II equipped. The Tucano was modelled as Mode S only and the JS41 was modelled as TCAS II equipped.

InCAS simulation suggests a geometrical CPA of 1.21nm and 638ft at 12:01:38.

InCAS simulation based on the stated equipage assumptions suggested that the JS41 pilot received two TAs at 12:00:59 and 12:01:25. Approximately 40 seconds after the second TA, the JS41 pilot levelled-off at a Mode C altitude of 3,600ft. At this point the pair were over 3.5nm apart laterally, and diverging both laterally and vertically.]

HQ AIR (TRG) comments that the Tucano pilot assessed he could continue safety in VMC without an ATS and that he had enough separation based on TI and TCAS to descend clear of the JS41. The student pilot was re-briefed after the event that a better course of action would have been to ensure lateral separation before attempting the descent. In this case, continuing the turn to the L would have maintained greater separation. CAP774 requires pilots under an ATS who have made an agreement with their controller not to deviate from that agreement without first informing and gaining an acknowledgement from the controller; whilst the Tucano pilot did not specifically state he would descend below FL80 it is clear that the controller understood that this was his intention. The Tucano TCAS alerts are triggered at much closer range than other systems to avoid nuisance warnings and in recognition of the increased manoeuvrability over a commercial airliner. However, it provides a significant increase in situational awareness.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequencies, radar photographs/video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC and operating authorities.

The Board initially discussed the JS41 pilot’s reported belief that she was under a RCS. Civilian pilot Members noted that confusion could be caused when pilots left CAS, passing from a RCS to ATSOCAS, with pilots mistakenly believing they were still under a RCS. It was opined that this misapprehension can be mitigated by controllers’ meticulous use of the phrase ‘leaving controlled airspace’. In this case it was noted that the JS41 operating company regularly flew ‘off airways’ on

6 this route and that the JS41 pilot may have been using RCS ‘in a generic sense’; alternatively, as she had requested a DS on first contact with Newcastle and the Airprox occurred shortly before the JS41 entered CAS, the reference to RCS may have been a memory/reporting error. The Board noted that the JS41 pilot correctly reported the TCAS RA and clear of conflict on the RT.

Turning to the actions of the Tucano pilot, a military pilot Member opined that he could have assisted the situation by electing to continue his L turn or by turning R instead of L. He also pointed out that the Tucano pilot’s SA was such that he did not believe the JS41 to be a factor and that the Newcastle APP had cleared him en-route, passing the RPS and instructing him to squawk 7000. ATC Members noted that the controller was providing an excellent service and had achieved a deconfliction plan when the Tucano pilot agreed to maintain FL80 but by subsequently clearing him en-route he had changed his deconfliction minima from 3nm and 1000ft (co-ordinated ac) to 3nm and 3000ft (intentions of the Mode C transponding aircraft not known). At that stage he was working under the belief, in hindsight mistaken, that the Tucano pilot would affect deconfliction. Whilst this belief may have been based on previous ‘normal’ military traffic behaviours, he had rendered his original deconfliction plan invalid. Finally, ATC Members were concerned at the lack of avoiding action to the JS41 pilot once the Tucano had flown within deconfliction minima.

In assessing the Cause and Risk, the Board agreed that once the controller had cleared the Tucano pilot en route he no longer had a deconfliction agreement and that he then did not take further action to achieve deconfliction minima, albeit there was limited time available. Despite this, the controller’s TI enabled the JS41 pilot to gain visual contact with the Tucano turning L over 2nm away. Given this visual sighting and the separation ranges and altitudes shown on recorded radar, the Board concluded that safety margins were not significantly reduced.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: In the absence of an agreement with the Tucano pilot, the controller did not take further action to achieve deconfliction minima.

Degree of Risk: C.

7 AIRPROX REPORT No 2012171

Date/Time: 6 Dec 2012 1417Z MD500 800-1000ft alt Position: 5226N 00009W 18:10 (Upwood G/S - elev 75ft) 17:58 Airspace: Lon FIR (Class: G) 17:45

Reporter: Duty Instructor RW24/06 17:33 1st Ac 2nd Ac 1 Type: ASK13 Hughes MD500 17:20

17:08 NM Operator: Civ Club Civ Trg ASK13  1400-1600ft hgt Alt/FL: 700ft 800-1000ft 16:56 0 QFE (NR) QNH (NR) 16:44 Weather: VMC CAVOK VMC NR CPA 1417 Visibility: 25km 10km 1416:32 Reported Separation: 500ft V/0.5nm H NR Recorded Separation: Diagram based on radar data and reports NR

GLIDER LAUNCH PARTY REPORTED

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE GLIDER CLUB DUTY INSTRUCTOR reports that an Airprox occurred during an ASK13 glider winch launch. The glider pilot was operating under VFR in VMC from RW24 at Upwood. The red and silver glider was not fitted with external lights, an SSR transponder an ACAS or RT equipment. As the glider reached a height of around 700ft, a helicopter was observed at a range of 2nm, converging from the S, straight and level at about 800-1000ft and heading approximately 350°. The helicopter intruded upon the ‘restricted airspace’, cut across the NE and N of the Upwood A/D boundary and passed within 0.5nm of the glider, as it climbed from 1400ft to 1600ft. The glider pilot did not see the helicopter, due to the steep climbing attitude during winch launch, and was unaware of the Airprox until after he had landed.

The Duty Instructor assessed the risk of collision as ‘Medium’.

THE MD500 PILOT reports transiting from a private helipad just S of RAF Wyton, returning to his operating base. He was operating under VFR in VMC with a BS from Wyton APP [134.050MHz]. The black helicopter had strobe and navigation lights selected on, as was the SSR transponder with Modes A and C. The ac was not fitted with an ACAS. In a level climb at 100kt and altitude 800- 1000ft [QNH NR], he was visual with Upwood G/S and at 2nm range could see a glider which was ‘ready to launch’ from the W’ly RWY. Consequently, he changed track to the E to avoid the ‘ATZ’. He watched the glider launch and continued his transit.

He assessed that there was no risk of collision.

ATSI reports an Airprox was filed by the gliding club Duty Instructor when, during the winch launch of a Schleicher AS-K 13 (ASK13) glider, a Hughes 369HE (MD500) helicopter was observed to converge with the ASK13 in the vicinity of Upwood.

1 Background

The ASK13 pilot was not in receipt of an ATS and was in the process of being launched from RW24 at Upwood. The MD500 had departed from a private site S of RAF Wyton for a VFR flight and was in receipt of a BS from Wyton APP [134.050MHz].

ATSI had access to the glider club duty instructor and helicopter pilot reports, recorded area surveillance and transcription of Wyton APP frequency. Meteorological information for Wyton was recorded as follows:

METAR EGUY 061350Z 19010KT CAVOK 01/M03 Q1012 BLU=

Glider Launching Sites are notified in the UK AIP, which states at ENR 1.1.5:

‘5.1 Glider Launching Sites

5.1.1 Glider launching may take place from designated sites which are regarded as aerodromes. The sites are listed at ENR 5.5. Where launching takes place within the Aerodrome Traffic Zone of an aerodrome listed within the AD section, details are also shown at AD 2 and AD 3.

5.1.2 Gliders may be launched by towing aircraft, or by winch and cable or ground tow up to a height of 2000 ft agl. At a few sites the height of 2000 ft may be exceeded (see paragraph 5.3).

5.1.3 Sites are listed primarily to identify hazards to other airspace users and listing does not imply any right for a glider or powered aircraft to use the sites.’

Upwood, situated in Class G uncontrolled airspace 4.8nm N of Wyton (see Figure 1), is listed in ENR 5.5 as follows:

Designation Vertical Remarks Lateral Limits Limits Activity Times Upwood, Cambs (AD) (W) 2000 ft agl Hours: HJ. 522612N 0000836W Site elevation: 75 ft amsl.

[UKAB Note(1): (W) denotes Winch/Ground Tow launch.]

Figure 1: VFR 1:250.000 (2012)

2 [UKAB Note(2): The 1nm radius circle around a G/S, as shown on VFR charts, does not denote any form of controlled or regulated airspace. Upwood G/S, as shown above in Figure 1, does not have an associated ATZ; the circle is printed only to highlight the presence of the G/S to other airspace users.

UKAB Note(3): A G/S is classified as an A/D in the UK AIP and RoA Rule 12 (Flight in the vicinity of an aerodrome) therefore applies:

… a flying machine, glider or airship flying in the vicinity of what the commander of the aircraft knows, or ought reasonably to know, to be an aerodrome shall conform to the pattern of traffic formed by other aircraft intending to land at that aerodrome or keep clear of the airspace in which the pattern is formed; …]

Factual History

At 1413:30 the MD500 pilot called Wyton APP, stating that he had just lifted from a site about ¼nm S of Wyton RW27 threshold. Permission was given to transit along the A/D E boundary. Wyton APP informed the MD500 pilot that he would be in receipt of a BS and the Chatham RPS, 1007hPa, was passed.

Swanwick Multi Radar Tracking (MRT) first detected the MD500 at 1413:48, 1.4nm E of Wyton. The MD500 pilot flew on a NW, then NNW track; no Mode C level information was detected. At 1416:00 Wyton APP requested that the MD500 pilot report leaving the frequency. This request was made twice with no reply. Shortly after, at 1416:30, Wyton APP informed another departure that Upwood gliding site was ‘now’ active. At 1417:40 Wyton APP broadcast that Upwood G/S was notified as active.

Figure 2 below shows the Swanwick MRT surveillance picture at 1417:49; the large cross denotes the Upwood RW06 threshold and the horizontal line shows ½nm range. The MD500 was displaying Mode A code 7000, with no Mode C; the ASK13 was not visible on the surveillance recording. Each track history update represents 4sec in time.

Figure 2: Swanwick MRT 1417:49

The ground reporter’s estimate of the MD500’s level was given as 800-1000ft above RWY height. The MD500 pilot reported his ac’s altitude as 800-1000ft. The ground reporter’s account describes the ASK13 as being at 700ft when the MD500 was first observed converging from the S. The MD500 pilot reported observing the ASK13 on the ground, ready for launch.

3 At 1418:30, Wyton APP called the MD500 pilot using callsign only; he reported ‘clear’ and thanked Wyton APP for the transit. The MD500 pilot was instructed to free-call en-route.

Analysis

The gliding site at Upwood is notified in the AIP in order to identify it as a hazard to other airspace users. No airspace restrictions exist in the vicinity of Upwood. The radar recording shows that the MD500 was initially on a course to cross the upwind end of RW24. Interpretation of the track history shows that at 1417:09 the MD500 pilot initiated a R turn, less than 1nm from the G/S. This was 31sec before Wyton APP made the general broadcast regarding Upwood activity but subsequent to the first mention of gliding activity on the frequency at 1416:30. The MD500 pilot stated in his report that he was visual with the glider on the ground. This assimilation may have been supplemented by the mention of gliding activity on the frequency in use. It is not known to this investigation whether or not the MD500 pilot’s pre-departure route planning had accounted for the possibility of activity at Upwood. The controller’s first mention of Upwood indicates that activity had just been notified to Wyton: ‘now’.

Under a BS pilots can expect to receive information and advice useful for the safe and efficient conduct of their flight. This may include information such as general airspace activity information. No form of flight path monitoring or TI should be expected under a BS and pilots remain wholly responsible for the avoidance of collision.

Conclusion

An Airprox was reported when an MD500 was observed converging with an ASK13 in the process of being winch launched from Upwood RW24. Surveillance information was insufficient to determine the exact proximity of the two ac. The MD500 pilot, previously on a track to cross the RW06 threshold, was observed to amend his course when within 1nm of the G/S. The MD500 pilot may have amended the ac’s course upon hearing reference to gliding activity at Upwood on the frequency in use.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the glider club DI, the helicopter pilot, radar photographs/video recordings and reports from the appropriate ATC authority.

The Board initially considered the actions of the glider pilot and concluded that he was operating normally from a promulgated and active G/S. The glider launch party had seen the helicopter after the winch launch had commenced and had one option available to affect deconfliction, to abort the launch, but with associated high risk to the glider pilot. Turning to the MD500 pilot’s actions, pilot Members were unanimous in their opinion that his transit did not appear to take sufficient account of the G/S location. The radar recording showed his intended track crossing the upwind end of RW24 but then deviating to the R when less than 1nm from the G/S, as he saw the glider ‘ready to launch’. His subsequent track took him adjacent to the RW24 threshold, which, if an ATZ had existed at Upwood as he thought, would have been well inside it without establishing RT contact prior to entry. Board Members emphasised that he would have been well advised to remain clear of the G/S, and the pattern formed by ac intending to land, on the ‘fail-safe’ basis that this undemanding plan would have afforded a measure of deconfliction from ac he might not see. The CAA Flt Ops Advisor stated that impact with the steel cable used for winch launching would most likely cause loss of control of a helicopter.

In summary, the Board agreed that the MD500 pilot had been unwise to plan to overfly a promulgated G/S below the maximum altitude of the winch cable, relying for deconfliction on his ability to see any gliders launching or in the circuit pattern. In the event, however, there was only one glider airborne and the MD500 pilot saw it in good time to avoid it by a safe margin but not without causing the launch party concern.

4

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The MD500 pilot flew close enough to a promulgated and active glider site to cause the launch party concern.

Degree of Risk: C.

5 AIRPROX REPORT No 2012173

Date/Time: 20 Dec 2012 1634Z (Night) Position: 5713N 00207W (2·5nm ENE CPA Aberdeen - elev 215ft) Radar derived 34:01 AS332L 015 Levels show EC135 011 Airspace: ATZ/CTR (Class: D) Mode C 1013hPa Radar head 011 015 Reporting Ac Reported Ac 014 011 013 012 Type: AS332L EC135 012 33:53 Aberdeen 012 33:49 Elev 215ft 013

Operator: CAT Civ Comm 33:41 AS332L 012 012 33:33 Alt/FL: 1000ft 1000ft 012 QNH (1009hPa) QNH (1009hPa) EC135 ATZ ABERDEEN CTR Weather: VMC CLBC VMC CLBC SFC-FL115 Visibility: 10km >10km 33:01 BRIDGE 1632:49 Reported Separation: OF DON 0 1 010

Nil V/1000m H 100ft V/400m H NM 010 Recorded Separation: 100ft V/0·8nm H OR 400ft V/0·3nm H

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE AS332L PILOT reports outbound to an off-shore rig from Aberdeen, VFR and in receipt of an ATS from Aberdeen Tower on 118·1MHz squawking 3671 with Modes S and C; TCAS was not fitted. The visibility was 10km flying 1500ft below cloud in VMC. They departed RW16 on a SHRUB VFR departure. At the same time another flight, the EC135, called departing the Aberdeen Royal Infirmary (ARI) on a VFR departure towards the Bridge of Don for Aberdeen. After take-off they turned L passing 500ft towards SHRUB and climbing through 700ft called ‘visual’ with the EC135, whose pilot was told to route to the Bridge of Don and join via the radar head. The EC135 pilot was asked if he could see their helicopter and he responded ‘yes’. On reaching Bridge of Don the EC135 continued N towards Balmedie and its pilot was asked by ATC again if he could see their helicopter and the pilot replied ‘yes’. Heading 090° at 120kt and 1000ft QNH 1009hPa the NHP requested a R turn to slot in behind the EC135 as closure seemed inevitable. The EC135 flight was instructed by ATC to take avoiding action and make a L turn. They did not hear the EC135 pilot respond and the helicopter continued on a N’ly heading. Shortly after this the EC135 flight made a L turn which placed it on a direct collision course. The HP initiated an expeditious climb to 1500ft to avoid, estimating the EC135 passed 1000m ahead with a high risk of collision.

THE EC135 PILOT reports inbound to Aberdeen, VFR having lifted from Aberdeen Hospital and in communication with Aberdeen Tower on 118·1MHz squawking a discrete code with Modes S and C; TCAS was not fitted. The visibility was >10km flying clear below cloud in VMC and the ac’s red strobes, position and landing lights were all switched on. He was told of traffic departing RW16 and proceeding NE’bound and was told to remain to the E and head towards the radar head on downwind L for RW16. He levelled at 1000ft QNH and when approaching the radar head heading 350° at 100kt the paramedic in the LH seat reported visual with an ac in his 8 o’clock at approximately 1nm. It moved closer at the same height appearing to be heading straight for their ac before moving to their 9 o’clock and finally passing close behind, about 400m away and 100ft below, he thought. There was a 220/40kt wind blowing, he thought, which may have meant the closing speed between ac may have been misjudged. Although he had not seen the other helicopter he was not concerned by its proximity as he was sure the other ac’s crew had their helicopter visual and that it was bound to pass behind, which it eventually did. He took no evasive action but after the event the Tower controller

1 was concerned by how close the ac had passed each other and reminded both crews that under the new night VFR rules pilots were responsible for their own collision avoidance.

THE OUTGOING ADC reports the AS332L departed RW16 on a SHRUB VFR and the EC135 flight called lifting ARI, as briefed, not above 500ft. The EC135 flight was instructed to track E with the AS332L departing. The AS332L flight was given TI on the EC135 and both crews reported each other in sight. The EC135 pilot was given joining instructions for RW16. Whilst this was taking place his relief ADC was plugging-in waiting for a handover and once he was satisfied with the situation he commenced the handover. Subsequently the relief controller checked with the AS332L pilot that he was still visual with the EC135 but the AS332L pilot was not. The relief controller issued instructions to the EC135 flight and the AS332L pilot reported he would be filing an Airprox.

THE INCOMING ADC reports he had just plugged-in to the ADC position and was receiving a handover from the out-going ADC. During the handover the AS332L was departing VFR to the E at night in poor Wx conditions but still in VMC. As the AS332L departed an EC135 flight at the ARI reported lifting to return to Aberdeen. TI was passed to, and acknowledged by, both helicopter crews and the EC135 pilot was instructed to initially route towards the Bridge of Don. The EC135 pilot then reported visual with the AS332L and was cleared to route to L base RW16. He accepted the position and the outgoing ADC unplugged. As the EC135 joined downwind the AS332L turned L to the E at about the midpoint of RW16. The AS332L crew then requested to deconflict from the EC135 by “slotting behind”. Both ac were continuously visible to him at this point but due to the Wx and light conditions he was unsure of their relative heights. As a precaution he gave avoiding action to the EC135 flight to turn L away from the AS332L, the L turn to allow the pilots to keep the other traffic visual. This was not acknowledged by the EC135 crew who continued downwind. The AS332L was then observed to climb over the EC135 and the AS332L crew reported that they, “would be filing on that one”, which he acknowledged.

ATSI reports that the Airprox was reported by the pilot of an AS332L when it came into proximity with a EC135 on the boundary of Aberdeen ATZ within the Class D CTR, airspace extending from the surface to FL115, at 1634:02 UTC (night).

The AS332L was operating VFR departing Aberdeen for an offshore oil rig and was in receipt of an ACS from Aberdeen Tower on frequency 118·1MHz.

The EC135 was operating VFR on a flight from Aberdeen Royal Infirmary to Aberdeen Airport and was in receipt of an ACS from Aberdeen Tower on frequency 118·1MHz.

CAA ATSI had access to written reports from the pilot of the AS332L and the Aberdeen AIR controller, area and local radar recordings together with RT recordings of Aberdeen Tower.

The Aberdeen METARs are provided for 1620 and 1650 UTC:

EGPD 201620Z 12022G34KT 8000 –RA FEW018 SCT022 BKN026 06/03 Q1007 NOSIG= and EGPD 201650Z 13024G37KT 6000 RA FEW018 BKN021 06/03 Q1007 NOSIG=

At 1630:30 the AS332L flight was given take-off clearance with a L turn out from RW16 by the Aberdeen AIR controller.

