QinetiQ
MK 10A Ejection Seat Modifications (2197 & 2198) for Tornado GR4/4A and F3 Aircraft Phase Two
QINETIQ/AT&E/CR00782/1
Cover + x + 70 pages December 2002 41.1111110k This document is subject to the release conditions printed on the reverse of this page
This document is issued for the information of such persons only as need to know its contents in the course of their official duties. Any person finding this document should hand it to a British Forces unit or to a police station for safe return to the Chief Security Officer, QINETIQ Ltd, Cody Technology Park, Farnborough, Hampshire GU14 OLX, with particulars of how and where found. THE UNAUTHORISED RETENTION OR DESTRUCTION OF THE DOCUMENT IS AN OFFENCE UNDER THE OFFICIAL SECRETS ACT OF 1911 - 1989. (When released to persons outside Government service, this document is issued on a personal basis and the recipient to whom it is entrusted in confidence within the provisions of the Official Secrets Acts 1911 - 1989, is personally responsible for its safe custody and for seeing that its contents are disclosed only to authorised persons.) Customer Information Customer Reference Number TOR3/09/97BD Task Title MAR Recom. for Ejection Seat Upgrade Customer Contact Name Tor9c,1111111111111 Staff Requirement/Target
Project Number C8FFT/014 Milestone Number Date Due (dd/mm/yyyy) 26/11/1999
This document contains commercially valuable information controlled by QinetiQ. Intellectual Property Department must by consulted before it is released outside QinetiQ.
© Copyright of QinetiQ ltd 2002 This document is intended for internal use only
ii QINETIQ/AT&E/CR00782/1 Authorisation
Prepared by 111111111111110°—' Title Trials Officer
Signature Date Location BCE
Authorised by 411.11111111.11 Title Technical Manager Air Launched Munitions
Signature Date
Principal authors Name 111111111111111111111 Appointment Tornado Project Manager Location BCE
QINETIQ/AT&E/CR00782/1 iii RESTRICTE11'
Record of changes
Issue Date Detail of Changes 1 December 02 Initial Issue
111011*A•
iv QINETIQ/AT&E/CR00782/1
RESTRICTED Executive summary
Phase Two modifications to the Mk10A ejection seat fitted to the Tornado GR4/4A and F3 aircraft were incorporated to address the extended aircrew mass range that was apparent in the RAF. The original specification range for nude mass of aircrew in 1975 was 56.56kg to 97.34kg. The new specification for nude mass is 50.98kg (female aircrew) to 107.86kg. This equates to boarding masses of 67.5kg to 135kg wearing full AEA. The weight of Aircrew Equipment Assemblies (AEA) and the mass of the seat itself have all increased since the introduction of the Tornado aircraft and Mk10A ejection seat.
Modification 02198 involved the replacement of the GQ1000 Mk2 parachute assembly (incorporated during the Phase One modifications) with the GQ5000 parachute and it's associated deployment system. The GQ5000 properties include a drive capability and a reduced rate of descent, as well as a reduced lines taught snatch load. It also incorporates a selectable steering capability, which offers the aircrew improved manoeuvrability and a reduced forward speed on landing if utilised correctly.
Modification 02197 involved the replacement of the original primary and secondary ejection gun cartridges with revised cartridges offering a reduced Dynamic Response Index (DRI) value (resulting in a reduced risk of injury, especially to the minimum weight ejectee), whilst maintaining an acceptable velocity (of the seat) on separation from the ejection gun (especially for the maximum weight ejectee). The revised cartridges offer a reduced DRI on the primary cartridge phase of operation, but increase the force during the secondary phase of operation to ensure sufficient velocity on seat/ejection gun separation.
