AGENZIA NAZIONALE PER LA SICUREZZA DEL VOLO (istituita con decreto legislativo 25 febbraio 1999, n. 66) Via A. Benigni, 53 - 00156 Rome - Italy tel. +39 0682078219-0682078200, fax +39 068273672
SECOND INTERIM FACTUAL REPORT (ANSV Board decision of July 9th 2002)
ACCIDENT INVOLVED AIRCRAFTS BOEING MD-87 REG. MARKS SE-DMA AND CESSNA 525A REG. MARKS D-IEVX
Milano Linate Airport October 8, 2001
INDEX
INDEX ...... I PURPOSE OF THE INVESTIGATION ...... III FOREWORD ...... IV GLOSSARY ...... V CHAPTER I - FACTUAL INFORMATION...... 1 1. SUMMARY ...... 1 1.1. FACTUAL INFORMATION ...... 1 1.2. INJURIES TO PERSONS ...... 5 1.3. DAMAGE TO AIRCRAFTS ...... 5 1.4. DYNAMICS OF AIRCRAFTS COLLISION...... 5 1.4.1. Significant parameters recorded on Boeing MD-87 DFDR at collision point ...... 5 1.4.2. Boeing MD-87 DFDR significant recordings seconds after the collision point ...... 6 1.4.3. Boeing MD-87 CVR-sound extract ...... 6 1.4.4. Preliminary analysis of collision scenario ...... 6 1.4.5. First point of contact ...... 6 1.4.6. Second point of contact ...... 7 1.4.7. Third point of contact ...... 7 1.5. ANALYSIS OF THE POST COLLISION SCENARIO ...... 8 1.5.1. The Cessna 525A...... 8 1.5.2. The Boeing MD-87 ...... 8 1.5.3. Final impact with airport baggage building ...... 9 1.6. OTHER DAMAGES ...... 9 1.7. INFORMATION ON PERSONNEL ...... 9 1.7.1. Pilots ...... 9 1.7.2. Pilots pre-accident duty time ...... 10 1.7.3. Air traffic controller...... 11 1.7.4. Air traffic controller’s duty time ...... 12 1.8. AIRCRAFT INFORMATION ...... 12 1.8.1. The Boeing MD-87 ...... 12 1.8.2. The Cessna 525A...... 12 1.9. WEATHER INFORMATION...... 13 1.10. NAVIGATION AIDS ...... 13 1.11. COMMUNICATIONS ...... 13 1.12. AIRPORT CONFIGURATION AND ASSOCIATED CHARTS AND MAPS INFORMATION . 13 1.12.1. Airport information ...... 13 1.12.2. Airport charts and maps ...... 14 1.13. FLIGHT RECORDERS ...... 14 1.13.1. DFDR Boeing MD-87 ...... 14 1.13.2. QAR Boeing MD-87 ...... 15 1.13.3. CVR Boeing MD-87 ...... 15 1.13.4. Cessna 525A ...... 15 1.14. WRECKAGE FINDINGS ...... 15 1.14.1. The Boeing MD-87 ...... 15 1.14.2. The Cessna 525A...... 17
ANSV I 1.15. FORENSIC INFORMATION...... 18 1.15.1. The Boeing MD-87 occupants ...... 18 1.15.2. The Cessna 525A occupants ...... 18 1.16. FIRE...... 18 1.17. SURVIVALASPECTS ...... 18 1.18. TESTS AND FURTHER ANALYSIS ...... 18 1.19. OPERATIONAL INFORMATION...... 18 CHAPTER II - ANALYSIS...... 19 2. ANALYSIS ...... 19 2.1. GENERAL ASPECTS ...... 19 2.2. HUMAN FACTOR ...... 19 2.2.1. Analysis of the professional experience of the pilots ...... 19 2.2.2. Pilots working schedule...... 20 2.2.3. Analysis of controllers background and professional preparation...... 20 2.2.4. Controllers working schedule ...... 21 2.2.5. Communications analysis - glossary ...... 21 2.2.6. Preliminary information...... 22 2.2.7. Communications analysis ...... 22 2.2.8. Pilots human factor ...... 36 2.2.9. ATC personnel human factor ...... 36 2.2.10. After impact other personnel human factor ...... 36 2.3. TECHNICAL FACTORS ...... 36 2.3.1. Aircrafts documentation...... 36 2.3.2. Radio equipment ...... 37 2.4. ENVIRONMENTAL FACTORS ...... 37 2.4.1. Weather conditions ...... 37 2.4.2. Airport layout ...... 38 2.4.3. Airport charts and maps...... 39 2.4.4. The radar ...... 41 2.4.5. Control Tower ...... 42 2.4.6. Analysis of the verbal communication (words) used...... 45 2.4.7. Clearance confirmation: read-back ...... 45 2.4.8. An occurrence happened on October 7, 2001 at time 13.56, relevant to “clearance read-back”. 46 CHAPTER III - CONCLUSIONS...... 49 3. CONCLUSIONS...... 49 3.1. FINDINGS ...... 49 3.2. CAUSES ...... 50 CHAPTER IV - SAFETY RECOMMENDATIONS...... 51 4. RECOMMENDATIONS...... 51 4.1. Recommendation ANSV-17/113-1/A/02 ...... 51 4.2. Recommendation ANSV-18/113-2/A/02 ...... 51 4.3. Recommendation ANSV-19/113-3/A/02 ...... 52 4.4. Recommendation ANSV-20/113-4/A/02 ...... 52 4.5. Recommendation ANSV-21/113-5/A/02 ...... 52 4.6. Recommendation ANSV-22/113-6/A/02 ...... 53 LIST OF ATTACHMENTS ...... 55
ANSV II PURPOSE OF THE INVESTIGATION
The investigation of this accident, as required by Article 827 of the Italian Navigation Code, was conducted following the requirements of ICAO ANNEX 13 to the Chicago Convention, December the 7th 1944, approved and made executive in Italy as stated in the legislative decree March the 17th 1956, n. 561.
ANSV (Agenzia Nazionale per la Sicurezza del Volo) performs its technical investigations “with the only purpose of accident and serious incidents prevention, excluding any appraisal of blame or responsibility” (Art. 3, paragraph 1, legislative decree February the 25th 1999, n. 66).
ANSV, during the investigation and when it is completed, will edit Interim Reports and Final Reports that may include Safety Recommendations, with the purpose of preventing accidents and serious incidents (Art. 12, paragraph 1 and 2, legislative decree February the 25th 1999, n. 66).
In all Reports ANSV will safeguard the privacy of all persons involved in the event and of those that contributed information during the investigation. Anonymity will be granted to all persons involved in the event (Art. 12, paragraph 3, legislative decree of February the 25th 1999, n. 66).
“Interim Reports, Final Reports and Safety Recommendations are never intended to apportion blame or responsibility” (Art. 12, paragraph 4, legislative decree february the 25th 1999, n. 66).
ANSV III FOREWORD
This document updates the progress made on the technical investigation as of this date July 8, 2002, adding to the preliminary report and the first Interim Report already published on December 27, 2001. It contains updated and new paragraphs.
The investigation is continuing, pending the release of certain information that have been kept by the Magistrate and made unavailable to ANSV investigative team, research has not yet been completed and some elements may be further modified.
Only when all of the work is completed will it be possible to draw final conclusions on the circumstances and causes of the accident, and further recommendations may be issued to competent domestic and international Organisations.
This document is released in accordance with and under the provisions of legislative decree n. 66 of February 25, 1999 institutive of ANSV. Copying, distribution or the use of this document for commercial purposes is forbidden.
SPECIAL FOREWORD TO ENGLISH EDITION
This report has been translated and published by the AGENZIA NAZIONALE PER LA SICUREZZA DEL VOLO to make its reading easier for English-speaking people. The intent was not to produce a literal translation and as accurate as the translation may be, the original text in Italian is the work of reference.
ANSV IV GLOSSARY
ACARS: Aircraft Communications Addressing and Reporting System. Data Link equipment that automatically sends to a ground station relevant technical data belonging to the aircraft. ACC: Area Control Centre. ACFT: Aircraft. AIP: Aeronautical Information Publication. AMSL: Altitude above mean sea level. AOC: Air Operator Certificate. APRON: Aircrafts parking and service area. ASMI: Aerodrome Surface Movement Indicator; a radar equipment suitable to control ground movement of aircrafts and other vehicles. ATA: Ali Trasporti Aerei; a local private general aviation terminal handling and aircraft servicing. ATC: Air Traffic Control. ATIS: Automatic Terminal Information Service; automatic weather voice radiobroadcast. ATPL: Airplane Transport Pilot Licence. BACK TRACK: Aircraft taxi movement in the opposite direction on an active runway. BCFG: weather identification word to identify broken fog layers. BREAK-BREAK: conventional (double) wording to separate the communications aimed at different stations without interrupting the transmission. BKN: weather identification word to identify a cloud coverage ranging from 5/8 to 7/8 of the total. CAT I: approach and landing operations in reduced visibility (down to 550 meters). CAT II/III: approach and landing operations in reduced visibility (less than 550 meters). CHD: child (PAX) up to age 12; usually accounted for a weight of 35 kgs, JAR-OPS 1.620. CPL: Commercial Pilot License. CSO: Capo Sala Operativa; ATC station manager. CVR: Cockpit Voice Recorder. DCA: “Direzione di Circoscrizione Aeroportuale”; Airport Authority, local representative of ENAC. DGAC: “Direzione Generale dell’Aviazione Civile”; national Authority for Air Transport, now renamed ENAC. DEW POINT: the temperature at which air moisture starts condensing. DFDR: Digital Flight Data Recorder. EGT: Exhaust gas temperature (of jet engine). ELT: Emergency Locator Transmitter; automatic accident emergency localisation broadcast. ENAC: “Ente Nazionale per l’Aviazione Civile”; national Authority for Air Transport, formerly DGAC. ENAV: “Ente Nazionale di Assitenza al Volo Ð ENAV S.P.A.”; a corporation responsible for Air Traffic Control and associated infrastructure. EPR: Engine Pressure Ratio; a value indicating a jet engine thrust level for certain types of engines. FAA: Federal Aviation Administration. FDR: Flight Data Recorder, analogue. FF: engine fuel flow indication. FG: weather message identification word for fog. FT: feet. ICAO: International Civil Aviation Organization. IDLE: throttle position that delivers the minimum thrust. IDENT: activation of a special transponder signal for the purpose of a selective, positive identification by ATC radar.
ANSV V ILS: Instrument Landing System. INFORMATION “CHARLIE”: weather information are coded by successive alphabet letters to assure that crews have the current available, CHARLIE will be followed by DELTA and so on. IPI: permanent instructions to Tower personnel. JAA: Joint Aviation Authorities; a european body for civil aviation coordination, equivalent, in perspective to FAA. JAR: Joint Aviation Regulations, issued by JAA, equivalent, in perspective to FAA FARs. JEPPESEN: an international company specialised in the production of aeronautical charts and other aeronautical material. KT (KTS): speed unit (knot/s), corresponding to nautical mile/s per hour. LBA: “Luftfahrt Bundesamt Abgesandt”; German Civil Aviation Authority. LVO: Low Visibility Operations; take-off with a visibility of less than 400 meters or an instrument approach and landing with a visibility of less than 550 meters (see CAT II/III operations). MIFG: weather identification word for mistfog. METAR: Meteorological Actual Report; airport meteorological information issued at regular time intervals (usually 30 minutes). NOTAM: Notice To Air Men; message containing relevant information for the safe conduct of flight operations. NOSIG: No Significant change forecasted in weather information issued. NLG:Nose Landing Gear. NM: Nautical mile, corresponding to 1852 meters. OVC: overcast, word indicating a weather situation characterised by a total cloud coverage. PAX: passenger (adult or child). PLA: Power Lever Angle, recorded data (DFDR) indicating the angular position of an engine power lever. QNH: conventional expression to define the atmospheric pressure referred to sea level, measured in hectopascals. RADOME: cover of the “nose” of the aircraft, normally made of a fibre compound protecting the aircraft radar antenna and transparent to electromagnetic impulses. READ-BACK: the correct, accurate and complete repetition of a received ATC message. REDUCED THRUST TAKEOFF: flexible thrust procedure adopted by operators (and approved by the authorities) to reduce engine wear and fuel consumption, when actual take-off weight is significantly lower than maximum allowed. REVERSE: position of engine thrust levers to obtain reverse engine thrust, used to improve stopping capability. ROGER: conventional term used in radiotelephony to confirm reception and understanding of a message; not to be used to confirm reception of a clearance (which must be read-back completely). RVR: Runway Visual Range; visibility values measured along a runway by means of optical instruments placed in predetermined and proper positions. RWY: Runway. SEA: “Società Esercizi Aeroportuali S.P.A.”; a corporation delivering handling and other assistance to airports in the Milano area and usewhere. STOP MARKINGS TYPE “A” AND TYPE “B”: standard, yellow painted horizontal ICAO runway- holding position markings to identify positions of proximity to a runway; when more than one runway- holding position is required, type “A” is the closest (closer) to the runway, one or more type “B” can precede the last type “A” closest to the runway (positive clearance is required before trespassing). SCT: scattered, word indicating a weather situation characterised by a cloud coverage ranging from 1/8 to 4/8. SHK: “Statens Haveri Kommissions”; Swedish Flight Accident Investigation Agency.
ANSV VI SLAT: a section of the leading edge of the wing. SLOT: conventional word to define a specific timeframe, assigned by ATC, during which the takeoff should take place. TAF: Terminal Area Forecast; weather conditions forecast. TRANSPONDER: airborne equipment that allows secondary radar on ground to identify a specific code of an aircraft. UCT: “Ufficio Controllo del Traffico”; a section of DCA responsible for traffic documentation and administrative aspects. UTC: Universal Time Coordinate; time zone reference to Greenwich, England. The day of the accident local time was UTC plus two hours: all times indicated in this document are UTC. V1, Vr, V2: predetermined take-off reference speeds; V1 is takeoff decision speed (for takeoff abortion), Vr is rotation speed (the speed at which the pilot starts rotating the aircraft nose-up), V2 is takeoff safety speed.
Note: In this Report, the communications transcriptions and original documents referenced are in Bold and Italic characters when they refer to the original language used; when they are in Italics only, they represent a translation.
ANSV VII ANSV VIII CHAPTER I
FACTUAL INFORMATION
1. SUMMARY
On the 8th of October, 2001, at 06.10 UTC (08.10 local time), an MD-87, registration marks SE- DMA operated by SAS (Scandinavian Airlines System), while on takeoff run on Rwy 36R, collided with a Cessna 525A, registration marks D-IEVX which taxied into the active Rwy, coming from West apron (general aviation). After the collision the MD-87 continued travelling (the aircraft was airborne for a short while) down the Rwy and came to a stop impacting a baggage building beyond the Rwy. The Cessna remained on the Rwy and was totally destroyed by post- impact fire. All occupants of the two aircrafts and four ground staff suffered fatal injuries. Four more ground staff suffered injuries and burns of various entity.
1.1. FACTUAL INFORMATION
To facilitate identification of the communications reported, in this chapter 1.1 (only in this chapter) the two Aircraft will be referenced to by their call sign, as follows: the Boeing MD-87 registration marks SE-DMA will be simply “SK 686”, while the Cessna 525A will be “D-IEVX”.
When the accident occurred, the meteorological conditions at Milano Linate Airport were the following (see attachment C): ATIS of 05.50 UTC: “Information ‘Charlie’. Wind var. 1 KT, Visibility min 050 meters, Present Weather fog, overcast 100 ft, Temperature 17¡, Dew point 16¡, 1013, NOSIG. Runway in use 36 Right. Thunderstorm activity forecast between SRN-LIME-COD-VOG- SRN, top of CB 7500 meters, moderate to severe turbulence. ATC CAT III procedure in operation. Report to Milano Arrival category of approach.”
METAR at 05.50 UTC: “VRB 1 KT, 0050 R36R/250V0600U FG OVC001 17/16 QNH 1013 NOSIG”. (“Wind variable at 1 knot, visibility 50 meters, visibility on runway 36R 250 meters, forecast 600 meters, fog, total cloud coverage at 100 feet, temperature 17¡ dew point 16¡, QNH 1013 hectopascals. No significant change”).
The Cessna 525A D-IEVX, had originated its flight in Cologne (Germany). At 04.54.37 the aircraft was approaching Milano Linate. The pilot was in contact with Milano Approach on frequency 126.75 and received the following meteorological information: “General Visibility 100 meters RVR on A and B 200 meters”.
The controller asked the Cessna’s pilot if he intended to perform an approach to Milano Linate and was given a positive answer. At 04.56.15 the pilot of the D-IEVX contacted Milano (Linate) Tower on frequency 118.1 and
ANSV 1 reported to be established for final approach on runway 36 Right. The controller cleared the pilot for landing and restated the meteorological conditions: “Wind calm general visibility 100 meters with fog, overcast at 100 feet , RVR 175, 200, 225 meters”.
At 04.50 the ATIS reported: “ INFORMATION ZULU, Wind var/02 KTS, visibility minim 100 meters, fog, overcast 100 ft, 17¡/16¡, 1013 NOSIG, 36 R. Thunderstorm activity forecast between SRN-LIME-COD- VOG-SRN, top of CB 7500 meters, moderate to severe turbulence.
The ATIS did not mention: ”CAT II/III in progress”, but the ceiling and visibility reported by ATIS were indicating to pilots, without any possible doubt, that the visibility conditions required CAT II/III landing minima.
At time 04.59.34 D-IEVX landed on runway 36R at Linate. The landing run took the aircraft beyond R6 intersection (see attachment A), the crew then requested and obtained permission to backtrack and to taxi on intersection R6 then proceed to general aviation apron (denominated West apron on AIP Italia and Jeppesen chart).