At 1631:20 the EC135 pilot contacted the Aberdeen AIR controller, lifting out of Aberdeen Royal Infirmary (situated approximately 3·5nm SE of Aberdeen Airport) requesting joining instructions for Aberdeen Airport. The Aberdeen AIR controller advised, “(EC135 c/s) roger I’ve just got a helicopter joining er just lifting will be going left er V F R not above a thousand feet sort of tracking northeast so if you can just track towards Bridge of Don for the moment”; the EC135 pilot replied, “(EC135 c/s) wilco”. The ATSU advised that the routeing to the Bridge of Don for the EC135 was to give both pilots time to be given TI and to visually acquire each other.

2 At 1631:50 the Aberdeen AIR controller passed TI to the AS332L flight, “(AS332L c/s) EC135 c/s just lifting A R I just tracking east at the moment V F R not above a thousand feet”; the pilot replied, “yeah copied that traffic (AS332L c/s)”.

At 1632:30 the AS332L crew reported turning E and at 1632:35 the pilot of the EC135 advised, “and (EC135 c/s) that’s us Bridge of Don are we happy you happy for us to come inbound now”. The AIR controller replied, “(EC135 c/s) yeah that traffic’s just airborne tracking northeast now so if you track east of the radar head and then left base for runway one six V F R not above a thousand feet Q N H one zero zero seven”.

At 1632:50 the pilot of the EC135 replied, “one zero zero seven set visual with that traffic and er we’ll continue er north around the head er for er one six (EC135 c/s)”. The ac were 2·6nm apart.

At 1633:00 the Aberdeen AIR controller updated the TI to the AS332L flight, “(AS332L c/s) er the EC135 c/s er just I believe west of Bridge of Don this time tracking north he’s visual with you”. The crew replied, “we’re visual with him as well (AS332L c/s)”.

The written report from the Aberdeen AIR controller stated that both ac had reported having each other in sight and a handover of controllers took place.

At 1633:30 the pilot of the AS332L transmitted, “yeah (AS332L c/s) so we slot in behind that er (EC135)”. The in-coming Aberdeen AIR controller asked of the AS332L, “(AS332L c/s) do you have him visual he’s not above a thousand at the moment”. At 1633:33 the EC135 was tracking N with the AS332L 1·5nm W, tracking NE, converging. The crew of the AS332L stated, “er he’s er he might not be above a thousand feet but we’re gonna nail him so we’re gonna turn right now”.

At 1633:41 the 2 ac were 1·2nm apart, converging, the EC135 having turned L about 30°. The Aberdeen AIR controller gave avoiding action to the EC135 flight (1633:45), “???? ???? (unintelligible words) (EC135 c/s) avoiding action please turn left immediately left immediately”; this was not acknowledged by the pilot of the EC135.

The ATSU advised that the incoming Aberdeen AIR controller was watching both ac out of the window prior to the Airprox. He became concerned at the relative positions of the 2 ac and believed that neither pilot was taking sufficient action to avoid the other. Based on the AIR controller’s visual sighting of the 2 ac, he gave avoiding action to the EC135 to turn to the L. The GMC controller, who was watching the situation at the time, confirmed that turning the EC135 L appeared to be the most appropriate course of action to resolve the situation.

[UKAB Note (1): The 2 ac close and at 1633:49, separation is 0·8nm with the AS332L having commenced a climb, passing FL013, and the EC135 having commenced a descent, indicating FL012. Four seconds later at 1633:53 the AS332L is climbing through FL014, 0·6nm to the W of the EC135 which is level at FL011. The CPA occurs at 1634:01 as AS332L continued to climb to FL015 and turned R with the EC135 passing to its NE tracking NW’ly at a range of 0·3nm maintaining FL011.]

The pilot of the AS332L reported on frequency that he would be filing an Airprox.

CAP493, the Manual of Air Traffic Services Part 1, Section 3, Chapter 4, Paragraph 3.1 states:

‘Separation standards are not prescribed for application by ATC between VFR flights or between VFR and IFR flights in Class D airspace. However, ATC has a responsibility to prevent collisions between known flights and to maintain a safe, orderly and expeditious flow of traffic. This objective is met by passing sufficient traffic information and instructions to assist pilots to 'see and avoid' each other....’

3 Having passed TI and received reports from both pilots that they had each other in sight when they were 2·6nm apart, the outgoing Aberdeen AIR controller had a reasonable expectation that the pilots would discharge their responsibility for collision avoidance appropriately.

When the pilot of the AS332L reported that they were in conflict with the EC135 and needed to take action to avoid, the incoming Aberdeen AIR controller became concerned that the confliction between the 2 ac was not being resolved and issued avoiding action to the pilot of the EC135. As the instruction was not acknowledged by the pilot of the EC135 and no discernible track difference can be observed on radar it is not possible to tell if the pilot of the EC135 responded to the instruction.

The Airprox occurred in Class D airspace when an EC135 and an AS332L flew into conflict with each other while both flights were operating VFR not above 1000ft. Both flights were passed appropriate TI and reported each other in sight prior to the Airprox. When the pilot of the AS332L advised that they needed to turn R to avoid the EC135 and it appeared that the confliction had not been resolved the incoming Aberdeen AIR controller gave avoiding action in an attempt to resolve the situation.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequencies, radar video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC authorities.

There appeared to be different viewpoints of this incident by all parties. ATC had assimilated the potential for conflict when the EC135 pilot reported lifting from the ARI and the flight was issued routeing instructions towards the Bridge of Don, away from the AS332L’s intended track on the SHRUB departure. This action gave the ADC time to discharge his responsibilities by passing TI to both VFR flights on each other and, after ensuring both crews were visual with each other, he issued the EC135 pilot inbound routeing instructions towards the downwind leg for RW16; this had placed the ac on converging tracks. Although this incident occurred within Class D CAS both crews were VFR and were responsible for maintaining their own separation from each other. Members noted that prior to the change in night VFR rules, both of these helicopter flights would have been SVFR at night in the CTR and would have been afforded separation from each other by ATC. The incoming controller was concerned as he could see the potential for confliction with the helicopters continuing towards each other but without any resolution visible. The AS332L crew asked if they had to “slot-in” behind the EC135 (turn R and give-way), apparently expecting confirmation that they could turn off their assigned routeing. Members agreed that at this stage the crew should have executed the turn to resolve the conflict and informed ATC of their actions. The ADC had asked the crew if they were visual with the EC135 and reiterated that the helicopter was not above 1000ft to which the crew replied that they were going to turn R. The ADC did not acknowledge the AS332L crew’s intended turn but instead gave the EC135 pilot a L turn towards the AS332L as, from his position in the VCR, this was the best way to resolve the situation. However, the EC135 had picked up a strong tailwind when routeing N’ly which had led to the geometry changing whereby the EC135 was going to cross ahead of the AS332L and this was not apparent to the ADC. Similarly, the AS332L crew would have had to execute a large heading change into the strong SE’ly wind to effect a significant change of flight path. The EC135 pilot did not acknowledge the instruction to turn L but it almost certainly placed doubt in the AS332L crews mind as to his intentions. In the end, at a late stage, the AS332L crew executed a climb to resolve the confliction, the R turn only becoming apparent on the radar recording at the CPA. This led the Board to agree that the AS332L crew did not take timely action to give-way to the EC135, as required by the RoA, which had caused the Airprox.

Looking at the risk element, although the EC135 had right of way it appeared its pilot was content to follow the ATC routeing instruction towards the downwind leg, perhaps in the mistaken belief that positive control from ATC would resolve any traffic confliction. The pilot reported being sure the AS332L was going to avoid his helicopter, without visually acquiring it himself, content with the information from the paramedic in the LH seat. It is unknown why the EC135 pilot did not

4 acknowledge the avoiding action L turn issued as they approached the CPA. That said, the Board acknowledged that the AS332L crew had good SA, were fully aware of the deteriorating situation and had eventually taken positive action which ensured that any risk of collision was effectively removed.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The AS332L crew did not take timely action to give way to the EC135.

Degree of Risk: C.

5 AIRPROX REPORT No 2012175

Date/Time: 30 Dec 2012 0853Z (Sunday) Position: 5110N 00003W (5nm FIN APP RW26L Gatwick - elev 203ft) Airspace: CTR (Class: D) Reporting Ac Reported Ac GATWICK CTR SFC-2500ft Type: B777-200 2 x Untraced Gatwick objects ~5nm Operator: CAT NK Alt/FL: 1500ft (QNH) (NK)

Weather: VMC NR NK B777 Visibility: >10km Reported Separation: Not radar derived or to scale 100-200ft V Recorded Separation: NR

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE B777 PILOT reports inbound to Gatwick, IFR and in communication with Gatwick Tower, squawking an assigned code with Modes S and C. About 4-5nm from touchdown RW26L heading 260° at 140kt and descending through 1500ft QNH, P2 spotted, and then drew his attention to, 2 flat silver discs ahead, 1 either side of the C/L and below their flightpath; these objects appeared to be very slow moving or stationary. All 3 pilots on the flightdeck saw the objects, which passed 100-200ft below; the crews in 2 subsequent ac also saw the objects. They informed ATC of incident and he assessed the risk as low.

RAC MIL reports tracing action did not reveal the identity of the reported objects. Looking at possible sources, there are no registered radio-controlled model flying clubs listed in the area. Maps show many open fields under the RW26 approach where persons could operate remote control ac. There are saucer-shaped or blimp-shaped model ac, up to 4ft in diameter, on sale to the public.

THE GATWICK WATCH MANAGER reports the B777 crew reported seeing 2 man-made objects, possibly toys, passing under their ac approximately 5-6nm on final. Further details from the crew, and from the crew of a following B767, added the objects were 2 white or silver discs at approximately 1000-1500ft. Details of the incident were passed to the local Police Authority and to LTCC Group Supervisor.

ATSI reports that the Airprox was reported by the pilot of a B777 inbound to Gatwick when 2 objects were observed to pass beneath the ac. The report below contains only a factual history of all available information as the identity and origin of the observed objects could not be determined.

The B777 was an IFR flight squawking Mode A 4456 and in receipt of an ACS from Gatwick Tower on 124·255MHz. The Gatwick Tower frequency was reviewed between 0850 and 0904 UTC. RT loading was reasonably constant during this period.

The Gatwick METAR was EGKK 300850Z 23009KT 9999 FEW040 06/02 Q1011=

1 The B777 flight called Tower at 0850:35 passing 3200ft at 11·5nm from touchdown and was instructed to continue approach.

Figure 1 is taken from the Gatwick 10cm radar replay at 0852:16 when a primary position indication symbol appeared on the outskirts of East Grinstead in the B777’s 11 o’clock range 3·4nm. The return disappeared on the next update of the replay.

Figure 1: Gatwick 10cm: 0852:16 UTC

At 0853:02 the Gatwick 10cm replay showed the B777 at 6·4nm from touchdown, passing 2200ft and at this time another primary position indication symbol appears 0·1nm behind the B772 (Figure 2). The unknown target disappeared on the next update of the replay.

Figure 2: Gatwick 10cm: 0853:03 UTC

The B777 passed 6nm from touchdown at 0853:12 as it descended through 2100ft. The B777 passed 5nm from touchdown at 0853:43 as it descended through 1800ft.

The next ac inbound to RW26L, a B767 flight (Mode A 3243) called Tower at 0854:32 passing 2900ft at 10·5nm from touchdown and was instructed to continue approach.

At 0855:11 a primary position indication symbol appeared at 5·3nm on the approach and offset to the north by 0·1nm. The B767 was at 9·1nm passing 2900ft. The target disappeared on the next update of the replay.

The surface wind (230/08KT) was passed to the B777 flight and it was cleared to land at 0856:16. After the read back the pilot stated that, at between 5–6nm from touchdown, a couple of man-made objects had passed underneath the ac. These were described as ‘some sort of toy’. The report was acknowledged by the controller. At this time the B767 was at 6·3nm from touchdown passing through 2300ft.

2 As the B767 approached 6nm from touchdown (passing 2200ft) the Gatwick 10cm replay showed a sequence of 6 primary position indication symbols moving E’bound approximately 1nm N of the FAT (Figure 3).

Figure 3: Gatwick 10cm: 0856:37 UTC

At 0857:17 the next inbound ac, an A319 called Tower, with 11nm to run and passing through 3000ft.

The B767 and A319 landed. There was no further mention, by pilots or controller, on the Tower frequency of the previously reported objects.

The controller and pilot reports subsequently indicated that the unknown objects were ‘2 white or silver discs at 1000–1500ft, which appeared to be very slow moving or stationary’. ATSI did not record the ground frequencies in use, where any further discussion of the objects may have taken place between ATC and the pilots of the 3 landing ac.

The incident was reported to the Police and London Terminal Control; however the nature of the objects has not been resolved.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the B777 crew, transcripts of the relevant RT frequencies, radar video recordings, reports from the air traffic Supervisor and reports from the appropriate ATC authorities.

The CAA FOI Advisor informed Members that the CAA is regularly approached with enquiries regarding various devices, including balloons/kites, to be used as camera platforms. Regulations require operators of model ac/UAVs with a mass greater than 7kg to seek approval for flight in an ATZ or CAS or above 400ft (ANO Article 166) and other limitations apply to surveillance ac (ANO Article167). For platforms less than 7kg, the operator has to be satisfied that the flight is safe without endangering an ac, person or property (ANO Articles 137 and 138). Model flying clubs are well regulated but other flying can take place anywhere else. There was no doubt that the B777 crew, and 2 subsequent flights, had seen a couple of objects, reported by the B777 crew as man-made and toy-like. However, with the dearth of other information available to the Board and with the objects sighted remaining untraced, the Board elected to classify this incident as a sighting report on final approach; the risk was deemed unassessable.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: Sighting report on final approach.

Degree of Risk: D.

3 AIRPROX REPORT No 2013002

Diagram based on radar data Date/Time: 12 Jan 2013 1511Z (Saturday) Promulgated and pilot reports Position: 5130N 00047W cct pattern (White Waltham – elev 133ft) Airspace: White Waltham ATZ (Class: G) Reporting Ac Reporting Ac

Type: PA28 Nanchang CJ6 PA28 Contact fades at 1510:33 10:21 Operator: Civ Trg Civ Pte 10:29 A07 10:13 Alt/FL: 200ft 250ft (QFE NR) (QFE NR) A06 1510:05 Weather: VMC NR VMC HAZE A06 10:37 A05 10:45 Visibility: >10km 10km A04 10:53 CJ6 A03 11:01 (Primary only Reported Separation: A03 returns) CPA A03 A04 0ft V/25m H 0ft V/160ft H 11:09

Recorded Separation: Contact reappears London CTR boundary NR

BOTH PILOTS FILED

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE PA28 PILOT reports that he was instructing a cct rejoin exercise with a student pilot. He was operating under VFR in VMC in receipt of an A/G service from Waltham Radio [122.600MHz]. He was seated on the RH side of the ac, with the student seated on the LH side. The blue and white ac had wingtip strobes and an LED landing light selected on, as was the SSR transponder with Modes A and C selected. The ac was not fitted with Mode S or an ACAS. He departed White Waltham at approximately 1430 and conducted one rejoin without incident. On the second rejoin he completed a normal join for RW11 LH via the O/H [at height 1300ft at this A/D]. He noted one other ac in the cct, a Piper Super Cub, and did not see any other ac at that time. As he turned downwind it became apparent that the pilot of an ex-military training ac was also operating in the ATZ but he didn’t recall any RT transmissions from him. As he approached short final, heading 110° at 65kt, he saw that the Super Cub pilot had begun a base turn from abeam the RWY threshold. He was uncertain whether the Super Cub pilot had seen him on final but continued the approach ‘whilst watching him continually’. Meanwhile, the CJ6 pilot whom he had expected to go either ahead of him or behind him, made one continuous turn from downwind to final approach, until he was exactly L abeam, on final approach at height 200ft. He made an RT transmission to request the other pilot’s intentions but, on receiving no response, decided to go around immediately. The other ac passed behind him and emerged on his RH side, apparently having elected to go around as well.

He assessed the risk of collision as ‘High’.

He stated he was surprised that the other pilot did not have his undercarriage selected down and was still uncertain if his intention was to land.

THE CJ6 PILOT reports intending to conduct a short flight to include aerobatic training/practice. He was operating in a non-radio ac under VFR, in VMC. The green camouflaged ac had navigation and landing lights selected on. The ac was not fitted with an SSR transponder or an ACAS. After departure he had cockpit indications of an electrical failure; he completed the emergency checklist, which included advice to land at the nearest suitable A/D, and decided to return to White Waltham. He flew a ‘PFL cct’ with a constantly descending turn onto short finals. As he rolled out at 350ft at

1 100kt he saw a PA28 in his R 1o’clock position at the same level and a range of 160ft. He performed a go around to the deadside, keeping the PA28 on his L.

He assessed the risk of collision as ‘Low’.

He commented that when downwind, he was ‘looking into sun for ac on base and final on a hazy afternoon’.

ATSI reports that the Airprox occurred at White Waltham A/D, within the ATZ, in Class G airspace, between a Piper PA-28-161 Cherokee Warrior III (PA28) and a Nanchang CJ6, an ex-military, 2 seat tandem, training ac. The White Waltham ATZ comprises a circle of radius 2nm, centred on the midpoint of RW07/25 and extending from the surface to a height of 2000ft aal (elevation 133ft).

Background

The PA28 departed from White Waltham under VFR at approximately 1430 for a cct rejoin training exercise with a student pilot. The CJ6 departed White Waltham non-radio for a VFR training flight, to include aerobatic practice.

White Waltham is operated by the West London Aero Club (WLAC) and lies on the boundary of the London Class A CTR, which extends from the surface to an altitude of 2500ft. The W portion of the ATZ lies within Class G airspace and the E portion, the White Waltham Local Flying Area (WW LFA), lies within the London CTR. Flights within the WW LFA are restricted to a maximum altitude of 1500ft.

The UK AIP, pages AD 2-EGLM-5 and 6 state:

‘White Waltham operate an Air/Ground radio on frequency 122.600MHz, in the winter from 0800 UTC to sunset. Users of the aerodrome should be familiar with the West London Aero Club Flying Order Book (FOB) which is available at the aerodrome or on the [WLAC internet site]. All joins normally overhead at 1300ft QFE; circuit height 800ft QFE.’

RW11 was in use; the promulgated cct pattern to be flown appears in the WLAC FOB and is shown in a proprietary flight guide and on the WLAC web site, as shown below.

2 The ANO Rule 45 (5) states:

‘If there is no flight information service unit at the aerodrome the commander shall obtain information from the air/ground communication service to enable the flight to be conducted safely within the zone.’

The White Waltham FOB, Section 1, Paragraph 2.5, states:

‘…all flights on private aircraft are to be booked in and out on the sheets provided in Operations…’

The proprietary flight guide entry for White Waltham, states:

‘(Remarks) Non-radio aircraft require telephone briefing from Operations prior to each flight.’

CAA ATSI had access to area radar recording, together with written reports from the two pilots concerned and a local investigation report. CAA ATSI also discussed the incident with the A/G Operator.

The Heathrow A/D weather was recorded as follows:

METAR EGLL 121450Z 09015KT 9999 BKN047 04/M02 Q1011 NOSIG= METAR EGLL 121520Z 09013KT 9999 FEW037 BKN045 04/M02 Q1011 NOSIG=

Factual History

At 1438:32, radar recording shows a contact airborne from RW11 at White Waltham squawking 7000 with Mode C indicating an altitude of 600ft. This correlated with times and routeings for the PA28 as reported in the PA28 pilot’s written report. He was observed to route to the SW of the A/D and, at 1445:39, rejoined the traffic pattern from VRP SIERRA. At 1449:43 he was O/H the A/D at 1300ft with one other intermittent primary contact observed in the cct [a PA18].