The assessment of the GQ5000 and its deployment system (Mod 02198) concluded that it was acceptable with regard to zero/zero ejection situations (in conjunction with the revised ejection gun cartridges) with the revised heavy weight seat occupant. It also performed satisfactorily (in conjunction with the revised ejection seat gun cartridges) in the high-speed sled test (initiation at 608kts). The system successfully passed all environmental trials, but had to have the low temperature specification altered, with the system being cleared for -50°C rather than the original -60°C. This occurred due to the two ply butyl rubber of the deployment inflation bladder failing after a soak at -60°C. The new higher temperature of -50°C was considered acceptable (system tested satisfactorily at -54°C). Resurgence of the packed parachute was found after further environmental trials and amounted to 4mm. This amount of resurgence was considered acceptable. The clearance between the upper surface of the headbox and the lower surface of the aircraft canopy, specifically the Linear Cutting Cord (LCC) was found to be acceptable. Modifications to the top flap of the headbox, which consisted of the introduction of a kevlar insert, and cross-stitching, ensured that little or no damage would occur to the fabric top flap should the LCC detonate within either a very close proximity, or in physical contact. Reconfiguration of the Drogue Withdrawal Line (DWL), with regard to reduction in the armoured sleeve and alterations to the stitching pattern resulted in a significant reduction in packed headbox height.
The assessment of the revised primary and secondary ejection gun cartridges (Mod 02197) concluded that the performance of the system was much improved over that achieved in the original Mk10A ejection seat qualification programme in regards to the DRI. The worst case scenario for the value of the DRI (high temperature (+70°C) cartridges, minimum weight seat occupant) produced a value of 20.44 (17% chance of injury), which compares favourably with the maximum allowable DRI in this situation of 22.2 (40% chance of injury). The worst case scenario for velocity at seat/ejection gun separation (-40°C cartridges, maximum weight seat occupant) was marginally reduced, but was still considered acceptable. However, the values for the maximum
QINETIQ/AT&E/CR00782/1 speed at which a heavy weight seat occupant can eject from the rear seat position and avoid a `hard' contact with the Tornado tail fin have been reduced (from the original specification of 625 Knots Calibrated Air Speed (KCAS)). The values now stand at 617 KCAS or below for the Interdictor Strike (IDS) aircraft and 622 KCAS or below for the Air Defence Variant (ADV) aircraft. The lower of the maximum airspeeds (617 KCAS) should be used for both aircraft types resulting in a single ejection envelope graph being produced for all Tornado documentation.
The revised simplified combined harness (introduced during Phase One modifications) was shown to be able to withstand the dynamic parachute inflation forces produced by a maximum weight ejectee and also the Tornado specification 40g impact forces produced by a maximum weight seat occupant in the event of an aircraft crash.
However, the ejection seat mounting points which attach the seat/occupant to the structure of the aircraft were not able to withstand the increased forces generated by a maximum weight seat occupant in a 40g crash scenario (original Tornado specification). The mounting points and the aircraft bulkhead were theoretically calculated to be able to withstand an impact force of 34g with a maximum weight seat occupant. Due to this, the specification for impact survivability has been reduced to a value of 34g.
Assessment of the GQ5000 parachute steering facility in a suspension trial highlighted difficulties in use due to the location of the steering handles on the parachute risers and the size of the handles themselves. This was compounded by the fact that location of the handles could only be achieved via feeling up the parachute risers. Bulky AEA (especially with an inflated life preserver) and an ejectee with a short functional reach added to the difficulties. However, the system was able to be used and was considered to improve the chances of survival of an ejectee by allowing a steering facility for avoidance of hazards when landing.
Many other minor alterations were necessary due to the embodiment of the Phase Two modifications, such as the replacement of the drogue release 'scissors' shackle with a Gas Shackle (GS), replacement of the Barostatic Time Release Unit/Manual Override (BTRU/MOR) cartridges with improved items and replacement of the Breech Type Time Delay Firing Unit (BTTDFU) with the Gas Fired Time Delay Unit (GFTDU).
QinetiQ is able to support the implementation of the Phase Two modifications 02197 and 02198 with regard to the Mk10A ejection seats fitted to the Tornado GR4/4A and F3 aircraft. However, some limitations exist with regard to the maximum ejection speed, the revised -50°C low temperature limit and 34g-impact value. Consideration should also be given to the training of aircrew on the use of the GQ5000 parachute.