The Jeppesen chart used by the Cessna 525A D-IEVX pilots and valid that day (see attachment G-4) reported the following in the box denominated LOW VISIBILITY PROCEDURES CAT II/III OPERATIONS RWY 36R “CAT III OPERATIONS Aircraft landed on runway 36R must vacate the Rwy via Twy R1 or R6 and report to Tower after passing the flashing white lights, that Rwy is vacated”.
The Control Tower accepted the request and cleared the aircraft accordingly and instructed the pilot to report runway vacated and when entering intersection R6. At time 05.01.09 the pilot reported to be on R6.
At time 05.23.40 ATIS did not yet report CAT II/III operations in progress. At 05.23.40 the pilot of flight AZ 2015 asked the Control Tower if Category III operations were in progress, and he received a positive answer: “CAT III in progress”. The pilot of flight AZ 2015 advised the Control Tower that the ATIS did not report that information. The tower controller thanked the pilot for the information and stated that he would take action. At 05.24 the ATIS started to report: “CAT III procedures in progress”.
Before his departure from Cologne, the pilot of the Cessna D-IEVX, had forwarded, via fax, a flight plan to operate his next flight from Milano-Linate to Paris-Le Bourget with two passengers on board. One passenger was a Cessna Aircraft manager and the other was a current Cessna owner and a prospective 525A customer.
At 05.41.39, after the boarding of 104 passengers was completed, the pilot of flight SK 686 requested Linate Ground, on frequency 121.8, for his engines start clearance. SK 686 was a flight scheduled to depart Milano Linate at 05.35 with destination Copenhagen. The Ground Control cleared the pilot to start engines and advised that their slot time for takeoff was at 06.16. At 05.54.23, after completing their ground operations, the SK 686 crew requested taxi clearance. The Ground Control instructed the pilot of flight SK 686 to taxi to the CAT III holding position and asked to be advised when the aircraft had entered the main taxiway:
ANSV 2 “Scandinavian SixEightSix taxi to the holding position Cat Three, QNH OneZeroOneThree and please call me back entering the main taxiway”.
At 05.58.23 the Cessna D-IEVX pilot requested start-up clearance to Linate Ground on frequency 121.8, for his filed flight Milano-Linate Ð Paris-Le Bourget. The Ground Control cleared the pilot to start engines and gave him a slot time for takeoff at 06.19.
At 05.59.41 the Ground Control instructed the pilot of flight SK 686 to contact the Control Tower on frequency 118.1, when abeam the fire station. Ground: “…passing the fire station, call Tower EighteenOne, bye”. SK 686: “Scandinavian SixEightSix, good bye”.
At 06.01.24 the pilot of SK 686 changed frequency and contacted the Tower on 118.1.
From this moment on the crew of SK 686 and the crew of the D-IEVX were tuned on two different assigned frequencies.
At 06.05.44 the pilots of the Cessna received the following taxi clearance from Ground Control: “DeltaVictorXray taxi north via Romeo Five QNH OneZeroOneThree, call me back at the stop bar of the ... main runway extension”.
The pilot of the D-IEVX acknowledged by saying: “Roger via Romeo Five and … OneZeroOneThree, and call you back before reaching main runway”.
D-IEVX started to taxi from its general aviation parkink position, he followed the yellow taxi line and turned to the left passing in front of the terminal building. The aircraft turned again to the left reaching the position where the yellow taxi line splits into two directions, one large radius trajectory to the left, northwards and one smaller radius to the right, southwards (see attachments F-1, F-2 and F-3). At that position, two markings, R5 and R6 were painted on the tarmac. This R6 marking was the last one available for the rest of the taxi distance to runway 36R/18L. The size and shape of the two markings did not conform to the ICAO standard, and were only partially visible (partially worn). The locations of the markings where the yellow taxi line bends are positioned to the left of the line and on a slanted angle from the pilot’s viewpoint. The recognition of the markings required particular attention even in good visibility. From that position green centreline lights were illuminated along the yellow line at the beginning of R6 taxiway, and probably visible from that position. The yellow line that turns to the left (towards R5) had no centreline lights all across the West apron (ATA).
Beyond the end of the parking apron, at its northern boundary, the yellow line leads to taxiway R5. The green central lights of the taxiway (R5) started beyond the end of the parking apron and were absolutely not visible from the position of the D-IEVX, with the reported visibility.
The Cessna entered taxiway R6 and continued taxiing; passing a runway-holding position marking (pattern “B”) preceded by a yellow marking “S5” that was clearly visible (oriented
ANSV 3 towards the approaching aircraft) and located before the intersection of taxiway R6 and the extension of runway 36L/18R. After having passed runway 36L, visible on the left side, continuing in the same direction, there was another runway-holding position marking (pattern “B”), immediately followed by a yellow marking “S4”, also easily readable but oriented in the opposite direction of the approaching aircraft. (See attachment F-4).
At 06.08.23 the pilot of D-IEVX reported: “DeltaIndiaEchoVictorXray, is approaching Sierra Four”.
At 06.08.28 the Ground controller asked confirmation of the position of the aircraft: “DeltaIndiaEchoVictorXray, confirm your position?”
At 06.08.32 the pilot D-IEVX answered: “Approaching the runway … Sierra Four”.
At 06.08.36 the Ground controller instructed: “DeltaVictorXray, Roger maintain the stop bar, I’ll call you back”.
At 06.08.40 the pilot of the aircraft D-IEVX answered: “Roger Hold position”.
After about 15 seconds from the end of this last communication, the Ground controller asked another aircraft, Air One 937, of its position and at 06.09.18, after receiving confirmation that, aircraft was near the taxiway (the main taxiway parallel and East of Rwy 36R) and almost abeam the Control Tower, the controller contacted the pilot of D-IEVX.
At 06.09.19 the Ground Control cleared the pilot of D-IEVX to continue taxi on the West apron and to follow the Alfa line: “DeltaVictorXray continue your taxi on the main apron, follow the Alfa Line”.
At 06.09.28 the pilot answered: “Roger continue the taxi in main apron, Alfa Line the... DeltaVictorXray”.
D-IEVX continued to taxi on R6. About 180 meters before Rwy 36R/18L, there is a lateral enlarged stopping area where the aircraft crossed a white “STOP” marking on the tarmac, (See attachment F-5), quite visible and a (pattern “B”) yellow runway-holding position marking. He crossed the runway-holding position marking and then a unidirectional Stop bar with lighted red lights (ON) (non switchable by controllers). To the left of that Stop bar a vertical sign (capable of illumination, with white characters on orange background) was signalling CAT III. Immediately before entering the runway, D-IEVX crossed another and last runway-holding marking (pattern “A”), yellow painted on the tarmac. AIP Italy and Jeppesen maps indicate that two white flashing lights are in place at that position, but no evidence was found of their existence (they were not present). Furthermore an (audible) warning system had been installed at that position but it had been removed or disconnected before December 16, 1998.
ANSV 4 D-IEVX crossed the (pattern “A”) runway-holding marking and entered Rwy 36R/18L
At 06.09.28, the Ground controller was communicating on frequency 121.8 with the pilot of D-IEVX. At the same time, the Tower controller called the pilot of Meridiana 683 on frequency 118.1 and without interrupting the communication cleared SK 686 for takeoff.
Tower: “Meridiana SeiOttoTre, buongiorno un attimo in ascolto Break-break Scandinavian SixEightSix Linate, clear for take off ThreeSix, the wind is calm report rolling, when airborne squawk ident”.
SK 686: “Clear for takeoff 36 at when…airborne squawk ident and we are rolling, Scandinavian 686”.
At the same time, D-IEVX entered runway 36R/18L initially following the green lights. Meanwhile on his right, SK 686 was on the takeoff run.
At 06.10.18 the ACARS equipment installed on the SK 686 transmitted to SAS Operations in Copenhagen the takeoff signal; the signal is automatically transmitted at the extension of the NLG strut.
At 06.10.21 the two aircrafts collided.
1.2. INJURIES TO PERSONS
All occupants of the two aircrafts 104 passengers and 6 crewmembers aboard the SK 686 and 4 occupants of the D-IEVX were killed and four ground staff suffered fatal injuries. Four more ground staff suffered injuries and burns of various entity.
1.3. DAMAGE TO AIRCRAFTS
The two aircrafts were destroyed at impact or by post-impact fire.
1.4. DYNAMICS OF AIRCRAFTS COLLISION
1.4.1. Significant parameters recorded on Boeing MD-87 DFDR at collision point
(one second time frame)
HDG = 356 degree (Runway heading) IAS = 146 KT Pitch attitude = +10.3¡ Elevator position = LH +17¡, RH +23¡ EPR = 1.91
ANSV 5 1.4.2. Boeing MD-87 DFDR significant recordings seconds after the collision point
Ground/air switch indicated airborne the first 12 seconds after collision, however the MLG obtained ground contact approximately 3-4 seconds prior to this. Vert./Long./Lat. acceleration in general all positive values the first 9 seconds after collision. Forward thrust generated by LH engine the first 8 seconds after collision. Rudder, elevator and aileron-motion. Left engine reverse deployed 11 seconds after collision.
1.4.3. Boeing MD-87 CVR sound extract Sound recorded in the cockpit area mike indicates that the duration of the collision was approximately 0,5 seconds. The collision sequence includes several energy peaks.
1.4.4. Preliminary analysis of collision scenario The Cessna left R6 intersection with runway 36R on a heading of approximately 135 degrees (plus/minus 10 degrees) and at a presumable taxi speed of 20 KT (equivalent to 10m/sec or 1m per 0.1sec). At time of collision it was crossing the runway centreline. The MD-87 reached intersection R6 and was performing a normal rotation prior to the point of collision (reference: CVR & DFDR readouts). The Nose Gear was airborne and Main Landing Gear legs partly extended (but with tires still in ground contact). Recorded data allow to separate and analyse different events that took place in succession although within a very short time frame (less than one second) in order to better understand their effect and their consequence.
1.4.5. First point of contact The rotation attitude maximum was 13,5 degrees Nose Up (reference: tailskid found untouched) and minimum 10.3 degrees Nose Up (reference: DFDR recordings). Based on the above assumptions; the lowermost point of the MD-87 Nose Wheel assembly was approximately 11-12 feet off (above) ground level at the aircraft angle of rotation. The uppermost surface of the Cessna fuselage was approximately 8.5 feet above ground level. Wings were significantly lower. Thus the MD-87 Nose Wheel assembly passed clear of the Cessna fuselage, wings and engines. However it probably struck the Cessna’s stabilizers (horizontal). Examination of the Cessna wreckage revealed that its horizontal stabilizer LH and RH outboard portion had extensive damages. (See attachment B-1, damages to the Cessna).
The MD-87 Nose Landing Gear (NLG) LH wheel and spray deflector most likely caused the Cessna 525A D-IEVX LH horizontal stabilizer damage. MD-87 spray deflector was most probably broken off at time of contact. However, the location of the spray deflector debris has not yet been established. Also evident damage on NLG LH wheel, but not on NLG RH wheel. Looking at the geometry/layout of the MD-87 NLG, it is probable that this was the first point of contact between the two aircrafts. (See attachment B-2, damages to Boeing MD-87).
ANSV 6 The hypothesis is sustained by the fact that the first point of contact recorded sound by the CVR was very loud, which correlates with a noise generation in the vicinity of the CVR area mike. The recorded impact noise lasts approximate 0.4 sec. With the relative speed of the two aircrafts this equals the aircrafts contact distance of approximately 35 meters. (See attachments B-3, sounds analysis and B-4, interaction between aircrafts).
1.4.6. Second point of contact
The MD-87 LH Main Gear wheels hit (“snagged”) the Cessna’s RH wing outboard portion, lower surface. Cessna RH wing leading edge front spar was found broken and this damage corresponds to MD-87 LH Main Landing Gear (MLG) strut diameter. Clear evidence of tire marks on lower surface of Cessna RH wing and aileron was found. Outboard section of wing was found damaged, and the severely bent aileron had become detached from the wing. The angle of the tire skid marks on the lower part of the Cessna RH wing gives the relative angle of the two aircraft. The force of impact to MD-87 LH MLG strut is insignificant and leaves no clear sign of damage, however a clockwise pivotal movement of the Cessna was initiated. (See attachment B-5, interaction between aircrafts).
1.4.7. Third point of contact Next contact event probably was the MD-87 RH Main Landing Gear wheel hitting the Cessna RH wing leading edge inboard portion. The contact was of very high force damaging both aircraft severely. The MD-87 main wheel n. 3 has extensive compression force marks whereas the main wheel n. 4 does not carry the same signature. This evidence sustains the relative angle of the two aircraft. The high force of impact broke the MD-87 RH MLG strut just above the hydraulic retraction cylinder. This breaking point matches a MLG extension of approximately 20 centimeters indicating that the MD-87 main wheels had a firm ground contact. (See attachment B-6, interaction between aircrafts). At this point several impacts took place within a very short time frame, which correlates generally with the second noise peak of the CVR sound analysis, which covers the highest sound peak in the collision sequence. MD-87 LH wing inboard slat fairing then probably hit Cessna RH horizontal stabilizer, MD-87 RH MLG door (fuselage mounted, in closed position), and MD-87 RH hydraulic service panel were struck by Cessna vertical stabilizer. (Parts of MD-87 wing filet were found inside Cessna vertical stabilizer). (See attachment B- 7, interaction between aircrafts). MD-87 RH MLG strut (cylinder) cut through the center part of the Cessna fuselage. The RH MLG lower part (piston including wheels and brake units) broke off, was forced aft. Assisted by the rotational energy the wheel assy rolled upward damaging the RH inboard flaps.
MD-87 RH main wheel assy then became jammed between MD-87 RH engine front, at six o’clock position, and the Cessna. The MD-87 engine was severely damaged by the impact (including electrical failures) and the subsequent sudden seizure of the engine rotors. (See attachments B-7 and B-8, interaction between aircrafts). MD-87 RH wing inboard flap hinge penetrated the Cessna fuselage and struck the Cessna LH engine. The MD-87 then was clear of the Cessna.
The combined forces on the MD-87 RH engine at the collision resulted in failure of engine mounts and the engine separation from the pylon, approximately one second later. At this
ANSV 7 moment the aircraft was airborne and the separated engine landed approximately 180 meters downfield from point of collision, as indicated by extensive runway surface damage and slid down the runway to R1. (See attachment B-8, interaction between aircrafts ).
1.5. ANALYSIS OF THE POST COLLISION SCENARIO
1.5.1. The Cessna 525A
After the aircrafts collision the Cessna was on fire and split in three major sections on the runway. Collision forces destroyed the D-IEVX in a post-collision fire. The airframe separated into three main sections during the collision: wing, empennage/tail cone and cockpit/cabin. The empennage/ tail cone section was the only one not to sustain significant fire damage. The wing and cockpit/cabin sections were mostly consumed in the post-collision fire. After the collision, three sections of the aircraft were observed on the runway the cockpit/cabin section was the southern most section and was facing south. The wing was north of the cockpit/cabin section and facing west. The empennage/tail cone section was the northern most section and was facing northeast. Each section was reportedly 10-15 meters apart. The right engine was in two pieces and was approximately 400 meters North of the main wreckage and laying on the right side of the runway. Both horizontal stabilizers were also lying North of the main wreckage on the runway. The emergency exit was not heavily damaged and the locking pin was extended. The rescue aspects of the post collision pertinent to this aircraft and its crew and passengers will be dealt with separately in the Final Report.
1.5.2. The Boeing MD-87
After the collision the pilot flying (PF) continued takeoff, the MD-87 became airborne and proceeded on runway heading but severely damaged. The RH engine had separated from the pylon. As indicated by the DFDR the left throttle was advanced, fuel flow and EGT increased, but no thrust increase was obtained, the EPR set at takeoff (1.91) decreased to 1,40. The RH engine had separated from the fuselage, which caused an instant thrust loss and the Center of Gravity (CG) to move forward, outside the forward limit. Preliminary calculations indicate that the CG being outside the forward limit created “an untrimmed stabilizer” condition. FDR data shows motion of rudder, elevator and aileron, which indicates that the pilot flying tried to maintain control of the aircraft and initially intended to continue the takeoff. During this phase DFDR show movements of the elevator and rudder to maintain the trajectory. Simultaneously the LH engine impended thrust loss, the aircraft could not accelerate sufficiently to produce adequate lift and the energy loss from the impact left the aircraft non- flyable and it touched down prior to end of runway at high speed. Due to damage to airplane systems resulting from impact with the Cessna and the separation of the right engine the actual speed at touchdown was not recorded by the DFDR. The last recorded speed being 146 kts before impact with the Cessna. DFDR data indicates that the MD-87 touched down at the end of the runway 10Ð14 seconds
ANSV 8 after the collision. Due to the missing RH MLG the RH wing tip came in contact with the runway surface. Initial tracks are parallel and marks on the runway surface indicate, that RH wing flap hinges were in contact with the ground and probably also LH MLG door. At this stage the crew selected reverse thrust and the LH reverse deployed (recorded by the DFDR and sustained by reverse lever position and reverse buckets deployment). Manual braking was applied but not obtained due to probable loss of hydraulic power. Skidding on the runway the MD-87 RH swivel started with RH wing tip as pivotal point. The aircraft slid sideways, with its longitudinal axis reaching approximately 45 degrees to the right of the aircraft direction of movement.
1.5.3. Final impact with airport baggage building
LH side of cockpit finally collided with the concrete construction of the baggage building and stopped instantaneously. LH wing tip hit a corner of the building and broke off (no fire marks on wing tip). Preliminary calculations indicate that the MD-87 speed at the time of impact was approximately 139 KT (72 m/s). The fuselage stopped abruptly on collision with the baggage building and the complete wing assembly detached from the fuselage and continued into the building and burst into fire. The tip of LH wing broke and slid beyond the left corner of the building without being ingested by fire. Engine n. 1 heavily damaged, remained jointed to the fuselage with the reverse deployed. The main body of the fuselage broke in three parts. The empennage broke off forward of aft bulkhead when hitting a corner and was stopped outside the building. The blow of the fuselage broke two pillars of the building bringing its top to collapse on the wreckage bursting into a violent post-impact fire that consumed all the fuel contained aboard. The horizontal stabilizer continued some meters and finally came to rest on top of the building. (See attachment B-9, MD-87 collision with airport baggage building).