At 1457:47, the PA28 pilot left the ATZ to the W and, at 1501:30, set course to rejoin from VRP WHISKEY. At 1506:57, he approached the O/H at 1300ft with the intermittent primary contact downwind. He was then observed to join crosswind and, at 1508:58, was downwind following the intermittent primary contact. At 1510:02, he turned onto final for RW11 at an altitude of 700ft with a primary contact, believed to be the CJ6, joining. The CJ6 pilot was observed to continue in a short cct pattern.

The CJ6 pilot’s report indicated that he was operating non-radio and, after his earlier departure, had become aware of a ‘fluctuating ammeter needle, with occasional hard over indication, which suggested arcing and Bus failure/low charge light’. The CJ6 pilot elected to return to White Waltham and completed a PFL cct with a constant descending turn onto short final.

At 1510:43, the PA28 pilot was on final, 0.4nm from touchdown, indicating an altitude of 400ft. The CJ6 pilot was on L base, in the PA28 pilot’s 8.30 position at a range of 0.4nm and converging at a much faster speed. The CJ6 radar return then faded from radar.

The PA28 pilot’s written report indicated that he had sighted the CJ6 in a continuous turn until abeam him on final approach. The PA28 pilot indicated that he transmitted and requested the intentions of the CJ6 pilot, but without any response. He reported that he elected to go around and noted that the CJ6 did not have any gear down.

The A/G operator, when questioned, indicated that he had observed the PA28 and the CJ6 on final approach. The CJ6 was below and moving to the right of the PA28. Both pilots had commenced a go around. The PA28 pilot turned crosswind early to increase separation. The White Waltham Aerodrome operator’s safety sub-committee completed an investigation, which included a number of recommendations. Their report noted that the CJ6 pilot had not booked out and had not informed

3 anyone that he was operating non-radio. White Waltham intend to review their procedures for the operation of non-radio ac and will amend the Operations Manual/FOB and appropriate pages of the UK AIP.

Analysis

White Waltham does not provide ATC or FISO services and requires pilots to comply with the Flying Order Book. In Class G airspace, pilots are ultimately responsible for their own separation on the principle of ‘see and avoid’. For flight within the vicinity of an aerodrome, RoA Rule 12 states that the commander shall:

‘conform to the pattern of traffic formed by other aircraft intending to land at that aerodrome or keep clear of the airspace in which the pattern is formed…’

The CJ6 pilot did not obtain information from the A/G operator to ensure that the flight was carried out safely within the ATZ and the pilot did not book out or report that he was operating non-radio. When the CJ6 returned to join the cct due to an electrical problem, the pilot joined for a short cct pattern and flew into conflict with the PA28 already established in the cct and on short final.

Conclusions

The Airprox occurred when the CJ6 pilot joined the cct at White Waltham without conforming with the cct pattern already established and flew into close proximity with the PA28, which was established on short final for RW11.

[UKAB Note(1): Rule 13(Order of landing) of the RoA states:

(1) An aircraft landing or on its final approach to land shall have the right-of-way over other aircraft in flight or on the ground or water.

(2) An aircraft shall not overtake or cut in front of another aircraft on its final approach to land.

…

(4) If the commander of an aircraft is aware that another aircraft is making an emergency landing, he shall give way to that aircraft.

…

Rule 17(Notification of arrival and departure) of the RoA at paragraph 2 states:

‘The commander of an aircraft arriving at or departing from an aerodrome in the United Kingdom shall take all reasonable steps to ensure, upon landing or prior to departure, as the case may be, that the person in charge of the aerodrome or the air traffic control unit or flight information service unit at the aerodrome is given notice of the landing or departure.’]

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, radar video recordings, reports from the air/ground operator involved and reports from the appropriate operating authorities.

The PA28 pilot appeared to be conforming to the pattern of traffic in the White Waltham cct so the Board concentrated its deliberations on the actions of the CJ6 pilot. The pilot did not notify his departure, contrary to Rule 17(2) (Notification of arrival and departure) of the RoA, or that he would be operating non-radio, contrary to the White Waltham FOB. The White Waltham A/G Operator was therefore unable to pre-emptively notify other ac in the cct that the CJ6 pilot was operating non-radio.

4 Having departed the cct, experienced the ac emergency and carried out the checklist actions, the CJ6 pilot made the decision to return to White Waltham A/D where he carried out a ‘PFL cct’. The RoA Rule 13(4) states that ‘If the commander of an aircraft is aware that another aircraft is making an emergency landing, he shall give way to that aircraft’. The Board concluded that the PA28 pilot could not have known of the CJ6 emergency and that it was therefore the CJ6 pilot’s responsibility to conform to the pattern of traffic intending to land, iaw Rule 12. However, the CJ6 pilot did not see the PA28 until he rolled out on final and had flown into confliction with it. Board Members were divided in their opinion of the severity of the confliction with some opining that safety margins had been much reduced below normal. However, noting the PA28 pilot’s report that the CJ6 made a continuous turn on to final from downwind, the majority of Members concluded that he had gained an early visual sighting of the CJ6 and was therefore always in a position to break away, effectively removing the risk of a collision.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The CJ6 pilot flew into conflict with the PA28 on final approach, which he did not see.

Degree of Risk: C.

5 AIRPROX REPORT No 2013003 Diagram based on pilot reports Date/Time: 12 Jan 2013 1514Z (Saturday) NOT TO SCALE Position: 5130N 00047W (White Waltham – elev 133ft) Airspace: White Waltham ATZ (Class: G) Reporting Ac Reporting Ac CPA 1514 Type: PA18 Nanchang CJ6 PA18 CJ6 Operator: Civ Trg Civ Pte Alt/FL: 240ft 250ft (QFE NR) (QFE NR) Weather: VMC CLBC VMC HAZE Visibility: 20km 10km Reported Separation: 100ft V/100m H NR V/100ft H White Waltham A/D Recorded Separation: NR

BOTH PILOTS FILED

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE PA18 PILOT reports that he was instructing a cct refresh exercise with an experienced, tail- wheel rated, student pilot. He was operating under VFR in VMC in receipt of an A/G service from Waltham Radio [122.600MHz]. He was seated in the rear seat, with the other pilot seated in the front seat. The yellow ac’s tail mounted strobe light was selected on. The ac was not fitted with an SSR transponder or an ACAS. He was aware from RT transmissions that one of his colleagues, in a PA28, had just had a ‘near miss’ with a CJ6. He was visual with the PA28 as it turned early crosswind but could not see the other ac. He was established on final approach, heading 110° at 50kt at a height of about 240ft and the pilot student had transmitted his intentions to ‘stop and go’ when the A/G operator asked him whether he had seen the CJ6. He looked to his L and had a fleeting view of the CJ6 in his L 8 o’clock position at a range of 300m before it passed underneath his ac, crossing from L to R. He believed the 2 ac were going to collide and that there was insufficient time to take avoiding action, before the other ac passed below.

He assessed the risk of collision as ‘High’.

THE CJ6 PILOT reports intending to conduct a short flight to include aerobatic training/practice. He was operating in a non-radio ac under VFR, in VMC. The green camouflaged ac had navigation and landing lights selected on. The ac was not fitted with an SSR transponder or an ACAS. After departure he had cockpit indications of an electrical failure; he completed the emergency checklist, which included advice to land at the nearest suitable A/D, and decided to return to White Waltham. He flew a ‘PFL cct’ with a constantly descending turn onto short finals. After sighting a PA28 he performed a go around to the deadside, keeping the other ac on his L. He observed the PA28 leave the cct pattern and ‘turned in again’, this time ‘keeping an eye over [his] shoulder for him’. Just before turning final he rolled wings level ‘to adjust’ and saw a ‘yellow Cub’ in his R 2 o’clock position, crossing from R to L slightly below, on very short finals at a height of 250ft. He extended on the base leg, flew behind the Cub and went around again.

He assessed the risk of collision as ‘Low’.

1 He commented that when downwind, he was ‘looking into sun for ac on base and final on a hazy afternoon’.

ATSI reports that the Airprox occurred at White Waltham A/D within the ATZ, Class G airspace, between a Piper PA-18-150 Super Cub (PA18) and a Nanchang CJ6, an ex-military, 2 seat tandem, training ac. The White Waltham ATZ comprises a circle of radius 2nm, centred on the midpoint of RW07/25 and extending from the surface to a height of 2000ft aal (elevation 133ft).

The PA18 was being operated under VFR in the visual LH cct for RW11. The CJ6 pilot departed White Waltham non-radio for a VFR training flight, to include aerobatic practice.

White Waltham is operated by the West London Aero Club (WLAC) and lies on the boundary of the Class A CAS London CTR, which extends from surface to altitude 2500ft. The W portion of the ATZ lies within Class G airspace and the E portion, the White Waltham Local Flying Area (WW LFA), lies within the London CTR. Flights within the WW LFA are restricted to a maximum altitude of 1500ft.

The UK AIP, pages AD 2-EGLM-5 and 6 state:

‘White Waltham operates an Air/Ground radio on frequency 122.600MHz, in the winter from 0800 UTC to sunset. Users of the aerodrome should be familiar with the West London Aero Club Flying Order Book (FOB) which is available at the aerodrome or on the [WLAC internet site]. All joins normally overhead at 1300ft QFE; circuit height 800ft QFE.’

RW11 was in use; the promulgated cct pattern to be flown appears in the WLAC FOB and is shown in a proprietary flight guide and on the WLAC web site, as shown below.

The ANO Rule 45 (5) states:

‘If there is no flight information service unit at the aerodrome the commander shall obtain information from the air/ground communication service to enable the flight to be conducted safely within the zone.’

The White Waltham FOB, Section 1, Paragraph 2.5, states:

‘…all flights on private aircraft are to be booked in and out on the sheets provided in Operations…’

The UK AIP, page AD 2-EGLM-1 (13 Dec 2012), AD 2.3 (12), Remarks, states:

‘This aerodrome is PPR by telephone only.’

2 The proprietary flight guide entry for White Waltham, states:

‘(Remarks) Non-radio aircraft require telephone briefing from Operations prior to each flight.’

CAA ATSI had access to area radar recording, together with written reports from the two pilots concerned and a local investigation report. CAA ATSI also discussed the incident with the A/G operator.

[UKAB Note(1): Both sets of primary only returns, judged to correspond to the 2 subject ac, fade before CPA].

The Heathrow A/D weather was recorded as follows:

METAR EGLL 121450Z 09015KT 9999 BKN047 04/M02 Q1011 NOSIG= METAR EGLL 121520Z 09013KT 9999 FEW037 BKN045 04/M02 Q1011 NOSIG=

Factual History

The PA18 pilot’s written report indicated that he was aware of an Airprox [2013/002] on short final for RW11, between a PA28 and a CJ6 at approximately 1511. The PA18 pilot reported that he had sight of the PA28 turning crosswind after a go around, but was unable to see the CJ6.

When questioned, the White Waltham A/G operator indicated that he had not seen the CJ6 reposition in the circuit, but sighted the PA18 and the CJ6 on short final for RW11. The A/G operator passed a warning, asking if the PA18 pilot was visual with the CJ6; the A/G operator indicated that the PA18 pilot had responded, ‘Affirm I am now’.

The PA18 pilot’s written report indicated that, when at 240ft QFE, he sighted the CJ6 behind and to the L, before it passed underneath his ac. The PA18 pilot initially thought that the risk of collision was high and considered there was insufficient time to take avoiding action.

The A/G operator reported that he had observed the CJ6 disappear below the tree line and then re- appear before going around on the RH side of the PA18.

The White Waltham Aerodrome operator’s safety sub-committee completed an investigation which included a number of recommendations. Their report noted that the CJ6 pilot had not booked out and had not informed anyone that he was operating non-radio.

White Waltham intend to review their procedures for the operation of non-radio ac and will amend the Operations Manual/Flying Order Book and appropriate pages of the UK AIP.

Analysis

White Waltham does not provide ATC or FISO services and requires pilots to comply with the Flying Order Book. In Class G airspace, pilots are ultimately responsible for their own separation on the principle of ‘see and avoid’. For flight within the vicinity of an aerodrome, RoA Rule 12, states that the commander shall:

‘conform to the pattern of traffic formed by other aircraft intending to land at that aerodrome or keep clear of the airspace in which the pattern is formed…’

The CJ6 pilot did not obtain information from the A/G operator to ensure that the flight was carried out safely within the ATZ and the pilot did not book out or report that he was operating non-radio.

After an Airprox with a PA28, the CJ6 pilot went around and repositioned for a further circuit and flew into close proximity with the PA18 already established in the circuit and on short final. Conclusions

3 The Airprox occurred when the CJ6 pilot, having gone around due to an earlier Airprox with a PA28, then repositioned for a second cct, without conforming with the cct pattern already established, and flew into close proximity with the PA18.

[UKAB Note(2): Rule 13(Order of landing) of the RoA states:

(1) An aircraft landing or on its final approach to land shall have the right-of-way over other aircraft in flight or on the ground or water.

(2) An aircraft shall not overtake or cut in front of another aircraft on its final approach to land.

…

(4) If the commander of an aircraft is aware that another aircraft is making an emergency landing, he shall give way to that aircraft.

…

Rule 17(Notification of arrival and departure) of the RoA at paragraph 2 states:

‘The commander of an aircraft arriving at or departing from an aerodrome in the United Kingdom shall take all reasonable steps to ensure, upon landing or prior to departure, as the case may be, that the person in charge of the aerodrome or the air traffic control unit or flight information service unit at the aerodrome is given notice of the landing or departure.’]

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, radar video recordings, a report from the air/ground operator involved and reports from the appropriate operating authorities.

The PA18 pilot appeared to be conforming to the pattern of traffic in the White Waltham cct so the Board concentrated its deliberations on the actions of the CJ6 pilot. The pilot did not notify his departure, contrary to Rule 17(2) (Notification of arrival and departure) of the RoA, or that he would be operating non-radio, contrary to the White Waltham FOB. The White Waltham A/G Operator was therefore unable to notify other ac in the cct that the CJ6 pilot was operating non-radio. Having departed the cct, experienced the ac emergency and carried out the checklist actions, he made the decision to return to White Waltham A/D where he carried out a ‘PFL cct’ which culminated in Airprox 2013/002 involving a PA28. RT calls by the PA28 pilot alerted the PA18 pilot to the presence of the CJ6 in the cct and the absence of RT calls from the CJ6 pilot should have alerted cct traffic and the A/G operator to the possibility that the CJ6 pilot was operating non-radio. The Board noted that extra consideration needs to be given to non-radio ac in what is normally an RT environment. The RoA Rule 13(4) states that ‘If the commander of an aircraft is aware that another aircraft is making an emergency landing, he shall give way to that aircraft.’. After some discussion, the Board concluded that the PA18 pilot could not have known that the CJ6 pilot had an emergency, only suspected that he was operating non-radio, and that it was therefore the CJ6 pilot’s responsibility to conform to the pattern of traffic intending to land, iaw Rule 12. The CJ6 pilot reported maintaining visual contact with the departing PA28; the Board opined that this, in conjunction with his short pattern cct, did not allow him time to assimilate the position of other cct traffic and therefore to conform to the pattern of traffic intending to land. In the event, he flew into conflict with the PA18 on final which he did not see until he rolled wings level just before turning final himself. Given this late sighting by the CJ6 pilot and the fact that the PA18 pilot’s sighting was too late to take avoiding action, Board Members were unanimous in their assessment of the severity of the confliction and that safety margins had been much reduced below normal.

4 PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The CJ6 pilot did not conform to the pattern of traffic formed and flew into conflict with the PA18 on final, which he had not seen.

Degree of Risk: B.

5 AIRPROX REPORT No 2013004

Date/Time: 16 Jan 2013 1311Z

Position: 5322N 00426W Wylfa PS (8·5nm NNE Valley) R322/2.1 11:11 022 Airspace: LFIR/Valley AIAA (Class: G) 11:23 Hawk(A) Lead L975 021 11:03 FL145+ 11:31 022 Reporting Ac Reported Ac 021 1310:35 035 L975 FL115+ Type: 2xHawk T Mk2(A)Hawk T Mk 2(B) CPA 029 11:31 11:23 020 Hawk(A)No 2 035 019 11:23 041 Hawk(B) 019 031 Operator: HQ Air (Trg) HQ Air (Trg) 11:11 Hawk(A) No2 018 11:11 031 11:03  11:03 034 VALLEY AIAA Alt/FL: 2000ft 1500ft 017 2000-6000ft QFE (1010hPa) QFE (1010hPa) Radar derived Levels show 1310:35 1 Weather: VMC CLBC VMC CLBC Mode C 1013hPa Hawk(B) 0 NM Visibility: 10km 20km 018

Reported Separation: Mona Elev 202ft Valley 1000ft V/0·7nm H Not seen Elev 37ft Recorded Separation: 1600ft V/0·6nm H

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE HAWK T MK2(A) NO2 PILOT reports flying solo recovering to Valley and in communication with Valley Director on 363·65MHz, squawking 3730 with Modes S and C; TCAS was fitted. The visibility was 10km flying clear below cloud in VMC and the ac was coloured black with strobe and nav lights switched on. During a pairs recovery to Valley as No2, Leader was level at 2000ft and his ac was 2nm in visual trail at 230kt descending through 2900ft, which was a non-standard recovery for Valley- based ac. The formation was receiving a TS, but only the Lead ac was allocated a squawk (of note, No2 was also squawking Lead’s code to enable TCAS functionality, but ATC were not aware of this). The Lead pilot had briefed ATC on the non-standard formation recovery by phone before flight and by radio during recovery (a pair would normally recover in arrow or close formation). Lead was flying with TCAS in TA/RA mode and, following a TA indication on his TCAS, gained tally of a single Hawk [Hawk (B)]. Assessing a possible confliction with his (No 2)’s ac, the Lead pilot made an immediate call on the formation chat frequency. At that instant No2 pilot, who was flying in TCAS TA/RA Mode, received a TCAS RA to “Climb-Climb” so he climbed to resolve the conflict. He got tally at an estimated 1nm range as Hawk(B) turned to match the Hawk Lead’s heading, directly between the formation and now slightly low (assessed at 1500ft), about 0·7nm away and 1000ft below. After 20sec Hawk(B) was seen to manoeuvre L towards Valley, shortly followed by an information call by Valley Director stating traffic was passing O/H the formation at 3000ft inbound to Valley. Now clear of the conflict, the formation recovered with no further incident. He assessed the risk of collision as ‘Medium’.