The escape system envelope for the fully modified Mk10A ejection seat fitted to the Tornado ADV and IDS type aircraft would be 0-617kts, 0-50,000ft for all aircrew.
vi QINETIQ/AT&E/CR00782/1 List of contents
Authorisation iii
Record of changes iv
Executive summary
List of contents vii
List of Figures ix
1 Introduction. 1 1.1 Task Number. 1 1.2 Originator. 1 1.3 Background. 1 1.4 Phased Introduction of Modifications. 2 1.5 Assessment Philosophy. 2
2 Description of Equipment. 4 2.1 GQ 5000 Parachute Assembly (Mod 02198). 4 2.2 Simplified Combined Harness Assembly. 5 2.3 BTRU/MOR Cartridges. 5 2.4 Primary and Secondary Gun Cartridges (Mod 02197). 6 2.5 Aircraft Canopy and Associated Jettison System. 6
3 Assessment of Evidence. 8 3.1 GQ 5000 Parachute and Bladder Inflation System Zero/Zero. 8 3.2 GQ 5000 Parachute and Bladder Inflation System 625Kts. 9 3.3 GQ 5000 Parachute and Bladder Inflation System Environmental Qualification. 11 3.4 GQ 5000 Parachute and Bladder Inflation System Canopy Clearance. 15 3.5 Simplified Combined Harness Assembly. 17 3.6 Revised BTRU/MOR Cartridges. 18 3.7 Ejection Gun Qualification (Revised Primary and Secondary Cartridges). 20 3.8 Revised Primary and Secondary Gun Cartridges (Lot Acceptance Test Limits). 21 3.9 Aircraft Tail Fin Clearance. 22 3.10 Ejection Seat/Aircraft Canopy Collision. 25 3.11 Ejection Seat Mounting to Aircraft (40g Crash Scenario). 27 3.12 GQ5000 Parachute and Harness Suspension. 27
4 Conclusions. 31 QINETIQ/AT&E/CR00782/1 vii 4.1 GQ 5000 Parachute and Bladder Inflation System. 31 4.2 Simplified Combined Harness Parachute Inflation Loading. 32 4.3 Simplified Combined Harness Crash Loading. 33 4.4 Revised BTRU/MOR Cartridges. 33 4.5 Ejection Gun Qualification with Revised Primary and Secondary Cartridges. 33 4.6 Revised Primary and Secondary Gun Cartridges (Lot Acceptance Test Limits). 34 4.7 Aircraft Tail Fin Clearance. 34 4.8 Ejection Seat/Aircraft Canopy Collision. 35 4.9 Ejection Seat Mounting to Aircraft (40g Crash Scenario). 35 4.10 GQ5000 Parachute and Harness Suspension. 36 4.11 Mk 10A Ejection Seat Performance. 36
5 Recommendations 37 5.1 Military Aircraft Release (MAR). 37 5.2 Use of the GQ5000 parachute. 37 5.3 GQ5000 Parachute Steering Facility. 37 5.4 Maintenance Documentation. 37 5.5 Seat Limitations Documentation. 37
6 References 39
7 List of abbreviations 42
8 Figures 44
A Appendix - GR4/4A MAR Change Pages 61
B Appendix - F3 MAR Change Pages 65
Report documentation page 69
viii QINETIQ/AT&E/CR00782/1 List of Figures
Figure 8-1 Number of Leg Fractures during Ejections from RAF Accidents 1972-1996 44 Figure 8-2 GQ5000 Bladder Deployment System 44 Figure 8-3 Original BTRU with Mechanical 'Scissors' Operating Mechanism 45 Figure 8-4 Revised BTRU with GS Ballistic Gas Supply Capability 45 Figure 8-5 Ejection Gun Assembly 46 Figure 8-6 Original BTTDFU 47 Figure 8-7 GFTDU (replacement of BTTDFU) 47 Figure 8-8 Canopy Jettison Initiator Unit 48 Figure 8-9 Canopy Rocket Motor 48 Figure 8-10 GQ5000 Headbox post 'In Contact' with LCC during Detonation showing Damage to Upper Surface of Fabric Top Flap 49 Figure 8-11 GQ5000 Headbox Kevlar Reinforced Fabric Top Flap showing no Damage Post 'In Contact' with LCC during Detonation 49 Figure 8-12 DRI Value Shown against Spinal Injury Risk 50 Figure 8-13 Comparison between Measured (608 knots) and Simulated (610 knots) Seat Trajectories (Rear Seat, 135kg Occupant) 50 Figure 8-14 Still 1 from Simulation of Test Ejection of Enhanced Seatat 610 knots (Rear Seat, 135kg Occupant) 51 Figure 8-15 Still 2 from Simulation of Test Ejection of Enhanced Seat at 610 knots (Rear Seat, 135kg Occupant) 51 Figure 8-16 Still 3 from Simulation of Test Ejection of Enhanced Seat at 610 knots (Rear Seat, 135kg Occupant) 52 Figure 8-17 Maximum Ejection Speed to achieve Fin Clearance, for the Tornado IDS, as a Function of Crew Mass 52 Figure 8-18 Maximum Ejection Speed to achieve Fin Clearance, for the Tornado ADV, as a Function of Crew Mass 53 Figure 8-19 Canopy Hinge 53 Figure 8-20 Canopy Hinge Separation Sequence 54 Figure 8-21 Suspended Test Subject (non-inflated life preserver) 55 Figure 8-22 Subject One with Parachute Steering Lines Located (by touch) 56 Figure 8-23 Subject One with Life Preserver Inflated (frontal) 57 Figure 8-24 Subject One with Life Preserver Inflated (side) 58 Figure 8-25 Subject Two Attempts Viewing Parachute Canopy (life preserver not inflated) 59 Figure 8-26 Attachment Points of Parachute Risers to Combined Harness over Shoulder (Subject Two) 60
QINETIQ/AT&E/CR00782/1 ix
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x QINETIQ/AT&E/CR00782/1 1 Introduction.