1.6. OTHER DAMAGES
The runway surface had scrape marks from the RMLG piston and other parts of the MD-87 hitting and then skidding towards the airport building. The MD-87 RH engine damaged the runway approximately at 180 meters post collision point. Other damage to the runway was caused by the post-impact fire of part of the Cessna. Destruction of the airport baggage building with all the baggage and equipment it contained.
1.7. INFORMATION ON PERSONNEL
1.7.1. Pilots Pilots of the Boeing MD-87 Captain: male, age 36, Swedish nationality License: ATPL (Airline Transport Pilot License) Type rating: Douglas DC9-80, Boeing MD series88, Boeing MD 90 LVO (Low Visibility Operations) Certificate of radio operator
ANSV 9 Medical: Class I Proficiency check: May 3, 2001, flight simulator, comment: “very high standard” Flight experience: 5842 h on type: 232 h Last 90 days: 121 h 121 h Last 30 days: 52 h 52 h Last 24 hrs: 02.46’ h 02.46’ h
First Officer: male, age 36, Swedish nationality License: CPL (Commercial Pilot License) Type rating: as co-pilot Douglas DC9, Boeing MD series 88, Boeing MD 90, Boeing 737, Boeing 727 LVO (Low Visibility Operations) Medical: Class I Proficiency check: September 4, 2001, flight simulator, comment: “above average” Flight experience: 4355 h on type: 1978 h Last 90 days: 148 h 148 h Last 30 days: 53 h 53 h Last 24 hrs: 02.46’ h 02.46’ h
Pilots of the Cessna 525A D-IEVX
Captain: male, age 64, German nationality License: ATPL (Airline Transport Pilot License) IFR Rating Type rating: Cessna 500/501, 525 (includes the 525A) 550/551, 560, LearJet 45 Instructor (FI,IRI,CRI,TRI) Medical: Class I, valid with waivers (glasses) Proficiency check: May 30, 2001 flight test, Cessna 525 for CAT I Flight experience: 12000 h on type: 2000 h Last 90 days: 100 h N.A. Last 30 days: 43 h N.A. Last 24 hrs: 01.10’ h 01.10’ h
First Officer: male, age 36, German nationality License: CPL (Commercial Pilot License) IFR Rating Type rating: Cessna 525 (include 525A) Medical: Class II Proficiency check: June 2, 2001 flight test, Cessna 525 for CAT I Flight experience: 5000 h on type: 2400 h Last 90 days: 74 h 71h Last 30 days: 26 h 24 h Last 24 hrs: 01.10’ h 01.10’ h
1.7.2. Pilots pre-accident duty time
Pilots of the Boeing MD-87
Rest period before duty time start: 9 hours from last flight. Duty time start: 04.50 of October 8, 2001.
ANSV 10 Pilots of the Cessna 525A
Rest period before Duty time start: 5 days from last flight Duty time start: 02.30 (presumably) of October 8, 2001
1.7.3. Air traffic controller
Supervisor Controller (CSO): male, age 53, Italian nationality License: Air Traffic controller Tower controller Approach controller Tower team manager Medical: valid Professional experience: 27 years at Milano-Linate airport Proficiency check: Not available No record of refreshment course completed over the past 20 years
Assistant Controller (Coordinator): male, age 54, Italian nationality License: Air Traffic Controller, Tower Controller, Approach Controller, Tower team manager Medical: valid Professional experience: 20 years at Milano-Linate airport Proficiency check: Not available No record of refreshment course completed over the past 20 years
Reserve Controller: male, age 44, Italian nationality License: Air Traffic Controller, Aerodrome Controller, Approach Controller, Aerodrome Approach Radar Controller Medical: Not available Professional experience: At Milano-Linate airport since May 1998 Proficiency check: Not available
Tower Controller: male, age 34, Italian nationality License: Air Traffic Controller, Aerodrome Controller, Approach Controller, Aerodrome Approach Radar Controller, Instructor (theory and practice) Medical: Valid Professional experience: Last 11 years at Milano-Linate airport Proficiency check: Not available
Ground Controller: male, age 36, Italian nationality License: Air Traffic Controller, Aerodrome Controller, Approach Controller Medical: Valid Professional experience: At Milano-Linate airport since April 1998 Proficiency check: Not available
ANSV 11 1.7.4. Air traffic controller’s duty time
Supervisor controller (CSO) Rest period before duty time start: 72 hours. Duty time start: 06.00 of October 8, 2001
Assistant controller (Coordinator) Rest period before duty time start: 16 hours. Duty time start: 05.00 of October 8, 2001
Ground controller Rest period before duty time start: 16 hours. Duty time start: 05.00 of October 8, 2001
Tower controller Rest period before duty time start: 10 hours. Duty time start: 06.00 of October 8, 2001
Reserve controller Rest period before duty time start: 10 hours. Duty time start: 06.00 of October 8, 2001
1.8. AIRCRAFT INFORMATION
1.8.1. The Boeing MD-87
The aircraft, Swedish registration marks SE-DMA, was owned by Orbit Leasing International Co.Ltd leased to Scandinavian Airlines system. MTOW was of 63.503 kg and the maximum passengers carrying capacity 110 PAX (Adults). The aircraft was LVO operations capable and certified for CAT III. Weight and balance was correct, mean aerodynamic chord (MAC) at 13% and well within limits. BOW was 36.904 kg 104 PAX (4 CHD) on board and 1.237 kg of baggage and mail for a total of commercial load of 10.681 kg; Total fuel 10.400 Kg. Total weight was 57.485 kg at start of taxi, well within the MTOW certified limit of 63.503 kg. Runway conditions and weather as well as performance and Company regulations allowed for a reduced thrust takeoff, which was planned. Takeoff was calculated with FLAP 11¡ configuration, with the following corresponding characteristic speeds in Kts: V1= 132, VR= 135, V2= 144. Based on the above data the takeoff distance travelled upon reaching 15 feet altitude was 1.389 meters.
1.8.2. The Cessna 525A
The aircraft was owned by ENSCHMANN Hermann-Dieter, German registration marks D- IEVX. AIR EVEX Gmbh from Dusseldorf (Germany) had requested LBA Germany to register the aircraft on its AOC; the formality had not yet been completed.
ANSV 12 MTOW was 5.613 kg (max ramp weight 5670 kg) and the maximum passenger carrying capacity 6/7 PAX, plus crew. The aircraft was not certified (nor capable) for LVO operations. There were no flight recorders (CVR/FDR) on board since this was not required for that class of aircraft with a MTOW of less than 5.700 kg. Takeoff weight is unknown.
1.9. WEATHER INFORMATION
See attachment C.
1.10. NAVIGATION AIDS
Not applicable.
1.11. COMMUNICATIONS
Findings analysis is still under investigation, in particular with regard to ATC, Fire Fighting and other airport personnel involved in the rescue. Telephone communications where not part of the findings available to this date since they are under the control of the Magistrate. Thereafter pertinent conclusions will be part of the Final Report publication. To this date a complete transcription of air-to-ground communications is available and leave room to some preliminary considerations. (See attachment D).
1.12. AIRPORT CONFIGURATION AND ASSOCIATED CHARTS AND MAPS INFORMATION
1.12.1. Airport information Milano Linate airport is located 4.32 NM East-Southeast of Milan (geographic position: 45 27’01” North and 09 16’46” East). The airport elevation is 353 feet AMSL.
Linate operates as an international and domestic airport, and is used for commercial, executive and general aviation traffic. The airport has two parallel runways, oriented at 356¡/176¡ ; 36R/18L (36 Right/ 18 Left) and 36L/18R (36Left/ 18 Right). The two runways are commonly referred to as: a) 36R/18L Main Runway; b) 36L/18R general aviation runway (“Turistica”). runway 36R/18L is 2.440 meters long and has a width of 60 meters, and is certified for LVO, CAT I/II/III operations. The threshold elevation of runway 36R is 338 feet (103,02 meters AMSL). The threshold elevation of runway 18L is 353 feet (107,59 meters). There is a difference of 15 feet (4,57 meters) between the threshold of runway 36R and 18L and this creates a positive slope toward the North. Runway 36L/18R is 600 meters long and has a width of 31 meters and is used for general aviation and military traffic. The two runways have two distinctive parking areas; referred to in AIP Italia as: North apron (“Piazzale Nord”) and West apron (“Piazzale Ovest”). A taxiway referred to (verbally only, not printed on any maps and no signs at apron) as Main taxiway runs parallel and East of runway 36R/18L throughout its whole length. The taxiway starts from the southern end of North apron and connects with the runway throughout four
ANSV 13 intersections. Starting from the North the intersections are referred to as R1, R2, R3, R4. Continuing clockwise, a taxiway referred to as R6 connects runway 36R/18L to the West apron southern end, intersecting the southern extension of runway 36L/18R and ending on runway 36R/18L (approximately opposite to intersection R2). Further to the North, taxiway R5 connects the West apron to the North apron intersecting the northern extension (overrun) of runways 18R/36L and 18L/36R.
1.12.2. Airport charts and maps
The official documents for Italian airports are published in the AIP Italy (Aeronautical Information Publication Italy). These documents are prepared by ENAV and contain all the rules, regulations and Aerodrome Information as issued by ENAC and ENAV. The permanent NOTAMS are also included in this document. The Cessna 525A D-IEVX crew was using the Jeppesen Route Manual. The SAS Boeing MD- 87 (SK 686) was using a Route Manual published by SAS Flight Support for SAS Operation. All referenced charts in this document (see attachments A and G) are those valid on the day of the accident. The above-mentioned Route Manuals and the associated aerodrome charts, contain information taken from the AIP.
1.13. FLIGHT RECORDERS
1.13.1. DFDR Boeing MD-87
The MD-87 was equipped with a Digital Flight Data Recorder (DFDR) Honeywell p.n. 980- 4100-DXUN, which was recovered without any damage to the recording. Data from this recorder was read at BFU (Germany) laboratories at the presence of the ANSV investigators and other Accredited Representatives from the entitled ICAO States.
All data were found coherent with the flight up to the collision with the Cessna (approx 39 seconds after start of takeoff). The DFDR has continued to record data for about 16 seconds after the collision. After the collision with the Cessna some parameters became erroneous or unreliable, but the acceleration data seems to be correct until final impact (into building).
The only speed registered is the IAS (Indicated Air Speed) which is unreliable or zero after the collision.
Significant data recorded are: - stabilizer trim was correctly set for takeoff; - takeoff FLEX thrust was EPR 1,91; - rotation was performed at 132-137 Kts (244-253 Kmh); - NLG (nose landing gear) lift-off was achieved at 144 Kts (267 Kmh) 37 seconds after start of takeoff run; - one second after lift-off of NLG, elevator was brought to its maximum (UP) deflection; - one further second later, 146 Kts (270 Kmh) the DFDR reading shows a condition of transit for the RH slat and the RH MLG; - at the same time the reading of the RPM of engine n. 2 becomes zero and the other engine parameters (EPR, FF, EGT) are frozen with incoherent values;
ANSV 14 - advancement of the throttles, with rise of FF and EGT for engine n. 1, but with thrust reduction (EPR 1,41); - flight parameters show that an altitude of 35 feet (10,67 meters) was reached in 10 seconds; - large and rapid travel of elevator position from neutral to 18 degrees UP; - coordinated activation of ailerons and rudder to achieve a decreasing heading (left direction variation); - one second before runway impact throttles are set to IDLE; - after ground contact throttles were set to reverse; - manual braking was applied; - no reading of hydraulic pressure to brakes assembly is recorded; - DFDR recording stops about 56 seconds after start of takeoff (more than 6 seconds after aircraft ground contact for lack of adequate thrust).
1.13.2. QAR Boeing MD-87
Quick Access Recorder type Penny&Giles p.n. 51434-1 is a magnetic ribbon recorder used for maintenance and it is not approved as crash recorder. The QAR was installed in the electronic bay, immediately after the NLG. The ribbon was found the day after the accident and it has been read on October 17, 2001 at the SAS facility in Copenhagen under the surveillance of ANSV and SHK Sweden. Parameters were found to be coherent with other DFDR data later available.
1.13.3. CVR Boeing MD-87
Cockpit voice recorder type Honeywell p.n. 980-6020-001 was installed on the right hand side of the AFT cargo bay. It was found only 10 days later because it had been removed and stored along with other debris. The CVR was read on October 25-26, 2001 at a BFU Germany facility and subsequently translated through SHK, assisted by SAS accident investigation team under the surveillance of ANSV. The recording starts at 05.39.55 and confirm the communications recorded by Ground and Tower. The recording of the cockpit crew communications is only comprehensible with difficulty because the pilots did not make use of headset with microphone and due to the high volume of surrounding noise. However the area microphone provided significant data of the collision with the Cessna. The data was analysed and the analysis provided foundation for and verification of the crash dynamics of the two aircrafts. The recording lasts 30 minutes and 26 seconds and is interrupted at 06.10.21.
1.13.4. Cessna 525A
There was no recording system installed for flight data (CVR/FDR) as it is not required for aircrafts with a maximum takeoff weight of less than 5700 Kg.
1.14. WRECKAGE FINDINGS
1.14.1. The Boeing MD-87
The MD-87 fuselage broke into three sections upon impact with the building: Front section: from behind the weather radar to the root/wing assembly leading edge.
ANSV 15 Intermediate section: from the leading edge position root/wing to the AFT cabin bulkhead. Tail section: from the AFT cabin bulkhead to the empennage.
The front section (forward fuselage), rested outside baggage building, the RH side apparently intact. It was recovered with the cockpit area intact but much of the passenger section overhead structure had been cut away by the fire brigade. The cockpit pedestal was deformed and displaced to the left and the control columns also appeared to have been displaced to the left. The cabin floor was mostly intact with seat track structure separated and collapsed on the LH side, the same happened to the overhead bins. Forward galley attach structure had either been separated at impact and/or removed to facilitate access to the occupants by the fire brigade.
The intermediate section (mid fuselage), from approximately above the wing box to just ahead of the aft pressure bulkhead. The mid fuselage was reported to have been under a portion of the baggage building’s concrete roof, which had collapsed onto the fuselage and wing structure (it was reported that the aircraft struck and sheared a building support column). With the exception of the slat bull wheel and a portion of the center wing box still attached to the right wing, none of the centre fuselage section was recovered intact. These items had been destroyed by impact forces, the roof collapse, or post-impact fire. The right wing, from the root/wing centre section centreline was essentially intact but fire damaged and badly scorched with some aluminum melting noted. The right main landing gear attach fitting was still mounted to the wing and the upper portion of the RMLG cylinder was still attached to the fitting. The lower portion of the RMLG cylinder was severed from the upper cylinder. Overhead bins had separated in this area but some were recovered separately. The largest recovered section had separated from the fuselage structure at the fuselage end of the attach mechanism; the smaller section had separated from the fuselage structure at the bin end of the attach mechanism. Part of the RH wing was interested by the post-impact fire and destroyed.
The tail section of the airplane from the pressure bulkhead aft including the vertical and horizontal stabilizers remained outside the building and was not consumed by post-impact fire. The center portion of the horizontal stabilizer structure and the tip of the vertical stabilizer came to rest on the roof of the baggage building just above the remainder of the tail section. The left engine was found outside and against the baggage building mostly intact, oriented vertically (nose down), with the thrust reversers (reverse thrust mechanism on engine body) in the deployed position.
Summary of Boeing MD-87 wreckage significant findings:
- LH NLG wheel damaged; - NLG spray deflector damaged and missing; - RH MLG strut broken; - RH MLG wheel assembly found far away from collision point; - RH engine nose cowl damaged at six o’clock position by RH MLG wheels; - RH engine separated from aircraft before aircraft touch down; - RH MLG door damaged and separated from aircraft at collision point; - RH hydraulic service panel ripped off at collision point;
ANSV 16 - LH inboard slat fairing ripped off at collision point; - aircraft broke apart by collision with cargo building ; - front fuselage remained outside building; - wing assembly detached from fuselage and slid into building and broke into fire; - empennage broke off and remained outside building.
1.14.2. The Cessna 525A
The Cessna 525A was destroyed by collision forces and a post-collision fire. The airframe separated into several sections during the collision: cockpit/cabin, wing assembly, empennage/tail cone, engines.
The cockpit/cabin section of the fuselage was mostly consumed by the post-collision fire. The radome and nose baggage area was charred, but not impact damaged.
The left wing showed no sign of collision forces; however it was mostly consumed in the post- collision fire. No control surfaces from the left wing were found.
The right wing separated during the collision and had no fire/heat damage. The outboard 1/3 of the leading edge in that area was also separated. Both the outboard right wing section and the leading edge exhibited rubber transfer marks. The marks began at the leading edge of the outboard wing rib and went aft and inboard; the wing separated just inboard of the marks. Those marks on the underside of the outboard right wing section displayed a tread pattern that appeared to be consistent with the Boeing MD-87 right main landing gear inboard tire (the left main landing gear tires were consumed by fire). The right aileron separated from the right wing and did not have fire/heat damage. The underside of the right aileron exhibited more rubber transfer marks. The aileron was bent at approximately 90 degrees.