THE HAWK T MK2(B) PILOT reports flying a dual training sortie inbound to Valley and in receipt of an implied BS from Valley Approach on Stud 5 squawking 3737 with Modes S and C; TCAS was fitted. The visibility was 20km clear below cloud in VMC and the ac was coloured black with HISLs and nav lights switched on. As part of a transit from Mona RLG (RW22) to Valley (RW13), the student pilot (front cockpit) initiated a RH turn off RW22 and rolled out heading approximately N. He switched to Valley Approach (Stud5) and informed them that they were in the transit from Mona at 1500ft QFE. The APP informed them that there was "no traffic to affect". After a brief period on this heading at 345kt the student spotted a single Hawk T2 [(A) Lead] crossing R to L in our 1 o'clock. He, the instructor in the rear seat, became tally shortly afterwards and estimated it at approximately 3nm and closing. The student initially decided to turn in front of the traffic, but changed his mind and lagged the Hawk's position and aimed behind him. A decision he considered sensible. The TCAS

1 triggered a "TCAS, TCAS" alert and ATC reported that "traffic believed to be us" had traffic 12 o'clock, 2nm, crossing, a pair, downwind for the ILS. This was in-keeping with the Hawk we had seen - although a second jet was not sighted in the vicinity of the first Hawk. He instructed the student to turn L to (a) avoid the Wylfa nuclear power station restricted area and (b) to turn back towards Valley as we were now following the previously sighted traffic. He took control to expedite the recovery and came further L onto a SW’ly heading. They informed APP that they would be joining for a straight in approach. After landing he was informed that the Hawk they had seen had been the lead element of a 2-ship flying in 2nm trail and that the wingman had taken avoiding action as they (Hawk(B)) had turned to go behind his leader. The rear ac [Hawk(A) No2], unsighted by him, filed an Airprox. He assessed the risk of collision as ‘Medium’.

[UKAB Note (1): The Valley METAR shows:- EGOV 161250Z 12005KT 9999 FEW020 BKN080 03/M01 Q1011 BLU NOSIG=

THE VALLEY DIRECTOR reports controlling a busy radar pattern vectoring ac to both Valley and Mona with all flights being vectored on the same frequency. The Approach Radar controller (RAD) informed him about a Mona to Valley transit ac [Hawk(B)] which was a VFR transit taking generally the shortest ground track between Mona and the IP to the RW in use at Valley. At the time the transit was not perceived to be a factor to the Hawk(A) formation which was being vectored for a ‘trails’ ILS. RAD then informed him that Hawk(B) was positioning for a straight-in approach so, after passing instructions to other flights in the pattern, he checked on Hawk(A)’s position in relation to Hawk(B). Hawk(A) formation was informed of Hawk(B)’s position which appeared 1nm behind Hawk Lead ac and 1nm ahead of Hawk(A) No2. Hawk(B) was indicating 1000ft above both Hawk(A) formation ac, he thought, the No2 being 2nm in trail of the Lead. Hawk(B) then positioned for a straight-in approach via Holyhead mountain whilst Hawk(A) formation was vectored for a slightly wider pattern for separation on the approach from Hawk(B)’s visual straight-in approach.

THE VALLEY APPROACH RADAR CONTROLLER reports Hawk(B) pilot called on frequency for a Mona to Valley transit. Looking at the ‘air picture’ at the time of the request, there was no instrument traffic to affect this particular profile. On DIR’s frequency was a Hawk T2 formation which was downwind in the RTC. The Mona to Valley transit should, according to the FOB, turn and be well ahead of the Hawk(A) formation and therefore not be a factor. RAD advised Hawk(B) flight that there was no instrument traffic to affect, to which he replied that he wanted to position for an 8nm straight-in approach to RW13. This then obviously changed the dynamic of the air picture and deviated from the standard Mona to Valley transit profile. Hawk(B) was never formally identified but a radar return with Mode 3A/C appeared to be tracking on a N’ly heading towards Hawk(A) formation in the RTC. RAD stated to Hawk(B) pilot that, “traffic believed to be you has traffic 12 o’clock 2nm crossing R to L indicating similar height”. Hawk(B) pilot replied he was visual with this traffic. RAD then went on to explain that the formation was positioning for the ILS. Hawk(B) pilot reported he was heading towards Holyhead mountain for his straight-in approach and then changed to Tower frequency. In the meantime RAD liaised with DIR confirming that there was going to be a visual straight-in ac positioning ahead of his instrument traffic. Hawk(B) pilot did not advise of any TCAS RA on his frequency.

THE VALLEY SUPERVISOR reports he was in the VCR advising the ADC that the ILS approach was a pairs approach which were 2nm apart, which is not a commonly practised recovery to Valley. His aim was to fully brief the ADC, ensuring that the clearances that could be issued were understood. Additionally the cct was busy with other traffic and he wanted to ensure that the ADC had informed the cct traffic of this particular ILS approach. Post incident and after discussion with the Approach Radar controller, RAD informed him that TI was passed to Hawk(B) pilot against Hawk(A) formation after initially stating that there was no instrument traffic to affect. RAD’s reason was that Hawk(B) had not taken the normal transit route iaw the FOB (B05-1 Para 9) and the instrument traffic, which would not normally be a factor, became an issue because Hawk(B) pilot later informed RAD that he was positioning for a visual straight-in approach. DIR also had an understanding that Hawk(B) was a standard Mona to Valley transit which joins through initials and would not be a factor. DIR stated that this was the reason the traffic was not called earlier to Hawk(A) formation. He believed 2 factors contributed to the incident. First, the ILS approach in trail

2 is not a commonly practised procedure at Valley and more clarity on carrying out the procedure needs to be understood by both ATC and aircrew. Second, a Mona to Valley transit is through initial; if a straight-in approach is required it should be requested on initial contact with Approach so that the pertinent information can be passed regarding the approach and measures can be taken to facilitate the request and sequence the ac if required.

BM SAFETY POLICY AND ASSURANCE reports that this Airprox occurred in VMC, 8·3nm NNE of Valley between a flight of 2 Hawk T2s (Hawk A flight) and a singleton Hawk T2 (Hawk B). Hawk(A) No 2 was operating in 2nm trail to Hawk(A) Lead and being vectored for a pairs trail ILS approach to RW13 at Valley, in receipt of a TS from DIR. Hawk(B) was conducting a VFR Mona to Valley transit, not in receipt of an ATS but in 2-way comms with Valley RAD.

All heights/altitudes quoted are based upon SSR Mode C from the radar replay unless otherwise stated. Valley QFE at the time of the incident was 1010hPa, equating to approximately 90ft difference between the reported heights and the radar replay derived altitude which is based on 1013hPa.

DIR was a highly experienced controller and reported that, at the time of the incident, he had been working for 2hr since his last break and described his workload as ‘high to medium’ with ‘medium’ task complexity. 4 speaking units were on frequency conducting IFR approaches to both Valley and Mona. RAD described his workload as low with only 1 ac on frequency and minimal task complexity.

The RAF Valley FOB states that ‘Before transiting between RAF Valley and Mona airfields, aircrew are to pre-note Tower with this intention before departing the visual circuit. A call is then to be made to Valley Approach in order to determine the position of any other joining or departing traffic. If a conflict appears likely, the transit traffic is to defer to other traffic and sequence accordingly’.

Figure 1 below depicts the ground track to be followed by ac conducting Mona/Valley transits, with the Mona RW22/Valley RW13 transit ground track highlighted in red. The apogee of the Mona RW22/Valley RW13 transit ground track is approximately 5·8nm NNE of Valley. Of note, the Valley FOB does not stipulate a height for the transit procedure but does stipulate that ‘ac are normally to join through Initial at 1000ft QFE’.

Figure 1: Depiction of Ground Track for Mona to Valley Transit.

Although the pilot of Hawk(B) stated that they were in receipt of an ‘implied BS’ during the Mona/Valley transit, no agreement was reached between Hawk(B) and RAD to provide a BS and the

3 Valley FOB does not state that a BS will be provided during the transit. That said, it is reasonable to argue that Valley ATC personnel would treat ac flying this profile as if they were in receipt of a BS.

Trails procedures are non-standard for the Hawk and are not incorporated within the Valley FOB. Although they will be included within the T2 simulator syllabus for students, it will not form part of the live flying syllabus. The unit investigation determined that the crews of Hawk(A) formation were all instructors and were flying the formation by way of a familiarisation and validation exercise. The pilot of Hawk Lead reported that they had ‘briefed ATC on the non-standard formation recovery by phone before flight and by radio during the recovery’. Although it has not been possible to determine the content of the phone briefing, the pilot of Hawk(A) Lead briefed DIR on the RT at 1304:25 stating that, “as pre-briefed, once Victor-Mike, err [Hawk (A) formation c/s] for Radar to ILS with (Hawk(A) No2 c/s)] in trail 2 miles.” Although it was not instructed by DIR, at 1306:59 Hawk(A) No2 began to squawk the SSR3A code assigned to Hawk(A) Lead. This was not challenged by DIR, nor was Hawk(A) No2’s SSR 3A validated nor the SSR Mode C information verified.

The incident sequence can be deemed to have commenced at 1310:30 as Hawk(B) free-called RAD departing Mona, transiting to Valley. RAD replied that there was, “no instrument traffic to affect”, which was acknowledged. Although Hawk(B) would have already been displayed on the Valley surveillance display, this point also reflects the moment at which Hawk(B) entered NATS surveillance coverage and was thus visible on the radar replay. Hawk(B) was 3·1nm WNW of Mona and 3·9nm ENE of Valley, tracking N’ly, indicating 1800ft. Hawk Lead was 5·4nm NE of Hawk(B), heading 290°, indicating descent through 3500ft to 2000ft QFE; Hawk(A) No2 was in 2nm trail to Hawk(A) Lead and 5·7nm NE of Hawk(B), commencing a L turn onto 290°, indicating 4100ft having not yet commenced descent. Figure 2 depicts the incident geometry at this point.

Hawk(A) Lead

Hawk(A) No2

Hawk(B)

Figure 2: Incident Geometry at 1310:35.

By 1311:03, Hawk(B) had extended 6nm NE of Valley, tracking N’ly, indicating 1700ft; Hawk(A) Lead and Hawk(A) No2 were 2·6nm NNE and 3nm NE of Hawk(B) respectively, heading 290°, indicating descent through 2200ft and 3400ft respectively. At this point, it is evident that Hawk(B) had turned L approximately 15°, which may accord with the pilot’s report that his student had ‘initially decided to turn in front of the traffic’ having visually acquired a single Hawk ‘crossing right to left in our 1 o’clock’ with the instructor estimating the lateral separation at 3nm. It later transpired that the crew of Hawk(B) had sighted Hawk(A) Lead but not Hawk(A) No2. The unit’s investigation stated that the

4 instructor in Hawk(B) was ‘somewhat confused’ by only sighting 1 Hawk, given that the ‘standard pairs recovery for Valley Hawks is echelon or arrow; in short, a 2nm trail was not expected’. The unit’s investigation also determined that the crew of Hawk(B) received a TCAS TA at this point and while the crew were conscious of the warning, they ‘did not check the TCAS display which might have provided SA on the trail [ac]’, Hawk(A) No2; it has not been possible to determine whether the TA was activated against Hawk(A) Lead or Hawk(A) No2. The instructor added that the student then changed his mind ‘and lagged the Hawk’s [Lead] position and aimed behind it’. The unit’s investigation determined that it was during this period that the crew of Hawk(B) ‘took the decision to position at 8nm for a flapless approach’; however, this decision was not relayed to RAD until 1311:36, after the CPA.

At 1311:04 and 1311:06, Valley Talkdown advised DIR, “Talkdown free” on the channel intercom. At 1311:08, an unrelated Hawk pilot advised DIR that he was, “checks complete”, which was acknowledged. At 1311:13, RAD advised Hawk(B) pilot, “traffic believed to be you has traffic 12 o’clock, 2 miles, crossing right to left, believed to be similar type pair, similar level.” At this point, Hawk(A) Lead and Hawk(A) No2 were 2nm N and 2·3nm ENE of Hawk(B) respectively, heading 290°, indicating 2200ft and descent through 3100ft respectively. Hawk(B) pilot advised RAD that they were, “visual” which RAD acknowledged, adding, “that is a pair about to..on the…for the ILS, shouldn’t affect your Mona transit.” Hawk(B) pilot acknowledged this at 1311:28.

CAP 774 Chapter 3 Para 5 states that:

‘Traffic is normally considered to be relevant when, in the judgement of the controller, the conflicting aircraft’s observed flight profile indicates that it will pass within 3 NM and, where level information is available, 3,000 ft of the aircraft in receipt of the Traffic Service. However, controllers may also use their judgement to decide on occasions when such traffic is not relevant, e.g. passing behind or within the parameters but diverging’.

At 1311:23, Hawk(A) No2 pilot’s response to their reported TCAS RA climb begins to become evident on the radar replay; Hawk(B) was 1·1nm SW of Hawk(A) No2, tracking NNE’ly, indicating 1900ft. Hawk(A) No2 reached the top of their TCAS RA-instructed climb at 1311:27, indicating 3500ft. The pilot of Hawk(A) No2 did not advise DIR that they had received a TCAS RA. Between radar sweeps at 1311:27 and 1311:31, Hawk(B) pilot initiated a further L turn to track approximately 290°. This was, as reported by the instructor, to avoid the Wylfa power station restricted area and to turn back towards Valley as ‘they were now following the previously sighted traffic’. The pilot of Hawk(A) No2 reported that they ‘got tally at an estimated 1nm range as the single Hawk [Hawk(B)] turned to match (Hawk(A) Lead)’s heading, directly between the formation’.

The CPA occurred 8·3nm NNE of Valley at 1311:31 as Hawk(B) passed 0·6nm ahead of Hawk(A) No2; Figure 3 depicts the incident geometry at this point. No TI was passed by DIR to Hawk(A) Lead or Hawk(A) No2, about Hawk(B), prior to the CPA. Subsequent to completing their DASOR, DIR has related that RAD warned them ‘off-landline’ that Hawk(B) was extending to conduct a “flapless straight in approach”; however, this would have been shortly after 1311:36 and hence after the CPA. DIR added that, having believed that Hawk(B) was conducting a standard Mona/Valley transit and joining through Initials, they did not believe that Hawk(B) was a factor and had been focussed on monitoring the progress of the other ac on frequency, particularly those conducting IFR approaches to Mona.

5 Hawk(A)Lead

Hawk(A) No2 Hawk(B)

Figure 2: Incident Geometry at 1311:31.

At the time of the incident, the SUP was in the VCR briefing the ADC on the forthcoming trails approach and monitoring the busy visual cct. Consequently, the SUP was not in a position to affect the outcome of the incident.

Given the published Mona/Valley transit profile, at the point that RAD advised Hawk(B) flight that there was, “no instrument traffic to affect”, he was correct in as far as Hawk(B) would have been expected to have been ahead of Hawk(A) Lead and Hawk(A) No2. Moreover, RAD’s use of this expression was accepted standard Valley procedure and, based on the findings of the unit investigation, is understood by aircrews. However, notwithstanding that RAD’s statement was accepted Valley procedure, BM SPA contends that, given that the Hawk formation would have been visible to Hawk(B) flight and of the proximity of the respective flight profiles, ‘good practice’ would have been for RAD to provide a warning to the transit traffic to develop aircrew situational awareness.

In terms of the Airprox itself, it occurred as Hawk(B) extended beyond the published ground track for the Mona/Valley transit procedure and thus introduced a confliction with Hawk(A) No2. Once Hawk(B) had extended beyond the route routinely followed by Mona/Valley transiting ac, only 10sec elapsed before RAD provided a warning of traffic to Hawk(B). Consequently, RAD reacted as quickly as could reasonably be expected, by providing a warning to Hawk(B) crew of the presence of Hawk(A) Lead and (A) No2; however, this warning did not explain that the pair of Hawks was in 2nm trail. Whilst ‘good practice’ would suggest that a more accurate warning detailing Hawk(A) Lead and Hawk(A) No2 individually was preferable, it is reasonable to argue that RAD would have been surprised by seeing Hawk(B) extend beyond the standard transit profile and was attempting to provide as timely a warning as possible. Moreover, given that RAD was providing an ‘implied BS’, a generic warning of the presence of Hawk(A) Lead and Hawk(A) No2 was arguably sufficient. The crew of Hawk(B) had already visually acquired Hawk(A) Lead and, based on RAD’s warning, were cognisant that they had been notified of a “similar type pair” but were not aware that Hawk(A) No2 was flying in trail and did not see it. It is noteworthy that Hawk(B) did not seek confirmation of the location of Hawk(A) No2, having been unable to sight it. From RAD’s perspective, Hawk(B) pilot’s confirmation that they were “visual” will have reduced their concern over the developing situation and, believing that Hawk(B) would ‘turn-in’ to initials shortly, thus removed their ability to further directly affect the incident.

From DIR’s perspective, it is reasonable to argue that Hawk(B) only became ‘relevant traffic’ from 1311:03 as it extended N of the typical Mona/Valley transit route. However, given the expected profile of Hawk(B), DIR had understandably prioritised his focus on the other ac on frequency and

6 was unaware of the proximity of Hawk(B) to Hawk(A) Lead and Hawk(A) No2 until the warning from RAD. Unfortunately, this meant that DIR did not detect the threat posed by Hawk(B) and, compounded by the short time available between 1311:03 and the CPA at 1311:31, was unable to provide TI to Hawk(A) Lead and Hawk(A) No2.

This incident stands as an excellent example of disconnected, random acts and events highlighting weaknesses in an organisation’s barriers against failure: the non-standard Hawk trail procedure and the flight by Hawk(B) outside the Mona/Valley transit profile which compressed the timelines available for ATC to react. In-turn, these shortened timelines caused the warning provided by RAD to Hawk(B) to lack explicit detail about the nature of the trail formation and, given DIR’s workload, caused DIR to not pass TI to Hawk(A) Lead and Hawk(A) No2. In this instance, the TCAS onboard Hawk(A) No2 resolved the conflict enabling the crew to avoid Hawk(B).

RAF Valley conducted a thorough investigation into this Airprox and made a number of recommendations to reduce the likelihood of a reoccurrence. BM SPA has also recommended that RAF Valley review those elements of the FOB regarding the requirements for ATS provision to ac conducting Mona/Valley transit profiles.

HQ AIR (TRG) agree with BM SPA that the ‘no traffic to affect’ call was misleading but did not fundamentally cause this Airprox as TI was passed in time to be effective. However, the lack of a proper description of the disposition of the pair caused confusion and led the crew of Hawk(B) to believe they had acquired and safely deconflicted from the ‘pair’. Mention of the fact that the pair were in fact in trail by 2nm, or giving the range and bearing to each of the pair separately would have provided the crew with better awareness. The key principle must always be to convey the displayed radar picture as effectively but succinctly as possible. It is disappointing to note the lack of use made by Hawk(B) of their TCAS capability, which was in stark contrast to the effective use of TCAS by Hawk(A) No2 pilot.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of Hawk(A) No2 and Hawk(B), transcripts of the relevant RT frequencies, radar video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC and operating authorities.

The Airprox sequence of events began when the crew of Hawk(B) did not follow the Mona-Valley transit procedure and did not inform ATC. In extending N’ly beyond the published ground track, Hawk(B) flew towards the intended track of Hawk(A) and Hawk(A) No2. When Hawk(B) crew called RAD they were informed there was no instrument traffic to affect them, which was accurate as the ac would have been ahead of Hawk(A) Lead and No2 had the normal transit track been flown. As soon as RAD noticed Hawk(B) had crossed the MATZ boundary he passed a traffic warning to the crew but he was still under the impression that the procedure was being followed. It was unfortunate that RAD had not been informed by DIR that Hawk(A) No2 was in 2nm trail from his leader or that RAD did not notice Hawk(A) No2’s squawk; the result was that in passing a warning to Hawk(B), RAD simply stated that the traffic was a pair of Hawks, thereby painting an incorrect ‘air picture’ to the crew of Hawk(B). Before receiving the ATC warning the crew had visually acquired Hawk(A) Lead and had elected to ‘slot-in’ behind it, which lead to Hawk(B) turning in front of Hawk(A) No2 which was not seen. Hawk(B) crew did not query with ATC that only a single Hawk could be seen, only reporting ‘visual’ with RAD and only informing RAD of their intention to position to 8nm final after the CPA. Hawk(B) crew would not have expected the Hawk ‘pair’ to be in 2nm trail as the procedure is not flown by Valley students and it was not an agreed procedure in the FOB. For his part, DIR was expecting Hawk(B) to remain clear of Hawk(A) Lead and No2’s track and only noticed its proximity after the CPA. Following a TCAS TA alert, Hawk(A) Lead saw Hawk(B) and warned No2 of its presence simultaneously with No2 crew receiving and following the TCAS RA climb guidance before visually acquiring Hawk(B) well below. These actions allowed the Board to conclude that any risk of collision had been quickly and effectively removed. The Board noted that Hawk(A) No2 pilot did not alert ATC to the TCAS RA or ‘clear of conflict’ iaw CAP413.