1.1 Task Number.
1.1.1 The work contained within this report was carried out under task number C8FFT014.
1.2 Originator.
1.2.1 This report was originated by of Air Vehicle Systems (AVS) Aircraft Test and Evaluation (AT&E), QinetiQ, MOD Boscombe Down, with inputs from11.11111111111, former Aircrew Equipment Assemblies (AEA) Trials Officer, QinetiQ Boscombe Down.
1.3 Background.
1.3.1 The Mk10A ejection seat was originally qualified for use in the Tornado aircraft in 1975. The original specification was to support a nude occupancy range of between 56.56kg and 97.34kg. It had been recognised that there was an increase in this occupancy range, therefore a new specification was introduced. Nude masses of 50.98kg, 86.64kg and 107.86kg were agreed for the minimum, medium and maximum occupant masses respectively. Along with the AEA, this gave boarding masses of between 67.49kg and 135kg. The increased ejected mass range had necessitated the inclusion of limitations into the MAR documents for both the Tornado F3 and GR4/4A with regard to the safe ejection envelope. Limitations on minimum and maximum speed ejections (also minimum ejected mass on GR4/4A) at different altitudes had all eroded the available envelope. Modifications to the ejection seat gun were necessary to satisfy the requirements for seat exit velocity and the DRI with regard to the seat occupant. It was proposed that an Optimised Ejection Gun Cartridge Set be introduced to restore gun velocity performance with an increased maximum weight occupant, whilst reducing the possibility of ejection related injury to the minimum weight occupant.
1.3.2 The increases in the masses of the aircrew, AEA and ejection seat had the effect of reducing the possible level of protection offered to the aircrew, specifically:
1.3.2.1 The attachment of the ejection seat to the aircraft structure and the retention of the pilot within the ejection seat in the event of an aircraft impact. Increases in the ejection seat and occupant mass could have had a detrimental effect on the crashworthiness of the ejection seat mounting points to the aircraft structure and the ejection seat harness integrity.
1.3.2.2 The increased ejection seat and occupant mass could also have had a detrimental effect on the clearance between the aircraft tail and the trajectory of the ejectee, particularly at higher aircraft velocities. It was critical that both the ejection seat and seat occupant for any specified mass, at ejection gun separation, had sufficient velocity to ensure that there was tail fin clearance.
1.3.3 There had been a concern with regard to the increase in the frequency and severity of lower limb injury resultant from ejection from fast jet aircraft, specifically with regard to ejections from Tornado, where a higher incidence had occurred when compared to any other aircraft type (Figure 8-1). This was investigated and a report produced by the Royal Air Force School of Aviation Medicine [1]. These injuries were mainly attributable to the aircrew hitting the ground while in the parachute during the final stages of an ejection sequence. Lower leg injury was well known, even with regard to experienced QINETIQ/AT&E/CR00782/1 Page 1 of 70 parachutists, which was compounded by the fact that a the majority of aircrew were not trained parachutists. The introduction of a steering capacity to the main parachute was designed to decrease the occurrence of lower limb injury by allowing aircrew some control over the terrain on which they would land (the cause of the majority of injuries). The GQ5000 was also introduced to moderate the descent rate and horizontal velocity of heavy weight aircrew.