The empennage/tail cone section, was the only one not to sustain significant fire damage. Both horizontal stabilizers were separated from the vertical stabilizer during the collision. Neither horizontal stabilizer nor elevator was complete (one piece). A large section of the right elevator remained attached to the stabilizer at the two inboard hinges. The outboard area was separated. The left horizontal stabilizer and elevator sustained heavy impact forces from the rear and bottom side. Rubber marks were observed on the bottom of the elevator in the area of the torque tube and on the bottom of the elevator and elevator trim tab. Rubber marks were also observed on the rear spar of the stabilizer. The vertical stabilizer remained attached to the matching structure of the tail cone. Parts of the MD-87 structural elements (wing filet fairing) were found embedded in the stabilizer. Collision forces reduced the vertical stabilizer chord by approximately 75%. The structure in the damaged area was pushed aft and slightly to the left.
The left engine remained partially attached to the pylon structure. There were two areas of impact damage on the inboard side of the left engine; the damage suggested the engine was struck by an object moving from the inboard to the outboard side of the engine and from the front to the back.
The right engine separated from the pylon structure during the collision; it further broke into two pieces. The two pieces traveled approximately 400 meters down the runway from the main wreckage. The outboard side of the right engine exhibited two areas of a side impact and
ANSV 17 one other area of damage. The distance between the two areas of damage was consistent with the distance between the two tires on the main landing gear of the MD-87.
Summary of the Cessna wreckage significant findings:
LH horizontal stabilizer outer part cut off; RH wing tip cut off including tire marks of MD-87 main wheel n. 1; vertical stabilizer top containing remains of MD-87 wing filet fairing; engine 1 penetrated and cut in a longitudinal angle; engine 2 detached from aircraft; LH horizontal stabilizer outer part cut off; aircraft separated into three main parts, front fuselage, wing assembly, empennage; front fuselage and wing assembly destroyed by fire.
1.15. FORENSIC INFORMATION
1.15.1. The Boeing MD-87 occupants Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
1.15.2. The Cessna 525A occupants Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
1.16. FIRE
Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
1.17. SURVIVALASPECTS
Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
1.18. TESTS AND FURTHER ANALYSIS
Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
1.19. OPERATIONAL INFORMATION
Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
ANSV 18 CHAPTER II ANALYSIS
2. ANALYSIS
2.1. GENERAL ASPECTS
In analyzing the available documentation and in consideration of the complexity of interaction between them it is only possible to produce a partial reconstruction of the course of events. Further investigation will be necessary to obtain a complete picture; it is only possible, at this stage, to make initial considerations that will be integrated by more informations in the final report. With reference to the ICAO model, this investigation, with the factual evidence available to this date, has focused on the three factors that are by experience conducive to accidents: the technical, the environmental and the human factor. To some extent they may all be present, but in this case two are more evident and intermixed, human and environmental factor.
2.2. HUMAN FACTOR
2.2.1. Analysis of the professional experience of the pilots
The Captain of the Boeing MD-87 Hired by SAS in 1990, ATPL licensed, Captain qualification at SAS in January 1999. His flying experience was matured on Douglas DC 9 10/50 and in April 2001 he completed the qualification on Boeing MD 80/88 (which comprises MD-87). He had totaled approximately 6000 flying hours. His personal technical documentation indicates the achievement of a very high professional standard. The DFDR data readings and their interpretation all confirm the above-mentioned positive professional consideration. His behavior in dealing with the post-impact section of the flight indicate a notable airmanship. Left reverse thrust deployment and application may have (albeit unconsciously) modified the path of the aircraft, preventing an even more diverging trajectory that could have involved other aircrafts parked on the North apron, eventually the passengers terminal.
The First Officer of the Boeing MD-87 Hired by SAS in 1997 with a previous experience of 2400 flying hours of commercial flying activity with other operators and as a flight instructor (Basic flight and IFR) with various flight schools. He had accumulated 2000 flying hours with SAS, on type (MD-87).
The Captain of the Cessna 525A During his long professional pilot experience he totaled 12000 hours of flight, most of them on “executive” aircraft. Around 1991 he had been hired by Air Evex Gmbh Dusseldorf, which operates “executive” (on demand) air transportation. He was qualified as Captain. He was CAT I qualified (RVR visibility down to 550 meters). No records were found of any specific training for operations with lower weather minima (in RVR less than 400 meters).
ANSV 19 Italian regulations require training and qualification criteria as described in DOC 41/23100/m3 of DGAC (now ENAC), since 1997 for low visibility operations (LVO). They are referred to Commercial Air Transport low visibility criteria operations JAR-OPS 1 subpart E and not applicable to private airplanes.
The First Officer of the Cessna 525A He had a flying experience of a total of 4355 flying hours, 1978 hrs on the Cessna 525. His activity is not very well documented since it was developed basically at various private entities. It has not been possible to obtain more specific professional background on his pilot qualification.
2.2.2. Pilots working schedule Pilots pre-accident working schedule, Boeing MD-87 Rest period before duty time start: 9 hours from last flight. Duty time start: 04.50 of October 8, 2001. Pilots pre-accident working schedule, Cessna 525A Rest period before duty time start: 5 days from last flight. Duty time start: 02.30 (presumably) of October 8, 2001.
2.2.3. Analysis of controllers background and professional preparation Supervisor Controller (CSO) The CSO professional record shows that he became a Civil Air traffic controller about twenty years ago after having performed the same duties in the Air Force. He has worked about 27 years at the Control Tower of Milano-Linate. In his record there is no indication of any recurrent training or of any proficiency check taken during the past 20 years.
Assistant controller (Coordinator) The assistant controller has the same professional record as the CSO. He too was qualified as Supervisor. In his record there is no indication of any recurrent training or of any proficiency check taken during the post 20 years.
Ground controller The Ground controller professional record shows that he had initially operated for 18 months as Tower controller at Pantelleria airport (LICG). From April 1998 he had been transferred to Milano-Linate. He last attended a course for Control Tower/Approach Control at Milano-Linate (Nov 22, 1998/Feb 02, 1999)
Tower controller The Tower controller professional record shows that he worked at Milano-Linate Airport during the previous 11 years. He last attended a course for radar aerodrome controller (Feb 05, 2001/Mar 03, 2001).
Reserve Controller His personal professional record shows that he worked as controller at Lamezia airport (LICA) for about 2 years and he was transferred to Milano-Linate in May 1998. He last attended a course for radar aerodrome controller (Mar 12, 2001/Apr 13, 2001).
ANSV 20 2.2.4. Controllers working schedule
Supervisor controller (CSO) Rest period before duty time start: 72 hours. Duty time start: 06.00 of October 8, 2001.
Assistant controller (Coordinator) Rest period before duty time start: 16 hours. Duty time start: 05.00 of October 8, 2001.
Ground controller Rest period before duty time start: 16 hours. Duty time start: 05.00 of October 8, 2001.
Tower controller Rest period before duty time start: 10 hours. Duty time start: 06.00 of October 8, 2001.
Reserve controller Rest period before duty time start: 10 hours. Duty time start: 06.00 of October 8, 2001.
The operational situation on that morning of Oct 8, 2001 was characterised by heavy traffic. Between 04.45 and 05.45, 21 flights were scheduled to depart plus many executives and incoming traffic.
2.2.5. Communications analysis - glossary
The following considerations are made from the human factor standpoint and do not imply a behavioral professional judgment. They only relate to human performance and try to shed light on possible thinking patterns that may have led to pilot/controller understanding and associated specific decisions/actions. The accompanying glossary is specific to this particular chapter.
GND Linate Ground Control TWR Linate Tower Control CVR CVR MD-87 Scandinavian 686 AM MD-87 Scandinavian 686 CVR - Area Microphone LP MD-87 Scandinavian 686 left seat pilot RP MD-87 Scandinavian 686 right seat pilot SK 686 Scandinavian 686 (involved in the accident) AP Air One airplanes radio call sign, followed by flight number AZ Alitalia airplanes radio call sign, followed by flight number BA British Airways airplanes radio call sign, followed by flight number IG Meridiana airplanes radio call sign, followed by flight number OS Austrian airplanes radio call sign, followed by flight number PE Air Europe airplanes radio call sign, followed by flight number SIRIO Sirio (executive) airplanes radio call sign, followed by flight number D-IEVX Cessna C-525A Cessna J2 (involved in the accident)
ANSV 21 I-LUBI Gulfstream departing from General Aviation apron I-DEAS Learjet departing from General Aviation apron LX-PRA Private executive departing from General Aviation apron
Simbology used in analysis
?? Impossible interpretation due to disturbances or other reasons ? Uncertain transmission source; (means a normal question mark when in the transcriptions) ( ) Uncertain transcription [ ] Comments Transmissions between SK 686 and other stations (any SK 686 CVR channel) Go ahead SK 686 pilots conversations or other audible transmissions in the cockpit (CVR Avanti, Ground 121,8 channel and area microphone) Go ahead SK 686 pilots conversations or other audible transmissions in the cockpit (CVR Avanti, TWR 118.1 channel and area microphone) Normal case: actually used language Blue italic case: mutual Italian-English translation Black italic case: English translation from Swedish or Danish (CVR) Part of transcripts in red characters: eminent transmissions segment or events In the following paragraph we shall expand and comment on certain elements contained in the recording and obtained surveying the local environment. These considerations are useful to understand the operational “climate” in which the accident occurred.
2.2.6. Preliminary information
Traffic density The traffic on ground as the communications recordings indicate, from time 05.54.23 (SK 686 startup clearance request) and 06.10.22 (the time of the accident) involves ten aircrafts (5 from North Apron and 5 executives from West Apron). Tower personnel From statements obtained from the persons involved, 5 controllers were on duty: the first on Ground frequency, the second on Tower frequency, the third, a coordinator (seated between the first two), the fourth, a supervisor behind the three already mentioned and one more, a fifth acting as a backup (see attachment G-1, that depicts the positions described). The Ground operator acting as “Delivery” (flight clearances issuance).
2.2.7. Communications analysis
Start of SK 686 taxiing The communications between SK 686 and Ground controller (GND) are performed in a correct way and with calm voice tone.
Ground Control Frequency 5.54.23 SK-686 Ground Scandinavian 686 requests taxiing from Alfa 13 5.54.28 GND Scandinavian 686 taxi to the holding position CAT 3, QNH 1013, and please call me back entering the main taxiway 5.54.37 SK-686 Taxi holding Cat 3, QNH 1013, call you when entering the main taxiway, Scandinavian 686.
ANSV 22 ------SK 686 taxiing Superimposition of SK 686 / Ground communications. The Ground, having had no immediate answer from SK 686 to the 05.57.47 request for position confirmation, further calls at 05.57.53. At the same time SK 686 was answering, and the two stations interfered with each other, mutually preventing listening to each others transmissions. In the next Ground call, at 05.58.04, the tone used, quite peremptory, could indicate the controllers haste to receive the required information in order to maintain the rhythm in managing the aircraft movements on the main apron. In fact, I-LUBI was ready to enter the apron and it could not until SK 686 had left the apron and entered the taxiway.
Frequenza Ground Control Cockpit Voice Recorder 5.57.31 I-LUBI Stop del Romeo 5, INDIA BRAVO INDIA I-LUBI Stop del ROMEO 5 INDIA BRAVO INDIA. Romeo 5 stop, India Bravo India Romeo 5 stop, India Bravo India 5.57.33 GND India Bravo India mantenete un attimo. GND INDIA BRAVO INDIA mantenete un attimo Break. Scandinavian 686 Ground break, Scandinavian 686, Ground India Bravo India hold on a moment. India Bravo India hold on a moment. Break, Scandinavian 686 Ground Break, Scandinavian 686 Ground 5.57.38 SK-686 Go ahead Sir RP Go ahead Sir 5.57.40 GND Your position please GND Your position please 5.57.43 SK-686 We still haven’t reached the main taxiway RP We still haven’t reached the main taxiway Scandinavian 686. Scandinavian 686. 5.57.47 GND Confirm on the main taxiway now Sir? GND Confirm on the main taxiway now Sir? 5.57.49 RP No, we have stand …. 5.57.50 LP? (Thirty six) 5.57.53 GND Sorry Scandinavian 686 could you RP No we are on the stand (thirty). please confirm are you on the main Scandinavian 686. taxiway now? 5.58.03 LP (Now you are on the main taxiway.) 5.58.04 GND Scandi 686, Ground GRD Scandi 686. Ground. 5.58.07 SK-686 Yes now we are entering the main RP Yes now we are entering the main taxiway, taxiway, Scandinavian 686. Scandinavian 686. 5.58.12 GND Thank you Sir, continue, I call you back GND Thank you Sir, continue, I call you back for for the transponder code. the transponder code. 5.58.15 SK-686 Scandinavian 686 RP Scandinavian 686 5.58.16 GND INDIA BRAVO INDIA Continuate sul GND INDIA BRAVO INDIA Continuate sul principale linea Alfa principale linea Alfa India Bravo India continue on the main… India Bravo India continue on the main… line Alfa line Alfa
At 05.58.26 the SK 686’s Captain criticizes the Ground request, from which comment one may suppose that the SK 686 crew felt somewhat uneasy in taxiing in poor visibility conditions without much help.
ANSV 23 Cockpit Voice Recorder 5.58.26 LP He wanted you to say that you were on the taxiway, even if it wasn’t anything ….
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Initial communications between D-IEVX and Ground Control In the meantime, at 05.58.23, Cessna 525A D-IEVX parked in the general aviation apron, has requested start-up clearance. It is probably the co-pilot speaking; he shows some hesitation and makes a mistake in reading back the delivery clearance. Probably he is not acquainted with the area (see attachment G-2). The mistake is perceived and corrected by the controller, and the correction is acknowledged by the pilot:
Ground Control Frequency 5.58.23 D-IEVX Linate buongiorno DELTA INDIA ECHO VICTOR XRAY request start up with information Charlie 5.58.29 GND DELTA …INDIA ECHO VICTOR XRAY… buon giorno please speak a bit louder thank you….. you are cleared to destination via Saronno 5 Alpha, Arles 8 transition, 6000 feet initial climb 5.58.46 D-IEVX DELTA INDIA ECHO VICTOR XRAY is cleared to destination Saronno 5 Alfa, after Argon 8 Alpha departure climb initially 6 thousand … D... VICTOR ….. XRAY 5.58.57 GND Ok Arles 8 Alpha the transition start up is approved according to the slot 06.19 5.59.03 D-IEVX DELTA VICTOR XRAY copied the slot, start up is approved, and confirm Arles 8 Alpha
------SK 686’s frequency change At 05.59.44 SK 686 leaves the Ground frequency and contacts the Tower. No problem in the communication:
Ground Control Frequency Cockpit Voice Recorder 5.59.14 GND Air One 937 buongiorno, slot 061….. 0610 RP (Yes that’s correct) start up in accordance; departure clearance Pikot 5 Alpha, Carpi 8 Alpha, 5000 feet 5.59.27 AP-937 In accordance Pikot 5 A Carpi 8Alpha 5000 AP-937 According to : ?? … 5000 feet Air One 937. feet Air One 937 5.59.32 GND 937 correct, break Scandinavian 686, when GND 937 correct, break Scandinavian 686, when airborne squawk zero triple 4. airborne squawk zero triple 4. 5.59.39 SK-686 zero triple 4 Scandinavian 686. RP zero triple 4 Scandinavian 686. 5.59.42 GND That is correct passing the fire station call GND That is correct passing the fire station call tower 18 1 bye. tower 18 1 bye. 5.59.44 SK-686 Ground Scandinavian 686, bye RP Ground Scandinavian 686, bye ------SK 686’s contact with Tower frequency The communication exchange at the first contact with the Tower is not standard, yet it is effective. The exchanges between the pilots that follow confirm the good understanding of the message. The three aircraft preceding SK 686 shall start take off roll at 06.04.15 (AZ-226), 06.05.40 (AZ-2019), 06.07.35 (AZ-410) respectively:
ANSV 24 Tower Control Frequency Cockpit Voice Recorder 6.01.24 SAS 686 Tower buongiorno Scandinavian 686 RP Tower buongiorno Scandinavian 686 sequence to 36 . sequence to 36R. 6.01.30 TWR ’giorno Scandinavian 686 number 4. TWR ’giorno Scandinavian 686 number 4. 6.01.32 SAS 686 686 RP 686 6.01.34 LP Four (then departure is on time) 6.01.39 RP We don’t know how many landings he has. 6.01.41 LP No
------Taxi clearance to D-IEVX At 6.05.27 D-IEVX requests taxi clearance on Ground frequency. These communications cannot be heard by SK 686, already in contact with the Tower; SK 686 will not have further opportunity to hear any communication between Ground Control and D-IEVX. The taxi clearance given by the controller to D-IEVX is pronounced at the usual speed, but the word “north”, a very short one, in rapid sequence within the verbal string and associated to more important information - such as the taxiway indication, altimeter setting, and the clearance limit - might not be perceived by the pilot who is normally not oriented to refer to instrument readings for taxiing. Instead, it is normal habit for pilots giving an almost exclusive attention to signals and indications outside the cockpit window, such as the marshal’s gestures, tracks and markings on ground (painted or lighted up) and the vertical boards at the taxiways edges. As a matter of fact, the pilot in his read-back omits the word “north”. Possible hypothesis are: 1) he has not mentally elaborated it, 2) he has deemed it insignificant, 3) he has perceived it but has promptly forgotten it, precisely because it appears unimportant in that very moment (perceptual filtering mechanism based on context referred salience of a given information). Moreover, in the read-back the pilot also omits two other important notices: he does not mention the word “stop bar”, and does not repeat the word “extension”, thus reducing the clearance limit read-back to just “call you back before reaching main runway”. Formulated in this way the read-back has the formal and substantial meaning of a clearance to continue towards the take-off runway and call back when approaching it. It is possible that at this moment the pilot had created a mental image of the future taxiing (pre-operative perception phase) based on recent experience at arrival, at roughly 04.59.00, in which he had used the Romeo 6 taxiway to leave the main runway and reach the ATA apron (general aviation parking). The fact that, when landing, the German pilots had requested and were granted a clearance to a short back track on the runway in order to enter R6, may have led to suppose a certain knowledge of the airport configuration (at least on the part of one of the two, likely the captain). The taxiway Romeo-6 is, moreover, the only direct link between the main runway and the general aviation apron (see the airport layout chart in the attachment G-3) and is frequently used, provided the weather conditions and traffic allow this to be done, for aircraft coming from ATA apron bound to holding position for takeoff from main runway. That means crossing the runway itself. Even the AIP (Aeronautical Information Publication) and the Jeppesen documentation say that in CAT-III conditions the aircraft taxiing from ATA will be instructed
ANSV 25 to proceed via R6 up to the Stop Bar (see attachment G-4). One may wonder whether it is a mere misprint or, instead, the said procedure aimed at avoiding traffic congestion on the North apron (commercial aviation apron). Ground controller does not go on talking. This lack of reaction to the incorrect read-back may be attributed to the following hypothesis: 1) the discrepancy between clearance and read-back is not remarked due to superficial listening (diffused attention); 2) the discrepancy is remarked (focalized attention) but extraction of essential data, although formally incorrect, is considered sufficient. Interviews with Air Traffic controllers have revealed a tendency to take for granted the understanding and compliance, on the part of the pilots, with the controllers’ instructions. Should this second hypothesis be the more realistic one, then a contributing factor to the controller’s behavior might have been the possible habit of Linate controllers to deal with executives airplanes’ pilots familiar with the airport maneuvering areas and the relevant procedures for moving around under various visibility conditions.