7

The BM SPA Advisor informed Members that as a result of this Airprox the FOB Mona-Valley transit procedures were reviewed and amendments identified. These include specifying a transit height, reiterating the need to fly the published ground track or seeking ATC approval before deviating and stipulating that flights are in receipt of an ATS unless the Mona-Valley was for Valley RW31.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: Hawk(B) crew deviated from the Mona-Valley transit procedure without informing ATC and turned in front of Hawk(A) No2, which they did not see.

Degree of Risk: C.

8 AIRPROX REPORT No 2013006 Diagram based on radar data and pilot reports Date/Time: 29 Jan 2013 1641Z Position: 5057N 00248W (7nm SW RNAS Yeovilton) Airspace: Yeovilton AIAA (Class: G) Wildcat (B) Reporting Ac Reported Ac Type: Wildcat AH1 (A) Wildcat AH1 (B) Operator: JHC Civ Pvt South Petherton A303 Alt/FL: 700ft 700ft QFE (NR) QFE (998hPa) CPA Weather: VMC CLBC VMC CLBL Visibility: 10km 10km Reported Separation: Wildcat (A) 0ft V/0.5nm H NR V/1000yd H Recorded Separation: NR

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE WILDCAT (A) PILOT reports undertaking a conversion training flight to the Wildcat AH Mk1, following the A303 as part of the promulgated Foul Weather Route (FWR), back to RNAS Yeovilton from RNAS Merryfield on completion of his sortie detail. He was operating under VFR in VMC and in communication with Merryfield TWR [378.525MHz]. The ATS provided was not reported. The grey camouflaged ac had HISLs selected on, as was the SSR transponder with Modes A, C and S. The ac was not fitted with an ACAS. At South Petherton [7nm SW Yeovilton], heading 060° at 100kt, the crew noticed a similar ac type at a range of 4nm, flying parallel to them on the LH side and at the same height, N of the A303. There had been no mention of any other ac by Merryfield TWR. The other Wildcat was then observed turning towards him; it was assumed that it would execute a tighter turn to pass behind. However, the other ac’s turn was not sufficient to achieve this and the crew perception was of a possibility of collision. The ac commander directed the pilot to turn away from the other ac and he made a positive turn away, to the R. He assessed that the 2 ac were converging rapidly and the other ac was also seen by the rear crew to conduct an avoiding manoeuvre.

He assessed the risk of collision as ‘High’.

THE WILDCAT (B) PILOT reports conducting a test flight. He was operating under VFR in VMC with a BS from Westland APP [130.800MHz]. The grey camouflaged ac had navigation lights and HISLs selected on, as was the SSR transponder with Modes A, C and S. The ac was not fitted with an ACAS. From Crewkerne, he elected to operate towards South Petherton as the cloud base looked much higher to the N. He knew this would take his flight path close to the Yeovilton W’ly [MATZ] stub but elected to continue with a BS from Westlands as he had good positional SA. He stated that although he also knew his flight path would take him over the Merryfield to Yeovilton FWR, he assumed that all traffic on this route would be at 500ft and below on the Yeovilton QFE. He operated between Merriott and South Petherton at about height 1400ft [998hPa], turning back to the S 1nm before the Yeovilton [MATZ] stub, and started a slow descent. Aware of possible traffic following the A303, he elected to level off at 700ft. As he was levelling off to the S of South Petherton, the LHS occupant called 'Lynx right and low, turning away'. The pilot immediately saw a Lynx or Wildcat helicopter turning to the S in his 2 o'clock position about 100ft below and at a range of 1000-1500yd. He judged that there was no confliction at that point. After turning about 20° L he continued on a S’ly heading before conducting further operations ivo Crewkerne and returning to Westlands. He stated

1 that on seeing the other ac he immediately realised it had probably been turning to avoid him; however, at that point there was no perceived risk of collision and therefore he did not raise an Airprox. He also commented that the nature of his sortie required ‘eyes-in time’ but that CRM was used to maintain one set of eyes looking out during set-up and data recording. He noted that this incident would probably have been avoided if he had called Yeovilton or Merryfield for a traffic update prior to flying in proximity to ‘their airspace’ and that he had also wrongly assumed that any FWR traffic would be below his level when at 700ft on 998hPa.

He assessed the risk of collision as ‘Low’.

THE YEOVILTON DUTY ATCO reports Wildcat (A) was recovering via the publicised FWR to RNAS Yeovilton. When the ADC first spoke to the pilot he called another ‘Westlands' ac in his vicinity. The pilot replied, possibly on the Merryfield TWR frequency, that he had narrowly avoided the ac in the vicinity of South Petherton. When the controller stood up to check the Hi-Brite, he saw a ‘Westlands squawk’ close to that location, which appeared to be to the N of the Westlands operating areas. Nothing else was mentioned on frequency and Wildcat (A) recovered normally.

He perceived the severity of the occurrence as ‘High’.

[UKAB Note(1): The Merryfield (MF) and Yeovilton (VL) ADC transcripts for the period of the Airprox are reproduced below:

From To Speech Transcription Time [Wildcat (A) C/S] is now complete, and we’d like to return Wildcat (A) MF ADC 1639:50 via the Foul weather Route [Wildcat (A) C/S] depart Foul Weather Route, Yeovil MF ADC Wildcat (A) 1640:12 QFE 1000 MF ADC VL Logger [Wildcat (A) C/S] on the Foul Weather Route 1640:36 ? MF ADC [Short transmission with no speech] 1644:26 MF ADC Wildcat (A) [Wildcat (A) C/S], continue with Yeovil Tower Channel 1 1644:30 MF ADC VL ADC [Landline call] Have you got [Wildcat (A) C/S]? 1644:40 This is [Wildcat (A) C/S] near South Petherton, we just Wildcat (A) MF ADC came very close to another aircraft, similar type, assume 1644:45 it’s from Westlands MF ADC Wildcat (A) [Wildcat (A) C/S], I’ve nothing else on this frequency 1644:55 Wildcat (A) MF ADC [Wildcat (A) C/S] to Channel 1 1645:00

From To Speech Transcription Time Wildcat (A) VL ADC Yeovil Tower, [Wildcat (A) C/S], South Petherton to join. 16:45:39 [Wildcat (A) C/S] Yeovil Tower, Join Point South, QFE VL ADC Wildcat (A) one Thousand the circuit is clear, Westland’s have traffic 16:45:39 in the sectors up to three thousand feet. Err, err, join for Point South and, err, there is one, err, Wildcat (A) VL ADC similar type which is in the South Petherton area, err, 16:45:49 orbiting. VL ADC Wildcat (A) [Wildcat (A) C/S] roger 16:46:00 ]

THE YEOVILTON OCCURRENCE MANAGER made the following comments: Wildcat (B) was not where Yeovil/Yeovilton ATC believed it to be. The last reported position was in the ‘Westland areas’ to the S of Yeovil. The Wildcat (B) pilot made an assumption that the FWR was in operation without checking with RNAS Yeovilton ATC. Ac can route along the FWR without it being in force. The height restrictions are only mandated in Green or worse (3.7 km visibility/700ft cloud-base). The Wildcat (B) pilot positioned himself in a location where he knew RNAS Yeovilton ac transit between VL and MF but elected to remain on a BS with Yeovil, despite having a ‘heads in sortie’ and elected not to get a service from VL whilst close to the MF and VL MATZ boundaries. Wildcat (A) perceived a risk of collision and Wildcat (B) did not.

2

He made the following observations: Pilots should advise the controlling authority if changing operating area, should always talk to the relevant controlling agency and always take the most appropriate/best ATS available. He also observed that fitment of TCAS could have cued both aircraft [pilots] earlier.

ATSI reports the Airprox occurred E of South Petherton (5057N 00248W), situated on the SW boundary of the Yeovilton/Merryfield CMATZ, between two Agusta Westland Lynx Wildcat AW159 helicopters, Wildcat (A) and Wildcat (B).

Background

Wildcat (A) pilot was operating under VFR, returning to Yeovilton A/D and following the promulgated FWR, used by ac routeing between Merryfield and Yeovilton A/Ds. He was in receipt of a BS from Merryfield TWR [378.525MHz]. Wildcat (B) pilot was operating under VFR on a test flight from Yeovil/Westland (Westland) A/D, planning to use the designated Westland Test Flying Area (TFA) to the S of the A/D. Wildcat (B) pilot elected to route N to South Petherton (see Figure 1), which is outside the TFA and is situated to the N of the FWR. Wildcat (B) pilot was in receipt of a BS from Westland TWR [125.400MHz].

Figure1: TFA (W) & (E) together with circled geographical positions.

Westland ATC were providing a combined A/D and APP control service, but this was planned to be split. A limited radar service can be provided by arrangement for inbound ac utilising the Sperry Type 424E primary radar equipment but, due to equipment limitations, Westland Radar can only provide a radar approach for one ac at a time. The Westland Manual of Air Traffic Services (MATS) Part 2, Paragraph 4.1.2, states:

‘The normal method of operation at Westland is for the functions of both Approach Control and Aerodrome Control to be combined. During periods when these services are being provided separately, Approach Control shall co-ordinate with Aerodrome Control all aircraft approaching to land and transit aircraft routing through the ATZ below altitude 2000ft.’

Westland ATSU reported that ac intending to operate N of the Westland TFA will be notified by Westland ATC to Yeovilton ATC and coordinated or transferred as required. A LoA exists between Westland and Yeovilton. The LoA paragraph 1.16.5 (c), states:

3 ‘Yeovil/Westland will pass traffic information to Yeovilton on aircraft operating under their jurisdiction, including imminent Test Flying within the TFA, giving a minimum of 5 minutes warning whenever possible to allow for any necessary liaison or co-ordination.’

The Yeovil/Westland MATS Part 2, Paragraph 1.2.4, states:

‘The Westland TFA is an area of Class G airspace within which helicopter test flights take place and instrument approaches are conducted. It extends from ground level to 3000 ft amsl. The TFA is divided into two sectors (W and E) by a N/S line drawn through the A/D Reference Point. The TFA is only recognised by ATC Yeovilton who will, whenever possible, co-ordinate use of the airspace with ATC Yeovil/Westland.’

The TFAs have been highlighted in Figure 1, together with the reported geographical positions of Sutton Bingham, Crewkerne, South Petherton, and Dinnington.

CAA ATSI had access to Westland RTF and area radar recording, together with written reports from the two pilots and Yeovilton ATC. The Yeovil/Westlands controller was not made aware of the Airprox and consequently did not file a report but was subsequently questioned about the incident. The area Multi-Tracking Radar recording showed only Wildcat (B) aircraft from 1639:04 until 1643:15.

The Yeovilton A/D weather was recorded as follows: METAR EGDY 291650Z 20019KT 9999 SCT012 BKN020 13/11 Q1002 GRN NOSIG=

Factual History

The Westland controller was providing a combined Aerodrome (TWR) and APP control service. A Merlin helicopter was operating with Westland APP [130.800MHz] and had requested a SRA to RW27. The Westland controller intended to split the frequencies in order to facilitate the SRA.

The Westland ATSU reported that the Wildcat (B) pilot had booked-out using the standard faxed booking out form, indicating an intention to operate in the Westland TFA (E and W).

At 1610:10, Wildcat (B) pilot contacted Westland TWR and reported ready for departure, initially to operate on the RWY. The TWR acknowledged the call and allocated squawk 0260. Shortly afterwards, Wildcat (B) pilot was instructed to line-up and wait on RW27. At 1613:50, Wildcat (B) pilot was cleared to operate as required on the A/D.

Details of Wildcat (B) pilot’s intended flight in the Westland TFA (E and W) together with the squawk 0260 were notified to Yeovilton ATC in accordance with the LoA.

At 1616:03, Wildcat (B) pilot reported ready for departure and TWR cleared him for take-off on RW27. At 1616:45, TWR instructed Wildcat (B) pilot to remain on the Tower frequency and agreed a BS, passing the Portland RPS [998hPa], which was acknowledged correctly.

At 1627:00, the A/D and APP frequency were split to facilitate the provision of the Merlin helicopter’s SRA on the APP frequency.

At 1628:25, TWR, aware that the Merlin pilot would be joining the cct after the SRA approach, passed TI and requested the position of Wildcat (B). The Wildcat (B) pilot reported at 500ft, approaching Sutton Bingham (see Figure 1) and advised, “we’ll hopefully remain south.”

The written report from Wildcat (B) pilot indicated that he elected to route from Crewkerne to South Petherton, due to a low cloud base of 800ft, and was aware that this would take him to the N of the Westlands TFA and across the Merryfield to Yeovilton FWR.

4 Radar returns showed only Wildcat (B) from 1639:04 until 1643:15. For illustrative purposes the radar position and time of Wildcat (B) have been added to Figure 2 below, together with the approximate track of Wildcat (A).

Wildcat (B)

Wildcat (A)

Figure 2: Plotted radar positions and times of Wildcat (B).

Between 1639:56 and 1641:00, Wildcat (B) was N of the TFA(W) area. The precise geometry of the encounter is unknown. However, Wildcat (A) pilot’s written report indicated sighting Wildcat (B) N of the A303 and flying parallel to Wildcat (A) before observing it turn R towards him. Wildcat (B) pilot’s written report indicated that he had turned S and, levelling at 700ft, had sighted Wildcat (A) in his R, 2 o’clock position and 100ft below. It is considered likely that the Airprox occurred shortly after 1640:36, when Wildcat (B) pilot turned S.

The Westland controller was not aware of the Airprox and therefore did not complete a report. Westland ATSU were not advised of the Airprox until the following week.

When questioned, TWR reported that operations on the day were routine, indicated that he expected Wildcat (B) would be operating within the TFA and did not consider it unusual that the helicopter might operate N of Crewkerne and W of the A/D. The controller indicated that he would have expected Wildcat (B) pilot to report his intention to operate N of the TFA and might also have expected a call from Yeovilton ATC had they observed this to have been the case.

The Westland ATSU reported that Yeovilton and Westland have a very good working relationship and that their joint LoA is continually reviewed and updated (i.e. October 2012 and March 2013).

Wildcat (A) pilot was in receipt of a BS from Merryfield ATC. It was not clear what procedures exist between Merryfield and Yeovilton ATC.

As a result of this incident the Westland Helicopter Chief Test Pilot indicated that all pilots will be reminded of the requirement to advise ATC if they intend to operate N of the TFA, in order that appropriate notification and any required coordination can be effected between Westland ATC and Yeovilton ATC in accordance with the LoA.

5 Analysis

Wildcat (B) pilot booked-out to operate in the TFA (E and W) and Yeovilton ATC were advised in accordance with the LoA. The Wildcat (B) pilot’s written report indicated that he elected to operate at South Petherton [outside the TFA] and was aware that he would cross the Merryfield to Yeovilton FWR. However, Wildcat (B) pilot did not advise ATC of his intentions. TWR was unaware of Wildcat (B) pilot’s intentions and was therefore not in a position to notify or coordinate with Yeovilton in accordance with the LoA.

The area radar recording did not show the Airprox and radar returns were intermittent but, from the data available to CAA ATSI, it is considered likely that the Airprox occurred shortly after 1640:36, when Wildcat (B) turned onto a S’ly heading.

Wildcat (A) pilot was in receipt of a BS from Merryfield ATC. The Westland TWR was not aware of Wildcat (A) and was therefore unable to pass any TI or warning to Wildcat (B) pilot.

Within Class G airspace, regardless of the service being provided, pilots are ultimately responsible for collision avoidance and terrain clearance.

Conclusions

Wildcat (B) pilot came into confliction with Wildcat (A) when he operated outside of the Westland TFA, in the vicinity of South Petherton and the Merryfield to Yeovilton FWR, without pre-notifying his intention to Westland ATC. The Westlands controller was not aware of the intention of Wildcat (B) pilot to leave the TFA and therefore was unable to notify Yeovilton in accordance with the LoA.

NAVY COMMAND agreed with the conclusions made by ATSI. The LoA between Yeovilton and Yeovil Westlands is deemed fit-for-purpose and was enacted appropriately on the day. The weather at the time meant that the FWR was not mandatory, but was available for use bi-directionally (in colour codes worse than GRN it becomes unidirectional). It was a flawed assumption that any ac using it would always be at or below 500ft; this was acknowledged by the pilot of Wildcat (B) in his report.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequencies, radar photographs/video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC and operating authorities.

It was noted that this was the first Airprox involving the Wildcat AW159 to be considered by the Board. Members therefore firstly first discussed operating differences from previous types of Lynx helicopter, including cockpit ergonomics and equipment levels. It was established that the new helicopter offered improved performance and that the ‘glass cockpit’ greatly improved crew SA. However, it was also noted that the amount of information available in-cockpit could result in more time spent ‘heads-in’ and hence detract from an effective lookout.

The RN ATC Member clarified the conduct of Merryfield to Yeovilton transits: as Merryfield has no radar, the Merryfield ADC pre-notes Yeovilton APP, who passes back deconfliction information, if any. However, the Wildcat (B) pilot was not mandated to inform Yeovilton APP if he left the TFAs and, in this case, Yeovilton APP did not anticipate him leaving. Both crews were aware of the FWR and the Wildcat (B) pilot believed he would be above any traffic using the FWR. As it was, although Wildcat (A) was following the FWR ground track, the weather conditions were such that the FWR was not mandated and the height deconfliction therefore did not exist. Members also noted that the crews were operating in Class G airspace and were not best served by procedures only relevant to Yeovilton and Yeovil traffic. Several pilot Members observed that pilots can sometimes overly rely on

6 local arrangements, which do not include other VFR traffic, in the mistaken belief that they afford some degree of priority or protection over other traffic.

Members also expressed concern at the Wildcat (B) pilot’s plan to operate using a BS whilst conducting an air test. Members considered that he would have been well advised to consider the available ATS in the context of Threat and Error management and the demands of his sortie. A considerable amount of time is spent ‘heads-in’ whilst conducting an air test and it was the Board’s opinion that the availability of an appropriate, radar based, ATS, in conjunction with an assessment of the prevailing weather conditions, could reasonably be used as a ‘go/no go’ criterion for such a sortie.

In the event, both pilots had an equal and shared responsibility to see and avoid and the Wildcat (A) pilot had right of way. Wildcat (A) pilot saw Wildcat (B) in good time and, when it appeared that Wildcat (B) pilot was not in visual contact, Wildcat (A) crew sensibly took effective and timely avoiding action to prevent a collision. The Board also considered that Wildcat (B) pilot’s use of a BS was not appropriate to the conduct of an air test in the open FIR and that this was a contributory factor.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: A conflict resolved by Wildcat (A) pilot.

Degree of Risk: C.

Contributory Factors: Wildcat (B) pilot utilised an inappropriate ATS while conducting an air test.