1.4 Phased Introduction of Modifications.
1.4.1 A number of modifications were pr oseOpAqdress aircrew protection. The Phase One modifications previously reported ], laid a fFundation for the introduction of the Phase 4"4"--:‘"444rtio modifications. The Phase Two modifications dealt directly with the implications of an increased mass range of aircrew.
1.4.2 Phase One comprised of the following modifications:
1.4.2.1 The introduction of a taller and re-profiled ejection seat headbox and a new head pad with improved impact attenuation properties (Mod 02196). The revised headbox had an increased volume in preparation for the larger GQ5000 parachute (Mod 02198). Currently, only the GQ1000 Mk2 parachute is cleared for use.
1.4.2.2 The addition of steering lines to the GQ1000 Mk1 parachute assembly resulted in the GQ1000 Mk2 parachute assembly (Mod 02196). The revised parachute allowed the ejectee some control over the intended landing site.
1.4.2.3 The introduction of a simplified restraint harness, (Mod 02200) with a parachute steering facility, to permit integration of the GQ1000 Mk2 steering lines (Mod 02196) and allow the aircrew to strap into the seat unassisted, it also offered increased security.
1.4.3 Phase Two, the subject of this report, comprised of the following modifications:
1.4.3.1 Replacement of the GQ1000 Mk2 parachute assembly with the GQ5000 parachute and associated deployment system (Mod 02198) within the taller headbox previously introduced during Phase One modifications.
1.4.3.2 Replacement of the primary and secondary ejection gun cartridges (Mod 02197) with revised cartridges to ensure that the heavy weight ejectee was provided with sufficient velocity to clear the aircraft tail fin. The revised cartridges also had to accelerate the ejectee from a stationary position to 'escape velocity' with the minimum risk of physical injury. This was particularly important for ejectees at the lighter end of the revised aircrew mass range.
1.4.4 Where possible, the opportunity was taken to make any additional safety improvements and to verify their integrity. For example, testing of the revised simplified harness (introduced in Phase One, Mod 02200) to ensure retention of the heavy weight seat occupant during a crash situation and examination of the ejection seat to aircraft mounting points to ensure retention of the seat to the airframe structure for that same crash scenario.
1.5 Assessment Philosophy.
1.5.1 Phase Two introduced further modifications and, due to the various aircrew and equipment weight increases, it was necessary to re-consider the Phase One modifications further where appropriate. Therefore, the assessment of the fitness for Page 2 of 70 QINETIQ/AT&E/CR00782/1 purpose and safety was largely a review of evidence provided by BAE SYSTEMS (BAES) and the Martin Baker Aircraft (MBA) company, including an audit of the Phase One assessments where applicable. Due to problems during the development of the Phase Two project, QinetiQ were not represented during a majority of the practical trials.
QINETIQ/AT&E/CR00782/1 Page 3 of 70 2 Description of Equipment.
2.1 GQ 5000 Parachute Assembly (Mod 02198).
2.1.1 The GQ5000 parachute and its deployment system were developed to replace the GQ1000 (Mk1 & Mk2) parachute.. Its properties included a drive capability, a reduced rate of descent, reduced lines taught snatch load and high-speed inflation performance with low speed inflation characteristics [3]. The selectable drive capability provided an ability for aircrew to manoeuvre to avoid obstacles whilst ensuring that descent without drive selected would not injure ejectees by means of excessive horizontal velocity on landing. The high-speed inflation characteristic revolved around the varying of the canopy porosity and ensured that if the canopy were deployed at excessive speed, it would not fully inflate until a safe velocity had been attained.
2.1.2 The GQ5000 canopy had a flying diameter of 6.5m and was packed into a cotton deployment sleeve, which was placed into the headbox assembly. The deployment sleeve ensured that the only material surface in contact with the parachute canopy was cotton, thus eliminating possible searing damage. The deployment sleeve incorporated a series of mouthlocks, which allowed the deployment of the parachute in an orderly lines first sequence. This lines first sequence ensured that 'slump' was minimised and that the canopy would not deploy until parachute lines taught.