Ground Control Frequency 6.05.27 D-IEVX Buongiorno DELTA INDIA ECHO VICTOR XRAY general aviation for taxi 6.05.32 Station calling, unreadable 6.05.35 D-IEVX The DELTA INDIA ECHO VICTOR XRAY 6.05.38 GND DELTA INDIA ECHO VICTOR XRAY Ground, confirm you are ready to taxi? 6.05.41 D-IEVX Affermative 6.05.43 GND DELTA VICTOR XRAY taxi North via Romeo 5 QNH 1013 call me back at the STOP BAR of the … main runway extension 6.05.56 D-IEVX Roger via Romeo 5 and 1013 and call you back before reaching main runway
Beside the above considerations, one notices that in communications made in the reviewed time span, the Ground controller seldom confirms whether read-backs are correct or not (acknowledgement). The OS 222 as well, might have noticed this, as after reading back the clearance just received from Ground at 06.00.52, explicitly asks for an acknowledgment of having correctly repeated it. (OS 222 communications are not included in this document). ------
Initial D-IEVX taxiing There are no communication between Ground and D-IEVX during initial taxiing and exiting from the general aviation apron. There are reasons to believe that D-IEVX left its parking position turning left, roughly 150¡ in direction, following as prescribed the straight part and then the 90¡ left turn of the yellow stripe painted on the apron pavement. During this travel it was “heard” (more than seen, because the dense fog) passing before the ATA hangar by two witnesses who were working inside it, with the sliding doors partially open. The reasons for the path followed afterward are also analyzed in another part of this report, as they are outside the context of verbal communications. Here we limit ourselves to observe aspects of the information available in iconic shape by the signals and documentations to which the pilots were able to resort. - The map of the taxiing tracks in the ATA apron published in the Linate layout plate (Jeppsen 20-9B derived from AIP) available to pilots did not correspond to the actual state of the taxiing lines on the ground (see attachments G-5 and G-6 to compare the published map and the real situation).
ANSV 26 - The yellow lines on the pavement were rather deteriorated and partially cancelled with black paint. The same black paint covered some segments of the old track that had been changed totally. - The low visibility conditions forced the D-IEVX pilots to concentrate on external visual references in order not to lose sight of the yellow line on ground. - The cut-out angle downwards from the left seat in the cockpit - where presumably the pilot taxiing was seated, allows observing the ground, in the direction of motion of the Cessna only beyond 8 meters from the observer’s point (see attachment G-7); due to dense fog, the ground segment visible by the pilot, ranges from the said 8 meters to approximately 30 meters of estimated visibility, therefore for a total of about 20-25 meters, or a running time of roughly 5 to 6 seconds at taxi speed (presumably very moderate at that moment) of 6-8 Kts (11-14 Km/h, equal to 4 m/sec circa). This leaves the pilots with approximately 5 to 6 seconds to interpret and follow the guide-tracks on ground. - The marks (alpha-numeric) meant to discriminate R5 and R6 leading tracks, painted on the pavement adjacent to the decision point at parting tracks, were rather worn out and written in “broken” digits and letters (not in conformity with ICAO, Annex 14). (See attachment G-8). - The taxi lights of taxiway R6 were lit, and could be seen well beyond the visual range within which the leading line painted markings were visible; this may have generated a conviction to be on the authorized path. It should be considered that at almost all airports green taxiway centerline lights unequivocally authorizes its use.
Communications between Ground and other aircrafts after the Cessna D-IEVX was cleared to taxi. About 7 seconds after the D-IEVX read-back, more communications take place between Ground and other executive aircraft parked on the same apron as D-IEVX (or is leaving) The clearance delivered to the aircraft marks LX-PRA is totally similar to the one given to Cessna D-IEVX, but the whole conversation is in Italian; this precludes any doubt to rise in the German crew, as they do not understand Italian. It is worth noticing that these communications take place in a time span of about 40 seconds from the last D-IEVX read-back, a period during which it was presumably at a point on the apron from which it might perhaps had followed the right taxiing direction provided the German pilots had an opportunity to compare their clearance with that given to the other plane:
Ground Control Frequency 6.06.10 LX-PRA LIMA ROMEO ALFA, buondì la messa per Firenze dall’ATA LIMA ROMEO ALFA, good morning the start up to Florence…from ATA 6.06.13 GND LIMA ROMEO ALFA buongiorno la messa vi è stata approvata ai 55 riportate pronti a muovere LIMA ROMEO ALFA buongiorno the start up was approved at 55 report ready to taxi 6.06.19 LX-PRA Scusate pronti a muovere ROMEO ALFA Sorry ready to taxi ROMEO ALFA 6.06.22 GND OK ROMEO ALFA rullate Nord Romeo 5 QNH 1013, vi dovete accodare ad un Citation … marche … DELTA INDIA ECHO VICTOR XRAY che sta rullando anche lui sul Romeo 5, ovviamente non è in vista, e come limite di autorizzazione avete le STOP BAR dell’estensione pista principale sul Romeo 5 OK ROMEO ALFA taxi North Romeo 5 QNH 1013, you have to follow a Citation … call sign … DELTA INDIA ECHO VICTOR XRAY taxing on Romeo 5, obviously it is not in sight, and as clearance limit you have the STOP BAR before main runway extension. 6.06.42 LX-PRA Seguiamo il tedesco e lo stop del….. sul Romeo 5, ROMEO ALFA We’ll follow the German the stop….on Romeo 5, ROMEO ALFA
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ANSV 27 SK 686’s taxiing to holding position “CAT I” (final holding point before entering the takeoff runway). In the meantime, SK 686 is cleared to continue taxiing, 13 seconds after AZ-410 takeoff:
Tower Cockpit Voice Recorder 6.05.59 TWR Scandinavian 686 you can continue taxi Scandinavian 686 you can continue taxi until until Cat 1. Cat 1. 6.06.04 SAS 686 Continue taxi until Cat 1. Scandinavian 686. RP Continue taxi until Cat 1. Scandinavian 686. TWR BRAVO INDIA manterrà, raggiungerà le TWR BRAVO INDIA manterrà, raggiungerà le barre di CAT 3 libere dall’MD-80 barre di CAT 3 libere dall’MD-80 Scandinavian Scandinavian davanti davanti BRAVO INDIA will maintain, will reach the BRAVO INDIA will maintain, will reach the CAT 3 bars clear from the MD-80 CAT 3 bars clear from the MD-80 Scandinavian ahead Scandinavian ahead
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Conversation between the SK 686 pilots during taxi The talks between the Scandinavian pilots denote a relaxed, quiet climate; they make some sarcastic remarks about something regarding (possibly) other plane taxiing:
Cockpit Voice Recorder 6.06.16 RP Bara kör du in där. Just go in there. 6.06.18 LP Ja Yes. 6.06.21 LP {xxxxxxx) [in italian] [laughing]} 6.06.27 LP Han hade sin privata Cat 3 holding. He had his private Cat 3 holding 6.06.29 RP Ja precis. Yes exactly!. 6.06.31 RP Där är en (vindhose) There is a (windsock) 6.06.34 LP? (Upp och ner!) (Up and down? or Upside-down?)
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Line-up clearance to SK 686 3 seconds after the start of the AZ-410 takeoff roll, SK 686 is cleared to enter the main runway 36R
Tower Control Frequency Cockpit Voice Recorder 6.07.41 TWR Scandinavian 686 line UP and wait 36 right. TWR Scandinavian 686 line UP and wait 36 right. 6.07.46 SK-686 Line up and wait 36 right, Scandinavian RP Line up and wait 36 right, Scandinavian 686. 686 [Sound from aircraft taking off can be heard] ..
ANSV 28 ------
Communications between D-IEVX and Ground At 06.08.23 D-IEVX notifies Ground controller of its position “approaching Sierra 4”, obviously inferred by the yellow mark on the R6 taxiway’s pavement - observed reversed by the D-IEVX pilots - painted near the transverse stripes, yellow as well, indicating a stop position for airplanes coming from the main runway, i.e. in the opposite direction to the D- IEVX. (See attachment G-9). It must be remembered that the German pilots had landed that very morning, approximately at 04.59, and had cleared the main runway on Romeo 6 after a short backtrack on the runway. This leads one to suppose that they were aware of their position, except that they probably ignored that the taxiway they were using was not the one they had been cleared to. From the strongly interrogative inflexion of the Ground controller’s voice in replying to D- IEVX communication, one can suppose that the information received was scarcely understandable for him (maybe “Sierra 4” did not conform to his mental image of the presumed D-IEVX position); nor the information “approaching the runway” may have appeared consistent to him. It seems evident, also in the light of further communications even after the accident, that the controller remained persuaded that D-IEVX was taxiing on taxiway R5, as it had been cleared to. In a case like this it is hardly possible for information likely to contradict a deep-seated mental image to “pass through” and bring about its correction. This phenomenon, affecting the human cognitive activity, is well known as “confirmation bias” and can be encountered in practically all the mishaps, incidents, accidents where data regarding the reality, even if extremely compelling ones, are unable to surpass the threshold of resistance to change the situation’s subjective perception. Stopping the airplanes taxiing on R6 at S4 and S5 positions is necessary in case of flight activity on the 36L/18R runway (the “turistica”). But according to interviewed general aviation pilots, the phraseology currently used is “hold before the ‘turistica’ extension”, or similar wordings; “Sierra 4” and “Sierra 5” are never cited. This may be one reason for the controller’s difficulties in understanding what the D-IEVX pilot meant by “Sierra 4”, and his concentration on this point might have driven his attention away from the much more important information “approaching the runway”. Moreover, as it can be seen from the following transcripts table, at the time precisely coincident with the Ground communication in question, the Tower operator, seated very near the Ground controller, was managing the communications with AZ-410 just airborne, therefore being unable to listen to what was being said at the Ground console position. One may wonder whether the co-coordinator, being seated between the two controllers, was able to pay attention to the Ground communications and, if so, he too incurred in the (presumed) incomprehension about the actual position of D-IEVX. However, the coordinator’s task is to support the two radio operators should they need to link with some external bodies (and provide the assistance required), rather than supervise or co-ordinate their actions. The Ground controller instructs D-IEVX to maintain the Stop bar position: “DELTA … VICTOR .. XRAY roger, maintain the Stop bar, I’ll call you back”. It should be said that the expression “maintain …” followed by an indication of position, altitude, heading etc., contains by itself a certain level of ambiguity. In fact, whereas in the U.S. it has the clear meaning of “remain in the given position if you are already there, or reach it and maintain it when reached”, in Europe it does not enjoy a similar meaning contemplating the above described alternative (maintain…or reach and maintain). All this taken into account, various hypotheses can be put forward: 1) The controller supposes that D-IEVX is in fact already at the Romeo 5 Stop bar position
ANSV 29 (the one he has authorized) or is approaching that position - albeit defined in an improper way - and does not notice the statement “approaching the runway”, or supposes it to be a lapse, ascribing this to the German pilot’s intention to say “apron” instead of “runway” (cognitive arbitrarity of this kind allow the percipient to maintain consistent his/her mental scenario). 2) The controller cannot clearly understand at which point of Romeo 5 the D-IEVX is, and, unable to solve this doubt, he gives an instruction apt to certainly safeguard safety (stop before the signal protecting active areas). In this case the psychological support is provided by the “completion bias”, satisfying the need to put an end, in the shortest possible time, to an ambiguous situation by making recourse to the first “satisfying” solution (strong but wrong hypothesis). 3) The controller has understood the actual position of D-IEVX and instructs it, at any rate, not to proceed beyond the Stop bar lights (a hypothesis difficult to agree with, in the light of what happened next; in this case, in fact, it would mean that a few minutes later he would have forgotten it). On the other hand, an aerodrome map indicating the general aviation apron and the taxiways west of the main runway was not readily available in the Control Tower. Only under the glass covering the supervisor’s desk, behind the active controllers and not visible by them, an aerodrome map was to be found, and this did not contain the indications regarding the existing markings on the R5 and R6 taxiways. Regarding the D-IEVX pilots, one can assume they felt quite certain of being on the taxiway leading to the main runway, but having not certainty about its designation. Among the hypothesis that can be put forward about the German pilots’ perception at that moment, one is that, having in the first place received a clearance to proceed up to the Stop bar (of Romeo 5), the successive passage of marks S5 and then S4 might have given them some doubt, and that precisely for this reason their position notification was actually an implicit request of confirmation that their path was correct. It is also possible, however, that they had read the signs “S” as an alphabetical sequence “R-S-T …” for the taxiway segmentation. It can however be considered almost certain that they were aware of their position in relation to the 36R/18L main runway, as they have explicitly declared.
Ground Control Frequency Tower Control Frequency 6.08.23 D-IEVX DELTA .. INDIA ECHO VICTOR XRAY is approaching Sierra 4 6.08.28 GND Ehmm … DELTA INDIA ECHO VICTOR XRAY confirm your position ???? 6.08.31 D-IEVX Approaching the runway, … TWR Alitalia 410, airborne 08, identified, squawk Sierra 4 ident, and contact Milano on 126.75 buongjorno. 6.08.35 GND DELTA … VICTOR .. XRAY roger, maintain the STOP BAR, I’ll call you back 6.08.40 D-IEVX Roger, … hold position [this part could AZ-410 IDENT 126.75 Alitalia 410, buongiorno be the other pilot answering]
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Ground’s clearance to D-IEVX for continuing taxi, and Tower’s takeoff clearance to SK 686 At 06.09.19 D-IEVX is cleared to continue taxiing. There is no absolute certainty about D-IEVX position on the Romeo 6 taxiway (it must however be comprised between the S4 point and the Stop bar) at the time of communication.
ANSV 30 However, calculating the distance from S4 to Stop bar to about 225 meters, which is nearly the same as the distance from Stop bar to the collision point, the average speed in the whole 450 meters, covered in a total of 1 minute and 41 seconds was approximately 8,6 Kts (16 Km/h), compatible with the low visibility conditions at the time. Assuming the plane maintained a roughly constant speed, it can be inferred that at the moment of receiving the clearance to continue beyond the Stop bar, D-IEVX had arrived in its vicinity or, at least in sight of it. If the D-IEVX communication at 06.08.40 (“holding position”) is interpreted as an actual stop at position S4 until a further clearance delivery, then the speed at approaching and entering the runway should have been higher than 16 Kts (more than 30 Km/h), very unlikely with the visibility at that moment. It is however certain that the D-IEVX pilots saw the Stop bar light and the green taxi lights to runway centerline lights. From the Ground communication it is now perfectly evident that the controller’s conviction that D-IEVX was, on the contrary, at the Stop bar lights of the Romeo 5 taxiway (see attachment G-10); if ever a doubt existed, caused by the previous communication (S4), it has by now been fully removed by the course of events and by the diffuse - and already cited - psychological “confirmation bias” of a mental image persisting in spite of information that contradicts it. On the other hand, the Cessna pilot answers correctly reading back the clearance, thus implicitly confirming the controller’s image of reality. Now, however, it is the pilots who seem not to notice the inconsistency of the clearance with their actual position. The hypotheses may be: 1) Superficial listening and stereotyped answer, formally correct yet not significantly linked to reality, denoting the extraction of the sole information perceived as significant: “continue your taxi”. 2) Conviction that by crossing the runway they would arrive at the main parking apron south end. It is possible that, at that moment, they have not consulted the aerodrome chart due to lack of perceived alternatives; in any case from the map one deduces that Romeo 2 (almost opposite to Romeo 6) ends near the southernmost part of the main apron. 3) Immediate replay, typical of dense traffic situations, with the intention to clear up any possible doubt regarding the “Alpha line” later on, once the main runway had been crossed, in his mind the most critical and urgent task to accomplish to comply with the clearance. As a part of the pilots’ mental set and training, the habit of rapidly dealing with the action perceived as requiring higher priority while verifying the immediate action outcome as compared with the prime target, and so postponing the assessment of future needs. 4) Ascribing to controller’s lapse the use of the words “main apron” instead of “main taxiway”. Here too, we find the already mentioned psychological mechanism that censures and denies any contradictory cue, however massive, in the framework of a general “exclusive goal orientation” rooted in a cluster of falsely consistent data. As absurd as it may appear, such a mental attitude can be encountered in nearly all the incidents/accidents in which the “human factor” played an important contributing role. As for the “Alpha line”, which by the way is not indicated in the AIP but only on the Jeppesen 20-9B map (see attachment G-11) where it only identifies the main taxiway centerline, the pilots could expect to identify it after crossing the runway. Moreover the next instruction to “call me back entering the main taxiway” may have fixed in the German pilots’ mind the idea of a fast crossing of the active runway so as to reach, in fact, the Alpha line on the main taxiway. On the other hand, the clearance to cross the Stop bar red lights, and the presence of lit green guide lights along the taxiway beyond the transverse red ones, were all elements that let no space for doubts. As can be seen from the following table, SK 686 was at the same time receiving its takeoff clearance on Tower frequency; the D-IEVX pilots were unable to listen this clearance as they were still in contact with the Ground control, while the SK 686 pilots could not hear the communication being exchanged between Ground and D-IEVX. Communications that
ANSV 31 however would have not alerted, probably, a crew already cleared for takeoff and unaware about the situation of taxiing traffic.