7 AIRPROX REPORT No 2013007 Diagram based on radar data Date/Time: 1 Feb 2013 1445Z Aberdovey Position: 5331N 00402W F191 (47nm SSE RAF Valley) 1 NM F197 F198 F198 F197 Airspace: Valley AIAA (Class: G) Hawk 0 TMk1 Reporting Ac Reported Ac F--- Type: Hawk T Mk2 Hawk T Mk1 F165 45:11 F--- 45:03 CPA 1445:18 Operator: HQ Air (Trg) HQ Air (Trg) 44:55 NR V < 0.1nm H F161 Alt/FL: 16000ft 16000ft 44:47 RPS (993hPa) RPS (1004hPa) F166 44:39 1444:31 Weather: VMC CLAC VMC CLAC F180 Visibility: 50km 50km

Reported Separation: F--- 0ft V/0.5nm H 0ft V/0.5nm H F206 Recorded Separation: F196 NR V/<0.1nm H Hawk TMk2

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE HAWK T MK2 PILOT (Hawk 1) reports conducting a general handling currency sortie after a 2- week weather lay-off. He was seated in the rear seat and was acting as Pilot Monitoring (PM), with the pilot student, PF, seated in the front. He was operating under VFR in VMC with a TS from LATCC(Mil) [280.350MHz]. The black ac had navigation, conspicuity and strobe lights selected on, as was the SSR transponder with Modes A, C and S. The ac was also fitted with TCAS II. Setting up for an Operational Training Manoeuvre (OTM) at an altitude of 19000ft. The crew observed a rapidly closing ‘TCAS contact’ in the 1 o’clock position, indicating 2000ft below at a range of approximately 8nm. ‘London Mil’ informed him 5sec later of traffic “North at 8nm tracking West 2000ft below”. The transmission was ‘clipped’ by his TCAS TA audio warning of “traffic traffic”. The PF initiated a climb in an attempt to deconflict vertically. However, the TCAS contact was observed to climb at a greater rate and soon indicated above, he thought. With the contact still closing, the ac was rolled inverted and a 25° nose down attitude selected. At the start of this manoeuvre the TCAS reverted to standby (as is usual during dynamic manoeuvering). Approaching 16000ft the ac was turned L through 60° and levelled at 15600ft, during which time the TCAS automatic resetting sequence had completed and it gave normal indications (clear of contacts) at 20nm scale. A gentle climb was initiated to set up for the next manoeuvre when the crew observed a further TCAS TA audio warning of “traffic traffic” and a TCAS contact inside 2nm in the 1 o’clock position indicating a descent from 2900ft above, closing rapidly towards a collision. The TCAS range scale was reduced to 6nm, at which point the contact appeared to be in the same position as his own ac. Despite the crew’s attempts, visual contact with the conflicting traffic had not been attained up to this point and he asked London Mil “request where the traffic is now”. As he finished this transmission he observed a Hawk T Mk1 in his R 5 o’clock, in a climbing L turn, co-altitude at a range of about 0.5nm, with 30° tail aspect. After enquiring with London Mil, he was informed that the conflicting traffic was also receiving a TS on the same frequency.

He assessed the risk of collision as ‘Medium’.

THE HAWK T MK1 PILOT (Hawk 2) reports conducting a general handling refresher sortie. He was seated in the rear seat and was acting as Pilot Monitoring (PM), with the pilot student, PF, seated in the front. He was operating under VFR in VMC with a TS from LATCC(Mil) [280.350MHz]. The black ac had ‘all lights’ selected on, as was the SSR transponder with Modes A and C. The ac was

1 not fitted with a Mode S capable transponder or an ACAS. He had informed London Mil that he would be operating in the height block 5000ft to 20000ft and had been in the same area for more than 10min. Just before the incident London Mil passed TI on traffic 12nm S at 500ft above, transiting N. No indication was given that this ac would be changing height and he did not recall London Mil informing the other ac of his height block. There was an updated TI call of traffic 8nm S, and the crew entered a LH Maximum Rate Turn (MRT), descending from about 18000ft. After the second orbit of the MRT, with the crew focusing their lookout through the top of the canopy, they both saw a flash of black, R to L across the front of the ac. The ac was immediately recovered and the crew saw a Hawk T Mk 2 in a gentle climb N-bound at approx 15-16000ft and 0.5nm away. It was believed that this was the same ac that had been called by London Mil earlier. Before entering the MRT, the crew’s SA led them to believe the conflicting Hawk was still a few miles away, transiting N but above them in height and maintaining level, so he elected to enter the MRT thinking this would increase vertical separation.

He assessed the risk of collision as ‘Medium’.

[UKAB Note(1): The RAF Valley weather was reported as follows: METAR EGOV 011450Z 33015KT 9999 FEW012 BKN015 BKN025 07/06 Q0996 WHT TEMPO FEW015 BLU]

THE LATCC(MIL) AREA CONTROLLER reports he had just begun his shift and was the only ATCO working in the band-boxed position with all ‘West Bank’ sectors open. [The 2 subject Hawks] were conducting general handling in similar altitude blocks in a similar area, with both under a TS. He had heard the previous controller calling TI to each about the other during their position handover so knew they were both aware of each other. Several minutes after handover he noticed both ac were flying on headings and at levels which would take them within 3nm and 3000ft of each other so he passed TI to both pilots, which was acknowledged by both. They continued to get closer and one of the Hawk pilots asked for further TI. He gave as accurate a picture as he could and recalled both ac being within 1nm, with no Mode C available on [the Hawk T Mk1]. [The Hawk T Mk2 pilot] then asked if the other Hawk was on frequency and he offered him the opportunity to talk directly, believing he wanted to negotiate with his colleague. [The Hawk T Mk1 pilot] transmitted that he was visual with the other Hawk. Both aircraft recovered to Valley soon after. The controller took no further action at the time as an Airprox was not declared by either pilot.

He assessed the risk of collision as ‘Negligible’.

THE LATCC(MIL) SUPERVISOR reports that an Airprox was not declared on frequency at the time or brought to her attention soon after and that she had no recollection of the event.

THE UNIT SAFETY MANAGEMENT OFFICER reports that the incident occurred due to the flight profile of the two Hawks in West Wales. The W Tac controller was operating the 4 "West Bank" sectors (NW/Central and W/SW) and the SUP would have been monitoring SE for pre-notes; a routine scenario for traffic levels at the time. There was no planner in situ. No landline conversations took place during the time period of the RT transcript. The controller made appropriate TI calls to the Hawk pilots when he deemed it necessary and with the information available to him. The pilots gave the impression that they would attempt to deconflict laterally but this did not occur. The controller also updated the TI when he could; the RT transcript indicates that both pilots made a change in altitude following the TI, which took them into confliction with each other.

BM SAFETY POLICY AND ASSURANCE reports that this Airprox occurred on Fri 1 Feb 2013 at 1445:19, between a Hawk T Mk2 (Hawk T2) and a Hawk T Mk1 (Hawk T1). Both Hawks were manoeuvering individually in altitude blocks within the North Wales Military Training Area (NWMTA), in receipt of a TS from LATCC(Mil) W Tac.

All heights/altitudes quoted are based upon SSR Mode C from the radar replay unless otherwise stated.

2

Information

Both aircrews reported VMC with unlimited visibility, operating 6000ft above cloud. W Tac reported low workload and task complexity, operating ‘band-boxed’ with the W, SW, NW and Central sectors.

The 2 Hawk pilots had been operating within 15nm of each other, on the same freq, for at least 15min prior to the start of the incident sequence and were aware of each other’s presence. W Tac controller stated in his DASOR that, while he was accepting a handover of the control position, he heard the off-going controller provide TI to the 2 Hawks on each other; this TI was passed between 1438:00 and 1438:27.

The incident sequence commenced at 1444:26 as W Tac provided TI to Hawk T2 pilot on Hawk T1 stating, “traffic North, 8 miles, tracking West, indicating 2000 feet below, similar type”, which was acknowledged. At this point, Hawk T2 was 8.9nm SW of Hawk T1, tracking NNE’ly, indicating FL196; Hawk T1 was tracking W’ly, indicating a climb through FL178; Figure 1 depicts the incident geometry at this point.

Figure 1: Incident Geometry at 1444:26

Based upon the report submitted by the pilot of Hawk T2, it was at approximately this point that they received a TCAS TA warning of the presence of Hawk T1 and initiated a climb ‘in an attempt to deconflict vertically’.

Immediately after the pilot of Hawk T2 acknowledged the TI, at 1444:35, W Tac provided TI to Hawk T1 on Hawk T2 stating, “traffic South, 6 miles, Northbound, similar type, now 500 feet above you”; the pilot of Hawk T1 acknowledged this TI, advising W Tac that he was, “looking”. At this point, Hawk T2 was 6.8nm SW of Hawk T1, tracking NNE’ly, indicating a climb through FL197; Hawk T1 was maintaining its W’ly track, indicating FL196. Comparison of the radar replay and R/T transcript timings demonstrated that, at the time that W Tac described Hawk T2’s altitude as “500 feet above” Hawk T1, Hawk T2’s SSR Mode C indicated FL201.

CAP 413 Chapter 5 Section 1.6.2 states that an ac’s ‘level should be described [as] indicating level (if known), unverified or 1000 feet above/below'; or, (when giving traffic information to an aircraft which is climbing or descending) '…1000 feet above/below cleared level.' However, when providing TI to ac conducting dynamic manoeuvring, on other ac conducting dynamic manoeuvring, describing the conflicting ac’s altitude in relation to the ac under service’s cleared altitude is impractical and would not improve pilot situational awareness. In these instances, accepted ‘good practice’ would be to advise the pilot of the conflicting ac’s manoeuvring block and either describe the conflicting ac’s level as a number of feet above and below the ac under service’s level at that point, or to state the level or altitude that the ac is indicating. Furthermore, CAP 413 phraseology only paints a partial picture to

3 the pilot as it does not describe the trend of the altitude, in that it does not include the ability to describe an ac as climbing or descending, nor does it include the ability to describe whether an ac is manoeuvring within a block of airspace. Again, adding these descriptors is considered ‘good practice’ in military controlling to enhance aircrew situational awareness.

The pilot of Hawk T2 reported on his DASOR that he observed Hawk T1 on his TCAS display climbing at a faster rate than his own and indicated above them. Figure 2 provides the SSR Mode C information for Hawk T2 (in red) and Hawk T1 (in blue) and starts with the data point immediately after Hawk T2 initiated the climb indicated on the radar replay at 1444:35, co-incident with the TI passed to Hawk T1.

Figure 2: SSR Mode C Information for Hawk T2 and Hawk T1

At 1444:44, Hawk T2 reached the ‘top of climb’ and ‘rolled inverted and a 25 deg nose down attitude [was] selected’ to deconflict from Hawk T1.

[UKAB Note(2): The following graph shows the vertical profile of each ac on the LH scale (taken from unprocessed Mode C radar data from 5 radar heads with overlapping coverage), and separation range on the RH scale (taken from a radar recording of the St Annes radar head with 4sec update rate).

]

4

At 1445:04, Hawk T2, indicating descent through FL167, turned L and adopted a N’ly track; Hawk T1 was 3nm N of Hawk T2, indicating FL197. Given the range scales utilised at Area radar, the turn by Hawk T2 would have become evident at approximately 1445:12. At 1445:11, Hawk T2, indicating FL159, turned L and adopted a NW’ly track. Simultaneously, Hawk T1, 1.9nm NNW of Hawk T2, initiated a maximum rate descending turn to the L, indicating descent through FL190. At the next sweep of the radar at 1445:16, Hawk T1’s SSR Mode C information ‘dropped-out’ from West Tac’s surveillance display; at this point, Hawk T2 was 1.2nm SE of Hawk T1 indicating FL161. At the range scales utilised at Area radar, the turn by Hawk T1 had not yet become evident and the radar returns of Hawk T2 and Hawk T1 were merging.

CAP 774 Chapter 3 Para 5 states that TI on relevant traffic shall be updated ‘if it continues to constitute a definite hazard, or if requested by the pilot’.

The CPA occurred at 1445:19 as Hawk T1 passed above and 0.1nm W of Hawk T2; vertical separation was not recorded due to the loss of Hawk T1’s SSR Mode C information. Based upon the respective pilot’s reports, it appears that the crew of Hawk T2 visually acquired Hawk T1 after the CPA; the crew of Hawk T1 acquired Hawk T2 at the CPA. Figure 3 depicts the incident geometry from 1444:32 to 1445:35.

Figure 3: Incident Geometry from 1444:32 to 1445:35

Almost co-incidental with the CPA, at 1445:20, the pilot of Hawk T2 requested “further traffic” from W Tac, who advised “Roger, on your 12 o’clock, in fact, he’s over the top of you now, last indicating 3000 feet above, Westbound”

Analysis & Conclusion

Given the surveillance display range scales that would have been utilised by W Tac, the TI provided to both Hawk T2 and Hawk T1 pilots was timely and generally accurate. That said, the aircrew’s SA would have been enhanced had W Tac included a description of the altitude trend of the respective Hawks. From W Tac’s perspective, up until the point that Hawk T2 adopted a N’ly then a NW’ly track, which would have become visible to W Tac at approximately 1445:12, Hawk T2 was passing behind and below Hawk T1 and thus fell outside the CAP 774 bounds of ‘relevant traffic’. Moreover, subsequent to completing their DASOR, W Tac has stated that he was conscious that the Hawk aircrews were aware of each other’s presence and that he did not want to overly burden them with R/T. Given the rapidly developing situation from 1445:12 to the CPA, W Tac was not in a position to affect the incident outcome, which occurred following the max rate turn and descent into confliction by Hawk T1.

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Recommendation

BM SPA has requested that MAA ATM Regs considers the inclusion of the TI phraseology issues highlighted within this report, in their ongoing work on TI phraseology with the Joint Phraseology Working Group.

HQ AIR (TRG) comments that there is an inconsistency in Hawk T1 pilot’s narrative in that he reports seeing Hawk T2 ‘after the second orbit’, whilst the radar replay shows the CPA occurring 100° or so into their first orbit; indeed it shows the completion of only a 180° turn. The crew have accepted that the incident may actually have occurred much earlier in the turn.

This incident highlights the limitations of both TCAS and ATS when dealing with manoeuvring traffic. Hawk T1 pilot’s climb to above Hawk T2’s level that was indicated on TCAS is not evident from the radar replay, which shows Hawk T1 climbing to, and then maintaining, around FL198 as Hawk T2 climbed to at least FL214. It is likely that the rate of climb on the host aircraft was beyond the capability of the TCAS to interpret; indeed it subsequently failed during the climb at 1444:38 having indicated a final differential of +200ft climbing, which is clearly at odds with the radar picture. Unfortunately, this erroneous information formed the basis of a decision to descend aggressively, at this stage with no TCAS information at all. This might still have been effective but for the subsequent turn to the W, which unfortunately brought the two ac back into confliction. A more appropriate avoiding action from Hawk T2 might have been a turn towards the E, given TI that Hawk T1 was tracking W although the crew’s overriding impression from TCAS was that the contact was approaching rapidly from the 1 o’clock. For their part, Hawk T1’s crew made a reasonable decision to descend, based upon their TI received just as Hawk T2 pilot briefly levelled above them. However, given that Hawk T2 pilot’s intentions were unknown, without any positive coordination between the two crews this was never going to be entirely reliable and maintaining a concentrated lookout and requesting updates to the TI might have been more effective. It was also apparent from Hawk T2 pilot’s comments immediately following the CPA that the crew were unaware that Hawk T1 had been receiving TI on them at the same time. Had W Tac referred to the other ac by its callsign rather than just as ‘traffic’, SA in both cockpits may have been improved and the crews may have been more likely to take positive deconfliction action themselves. It appears that W Tac had a misplaced confidence in the awareness that the two crews had of each other and updated TI to Hawk T1 following Hawk T2 pilot’s manoeuvre might also have alerted him to the renewed conflict potential.

The balance between the inflexibility of rigidly sectorised airspace and the risk of collisions is a delicate one for the Hawks’ Duty Holder. BM SPA’s recommendations on phraseology are supported as are any RAF Valley-specific methods that might improve internal coordination. The crews commented that before being mandated to utilise a TS they would all have operated on a common frequency and deconflicted geographically. A TS combined with use of TCAS can still be effective but requires crews to strictly limit their manoeuvring to allow TCAS to function, and, if required, to avoid laterally based on TI to avoid unsighted, manoeuvring, traffic. This incident will need to be considered when assessing the effectiveness of the current deconfliction processes.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequency, radar photographs/video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC and operating authorities.

A military pilot Member noted that the 2 crews seemed to be making decisions based on historical information, which was compounded by the TCAS indications received by the Hawk T2 crew. There is a discrepancy between the ac vertical profiles on recorded radar and Hawk T2 pilot’s report of the TCAS indications. It seemed likely that this was a result of the ac conducting dynamic manoeuvring above the limits for reliable surveillance radar tracking and/or that TCAS is not designed to be used

6 in a dynamically manoeuvring environment. Military pilot Members agreed and noted that the Hawk T2 TCAS is designed to enter a ‘standby’ mode once past a set threshold of manoeuvre intensity. It was also noted that the Hawk crews were mandated by local flying orders to use a TS, whereas previously crews could have deconflicted by reference to geographical locations on a common frequency. This arrangement highlighted the difficult balance required for deconfliction between RAF Valley based ac and between Valley-based ac and other airspace users. The BM SPA Advisor noted that the Hawk T2 pilot had earlier stated he would operate in a different location in order to facilitate deconfliction. It was not known why he had then subsequently changed location.

Members next discussed how the ATS was utilised. Some were of the opinion that the LATCC(Mil) controller could have provided better SA if he had included information on the ‘vertical tendency’ of the ac (eg ‘2000ft below, climbing’) although it was accepted that this option was not provided in CAP413. The BM SPA Advisor noted that his recommendations for phraseology change had been accepted and would appear in CAP413 shortly. Members agreed that both pilots would have been better placed had they requested updated TI before starting their dynamic manoeuvres and all were agreed that the controller could not have done much more within his provision of a TS; it was the pilots’ responsibility to request a DS if that was required. It was also noted that after the Airprox the Hawk T2 crew did not seem to be aware that they were on the same frequency and being controlled by the same controller as the Hawk T1. Members opined that the T2 crew took aggressive action when a better option may have been to use the ATS and TCAS information available to them in order to assess the situation and make a deconfliction plan that was effective. The T2 crew knew there was traffic N of them heading W from the TI but they turned L in addition to descending based on their TCAS information. Similarly, the T1 crew knew there was traffic S of them and they would have been better placed by asking for updated TI before entering their MRT to their L towards that traffic, albeit their SA placed the T2 above them and remaining above.

The Hawk T2 crew did not gain visual contact with the other ac until after the CPA and the Board assessed that the Hawk T1 crew gained visual contact at, or very shortly before, CPA. In any case, neither crew saw the other ac in time to take any avoiding action; the cause was, effectively, non- sightings by both crew. It was apparent from radar recordings that the ac had passed in close proximity and the Board were persuaded by the Hawk T1 pilot’s statement that he had seen “a flash of black, R to L across the front of the ac” that separation was reduced to the minimum and that the ac had avoided collision by providence.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: Effectively non-sightings by the crews of both ac.

Degree of Risk: A.