2.1.3 An additional system introduced with the integration of the GQ5000 parachute with the Mk10A ejection seat (Mod 02198) was a rapid parachute deployment system [4]. It comprised of an inflation bladder, which was located at the base of the headbox beneath the parachute, and a compressed gas storage facility and delivery arrangement, located on the underside of the headbox (Figure 8-2). The inflation bladder was pressurised with the compressed gas on the deployment cycle of the ejection sequence and aided rapid extraction of the parachute from the headbox assembly. The pressurised gas inflation system had integrated a combined piercer/gas bottle unit, with the gas bottle being charged with nitrogen (N2) at a pressure of 225 bar. The inflation system was incorporated into the Ballistic Signal Transmission System (BSTS) of the BTRU/MOR circuit, which resulted in the bladder inflation sequence initiating when either the BTRU or MOR cartridges were fired.
2.1.4 Due to the introduction of the GQ5000 parachute and its associated deployment system (Mod 02198) it was necessary to fit BTRU/MOR cartridges with increased performance. The incorporation of the bladder inflation pipeline assembly, required to operate the piercing system, as well as the new gas operated release shackle, had increased the overall gas volume of the BTRU/MOR circuit. The uprated BTRU/MOR cartridges were to provide sufficient pressure under minimum pressure conditions (maximum system volume and low temperature) to initiate all relevant seat devices. It was also necessary to ensure that under maximum pressure conditions (minimum system volume and high temperature) the ballistic gas pressure did not rupture the ballistic gas circuit.
2.1.5 The mass of the GQ5000 parachute and sleeve together was 6.7 kg (Mod 02198). The original Phase One modification of replacing the headbox with a headbox of increased volume allowed the stowage of the GQ5000 parachute, deployment sleeve and inflation bladder.
Page 4 of 70 QINETIQ/AT&E/CR00782/1 2.2 Simplified Combined Harness Assembly.
2.2.1 The revised simplified combined harness assembly (introduced in the Phase One modifications) was intended to replace the original combined harness assembly, so named due to its role as a restraint for the occupant within the ejection seat in addition to acting as a parachute harness. The simplified aspect revolved around unassisted strapping in and as such offered quicker ingress times. The harness was also introduced to provide the benefits of safer restraint and an increase in aircrew confidence/security.
2.2.2 The addition of steering lines to the GQ1000 parachute within Phase One modifications required the incorporation of a steering facility integrated into the harness. The new harness fastened positively around the torso, which avoided creating a gap behind the aircrew at shoulder level when leaning forward. It also stopped harness migration off of the aircrew shoulder when looking aft. The harness was also compatible with the GQ5000 parachute (Mod 02198).
2.2.3 The simplified combined harness was in use in Harrier, Tucano and Jaguar aircraft.
2.3 BTRU/MOR Cartridges.
2.3.1 The BTRU/MOR cartridge assembly, MBEU 98777 issue 2, was a cylindrical brass case containing discs of a propellant and magnesium powder [5]. The cartridge was initiated via a firing pin striking a percussion cap at the firing end. On initiation, high-pressure ballistic gas was generated, which exited a hole in a washer assembly after rupturing a bursting disc. The dimensions of the revised cartridge were the same as its predecessor, therefore not requiring an alteration to any other hardware.
2.3.2 The BTRU was a cartridge operated unit, which in the ejection sequence controlled the release of the drogue parachutes, deployment of the main parachute and release of the occupant from the seat. However, it inhibited these operations until environmental conditions were safe for them to occur. There were two types of inhibitor within the assembly, a barostat and a G-controller.
2.3.2.1 The barostat prevented operation until the seat fell below a pre-determined height. This height could be either 10,000ft or 5,000m dependant on the fitment of an adapter ring to the barostatic capsule.
2.3.2.2 The G-controller prevented operation at altitudes over 7,000ft and G-loading in excess of +2.5g. The system remained inhibited if the seat fell below 7,000ft whilst the G- loading remained in excess of +2.5g. If the system were to be operated below 7,000ft, then the G-controller would allow operation, regardless of G-loading.
2.3.3 A trip rod attached to the ejection gun crossbeam was operated as the seat rose. This in turn removed the sear from the BTRU, which initiated a 1.5-second delay to allow the seat to clear the aircraft and for the drogues to deploy. Once the delay period was completed, unless inhibited as previously described (para's 2.3.2.1 and 2.3.2.2), the firing pin would be allowed forward under spring pressure to fire the BTRU cartridge and commence the release sequence.