Ground Control Frequency Tower Control Frequency 66.09.19 GND DELTA VICTOR XRAY continue your taxi IG-683 Linate buongiorno dalla Meridiana … 683 on the main apron follow the Alpha line 6.09.25 TWR Meridiana 683 buongiorno, un attimo in ascolto; break, break, Scandinavian 686, Linate, cleared for takeoff 36. The wind is calm, report rolling, when airborne squawk ident. 6.09.28 D-IEVX Roger continue taxi main apron, Alfa line the DELTA VICTOR XRAY 6.09.32 GND That’s correct and please call me back entering the main taxiway 6.09.37 D-IEVX Will call you on the main taxiway SK-686 Cleared for takeoff 36 set, when airborne squawk ident, and we are rolling Scandinavian 686
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Communications prior to collision Immediately following the previous D-IEVX communication, Ground frequency is occupied by other transmissions for nearly 10 seconds and then busy again after 10 seconds of silence. It is therefore possible to hypothesize that D-IEVX had no opportunity - if ever meant to - of asking for further clarification before leaving its holding position. Moreover, between approximately 06.10.06 and 06.10.15 (i.e. during the 9 seconds circa of the SK 686 takeoff roll) the Ground and Tower controllers were both simultaneously committed, each on his own frequency, in speaking with other aircrafts, and therefore unable to carry on the usual, reciprocal monitoring of the situation. Among other considerations, it should be noted that the Tower controller, who was replying to a request by a Meridiana flight concerning the visibility, had presumably to consult the RVR monitor, and also had to repeat the digits as the crew had read them back incorrectly. These meticulous remarks try to illustrate a situation in which the operation was considered fully normal in the Tower and such as not to alert a particular attention even on the part of the co- coordinator, seated between the two controllers.
At 06.10.21 SK 686 and D-IEVX collide at a position on the runway centerline corresponding roughly to the taxiway R6 intersection. An ELT signal activates (emergency signaling equipment, installed in the SAS aircraft); the signal, audible on the emergency frequency 121.5 is recorded both on Ground and on Tower channels, and on the SK 686 CVR. It should also be heard in the Tower room, since the passive listening of that frequency is continuously carried out in the ATC centers, even if the volume is set to minimum. Of course, hearing a signal does not guarantee that its significance be perceived, due to various reasons such as its sudden transmission, or, on the contrary, being used to hear it when testing the radio systems, as it is usually done in the first 5 minutes of each hour, or it being interpreted as an anomalous disturbance.
At 06.10.33 (12 seconds after the collision, taking into account the tenths of seconds not shown in the table) a call attempt probably on the part of SK 686 is recorded, audible on the Tower frequency. Very likely this call preceded the MD-87’s impact with the hangar.
ANSV 32 From the immediately successive communications it can be seen that the Ground controller has no (conscious) perception at all of what has happened, at least until 06.10.48 when he replies to a request from I-LUBI about the D-IEVX position, “E' sul piazzale principale” (“He is on the main apron”). This last communication, made with no trace of hesitation, definitely demonstrates that the Ground controller is - and probably has been all the time - persuaded that D-IEVX had taxied on taxiway Romeo 5.
Ground Control Frequency Tower Control Frequency Cockpit Voice Recorder 6.09.40 AP-937 È sulla via principale la e 937………..151 per la SIRIO messa (comunicazione 051 sovrapposta) It is on main way the 937 Sirio 051 for start (double communication) 6.09.44 TWR Roger TWR Roger. 6.09.45 GND Air One 937 grazie TWR INDIA BRAVO INDIA TWR INDIA BRAVO INDIA continui, il codice allineamento e attesa in LP (…) (…Compasses trasponder è 4611 sequenza dopo il decollo checked, true) auto throttle on, set thrust Air One 937 thank you INDIA BRAVO INDIA line continue, the code is up and wait in sequenze 4611 after the takeoff … 6.09.47 [Sound from rolling]
6.09.49 I-LUBI Punto attesa in sequenza I-LUBI Punto attesa in sequenza dopo il decollo, INDIA dopo il decollo, INDIA BRAVO INDIA BRAVO INDIA Holding point in sequence Holding point in sequence after the takeoff, INDIA after the takeoff, INDIA BRAVO INDIA BRAVO INDIA 6.09.51 TWR Il Meridiana che stava TWR Il Meridiana che stava chiamando avanti chiamando avanti Meridiana calling, go Meridiana calling, go ahead ahead 6.09.53 IG-683 Sì, la Meridiana 893, IG-683 Sì, la Meridiana 893, volevamo gentilmente volevamo gentilmente sapere la RVR sapere la RVR Yes, Meridiana 893, we Yes, Meridiana 893, we wish know the RVR, wish know the RVR, please please 6.09.54 AP-937 4611 la 937 4611 the 937 6.09.56 GND È corretto passando i RP (Set thrust, instruments pompieri contatti la Torre are checked ….. and 118.1 buongiorno 130). Is correct passing the fire station contact Tower 118.1 good morning
ANSV 33 6.09.58 TWR Sì, al momento abbiamo TWR Sì, al momento abbiamo 225-200-175, Alfa Bravo 225-200-175, Alfa Bravo Charlie rispettivamente Charlie rispettivamente Yes, we have now 225- Yes, we have now 225- 200-175, Alfa Bravo 200-175, Alfa Bravo Charlie respectively Charlie respectively 6.10.03 AP-937 Passando I pompieri LP (130 checked) [Concealed 118.1. con la Torre by radio traffic]. buongiorno Air One 937 Passing the fire station 118.1 with the Tower good morning Air One 937 6.10.06 SIRIO Ground buongiorno è la IG-683 200-165-175, 893 a tra IG-683 200-165-175, 893 a tra 0051 Sirio 0051 per la poco poco messa…. Parigi Le 200-165-175, 893, in a 200-165-175, 893, in a Bourget short time short time Ground good morning is Sirio 0051 for the start up… Parigi Le Bourget 6.10.11 GND 0051 buongiorno, messa TWR Eeeh, ….. sì …. 225-200- TWR Eeeh, ….. sì …. 225- in moto approvata in 175, a tra poco 200-175, a tra poco accordo allo slot 0627 a Eeeh, ….. yes …. 225- Eeeh, ….. yes …. 225- destinazione Saronno 5 200-175, shortly 200-175, shortly Alfa Ometo 8 Alfa, 6000 piedi la salita iniziale 0051 good morning, start up approved in accord the slot 0627 destination Saronno 5 Alpha, Ometo 8 Alpha, 6000 feet the initial climb 6.10.14 AM RP Veee one 6.10.16 IG-683 Ricevuto IG-683 Ricevuto IG 683 Received AM RP Rotate [4.8 seconds before impact]. 6.10.19 AM [Clicking noise from nose wheel lift off, vibration noise from nose wheel and instrument fan spinning down. Sound from runway decreasing] 6.10.20 RP? (Va sat.. !?) [Callout starting 0,5 seconds before impact.]
ANSV 34 6.10.21 [Si sente il segnale di [Si sente il segnale di AM [Heavy noise from un trasmettitore di emergenza ELT in impact, heard on all emergenza ELT (si trasmissione] CVR tracks. Time from attiva in caso di crash). [Emergency ELT signal start of impact to end Presumibilmente tale can be heard of recording is 0.65 segnale proviene dallo transmitting] seconds. SK-686 Sound from ELT, heard (l’analisi del suono on all tracks last except dell’ELT e la sua Service Interphone, registrazione nel CVR during last 0.2 al momento dell’im- seconds.] patto lo confermano)] [Emergency ELT signal can be heard transmitting. Likely to originate from SK-686 (Sound analysis and its record on CVR confirms it)] 6.10.27 SIRIO Con la Saronno 5 Alfa, 0051 l’Ometo 8 Alfa, 6000 iniziali per la 0051 With the Saronno 5 Alpha, the Ometo 8 Alpha, 6000 initial for the 0051 6.10.32 GND È corretto It is correct 6.10.33 SK-686 (…) [incomprehensible SK-686 (…) [incomprehensible instantaneous call] instantaneous call] 6.10.34 I-DEAS INDIA ALFA SIERRA AZ-2021 Buongiorno torre, Alitalia pronto a rullare dall’ATA 20 21, abbiamo appena INDIA ALFA SIERRA oltrepassato i pompieri, ready to taxi from ATA … la stazione dei pompieri Good morning Tower, Alitalia 20 21, we just went beyond the firemen, … the fire brigade station 6.10.38 GND INDIA ALFA SIERRA un attimo solo, break, LIMA ROMEO ALFA confer- mate che siete sul [Tower Control operator Romeo 5? changes] INDIAALFA SIERRA, just a moment. Break, LIMA ROMEO ALFA confirm you are on Romeo 5?
ANSV 35 6.10.40 TWR Buongiorno 20 21, riporti alle barre di terza categoria Good morning 20 21, report at the third Category bars 6.10.43 LX-PRA Stiamo aspettando di AZ-2021 Riporteremo alle barre di uscire… di vedere uscire terza categoria, Alitalia il tedesco, noi non 2021 l’abbiamo visto; voi Will report at the third sapete dov’è? Category bars We are waiting to exit ….. to see the German going out, we did not see him; do you now were is he? 6.10.48 GND È sul piazzale principale, direi che potete andare He is on the main apron, I think you can go 6.10.51 LX-PRA Direi di si, grazie, muoviamo I would say so, tanks, we move
------2.2.8. Pilots human factor Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication. 2.2.9. ATC personnel human factor Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication. 2.2.10. After impact other personnel human factor Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
2.3. TECHNICAL FACTORS
2.3.1. Aircrafts documentation The Boeing MD-87, registration marks SE-DMA, was delivered new to SAS on September 21, 1991 and had accumulated 25.573 flight hours. The complete technical documentation is kept by SAS and maintenance has been performed according to regulations under Swedish Authority control. There are no indications available that the aircraft was not perfectly efficient.
ANSV 36 The Cessna 525A, registration marks D-IEVX, was delivered new three moths before and, FAA Certificated for Airworthiness on August 7, 2001 for its transfer to Europe. Subsequently Airworthiness Certification was also granted by LBA (the German Certification Authority) on September 5, 2001. At the moment of the accident the aircraft had totaled 28 flight hours. There are no indications available that the aircraft was not perfectly efficient.
2.3.2. Radio equipment
The quality of the air-to-ground radio communications involving the two aircrafts (Control Tower recorded messages), have been satisfactory and do not indicate that the minor misunderstanding and subsequent necessary repetitions were due to technical malfunctions. However, findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the final report publication.
2.4. ENVIRONMENTAL FACTORS
2.4.1. Weather conditions A number of METAR published by Milano-Linate weather station were analysed; 61 of them covering the period between Oct 7, 2001 00:20 and Oct 8, 2001 06:20. (See attachment C). On Oct 7, 2001 the general weather was that of a cold front situation moving slowly north- easterly.
Light winds are recorded, with ground temperatures ranging from +17¡C to +19¡C. Difference between temperature and due point was consistently 1¡C, with the exception of seven messages when it was 2¡C.
Until 20:50 on Oct 7, visibility ranged from a minimum of 1800 meter and a maximum of 3500 meters, up to 01:50 of Oct 8 when mist started to appear (02:20ÐMIFG) and then shallow fog (03:20-BCFG) and then fog (04:50-FG).
Barometric pressure has been close to standard ranging from 1010 to 1013 hectopascal. The last four bulletins read 1013.
The ATIS of Oct 08, 2001 (see attachment C) at 05:50 UTC (Information Charlie) reported: “Information ‘C’. Wind Variable 1 kt, Visibility 050 meters, Present weather fog, overcast 100 feet, Temperatures 17/16, 1013, NOSIG. Runway in use 36R. Thunderstorm activity forecast between Saronno, Malpensa, Codogno, Voghera, Saronno, Top of CB 7500 meters, moderate to severe turbulence. ATC CATIII procedure in operation. Report to Milano Arrival category of approach.”
The thunderstorm forecast was not consistent with the actual weather conditions of that morning and/or the message was not updated.
The TAF issued by the Milano Linate meteorological office with validity at 00:00 of Oct 08 through 18:00 of the same day, reported fog forecast with visibility values of 300 meters. The TAF issued with validity 06:00 confirmed the same fog forecast.
ANSV 37 2.4.2. Airport layout
Following World War II, Linate airport was adequate for handling the air traffic volume at that time. The ground movement of commercial aviation and general aviation was handled using the two runways: 36R/18L and 36L/18R. In the mid-sixties the section of taxiway R6 that joins the threshold of runway 36L used primarily by general aviation (so called “Turistica”) with runway 36R/18L (“the Main runway”) did not exist. (See attachment E). Later on taxiway (intersection) R6 was built and became usable.
Ground traffic (taxi) of general aviation was handled separately using the West apron, taxiway R5/R6 and runway 36L/18R. Commercial aviation aircraft used Runway 36R/18L, the Main taxiway (parallel to runway 36R/18L) and the North apron. The nature of the traffic and the absence of heavy traffic congestion provided for easy handling of airplanes using the two areas at the same time. A high percentage of the traffic volume was local, regional or national. Over the time, this created a culture of familiarity between the local Air Traffic controllers and the pilots operating at Linate airport. Over the time however, the performance of aircraft used by general aviation became similar to that of commercial aviation and frequently required the use of runway 36R/18L, particularly as light aircraft became IFR equipped (and subsequently CAT I, CAT II/III capable). Nowadays the number of aircrafts able to use runway 36L/18R is very limited due to its length and physical state. Changes and adaptation of operational requirements to meet the new needs of general aviation happened over a long period of time and often with some delay. It is believed that the use of Linate airport by general aviation has evolved and changed from local/regional/national to international. Airport Authorities (and other responsible bodies in general) have not taken adequate action to conform to these new operational needs or did so in a limited way. Airport visual aids (Markings and Signs) positioned on the North Apron and along the Main taxiway and runway 36R/18L only partially conform to ICAO standards. Those used in the West apron, runway 36L/18R and taxiways R5 and R6 have not been updated and lack maintenance and are not consistent with ICAO requirements. Retracing the Cessna 525A movements after it received taxi clearance from Ground Control, and a study of the airport area as it was on the morning of October 8, 2001, provides the following evidence: - yellow taxi lines that the aircraft follow when leaving their parking positions are sufficiently visible but do not indicate the parking specific number; - horinzontal markings on the airport pavement of intersections R5 and R6 are not ICAO standard and their interpretation is not clear; - they are partially worn and are positioned on a slanted angle from the pilots’ viewpoint; - the painted numbers could be easily misinterpreted; - vertical signs with R6 markings do not exist (only one CAT III sign is present); - near the runway 18R extension (overrun) area there are two horizontal signs: S5 and S4 together with holding-position markings pattern “B”. These markings are not shown on AIP nor at Jeppesen charts;
ANSV 38 - before the intersection with runway 36R/18L, there is a white “STOP” marking on the tarmac followed by a yellow holding-position marking (pattern “A”), then a unidirectional Stop bar with lighted red lights (ON) (non-controllable) and finally, to the left of that Stop bar a vertical sign (capable of illumination, with white characters on orange background) signalling CAT III; - taxiway R6, from the West Apron to its intersection with runway 36R/18L and beyond towards the runway centreline, is marked by a yellow centreline and green lights; - Stop bars red lights are not controllable by ATC. That is a deviation from ICAO Annex 14 and Doc. 4444 that state: “StopBars shall be switched on to indicate that all traffic shall stop and switched off to indicate that traffic may proceed.” This situation resulted in that aircrafts from West apron regularly had to cross Stop bars illuminated in red (at R5 and R6); - the centreline green lights of taxiways are not divided in sectors and controllable by ATC: they are either all on or all off; - at the Stop Bar of taxiway R6 there had been an associated anti invasion sensors system, deactivated in 1998.