7 AIRPROX REPORT No 2013008

Date/Time: 12 Feb 2013 1335Z Position: 5602N 00149W (15nm NE SAB VOR) FA20 1332:09 119 Airspace: SFIR/OTA E (Class: G)

Reporting Ac Reported Ac 0 1 Radar derived Type: DA42 TwinStar FA20 Falcon NM Levels show Mode C 1013hPa Operator: Civ Comm Civ Comm 32:57 Alt/FL: FL100 FL120 119 34:13 34:13 SAS (1013hPa) SAS (1013hPa) 120 119

34:17 34:09 Weather: VMC CLAC VMC CLAC 120 DA42 33:45 120 122 34:37 Visibility: >50km >30km 1332:09 127 126 100 34:09 103 CPA 32:57 33:45 101 34:41 Reported Separation: 100 100 34:13 DA42 102 102 34:37 FA20 126 34:17 102 <1000ft V/500m H 2000ft V 102 SAB Recorded Separation: ~12nm 1700ft V/0·6nm H OR 2300ft V/0·2nm H

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE DA42 PILOT reports en-route from Wick to Gamston, IFR and in receipt of a DS from Scottish Radar squawking an assigned code with Modes S and C. The visibility was >50km flying clear above cloud in VMC and the ac was coloured white/yellow with strobe lights switched on. The Commander was seated in the RH seat and the AP was engaged. They had planned FL75 for the cruise and requested FL95 once airborne; however, they were subsequently assigned a non-standard FL, FL100, by Aberdeen Radar, the ATSU which they had talked to prior to transfer to Scottish when S of Aberdeen. There was an OVC layer of cloud at 6000-7000ft but above this it was clear. Shortly before passing abeam SAB VOR heading 170° on a direct track to NATEB level at FL100 and 145kt they were given TI on unknown traffic in their 1 o’clock climbing through their level. It was on an opposite direction track and they subsequently became visual with the traffic. The controller gave them a heading to steer to the L in order to stay clear of the traffic and, as they were visual and considered it not to be a threat, they asked to return back onto track which was agreed. The controller advised that the other ac looked as if it was carrying out GH squawking 7000 and that its speed was showing 265kt, all of which was unverified. At this point both crewmembers lost sight of the ac in question behind them and they were informed that it appeared to have turned around and was heading back towards their ac. As a result of this the controller gave them a heading change to the L to remain clear of the traffic, approximately heading 145°. This was updated shortly afterwards with another heading change to the L onto 090°, then 040° and then lastly R 180°. All the while the other ac was behind them and <1000ft above, he thought, and closing. Whilst in the last turn to the R he disengaged the AP as he felt the turn from 040° to 180° required more than the standard AP rate 1. Whilst in this turn he became visual with the other ac, a blue coloured Falcon with pods in a banking R turn <1000ft above and passing 500m away. He remained visual with it from then on until he was certain his ac was completely clear to the S. At no time did he believe the other ac’s crew was aware of their presence in proximity to his ac. He assessed the risk as medium.

THE DA42 OPERATOR carried out a review after discussing the incident with the Commander and the Prestwick controller. The incident occurred in Class G airspace about 14nm NE of SAB VOR and there were no NOTAMS issued to affect the flight. The DA42 had been vectored 5 times to avoid the manoeuvring FA20 Falcon and their on board equipment showed gross deviation had been taken by the DA42. He spoke to the Head of Flight Operations of the FA20’s company and the following

1 information was proffered. The FA20 crew was clearing the airspace as part of a military exercise that started in Class G airspace and the crew was busy on the RT to other traffic and were not in receipt of an ATS. The FA20’s onboard equipment could not detect the DA42’s Mode S transponder code and were unable to deduce the DA42 flight was working Scottish. The manoeuvre was intended to culminate in a wing-waggle flypast and its crew believed that 2000ft vertical separation existed as they passed. He believed that the FA20 operator should review their clearing procedures and offered these possible options:- 1) Fitting better TCAS systems that can resolve squawk codes and from that deduce which ATSU the ac is working; 2) Ensure coordination is effected with at least 1 ATSU either prior to operations or in real time; 3) Ensure verification procedures are less aggressive and therefore not open to misinterpretation; 4) Educate ATSUs on the nature of their actions/capabilities. An internal review within the DA42 Company did not highlight any procedural or operational issue that could have been further applied to mitigate the incident.

THE FA20 PILOT reports flying in OTA E in support of a formation of 3 Tornado ac, operating autonomously on OTA E frequency and squawking 7000 with Modes S and C; TCAS was fitted. The visibility was >30km flying 6000ft above cloud in VMC and the ac was coloured blue with HISLs and nav lights switched on. They arrived in the OTA from the S, descended for a Wx check and then climbed in the vicinity of St Abbs VOR to FL120. They had a TCAS return at 20nm on an ac at FL100 near St Abbs which they avoided and tried to pick it up visually. It became apparent that this contact was proceeding S very slowly through the heart of OTA E and would be a factor in the forthcoming medium-level evasion training that they were about to control. They elected to investigate the contact to ascertain its type so they could include it in their airborne picture for the Tornados. Heading 160° at 250kt they gained visual contact at about 3nm and closed to its OH maintaining FL120 throughout. Having identified the ac as a Diamond TwinStar they turned away to the N back towards St Abbs. At no time did they descend below FL120 giving separation of 2000ft. No calls were heard on UHF Guard or the OTA frequency. Owing to the task in hand, the crew was working on 1xVHF and 2xUHF frequencies and did not have the capacity to contact an ATSU. He assessed the risk as none.

THE FA20 HEAD OF FLIGHT OPERATIONS comments that although a discussion with the DA42 operator took place shortly after the incident, the points raised in their report needed clarification. The FA20 crew was operating in Class G airspace and was not required to be talking to any ATC agency. The Wx was CAVOK and the crew was working 3 frequencies including a frequency which all high-performance military assets use when operating on OTA E. The crew was not clearing the area nor had any remit to do so, they were establishing the level of risk in commencing an exercise involving high-performance military ac in the vicinity of a potential conflict. As the contact was not spurious it allowed the Capt and crew to manage the exercise area so that the risk to the DA42 was minimised. The TCAS onboard enabled the FA20 crew to deconflict perfectly adequately from the DA42; there is no IFF interrogation equipment onboard and the crew would not have been able to identify the agency working the DA42 from its code. The FA20 crew established TCAS contact at 20nm and visual contact at 3nm and once the DA42’s track, height and speed been established the crew were better able to ensure that no high-energy manoeuvres occurred in the area. In order to clearly demonstrate that the FA20 crew had seen the DA42 a clear wing-waggle was given. The flight data download revealed that the FA20 was at 12000ft and flew no closer than 1600ft.

THE PRESTWICK TAY TACTICAL/PLANNER CONTROLLER reports operating the Sector bandboxed with low traffic levels. The DA42 was tracking ADN-NATEB at FL100 under a DS when he observed a 7000 squawk tracking N’bound from NATEB at approximately FL120. Initially it looked as if the traffic was passing well to the E of the DA42 and then it descended to low-level and began tracking NW before climbing again. He gave the DA42 flight an early L turn onto 140°, in an attempt to ensure 5nm separation, and TI. The DA42 flight took the turn and then reported visual before asking to continue again towards NATEB so he ascertained that the DA42 pilot was still visual with the traffic and happy to be responsible for his own separation, which was agreed. The traffic passed to the NW and clear of the DA42; however, it then began turning S and tracking towards the DA42, approaching from behind on a similar track and catching owing to the speed differential. He began passing TI and an initial L turn to obtain space then an avoiding action turn to the L onto 040° with continuous TI as the targets closed within 2nm of each other. Further avoiding action onto 180°

2 and then 270° was given to obtain space between the radar targets; at this point the radar returns were merged and indicating 2000ft Mode C differential on radar (unverified). It was difficult, even when rotating the ac labels, to see which target related to which ac. The DA42 pilot indicated that the other ac was too close and wished to file an Airprox. The controller believed the pilot of the other ac, later traced as a FA20, had showed poor airmanship in pursuing the DA42 in such close proximity.

ATSI reports the Airprox occurred 15nm NE of the St Abbs (SAB) VOR/DME, between a DA42 and a Falcon 20 (FA20).

The DA42 flight was operating IFR on a flight from Wick to Retford/Gamston routeing ADN (Aberdeen) to NATEB and was in receipt of a DS from Scottish Control (TAY sector) on frequency 124.500MHz. The FA20 flight was operating VFR having departed from Durham Tees Valley to participate in a training exercise together with 3 Tornado GR4 ac. The FA20 pilot’s written report indicated that the FA20 was to act as the control aircraft for a planned exercise in the ‘Operational Training Area (OTA) E’ and was listening out on the OTA ‘E’ and guard frequencies, but was not in receipt of an air traffic control service.

OTA ‘E’ is a military training area which lies partly over land and sea on the Northumbrian/Scottish coastline. It is not promulgated but forms part of a general training area. Boulmer Fighter Control provides an operational frequency, callsign ‘Hotspur,’ for participating ac.

The TAY controller had been on sector for 30min and reported traffic levels and complexity as low with no distractions.

CAA ATSI had access to RT recordings of Scottish TAY sector and area radar recordings together with written reports from the controller, ATSU and the pilots of both ac.

The Newcastle and Edinburgh Airport METARS were:

EGNT 121320Z 13005KT 090V160 9999 FEW032 02/M01 Q1018= and EGPH 121320Z 12009KT 040V140 9999 FEW035 03/M02 Q1018=

At 1300:35 UTC, the DA42 squawking 5416 passed W abeam the ADN VOR and was coordinated into the TAY sector at FL100, routeing direct to SAB and requesting a DS. The controller advised that the DA42 could route direct to NATEB.

The FA20 having departed from Durham Tees Valley airport, was transferred to Newcastle Radar at 1308:05 on squawk 3760 for a TS whilst in transit.

At 1310:15, the DA42 flight contacted the controller reporting at FL100 routeing direct to NATEB. The DA42 was leaving CAS and a DS was agreed.

At 1315:20, FA20 crew reported happy to go en-route squawking 7000 and the radar service was terminated. The FA20 was 21nm NNE of NATEB leaving FL130 in the descent. At 1323:24, the FA20 faded from radar as it passed through FL007 in the descent, (IAS 326kt). The distance between the 2 ac was 25nm. The FA20 re-appeared on radar at 1324:11, as it passed FL023 in the climb, turning L onto a W’ly track and at 1325:06, was passing FL064 (IAS 210kt) in the DA42’s half- past 10 position.

At 1326:02, the controller instructed the DA42 to turn L heading 140° and advised of traffic 11 o’clock at a range of 8nm crossing L to R indicating FL090 unverified (Fig.1).

3

(Fig.1 – Prestwick MRT - 1326:02.)

The DA42 pilot reported the other traffic in sight at 1326:30, and asked if they could go back on track. The pilot confirmed that he was happy to maintain his own separation from the other traffic, which was going away from them and the controller instructed the DA42 flight to route direct to NATEB.

At 1327:16, the DA42 flight commenced a R turn to resume own navigation for NATEB with the FA20 at FL118 (IAS 220kt) 6·1nm to the SW of the DA42, tracking away (Fig.2).

(Figure 2 – Prestwick MRT - 1327:16.)

The FA20 flight commenced a R turn at 1327:52, onto a N’ly track at FL120, passing 7nm W abeam the DA42 at 1328:13.

At 1329:28, the FA20 was 10·6nm NW of the DA42 commencing a R turn. The FA20 pilot’s written report indicated he had observed a TCAS contact at FL100 routeing south through OTA ‘E’ and elected to investigate the contact in order to be able to update the GR4 aircraft [not TCAS equipped]. At 1330:30, the FA20 was 10·3nm behind the DA42 at FL119 (IAS 262kt).

4 At 1331:10, the controller advised the DA42 pilot that the unknown traffic was now in DA42’s 6 o’clock, FL120, at a range of 8·4nm and at a faster speed. The DA42 pilot reported that they had lost sight of the other ac and at 1331:26 the controller instructed the DA42 to turn L onto heading 130°. The DA42 pilot asked if ATC knew who the other contact was and the controller responded that there was no way of telling, but it was likely to be military traffic and was indicating a speed of 260kt. The distance between the 2 ac reduced to 5·9nm and at 1332:09 the controller issued avoiding action, “(DA42 c/s) avoiding action further left turn heading 090 degrees that traffic is currently in your seven o’clock at a range of 5·9 miles indicating FL120 unverified” (Fig.3).

(Fig.3 – Prestwick MRT - 1332:09.)

At 1332:56 the controller updated the TI on the FA20 which was now 7 o’clock at a range of 4nm still indicating FL120 and tracking 170°. The deconfliction minima (5nm/3000ft) were lost at 1332:58. Radar showed the FA20 adjusting its heading to intercept that of the DA42. At 1333:14, the controller updated the TI indicating that the unknown traffic was 7 o’clock at 3nm indicating FL120 and turning towards the DA42. The controller then gave a further avoiding action L turn onto a heading of 040°. This was followed at 1333:44 by another avoiding action R turn onto a heading of 180°, with updated TI on the position of the unknown traffic, 6 o’clock at a range of 1·7nm at FL122 (Fig.4).

5

(Figure 4 – Prestwick MRT - 1333:41.)

At 1334:00, the controller passed the DA42 flight further TI on the unknown traffic, at 6 o’clock, 1·2nm indicating FL121 and an indicated airspeed of 250kt. This was acknowledged by the DA42 pilot who then reported the other ac in sight. Between 1334:09 and 1334:13, the minimum vertical distance between the 2 ac was recorded as 1700ft, at 0·8nm and 0·6nm range, respectively. At 1334:18, the DA42 pilot, (using non-standard phraseology) reported that the other aircraft (FA20) was very close (Fig.5).

(Figure 5 – Prestwick MRT - 1334:17.)

As the FA20 turned R it climbed to FL127 and then descended to FL126. At 1334:38 the controller again issued avoiding action, instructing the DA42 flight to turn R onto heading 270°, reporting that the traffic was now directly above at FL126 indicating a descent. The lateral distance between the 2 ac was 0·3nm and the vertical distance was 2400ft (Fig.6).

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(Figure 6 – Area radar recording at 1334:37.)

At 1334:41, (CPA) the DA42 pilot reported that they were now fully visual and able to identify the type and operator of the FA20. The FA20 was in a R turn crossing 0·2nm ahead of the DA42 and 2300ft above (slant distance 2657ft). The FA20 then broke away to the W and the controller instructed the DA42 pilot to roll out onto a heading of 180°. The DA42 pilot asked the controller to file an Airprox report. The Mode S data indicated the Aircraft ID (later traced to give the ac type and registration).

At 1340:15, the Tay Controller contacted Leuchars Radar to request any information on the traffic squawking 7000 in the SAB region at FL120. Leuchars advised that they had not been in contact with the ac at any point during the day.

At 1342:32 the DA42 flight was transferred to Newcastle Radar.

The Scottish Local Area Supervisor (LAS) reported that neither Scottish Military nor Hotspur had any contact with the FA20 flight. A route brief obtained from NATS AIS for the day showed that there were no NOTAMs promulgating an exercise in the area.

The FA20 flight was not in receipt of any air traffic control service and in view of the forthcoming exercise had decided to investigate the DA42 to ascertain its type. It was likely that the FA20 pilot, whilst deciding to remain 2000ft above the DA42, did not fully appreciate the predicament of the TAY controller in trying to achieve the required deconfliction minima of 3000ft or 5nm. CAP744 Chapter 4, Page 1, Paragraph 6, states:

‘The deconfliction minima against uncoordinated traffic are: • 5nm laterally (subject to surveillance capability and regulatory approval); or • 3000 ft vertically and, unless the SSR code indicates that the Mode C data has been verified, the surveillance returns, however presented, should not merge. (Note: Mode C can be assumed to have been verified if it is associated with a deemed validated Mode A code. The Mode C data of aircraft transponding code 0000 is not to be utilised in assessing deconfliction minima).

‘…furthermore, unknown aircraft may make unpredictable or high-energy manoeuvres. Consequently, it is recognised that controllers cannot guarantee to achieve these deconfliction minima; however, they shall apply all reasonable endeavours.’

The TAY controller agreed to provide a DS and subsequently provided TI together with updates and avoiding action in order to try and achieve the deconfliction minima. It was not possible to determine

7 what action the FA20 pilot might have taken, had the DA42 flight been given an instruction to descend.

CAP 774 Chapter 1, Page Paragraph 2, states:

Within Class F and G airspace, regardless of the service being provided, pilots are ultimately responsible for collision avoidance and terrain clearance, and they should consider service provision to be constrained by the unpredictable nature of this environment. The Class F and G airspace environment is typified by the following: • It is not mandatory for a pilot to be in receipt of an ATS; this generates an unknown traffic environment; • Controller/FISO workload cannot be predicted; • Pilots may make sudden manoeuvres, even when in receipt of an ATS.

The Airprox occurred when the FA20 crew elected to investigate the track of the DA42 and intended to remain 2000ft above the DA42. However, as a consequence, the TAY controller was unable to provide the DA42 flight with the required deconfliction minima of 3000ft or 5nm.

UKAB Note (1): The Mil AIP entry at ENR 5-2-10 Para 6.1 promulgates an Advisory Service Area (ASA) stating:-

‘An ASA is an area of Class G airspace of defined dimensions where Military fixed wing fast jet aircraft are carrying out autonomous operations within the area are to receive, where possible, an ATSOCAS from a nominated source.’

Para 6.2 Leuchars ASA promulgates the areas coordinates and states:-

(a) ‘Operating levels are from 5000ft AMSL to FL195 (FL245 when TRA007 is active).

(b) When operating in this area pilots are to request a service from one of the following sources:- i) ScATCC (Mil) ii) ASACS iii) RAF Leuchars

(c) Crews are responsible for selecting: i) The ATS provider. ii) The type of ATS required; Basic Service, Traffic Service or Deconfliction Service.

(d) Crews can request a quiet frequency if necessary (subject to Unit capacity). Crews should consider accepting requests for coordination against CAT where possible/able but there is no compulsion to do so.

(e) If no ATS is available, crews are to continue to operate autonomously iaw Class G regulations.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequencies, radar video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC and operating authorities.

Members were disappointed that the FA20 crew had taken it upon themselves to visually identify the DA42, which was traffic they considered to be a factor to the training exercise in OTA E, contained within the Leuchars ASA, that was about to commence. It would have been better had the FA20 crew arrived earlier and established contact with one of the ATSUs listed for the ASA which would

8 have been able to establish the identity of the DA42 through coordination with the controlling ATSU. The FA20 crew would then have been in receipt of all the facts from which they could update the air picture to the incoming military fast-jets. A military pilot Member remarked that had a military ac been involved, as soon as the other ac was identified as a civilian ac, the pilot would break-away at range to avoid flying in close proximity. As the FA20 was flying in support of a military exercise in OTA E, Members agreed that best practice would have been for the crew to comply with the requirements promulgated in the Mil AIP for flight in the Leuchars ASA. To that end, the Board agreed to recommend this to the FA20 operator.

In this incident there was a disconnect between the interested parties. The FA20 crew was unaware that the DA42 was in receipt of a DS and the ScACC TAY controller was applying all reasonable endeavours to achieve deconfliction minima (5nm laterally or 3000ft vertically). The TAY controller and DA42 were unaware that the FA20 crew had located the DA42 on TCAS, then visually and were intentionally flying a profile to maintain 2000ft vertical separation from it whilst identifying the ac. In doing so the FA20 crew flew close enough to cause the TAY controller and DA42 crew concern, which had caused the Airprox.

Members commended the actions taken by the TAY controller who persevered with issuing instructions to the DA42 crew in trying to resolve the confliction. Despite his best endeavours, the TAY controller was unable to achieve deconfliction minima but the visual sighting of the DA42 by the FA20 crew and the flight profile flown was enough to allow the Board to conclude that any risk of collision was effectively removed.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The FA20 crew flew close enough to cause the TAY controller and DA42 crew concern.

Degree of Risk: C.

Recommendation: The FA20 operator is recommended to comply with the Leuchars ASA requirements when operating in OTA E.