2.4.3. Airport charts and maps
All charts and maps under scrutiny, AIP and Jeppesen, are those valid the day of the accident. The documentation present in the AIP manual regarding Milano Linate Airport available on October 8, 2001 contained the following charts: - Aerodrome Chart ICAO, AGA 2-25.5 dated February 25, 1999. - Aircraft Parking/Docking Chart AGA 2-25.7 dated January 29, 1998. - Provisions for general aviation aircrafts AGA 2-25.3 dated April 22, 1999 (see attachment A). When comparing the information published in these manuals and the actual situation on the ground at the airport, we find that some of the markings on the ground could have been misunderstood; some of the signs and markings were not present and some of the requirements were not complied with. The following are instructions issued for special procedures to be applied during Low Visibility Operations (low visibility conditions). “Aircrafts from and to Linate West (A.T.A.) will be stopped by the Tower at the “STOP” sign on TWY R6. TWYL R2 and R3 shall not be used. Aircraft landed on RWY 36R in CAT III conditions will report runway vacated to the Tower and will exit at TWYL R1-R6 as soon as they have passed the white flashing lights located by the TWYL edges. In accordance with DGAC provisions N.42/1693/A3/4.1 dated Nov, 5 1997, all aircrafts before taxing on the part of TWYL R5 located along the extension of RCL RWY 36R, must request and obtain specific clearance from the ATC”. They clearly indicate that during Low Visibility Operations, aircrafts taxiing to and from West apron must hold at the Stop marking located on taxiway R6. These instructions could also be interpreted as an obligation for all aircraft to strictly follow taxiway R6. Instructions could also be interpreted that following taxiway R6 aircrafts should taxi back- track on 36R. The note that forbids the use of taxiways R2 and R3 is self-explanatory; this could be interpreted as an obligation for departing traffic taxiing from West apron (via R6) to backtrack south on 36R/18L in order to reach their line up position (not to interfere with other traffic using the taxiway parallel to the same runway). There are two possible interpretations of this part of the taxiing procedure:
ANSV 39 - during low visibility conditions, only taxiway R6 should be used. - during low visibility conditions both R5 and R6 can be used. Other instructions are published, including the presence of a Stop marking along TWYL R6 but make no mention as of its precise location; and more as mentioned already: “Aircraft landing during CAT III operations on RWY 36R shall report runway vacated to the Tower using TWY R1-R6 as soon as they have passed the flashing white lights located on the edges of TWYL”. On R1 and R6 intersection the “white flashing lights” were not installed.
Aircraft Parking and Docking Chart shows the two areas used for parking (West apron and North apron). It also shows intersections R1, R2, R3, R4, R5 and R6 and the parking numbers of the North and West aprons. The aerodrome chart does not show the names of the taxiways within the parking areas or the name of the Main taxiway. There is no mention in the AIP of any markings or signs that are actually located on taxiway R6 (specifically S5 and S4 markings); their existence (S5 and S4 markings) was only reported in a document stored in the TWR/Ground facility but (found to be) unavailable to controllers. In 1996, use of some of the parking bays on West apron for commercial aviation was envisaged, as Air Traffic had substantially increased. A meeting was held on March 13, 1996; DCA, ENAV, SEA and ATA formed a committee that recommended that certain measures be taken. The report submitted mentions an agreement for the use of the parking area on the West apron area by 3rd level aircrafts (ATR type) and narrow body aircrafts (aircraft with a corridor dividing two symmetrical groups of seats). The report also mentions the need to create new markings and signs for ground movement. Some of these recommendations have been implemented and are published on AIP aerodrome charts (parking positions from 51 to 56 and realignment of the centre taxiway of the West apron). Other markings and signs were added but the AIP did not show their location at that time. These markings and signs are: - intermediate holding position on intersection R5 and R6; and - markings S1, S2, S3, S4, S5. It was also recommended that other markings and signs be added, but these were never implemented. Namely signs showing runway 36L length at taxiway R6 intersection and a traffic light to direct the Italian Air Force ground movement on taxiway R5. A copy of the report that refers to the implementation of this project and the airport chart depicting the location of these new markings and signs was available in a folder in the Control Tower. The use of these parking positions lasted for a short time. In that report the need to move one of the parking positions is mentioned because it was located too close to a gas station. (The request had been forwarded by the Milan Fire Department Provincial Authority). AIP does not mention the existence or the location of the gas station on the West Apron. Jeppesen is an international company that produces aerodrome charts contained in Route Manuals, based on source information acquired from different nations, and other equipment used in aviation. It was recently bought by the Boeing Company. Jeppesen aeronautical publications are used by many Italian and foreign airlines operators. According to JAA directives operators must ensure that the following is abided: (JAR OPS 1.1040) states: an operator must ensure that the information taken from approved documents, and any amendment of such approved documentation, is correctly reflected in the Operations Manual and that the Operations Manual contains no information contrary to any approved manual.
ANSV 40 The Jeppesen Route Manual, the charts used by the Cessna 525A D-IEVX crew at Milano Linate airport on October 8th, 2001, contained information taken from AIP with few minor differences: - On the parking/docking chart (Plate 20-9B dated June 2001) the Main Taxiway that runs parallel and close to runway 36R/18L is called taxiway “A” for a brief (initial portion, from north to south, between the Apron and intersection R2). (See attachments G-5 and G-11). - On both taxiway R1 and R6, before entering the runway, two flashing white lights are shown on the Jeppesen charts (the white lights are described and not shown in the AIP, while they are shown on the Jeppesen). - The Fire Station is not shown on the aerodrome charts. Jeppesen charts do not report the instructions of the paragraph that refers to the ”Use of taxiways” that is found in AIP which states: “Before taxing along the line of TWYL R5, located along the extension of the RCL (Runway Central Line) of RWY 36R, all aircraft must REQUEST and OBTAIN a specific clearance from ATC.”
2.4.4. The radar
Radar ASMI. Aircraft ground movement control is very important to assure an orderly and speedy flow of traffic, in order to keep to a minimum the penalties imposed by Low Visibility Operation. ASMI Radar (Aerodrome Surface Movement Indicator) is an extremely valid equipment to facilitate such safe and orderly flow of aircraft on the airport movement area and reduce even further excessive penalties.
Therefore when this equipment (or its substitute) is missing the airport suffers from an immediate degradation of its performance, in terms of number of traffic allowed per hour (otherwise possible even in LVTO, low visibility takeoff, when the airport is rightly equipped).
At Milano Linate airport an ASMI Radar has been in use for many years to control Ground movements in low visibility. It was a quite dated equipment (early analogue technology) which presented many shortcomings over the years (interferences, poor reliability, weak definition on part of the airport maneuver area).
For that and other reasons the ASMI was officially “out of service” (NOTAM n. 4880 of Nov 29, 1999). We quote from document DOP 2/97 issued by ENAV Ð Technical Operations Department. “In conditions of visibility 3, (visibility which in not sufficient for the pilots to self maneuver taxi and for the Control personnel to monitor visually all vehicles on the Maneuvre Area) at airports which are not ASMI functioning equipped, an aircraft will be cleared for taxi from parking stand to, with or without the assistance of a follow-me, towards the holding position only when: any arriving aircraft has confirmed that he has reached his parking position; the aircraft who precedes him for departure has communicated his takeoff.”
This procedure was successively clarified and amended by ENAC with document n. 3333/AIA of Oct 22, 2001, which states: Conditions of visibility 3: substitute: “visibility which in not sufficient for the pilots to self
ANSV 41 maneuver taxi and for the Control personnel to monitor visually all vehicles on the Maneuver Area”. With: “RVR visibility of 400 meters or less”.
2.4.5. Control Tower
The operational environment of Control Tower is officially regulated in DOP 2/97 as per ICAO doc. 4444. On October 8, 2001 when the accident occurred the duty roster called for 5 persons on duty: one supervisor and four controllers.
This is an analysis of the radio communications that were made on the 7th and 8th of October 2001 early morning; they have been grouped by aircraft, without taking into account the chronology of events. (See attachment H). In particular for communications made by Ground Control on frequency 121.8 Mhz and relative to aircrafts moving from West apron, deformity from existing regulations and published procedures can be recognised. In particular taxi instructions from West apron involving taxiways R5 and R6: - the phraseology adopted extensively was not standard; - communications were often conducive to potential misinterpretation by pilots; - read-back rule was not adopted on many occasions; - the English language has not been used uniformly; - Ground Control instructions do not match with the information available through the maps in use by the pilots.
This analysis was developed of the communications transcription of West apron traffic on October 7 and 8, 2001. For better understanding, only relevant fragments of communications have been used. They have been numbered and reported with the answers of the crews.
n.1 GROUND LimaCharlieGolf a Sud Romeo Sei, QNH 1013, si fermi alla barra di stop prima della Principale. LX-JCG Romeo Sei, si ferma alle barre rosse, LimaCharlieGolf. GROUND: LimaCharlieGolf to the South RomeoSix, QNH 1013, hold at the stop bar before the Main. LX-JCG: RomeoSix, holds at the red bars, LimaCharlieGolf.
n.2 GROUND VentiseiQuattordici anche lei a Sud Romeo Sei, QNH 1013, si accoderà ad un Falcon 10 che al momento non è in vista da qua. ERJ-2614 1013, dietro al Falcon 10 VentiseiQuattordici. GROUND: TwentySixFourteen, you too to the South RomeoSix, QNH 1013, you will follow a Falcon 10 that is not visible from here at the moment. ERJ-2614: 1013, behind the Falcon 10, TwentysSixFourteen.
n.3 GROUND India VentunoSettantatre rulli … Romeo Cinque, QNH 1012, mi riporti prima di entrare sul piazzale principale.
ANSV 42 I-2173 Romeo Cinque, 1012, riporterà prima d’interessare il piazzale, India VentunoSettantatre. GROUND: IndiaTwentyoneSeventythree, taxi ... RomeoFive, QNH 1012, report before entering the Main Apron. I-2173 RomeoFive, 1012, will report before entering the Apron, IndiaTwentyoneSeventythree
n.4 GROUND TreSetteUno, a Sud Romeo Sei, QNH 1012, si fermi allo stop della principale. SNM-371 1012, via Romeo Sei, si fermerà. GROUND: ThreeSevenOne, to the South RomeoSix, QNH 1012, hold at the stop of the main. SNM-371: 1012, via RomeoSix, we will stop.
n.5 GROUND DeltaOscarMike taxi south via Romeo Six, QNH 1012, clearance limit at the stop bar, before the main runway. D-CGOM Clearance limit the stop bar before the main runway, clear by Romeo Six, OneZero OneTwo, OscarMike.
n.6 GROUND YankeeZulu your slot is still at time 12.24, so taxi North, via the Romeo Five, QNH 1012, call me back before entering the main apron. HZ-FYZ North, Romeo Five, the slot 12.24, call you before the main apron, QNH 1012, Fox YankeeZulu clear to taxi. n.7 GROUND IndiaBravoCharlieOscarMike, taxi … può rullare a Sud su Romeo Sei, QNH 1012, si ferma alle barre di stop della principale. I-BCOM Rullerà a sud, Romeo Sei, 1012 l’altimetro, riportando alle stop, OscarMike. GROUND: IndiaBravoCharlieOscarMike, taxi ... you can taxi to the South on RomeoSix, QNH 1012, hold at stop bars of the main. I-BCOM: Will taxi to the South, RomeoSix, 1012 the altimeter, reporting at stops, OscarMike.
n.8 GROUND TwoSevenThree, ok, taxi Romeo Six, 1011, report the stop bar at the end of Romeo Six. SWZ 273 1011, and we taxi to Romeo Six and start up is approved, for SwissBird TwoSevenThree. n.9 GROUND RomeoAlfa, andrà per Romeo Sei, 1011, riporti in fondo agli stop. LX-PRA riporteremo, RomeoAlfa. GROUND: RomeoAlfa, will proceed via RomeoSix, 1011, report at the end at the stops. LX-PRA: Will report, RomeoAlfa.
n.10 GROUND IndiaVictorAlfa, rulli a Nord, su Romeo Cinque, l’H 1010, riporti gli stop. I-DDVA 1010, richiamerà agli stop, VictorAlfa. GROUND: IndiaVictorAlfa, taxi to the North,via RomeoSix, the H 1010, report the stops. I-DDVA: 1010, will call back at the stops, VictorAlfa.
ANSV 43 n.11 GROUND GolfGolfGolf, taxi South Romeo Six, QNH 1010, report the bars. G-OMGG Romeo Six,1010, GolfGolfGolf.
n.12 GROUND Roger, taxi holding 36R, via Romeo Five taxiway, report before crossing the extension of the centreline of the main runway, QNH 1010. A6-DAS QNH 1010 clear to taxi Romeo Five we will call you before crossing centreline, Alfa AlfaSierra.
n.13 GROUND Ok, DueCinqueNoveTre, può fare Romeo Sei, ha ragione, riporti prima dell’attraversamento. ERJ 2593 Grazie. GROUND: Ok, TwoFiveNineThree, may use RomeoSix, you are right, report before crossing. ERJ-2593: Thank you.
n.14 GROUND CharlieNovemberXray, taxi via Romeo Six, South, QNH is 1010, call me back at the stop bar, before crossing. CS-DNX Ok Romeo Six, south, 1010, and we’ll call you back ee … we’ll call you back before crossing, November..Xray.
n.15 GROUND RomeoPapa può rullare a Sud, riporterà gli stop prima dell’attraversamento, 1010 l’H (acca). I-RVRP 1010, riporterà prima degli stop, RomeoPapa. GROUND: RomeoPapa may taxi to the South, you will report the stops before crossing, 1010 the H. I-RVRP: 1010, will report before the stops, RomeoPapa.
n.16 GROUND BravoIndia, rulli a Sud, Romeo Sei, 1010 l’H(acca), riporti agli stop. I-LUBI Sud, Romeo Sei, 1010, riporteremo gli stop, IndiaBravoIndia. GROUND: BravoIndia, taxi to the South, RomeoSix, 1010 the H, report the stops. I-LUBI: South, RomeoSix, 1010, will report the stops, IndiaBravoIndia.
n.17 GROUND OscarHotelHotel, taxi via North, Romeo Five, QNH 1011, call me back, before entering main apron. OE-FHH Taxi via North, OscarHotelHotel.
n.18 GROUND SevenFourFour, taxi to the North, Romeo Five, QNH 1011, report the bars. SRK 744 Romeoo…5, to the North.
n.19 GROUND NovemilaDue su Romeo Cinque, 1012, riporti gli stop. I-9002 1012, al Romeo cinque, riporteremo allo stop, IndiaNoveDue.
ANSV 44 GROUND: NinethousandTwo on the RomeoFive, 1012, report the stops. I-9002: 1012, at RomeoFive, will report the stop, IndiaNineTwo.
n.20 GROUND EcoRomeoJuliet DueCinquetreUno rulli a Sud, Romeo Sei, QNH UnoZeroUnoDue. La … RVR al momento 400-450-400. ERJ2531 È … copiato, 1012, via Romeo Sei, la Venticinque Trentuno. GROUND: EcoRomeoJulietTwoFiveThreeOne taxi to South, RomeoSix, QNH 1012, the ... RVR at the moment 400-450-400. ERJ2531: Is ... copied, 1012, via RomeoSix, Twentyfive Thirtyone.
n.21 ROUND IndiaBravoIndia a Nord Romeo Cinque, QNH 1013, riportate in vista dello stop bar estensione pista principale. I-LUBI Romeo Cinque, riporterò stop bar estensione Principale, IndiaBravoIndia. GROUND: IndiaBravoIndia to the North, Romeo Five, QNH 1013, report in sight of stop bar extension of main runway. I-LUBI: Romeo Five, will report stop bar Main extension, IndiaBravoIndia.
n.22 GROUND DeltaVictorXray taxi North via Romeo Five QNH OneZeroOneThree, call me back at the stop bar of the ... main runway extention. D-IEVX Roger via Romeo Five and … OneZeroOneThree, and call you back before reaching main runway. 2.4.6. Analysis of the verbal communication (words) used
The word “main” (“principale”) has been used without discrimination when issuing clearances to mean both the Main runway and the Main apron. The words “report the stop”, “report the bars”, have been used indifferently both in clearances involving R5 and R6, without any other identification word. Wordings like “report before crossing”, “entering main”, which when added to clearances like “via R5” or “via R6”, could be interpreted correctly, are also potentially misleading. The words used both by controller and pilots to identify areas and taxiways are not in conformity with the information reported on the Jeppesen charts. a) To mean (signify) the West apron, controllers refer to it alternatively with the words: General Aviation, ATA, West apron. Only one denomination for that area is reported on AIP and Jeppesen charts, the West apron. b) Controllers refer to the Main apron alternatively with the words: Main parking, Main, principal (“principale”), Main apron. Which is referenced on AIP Italia and Jeppesen charts as: North apron. c) Controllers refer to the Fire Brigade Station as a significant reporting position to identify the position of taxiing aircraft. Jeppesen maps make no reference to the existence of the Fire Brigade Station. 2.4.7. Clearance confirmation: read-back Pilots have acknowledged all taxi clearances issued by controller, but when the read-back did not conform to the clearance, the controller failed to recognise and correct the difference.
ANSV 45 Six read-backs are missing part of the clearance (4, 8, 10, 11, 14, 18, 22). In four cases the entire clearance is missing from the read-back (9, 13, 15, 17).