9 AIRPROX REPORT No 2013012

F86A Diagram based on radar data Date/Time: 27 Feb 2013 1524Z

Position: 5208N 00004E Cambridge ATZ (6nm SW Cambridge) A30 Airspace: Lon FIR (Class: G) 4 Reporter: Cambridge APP

1st Ac 2nd Ac A24 Type: Cessna C510 F86A Operator: Civ Pte Civ Pte A18 1524:03 Alt/FL: 1800ft 3000ft 2 NM

QNH(NR) QFE(NR) 24:15

Weather: VMC CLBC VMC CAVOK A15 C510 1500ft alt Visibility: >10km >10km 24:27 Reported Separation: A14 300ft V/1nm H 0ft V/1nm H 24:39 0

Recorded Separation: CPA 1524:50 Duxford ATZ 100ft V/0.4nm H 100ft V/0.4nm H

CONTROLLER REPORTED

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE CAMBRIDGE RADAR APPROACH CONTROLLER reports he observed a fast moving unknown contact tracking towards Cambridge from the NW. As it passed about 2nm ahead of a Merlin helicopter, at a similar level of 3500ft and to which TI had been passed, it descended and accelerated. It passed 4nm SW of Cambridge A/D, tracking towards Duxford A/D, indicating 1900ft descending. He tried to warn the ADC as he was ‘working a C510’. The C510 pilot was completing a visual RH cct to RW05, having completed a training instrument approach to RW23. The C510 pilot began a R base turn some 3-4nm SW of Cambridge at 1600ft as the contact passed close to him, possibly 300ft above, at about 300kts. The conflicting a/c was observed on radar joining the Duxford cct.

THE C510 PILOT reports conducting an OPC, operating in ‘uncontrolled airspace’ in the Cambridge RW05 RH cct. He was operating under VFR in VMC with a BS from Cambridge [125.900MHz]. The white and black/grey striped ac had navigation, recognition and strobe lights selected on, as was the SSR transponder with Modes A, C and S. The ac was fitted with TCAS I. Whilst turning through about W, at 180kt and an altitude of 1800ft [QNH NR], he observed a TCAS ‘contact alert’ with traffic indicating at a range of about 5nm. He saw the traffic at 2nm and it passed down his RH side, at a range of about 1nm and about 300ft below. He observed the other pilot ‘wing-waggling’ as he passed.

He assessed that there was no conflict and that the risk of collision was ‘None’.

THE F86 PILOT reports conducting a visual recovery to land at Duxford, heading S at 240kt. He was operating under VFR in VMC with a BS from Duxford Information [122.070MHz]. The silver ac had the SSR transponder selected on with Modes A, C and S. The ac was not fitted with an ACAS. He saw a white, twin-engine, business jet about 6-7nm away, heading N. The other ac was not configured for landing. Each ac passed down the RH side of the other, at about the same altitude and travelling in opposite directions with about 1nm H separation. He ‘wing-waggled’ to acknowledge visual contact with no response from the other ac.

1

He observed that neither ac was flying in CAS, that the weather was good and that the low sun made it easier for him to see the other ac. He stated that he was in visual contact with the ‘business jet’ at all times.

He assessed that there was no conflict and that the risk of collision was ‘None’.

ATSI reports that an Airprox was reported by Cambridge APP when a North American F86A Sabre (F86) came into confliction with a Cessna 510 ‘Citation Mustang’ (C510) 6nm SW of Cambridge A/D in Class G uncontrolled airspace at altitude 1500ft.

Background

The C510 pilot had been operating under IFR, inbound to Cambridge, via airways, from Jersey and prior to the Airprox had undertaken several exercise manoeuvres using the navigational facilities available at Cambridge. At the time of the Airprox the C510 pilot was in receipt of an ACS from Cambridge TWR [125.900MHz]. The C510 was transponding SSR Mode A code 6165.

The F86 pilot was on a VFR flight and had departed Duxford at 1446 UTC. He flew to the NW and manoeuvred in Class G airspace, approximately 15nm N of Cambridge, before setting a course for RAF Coningsby. After manoeuvring in the vicinity of Coningsby under an ATS, the F86 pilot then tracked S for his return to Duxford. At the time of the Airprox the F86 pilot was in contact with Duxford Information [122.075MHz]. The F86 was transponding the general SSR conspicuity code 7000.

Cambridge APP was manned by a trainee and mentor. The mentor controller described the traffic levels and complexity as light. Services were being provided with the use of the A/D based AR15 radar and a SSR feed from the Debden radar.

ATSI had access to the Cambridge APP (mentor) controller’s report, the F86 pilot’s report, recorded area surveillance and transcriptions of Cambridge Approach [123.600MHz], Cambridge TWR and Duxford Information. Additionally ATSI undertook fact-finding site visits to Cambridge and Duxford A/Ds.

Meteorological information for Cambridge A/D was recorded as follows: METAR EGSC 271520Z 02011KT 360V080 9999 FEW025 07/01 Q1034=

The F86 pilot was subject to a CAA Permission pursuant to Rule 21(Speed limitations), paragraph 3, of the RoA, which permitted him to fly at a speed that, according to the airspeed indicator, was more than 250kt, and below FL100, in so far as was necessary for the purposes of display practice, display flying training and transit. The permission was granted subject to several conditions, which included:

‘(c) the said flights shall only be made in weather conditions which enable the aircraft to remain at least 3 kilometres horizontally and 1000 feet vertically away from cloud and in a flight visibility of at least 10 kilometres;

(d) on the said flights the aircraft shall not fly unless it is using a radar service, except when it is flying within an Aerodrome Traffic Zone (ATZ) …’

Cambridge A/D has an ATZ of radius 2.5nm, centred on RW05/23 and extending from the surface to 2000ft aal (elevation 47ft). Duxford A/D has an ATZ of radius 2nm, centred on RW06/24 and extending from the surface to 2000ft aal (elevation 125ft).

Factual Information

The F86 pilot contacted Duxford Information at 1519:45 reporting, “approximately three or four minutes out for recovery”. He was informed that Duxford was using RW06 RH with QFE 1028hPa

2 and was requested to report downwind. Figure 1 below shows the Stansted 10cm radar picture at 1519:45. The F86 pilot was 30.8nm N of Duxford at FL028 (which converts to altitude 3367ft on Cambridge QNH 1034hPa). The surveillance recorded ground speed of the F86 was 365kt.

Figure 1: Stansted 10cm Radar at 1519:45

At 1521:30, the C510 pilot was instructed by Cambridge TWR to break L from an approach to RW23 and to reposition RH downwind for RW05. Previously in the approach the C510 pilot had been instructed to make his cct height 1600ft. The Stansted 10cm radar showed the C510 pilot climb away from the A/D on a S’ly track to enter the visual cct. At 1522:40, the C510 pilot reported downwind to land and was instructed to report final. He was number two to a C172, which was at 4nm on final approach to RW05.

At 1523:10, Cambridge APP (trainee) controller informed a Merlin helicopter pilot on frequency (Mode A 6170), “fast moving traffic ten o’clock f- three miles left right also at three thousand feet now looks like it’s descending towards you”. The Merlin pilot reported visual. APP then passed further TI to which, at 1523:40, the Merlin pilot stated, “I think he’s seen us”. APP (mentor) recalled that the presence of the fast moving 7000 squawk was assimilated approximately 5sec prior to the Merlin pilot being passed initial TI.

Figure 2 below shows the F86 tracking S, with a ground speed of 292kt, and the C510 downwind RH for RW05.

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Figure 2: Stansted 10cm Radar at 1523:40

At 1524:22, APP telephoned TWR and informed him of the presence of the F86, giving its position as approximately 4nm SW of the A/D and observing that Tower’s traffic, the C510, was turning towards the F86 at that time.

At 1524:30, the C510 pilot began a R turn onto base leg at 1500ft. Figure 3 below shows the F86 at 1600ft, N of the C510 by 1.9nm, with the C510 pilot turning towards the F86. The F86’s recorded ground speed was 329kt.

Figure 3: Stansted 10cm Radar at 1524:36

4 At 1524:40, TWR attempted to transmit to the C510 pilot but was interrupted by other traffic, which was told to standby. TWR then informed the C510 pilot, “traffic information not working Cambridge radar but crossing opposite direction to yourself similar height er is an aircraft southwest bound”. The C510 pilot responded, “yeah it’s a fast jet of some sort”.

Figures 4 and 5 below show the F86 and C510 as recorded by the Stansted 10cm radar at 1524:46 and 1524:50 respectively. Minimum distance between the two ac is shown on Figure 5 as 0.4nm H and 100ft V.

Figure 4: Stansted 10cm Radar at 1524:46 Figure 5: Stansted 10cm Radar at 1524:50

At 1524:50, the F86 pilot reported to Duxford Information that he was, “thirty seconds to the break”. Duxford Information reported, “Sabre no er circuit traffic this time nothing known to affect and report downwind”.

Cambridge TWR telephoned Duxford at 1528:10 to enquire as to the identity of the ac that had just flown through the Cambridge RW05 final approach track. The identity of the F86 was confirmed and Duxford were informed that it had flown into confliction with traffic under a service from Cambridge.

In a subsequent conversation between the C510 pilot and Cambridge TWR, the C510 pilot reported, “we had him on TCAS and er we saw him early enough to avoid any problems”.

Analysis

The F86 pilot called Duxford Information whilst 30nm N of the A/D and flying at a recorded ground speed of 365kt. As Duxford Information is a non-surveillance based service the F86 was not in receipt of a radar service; nor was it within an ATZ. The recorded ground speeds range between 292kt and 365kt. There is no evidence to indicate that the F86 was subject to significant tailwinds and therefore it is likely that the airspeed indicator of the F86 was displaying in excess of 250kt.

The C510, Merlin, F86 and other ac in the vicinity of Cambridge were operating in Class G airspace where the responsibility for collision avoidance rests solely with the pilots concerned. In electing not to call Cambridge APP for a radar service, the F86 pilot would likely be operating solely on the principles of ‘see and avoid’ which, at increased speeds, could limit the pilot’s ability to assimilate other traffic/conflicts and also impede other airspace user’s ability to avoid collision.

The C510 pilot was positioning downwind RH for RW05 behind slower traffic. As such, and with a higher approach speed, the C510 pilot’s cct took him outside the protection of the Cambridge ATZ.

Additionally, the speed of the F86 reduced the time available to Cambridge APP to assimilate its presence, pass TI to traffic working APP, assimilate the need to inform TWR of the conflicting traffic

5 and pass the details to the TWR controller. Once this chain of events had been completed, with TWR passing TI to the C510 pilot, CPA had already occurred.

Conclusion

An Airprox occurred 6nm SW of Cambridge A/D when an F86 pilot, flying at a speed likely to have been greater than 250kt indicated and not in receipt of a radar service, transited the final approach track for Cambridge RW05 and came into confliction with a C510 turning R base at altitude 1500ft.

[UKAB Note(1): The F86 pilot crossed the Cambridge A/D extended C/L at altitude 1500ft and range 5.5nm.]

The presence of the F86 had been assimilated by Cambridge APP and TI was passed to his own traffic. Additionally Cambridge APP notified TWR of the presence of the F86 in order that the C510 pilot could be passed TI.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, transcripts of the relevant RT frequencies, radar photographs/video recordings, reports from the air traffic controllers involved and reports from the appropriate ATC and operating authorities.

The Board first considered the actions of the Cambridge controller. It was clear that he had been alarmed at the high speed contact closing rapidly with traffic that he knew was in receipt of an ACS from Cambridge TWR. Although TWR was not able to pass TI to the C510 pilot in time to affect the outcome, the Board commended Cambridge APP for his effort to alert the TWR to the presence of a potential confliction.

The Board noted that the C510 pilot, having been instructed to join the RW05 RH visual cct, had extended downwind for RW05 RH in order to sequence behind a slower ac ahead of him. At the CPA he was some 6nm SW of Cambridge A/D, a position that was close to the boundary of the Duxford ATZ and which Members considered to be outside any reasonable estimation of the Cambridge visual cct. Members opined that once he had left the Cambridge ATZ he would have been better served by switching to APP and requesting an appropriate radar-based ATS. It was also possible that, by staying in the visual cct, he was devoting an increasing amount of time to maintaining visual contact with the A/D, particularly as his range from the A/D increased, to the detriment of his lookout. However, his TCAS provided timely warning of the approaching traffic and he was able to gain visual contact at a reported range of 2nm as he started his R turn. Turning to the F86 pilot’s actions, the Board ascertained that he was not in receipt of a radar service and from the available data was likely flying in excess of 250kt indicated airspeed. Given the weather conditions, Members did not consider that the F86’s speed was an impediment to the pilot’s responsibility to ‘see and avoid’ or a factor in other traffic seeing him. Nevertheless, he would have been better served by obtaining a radar service from Cambridge to alert Cambridge ATC and to obtain TI; that said, he would have needed to be in contact with Duxford at the point at which the Airprox occurred prior to entering the ATZ. The Board also considered that he should have planned his recovery such that he avoided crossing the Cambridge active RWY C/L at a height and range that placed him directly in conflict with traffic in the RTC.

Both pilots were operating under VFR in class G airspace and had an equal responsibility for collision avoidance. It was considered that the F86 pilot had right of way and, given his range from Cambridge, had complied with Rule 12 (conform to, or remain clear of, the pattern of traffic intending to land).

A small minority of Members considered that effective and timely action had been taken to prevent ac collision but the majority agreed that, whilst the occurrence had appeared alarming to the Cambridge controller due to the speed of the F86, both pilots had seen the other ac in good time and had

6 passed clear of each other in class G airspace. As such, although the Cambridge controller had perceived a conflict, which he was correct to report, by analysis the occurrence was established to be benign.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: Controller perceived conflict.

Degree of Risk: E.

7 AIRPROX REPORT No 2013013 Diagram based on radar data Wethersfield G/S Date/Time: 3 Mar 2013 1643Z (Sunday) Primary returns only Position: 5158N 00030E Viking T1 (Wethersfield G/S) CPA 1642:43 NR V < 0.1nm H 42:31 Airspace: Lon FIR (Class: G) 42:19 Group of Reporting Ac Reported Ac primary returns 2 prior to1641:33 Type: Viking T1 PA28 42:07 Operator: Mil Club Civ Club Stansted CTR 41:55 Alt/FL: 550ft ~1200ft QFE (1010hPa) QNH (1021hPa) NM 41:43 Weather: VMC NR VMC CLBC

Visibility: 10nm >10km PA28

Reported Separation: Stansted TMZ 0 200ft V/0m H 100ft V/300m H

Recorded Separation: Andrewsfield ATZ NR V/<0.1nm H

PART A: SUMMARY OF INFORMATION REPORTED TO UKAB

THE VIKING T1 PILOT reports being tasked to fly a training flight. He was operating under VFR in VMC with an A/G service from Wethersfield Radio [129.970MHz]. The white and ‘dayglo’ orange striped ac was not fitted with an SSR transponder or ACAS. He turned R to commence the RH downwind leg for RW10 when, abeam the winch at 750ft and passing through a heading of about 220°, he saw an aircraft about 2nm away in his low 9 o'clock position. He assessed it to be a single propeller engine, low-wing, fixed undercarriage ac with white upper and black lower fuselage. There appeared to be no conflict. He continued the downwind leg and, passing 700ft, commenced another lookout scan but could not locate the previously seen ac. Assuming the ac had changed course, he continued the downwind leg until abeam the caravan at 600ft, where he looked out to the R and saw the ac pass underneath. No action was taken at the time due to his workload.

He assessed the risk of collision as ‘Medium’.

THE PA28 PILOT reports climbing to the N after departing from Andrewsfield. He was operating under VFR in VMC; he was not in receipt of an ATS but was ‘monitoring Stansted’ [120.625MHz]. The black and cream ac had the SSR transponder selected on with Mode A only selected. The ac was not fitted with an ACAS. He saw a glider and recognised that the ac were converging with his ac approaching from the glider’s rear L side. He thought the glider pilot would not be able to see him, so he altered course to the R and passed behind. He realised this manoeuvre now placed him close to the boundary of the Wethersfield ATZ, which he knew, and the presence of the glider confirmed, was active. He stated that he couldn't climb because the base of the Stansted TMA was above him at 1500ft. He therefore turned L in order to remain clear of the Wethersfield ATZ and to pass the glider, keeping it in view throughout on his L side at what he considered to be a safe distance. He stated that he was aware that the glider pilot would not be able to see him until his manoeuvre was ‘nearly complete’. He was unable to maintain as much separation from the glider as he would have liked, as he was now between the glider and the ATZ but, in what he considered was a ‘fairly swift manoeuvre’ he did not perceive any collision risk.

He assessed the risk of collision as ‘None’.

1 [UKAB Note(1): The 1nm radius circle around a G/S, as shown on VFR charts, does not denote any form of controlled or regulated airspace. Wethersfield G/S, as shown in the diagram, does not have an associated ATZ; the circle is printed only to highlight the presence of the G/S to other airspace users.

UKAB Note(2): A G/S is classified as an A/D in the UK AIP and RoA Rule 12 (Flight in the vicinity of an aerodrome) therefore applies:

… a flying machine, glider or airship flying in the vicinity of what the commander of the aircraft knows, or ought reasonably to know, to be an aerodrome shall conform to the pattern of traffic formed by other aircraft intending to land at that aerodrome or keep clear of the airspace in which the pattern is formed; …]

HQ AIR (TRG) comments that the PA28 pilot’s decision to alter course to route between the glider and its A/D appears to have been instrumental in this incident, where the glider pilot was clearly concerned by the proximity of the PA28. An early change of course to the L, to route well ahead, a reduction in speed, or an orbit might all have been better options than the one selected. The Wethersfield Duty Instructor had observed the approaching PA28 and transmitted a warning to the gliders in the visual circuit.

PART B: SUMMARY OF THE BOARD'S DISCUSSIONS

Information available included reports from the pilots of both ac, radar photographs/video recordings and a report from the appropriate operating authority.

Members agreed that the glider pilot was operating normally from an active and promulgated G/S. Members opined that, having spotted the PA28, he would have been well advised to monitor its flight path but recognised that it was not always practical in a high workload environment. Members also noted that, although both pilots were operating in class G airspace, under Rule 12 the glider pilot could have expected some degree of protection in the cct pattern and that it was the PA28 pilot’s responsibility either to conform to the pattern of traffic or to remain clear of it. Turning to the actions of the PA28 pilot, Board Members were unanimous in their opinion that he appeared not to have planned ahead sufficiently. Several pilot Members opined that flight within constrained airspace requires prior planning or alternative routeing to avoid the airspace. Having seen the glider, the PA28 pilot had sufficient space and time to exercise a number of options: to turn to the L, to turn R and route around Wethersfield G/S to the E and N, to climb well above the glider or to orbit L or R until the glider was clear. Any of these options would have mitigated confliction but the PA28 pilot essentially continued on course. The Board noted the PA28 pilot’s report referred to the Wethersfield ‘ATZ’ and wondered whether he was using the term loosely to describe the area surrounding the G/S; if an ATZ had existed at Wethersfield G/S, the PA28 pilot would have been wrong to enter it without prior communication with the A/D controller. In summary, the Board opined that although the PA28 pilot took effective and timely action to avoid collision, he placed both himself and the glider pilot in an avoidable situation and flew close enough to the glider pilot to cause concern. The Board commended the actions of the G/S duty instructor who had seen the approaching PA28 and warned cct traffic of its presence over RT.

PART C: ASSESSMENT OF CAUSE AND RISK

Cause: The PA28 pilot flew close enough to cause concern to the Viking pilot downwind in the Wethersfield circuit.

Degree of Risk: C.

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