2.4.8. An occurrence happened on October 7, 2001 at time 13.56, relevant to “clearance read-back”
The episode occurred the day before the accident. In spite of its potential gravity it was not signalled and no mention of it is made on any official documentation. METAR of 13.50 reported: “LIML 071350Z 12005 KT 2100 RA SCT 008 TCU BKN015 20/19 Q1011 NOSIG”. The exchange of communication between I-DDVA and ground control is as follows: I-DDVA IndiaVictorAlfa, dall’ATA, è pronto a muovere. I-DDVA: IndiaVictorAlfa, from ATA, ready to move. GROUND IndiaVictorAlfa, rulli a Nord, su Romeo Cinque, l’acca 1010, riporti gli stop. GROUND: IndiaVictorAlfa, taxi to the North, on Romeo Five, the H 1010, report the stops. I-DDVA 1010, richiamerà agli stop, VictorAlfa. I-DDVA: 1010, will call back at the stops, VictorAlfa. I-DDVA Il VictorAlfa è già nel Romeo Sei, cosa fa, si mette nella prima baia qua a sinistra? I-DDVA: VictorAlfa is already on RomeoSix what do we you do, we enter the first bay here on the left? GROUND VictorAlfa l’avevo istruito sul Romeo Cinque, a… un attimo in attesa. GROUND: VictorAlfa I instructed you via RomeoFive, a ... wait a moment. I-DDVA Sì comunque abbiamo copiato Romeo Sei, abbiamo ripetuto Romeo Sei, sicuramente abbiamo sbagliato. I-DDVA: Yes, anyway we copied Romeo Six, we read-back Romeo Six, for sure we made a mistake. ERJ-2614 Ground la JetItalia si mette qui sulla pista turistica e fa passare il ... l’HS. ERJ2614: Ground the JetItalia moves here, on the tourist(Rwy), and lets the ... HS overtake. GROUND Ok e … si … mantiene quella posizione, la richiamo … è stato un errore del collega che ha rullato su... allaaa.. sul raccordo Romeo Sei, anziché Nord, sul Romeo Cinque. La richiamo per continuare. GROUND: Ok, and ... yes ... maintain that position, I’ll call you back .. It has been a mistake of your colleague, that taxied on ... the ... on the taxiway RomeoSix, instead off North, on RomeoFive, I’ll you call back to continue. ERJ-2614 Capito. ERJ-2614: Understood. I-DDVA Ciao (segue nome). I-DDVA: Ciao (Bye) (name withheld) ERJ-2614 Ciao, ciao. ERJ-2614: Ciao (Bye), ciao (bye). I-DDVA Vuole che il VictorAlfa si faccia la turistica e si riprenda il Romeo Sei? I-DDVA: Do you want VictorAlfa to make (proceed on, taxi on) the tourist (Rwy 36L/18R) and then joins Romeo Six? GROUND VictorAlfa lei è già sul Romeo Sei, il Romeo Cinque è quello a nord. Lei può continuare in fondo e riportare alle ..agli stop in fondo, il suo codice QuattroSeiSeiQuattro. GROUND: VictorAlfa, you are already on RomeoSix!, RomeoFive is the one to the North. You
ANSV 46 may continue to the end and report at... the stops at the end, your code is Four Six Six Four. I-DDVA Quattro Sei Sei Quattro, continua sul Romeo Sei. I-DDVA: Four Six Six Four, we continue on Romeo Six. GROUND VictorAlfa, corretto, contatti 118.1, buongiorno. GROUND: VictorAlfa correct, contact 118.1, good morning. Now we are focussing on one particular communication : GROUND IndiaVictorAlfa, rulli a nord, su Romeo Cinque, l'ACCA 1010, riporti gli stop. I-DDVA 1010, richiamerà agli stop, VictorAlfa. GROUND: IndiaVictorAlfa, taxi to the North, on Romeo Five, the H 1010, report the stops. I-DDVA: 1010, will call back at the stops, VictorAlfa. A clearance is issued, the read-back is incorrect and the controller (is not aware of the difference or) does not make the pilot aware of the difference. Then at 13.58 the controller becomes aware that I-DDVA is taxiing via R6 instead of R5, as instructed. I-DDVA: Il VictorAlfa è già nel Romeo Sei, cosa fa, si mette nella prima baia qua a sinistra? GROUND: VictorAlfa l’avevo istruito sul Romeo Cinque, a… un attimo in attesa. I-DDVA: VictorAlfa is already on Romeo Six what do we do? We enter (stop) at the first bay here on the left? GROUND: VictorAlfa I instructed you via Romeo Five, a ... wait a moment. ERJ-2614 Ground la Jet Italia si mette qui sulla pista turistica e fa passare il ... l’HS. GROUND Ok e … si … mantiene quella posizione, la richiamo … è stato un errore del collega che ha rullato su... allaaa.. sul raccordo Romeo Sei, anziché Nord, sul Romeo Cinque. La richiamo per continuare. ERJ-2614: Ground la Jet Italia moves here on the tourist Rwy, and give way to ... HS. GROUND: Ok, and ... yes ... maintain that position, I’ll call you back .. It was a mistake of your colleague, that taxied on ... the ... on taxiway Romeo Six, instead of North, on RomeoFive. I’ll call you back to continue. The episode has not been given any further attention by the controller and it has not been recorded in any official report available.
The following are statistical comments on communications recorded from October 7, 2001 at 08.15, to October 8, 2001 at 06.06 and to 24 movements involved in the use of West apron. - 10 times clearances were issued instructing taxi via R5; - 14 times the clearance was via R6; - 9 times the clearance was via R6 and via R2; - 5 times the clearance was via R6 followed by a backtrack on Rwy 36R; - 13 times out of 24 communications were in the Italian language; - 8 communications were in English; - 2 were started in English and concluded in Italian; - 1 was started in Italian, continued in English and finished in Italian.
Findings analysis is still under investigation. Thereafter pertinent conclusions will be part of the Final Report publication.
ANSV 47 ANSV 48 CHAPTER III CONCLUSIONS
3. CONCLUSIONS
The following conclusions and the related safety recommendations are pertinent to the documentation available and analyzed to this date and belong to the intermediate state of this technical investigation. The Final Report with the publication of the final outcome and the completion of all items as suggested in ICAO Annex 13, will contain conclusions and all recommendations to National and International Administrations concerned.
3.1. FINDINGS
On Oct 8, 2001 at Milano-Linate airport, after the accident, the following evidence was recorded: -Weather conditions were making normal taxi movement of aircrafts quite difficult. -Weather forecast (ATIS) was not consistent with actual weather conditions. -West apron and on R5 and R6 taxiways lacked most of the visual aids (horizontal/vertical) required. - Existing visual aids configuration of West apron was degraded and not consistent with ICAO requirements. - Airport information contained in AIP Italy was incomplete and not descriptive of actual conditions. - Instruction/information contained in Jeppesen charts were not fully consistent with instruction contained in AIP Italia. - Procedures mandated for LVO, in the absence of ASMI, were not enforced. - ENAC/UCT Linate failed to notice the landing of the Cessna 525A D-IEVX below landing minima. - After its landing the Cessna 525A D-IEVX had reached West apron after performing a back- track on runway 36R and taxied via R6. - The CSO was not at his working position when the accident occurred. - air-to-ground phraseology communications were not in conformity with the ICAO recommendations. - Controllers did not implement read-back confirmation procedures consistently. - Controller(s) ignored the presence/location of S4. - air-to-ground communications were widely conducted in the Italian language and intermixed with English language. - It can be assumed that the Ground Controller firmly believed that Cessna 525A D-IEVX was taxiing on R5. - 40 seconds after having instructed D-IEVX to taxi, the same taxi instruction was given to LX-PRA parked on the same apron, but the communication was in Italian and could not be perceived by the German crew.
ANSV 49 3.2. CAUSES
The documentation available and analyzed by ANSV, at this point of the investigation, allows to reasonably identify two principal contributing factors: human factor and environmental factor. It is believed that there is no contributing technical factor to the dynamics of the accident; there is no evidence of any technical breakdown or malfunction that may have caused or contributed to the event. Causes and contributing factors originating (prior to) the accident will be detailed in the final report but it can already be stated that there was no contribution to the accident caused by the Scandinavian Crew.
ANSV 50 CHAPTER IV SAFETY RECOMMENDATIONS
4. RECOMMENDATIONS
With reference to ICAO Annex 13, chapter 6, paragraph 6.8 and in relation to the present state of maturity of the technical investigation, the “Agenzia Nazionale per la Sicurezza del Volo” – ANSV, for the sole scope of improving flight safety, issues the following safety recommendations to the competent aviation authorities:
4.1. Recommendation ANSV-17/113-1/A/02
Subject: Usage of the English language in Air/Ground communications / Read-back.
Addressed to: ENAC, ENAV
Text: With reference to analysis of Air/Ground communications of this accident, ANSV recommends to mandate that the ICAO requirements regarding the usage of the English language shall be enforced and that its abidance shall be monitored. It is also felt necessary that standard read-back procedures are enforced (ICAO Annex 10, paragraph 5.2.1.8 - Exchange of communications 5.2.1.8.2.2 PANS). Similarly, ANSV calls for the enforcement by Air Transport Authority, of the new ICAO recommended procedure that calls for explicit clearance to be issued when “active runways crossings” are involved and containing explicit mention of the runway to be engaged. ICAO DOC 4444 and DOC 9432- An/925 “Manual of Radiotelephony”. Exceptions should be confined to situations that emanate from a typical domestic only traffic and/or that the usage of the domestic language would facilitate handling of an emergency situation.
4.2. Recommendation ANSV-18/113-2/A/02
Subject: Consistency of aerodrome approved and published information with international standard and correspondence between the information published and the physical state of airports - follow-up to ANSV safety alert prot. N 1238/INV/113-14/01 of Oct 10, 2001 (see attachment J).
Addressed to: ENAC
Text: With reference to ANSV alert message n. 1238 issued on Oct. 10, 2001, and to findings obtained during this investigation, ANSV recommends that the state of airport visual aids of all domestic airports as well as the published taxi procedures shall be checked and found to be in accordance to published AIP.
ANSV 51 All information to shall be unequivocal and in conformity with internationally adopted standards (ICAO Annex 14); furthermore such correspondence shall be reflected in operators documentation.
4.3. Recommendation ANSV-19/113-3/A/02
Subject: Reporting and registration by ATC of abnormal operational safety events.
Addressed to: ENAV and ENAC
Text: With reference to findings obtained in this investigation, ANSV recommends that procedures shall be adopted to systematically report any incident or abnormal operation in breach of safety. Registration of such events should be monitored by ENAC with a view to update and enhance the quality of procedures and their compliance by all concerned, to achieve and maintain adequate operational safety.
4.4. Recommendation ANSV-20/113-4/A/02
Subject: Professional qualification proficiency and recurrence of training for air traffic controllers.
Addressed to: ENAV and ENAC
Text: With reference to findings obtained in this investigation, ANSV recommends to mandate for increased training and recurrent training of all air traffic controllers, necessary to validate individual continuing proficiency for the task required for air traffic control.
4.5. Recommendation ANSV-21/113-5/A/02
Subject: Criteria for aircrafts ground movement routing - follow-up to safety alert prot. N 1336/INV/113-35/01 of Nov 6, 2001 (see attachment J).
Addressed to: ENAC, ENAV
Text: With reference to findings obtained in this investigation and to ANSV safety alert 1336 issued on Nov 6, 2001, ANSV recommends the adoption of the model clearly defined in the ICAO Airport Design Manual for the denomination of all elements of the Airport movement area. Such model shall allow the implementation of “standard taxi routings” containing all necessary information to air crews (denomination, routing, compulsory stop points). Such model should be adoptable by all Airports. ANSV further recommends that Stop bar lights must be controllable by Ground controllers (On/ Off control function), as described in ICAO Annex 14.
ANSV 52 4.6. Recommendation ANSV-22/113-6/A/02
Subject: Applicability of Mandatory Low Visibility Procedures.
Addressed to: ENAC, ENAV
Text: With reference to findings obtained in this investigation, ANSV recommends the application of the same regulations, now compulsory for Commercial aircrafts, involved in Low Visibility Operations (LVO-CAT II-III, LVTO), to all aircrafts operating in the same weather conditions.
ANSV 53 ANSV 54 LIST OF ATTACHMENTS
ATTACHMENT A: official AIP Italy documentation of Milano Linate airport: airport map, apron and parking map, layout of parking positions and provisions for general aviation aircrafts
ATTACHMENT B: B1-B9, tables describing the impact
ATTACHMENT C: METAR and ATIS
ATTACHMENT D: D1-D2, transcription of Air-to-ground communications Ground /Tower
ATTACHMENT E: aerial view of Milano Linate airport (19sixties, date uncertain)
ATTACHMENT F: photographs of markings on taxiway R6
ATTACHMENT G: G1-G11, tables describing communications analysis
ATTACHMENT H: transcription of Air-to-ground communications grouped by aircraft
ATTACHMENT J: alert messages issued by ANSV
The attachments included are copies of original documents made available to ANSV through various sources. These documents, safeguard the privacy of all individuals involved in the event, as indicated in Legislative Decree of February the 25th 1999, n. 66.
ANSV 55 ANSV 56 ATTACHMENT A: airport, apron and aircraft parking map, layout of parking positions and provisions for general aviation aircrafts showed on AIP Italia official documentation of Milano Linate airport.
ANSV 57 Attachment A
ANSV 58 Attachment A
ANSV 59 Attachment A
ANSV 60 Attachment A
ANSV 61 Attachment A
ANSV 62 Attachment A
ANSV 63 ANSV 64 ATTACHMENT B: tables descriptive of the impact. B 1 - Damages to Cessna D-IEVX B 2 - Damages to MD-87 SE-DMA B 3 - Extracts from sound analysis (CVR) B 4 - Interaction between the two aircrafts (Fig. 1) B 5 - Interaction between the two aircrafts (Fig. 2) B 6 - Interaction between the two aircrafts (Fig. 3) B 7 - Interaction between the two aircrafts ( Fig. 4) B 8 - Interaction between the two aircrafts (Fig. 5) B 9 - Aircraft collision with airport baggage building
ANSV 65 Attachment B1
Cessna damages
ANSV 66 Attachment B2
MD-87 damages
ANSV 67 Attachment B3
Sound analysis extract (CVR)
First point of contact Third point of contact Citation LH Horizontal Citation RH Wing and MD 87 RH Stabilizer and MD 87 NLG MLG
ANSV 68 Attachment B4
Aircraft interaction - Fig 1
ANSV 69 Attachment B5
Aircraft interaction - Fig 2
ANSV 70 Attachment B6
Aircraft interaction - Fig 3
ANSV 71 Attachment B7
Aircraft interaction - Fig 4
ANSV 72 Attachment B8
Aircraft interaction - Fig 5
ANSV 73 Attachment B9
Aircraft collision with building
Note: aircraft angle not confirmed.
ANSV 74 ATTACHMENT C: meteorological information. METAR of Milano Linate valid from 00.20 of October 7 to 06.20 of October 8, 2001 ATIS of Milano Linate from 00.13 to 06.12 of October 8, 2001
ANSV 75 Attachment C
ANSV 76 Attachment C
ANSV 77 Attachment C
ANSV 78 ATTACHMENT D: transcription of radio Air-to-ground communications. D 1 - transcription of Air-to-ground communications on Linate Ground frequency (121.8) from 05.41.39 to 06.12.27 of October 8, 2001 D 2 - transcription of Air-to-ground communications on Linate Tower frequency (118.1) from 04.56.15 to 06.13.10 of October 8, 2001
ANSV 79 Attachment D1
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 80 Attachment D1
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 81 Attachment D1
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 82 Attachment D1
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 83 Attachment D1
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 84 Attachment D1
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 85 Attachment D2
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Torre 118.1
ANSV 86 Attachment D2
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Torre 118.1
ANSV 87 Attachment D2
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Torre 118.1
ANSV 88 Attachment D2
Linate October 8, 2001 Air-to-ground comunications T/B/T Freq. Torre 118.1
ANSV 89 ANSV 90 ATTACHMENT E: aerial view of Milano Linate airport (19sixties photograph, date uncertain).
ANSV 91 Attachment E
Notice that taxiway R6 did not exist between runway 36L head and runway 36R/18L
ANSV 92 Attachment E
ANSV 93 Attachment E
Notice that taxiway R6 did not exist between runway 36L head and runway 36R/18L
ANSV 94 ATTACHMENT F: photographs of taxiway R6 markings. F1 - Exit lines departing from Apron West (general aviation) F2 -Split of centreline at R5 and R6 decision point exiting parking area on Apron West (prospective view at cockpit height) F3 - Centerline divergence towards R5 and R6 F4 - Taxiway R6: runway-holding position marking pattern B with S4 marking F5 - Taxiway R6: STOP marking preceding a second pattern B marking
ANSV 95 Attachment F1
ANSV 96 Attachment F2
ANSV 97 Attachment F3
ANSV 98 Attachment F4
ANSV 99 Attachment F5
ANSV 100 ATTACHMENT G: tables describing analysis of communications. G 1 - Milano Linate Tower: personnel distribution and working positions G 2 - Jeppesen map describing standard instrument departures from Milano Linate G 3 - Jeppesen map of Milano Linate (20-9) G 4 - Jeppesen chart with operational information of Milano Linate (20-9A) G 5 - Jeppesen map describing parking area and taxiways at Milano Linate (20 9B) G 6 - Milano Linate airport: expanded view of previous Jeppesen map (20-9B) G 7 - Illustration of cut-off vision angle from left pilot seat of Cessna G 8 - Split of centreline at R5 and R6 centreline exiting West apron (side vision) G 9 - Taxiway R6: runway-holding marking pattern “B” and S4 and S5 markings (side vision) G 10 - Expanded view of Jeppesen chart (20-9B) with indication of Stop bars present on R5 and R6 G 11 - Expanded view of Jeppesen chart (20-9B) identifying a portion of parallel taxiway to runway 36R/18L as A (Alfa)
ANSV 101 Attachment G1
Control Tower at Milano Linate: personnel distribution and working positions
ANSV 102 Attachment G2
ANSV 103 Attachment G3
ANSV 104 Attachment G4
ANSV 105 Attachment G5
ANSV 106 Attachment G6
Expansion from Jeppesen (20-9B) Ð actual state of guidance lines for taxi and park on apron West ATA (general aviation); yellow marked to distinguish them from those published in attachment G-5 (the only one available to crews)
ANSV 107 Attachment G7
ANSV 108 Attachment G8
ANSV 109 Attachment G9
ANSV 110 Attachment G10
ANSV 111 Attachment G11
ANSV 112 ATTACHMENT H: transcription of Air-to-ground communications recorded on Linate Ground frequency (121.8) on October 7 and 8, 2001 grouped by aircraft.
ANSV 113 Attachment H
Linate October 7-8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 114 Attachment H
Linate October 7-8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 115 Attachment H
Linate October 7-8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 116 Attachment H
Linate October 7-8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 117 Attachment H
Linate October 7-8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 118 Attachment H
Linate October 7-8, 2001 Air-to-ground comunications T/B/T Freq. Ground 121.8
ANSV 119 ANSV 120 ATTACHMENT J: alert messages issued by ANSV.
ANSV 121 Attachment J
ANSV 122 Attachment J
ANSV 123 ANSV 124