2.3.4 The MOR contained a cartridge which, in the event of BTRU and/or drogue gun failure, was fired by the operation of the manual separation handle. The hot, high pressure gases from the MOR cartridge travelled through a tube to the BTRU where they face
QINETIQ/AT&E/CR00782/1 Page 5 of 70 fired the BTRU cartridge, as well as passed to the drogue gun secondary firing unit. Operation of the BTRU and the drogue gun would then continue as specified.
2.3.5 During the course of the trials, the original 'scissors' shackle was replaced with a GS, which necessitated removal of the mechanical 'scissors' shackle operating mechanism from the BTRU and its replacement with a pipe to supply ballistic gas to the new GS [6] (Figure 8-3 and Figure 8-4).
2.4 Primary and Secondary Gun Cartridges (Mod 02197).
2.4.1 The ejection gun provided the initial thrust on the ejection seat on ejection sequence initiation and was powered by one primary and two secondary cartridges [7] [8] (Figure 8-5). The gun consisted of an outer cylinder, which contained two telescopic piston tubes, giving a gun stroke of 1.83 metres.
2.4.2 The primary cartridge assembly, MBEU 62377-2 issue 1 was a cylindrical brass case containing nitro-cellulose and gunpowder propellant. The cartridge was initiated via a firing pin striking a percussion cap at the firing end. On initiation, high-pressure ballistic gas was generated, which exited a hole in a washer assembly after rupturing a bursting disc.
2.4.3 The secondary cartridge assembly, MBEU 115912 issue 1 was a cylindrical brass case containing nitro-cellulose and gunpowder propellant. After the rupturing of a bursting disc, the ballistic gas from the primary cartridge initiated the secondary cartridges within the ejection gun (face fired).
2.4.4 The primary cartridge Nitro-cellulose filling was reduced from 630 grains to 570 grains and the secondary cartridges were increased from 680 grains to 760 grains. The reduced primary cartridge filling was to allow a reduced DRI during the primary cartridge phase of operation — this was where the injury risk to the ejectee was at its highest. The initial cartridge design and fillings were optimised utilising a thermo-mechanical model and then tests were carried out of the performance at ambient temperature. The results of the tests were then utilised to verify predicted performance.
2.4.5 The inner piston tube of the ejection gun incorporated the BTTDFU and was attached to the seat structure at its upper end. Due to the replacement of the 'scissors' shackle with the GS drogue bridal release system (discussed later in this report), there was insufficient space for the original BTTDFU and its associated sear and sear removal system [6] and was replaced by the GFTDU (Figure 8-6 and Figure 8-7).
2.5 Aircraft Canopy and Associated Jettison System.
2.5.1 The Tornado canopy was an assembly constructed from a stretched acrylic transparency manufactured in two sections, joined by an aluminium alloy strap [9]. The assembly had a mass of around 140kg [10]. It was hinged and pivoted at the rear, providing access to the front and rear cockpits.
2.5.2 The canopy was raised and lowered hydraulically by a single canopy jack, with the locking being carried out mechanically via a shootbolt mechanism [11]. Internal handles in each cockpit and an external handle on the front left-hand side of the fuselage controlled canopy movement.
2.5.3 Jettisoning of the canopy was accomplished via two rocket motors, situated one each side at the forward corners. Actuation of the Canopy Jettison System (CJS) was Page 6 of 70 QINETIQ/AT&E/CR00782/1 initiated by either operation of the canopy jettison handle, or as part of the automatic ejection sequence.
2.5.4 The jettison sequence commenced with either the ejection sequence or the canopy jettison handle operating the canopy jettison initiator unit [7] (Figure 8-8). The initiator unit comprised of two breech units in a main body, a bell-crank and a piston unit. Expending gases, generated by the firing of the unit cartridges, were fed to the Canopy Unlocking Jacks (CUJ's) and canopy jack mechanism via two outlet connections [12].
2.5.5 The expanding gases detached the canopy jack by operation of the canopy jack release mechanism, which activated the canopy jack trunnion assembly release plunger.
2.5.6 The expanding gases also rotated the locking/unlocking torque shaft via the CUJ's which unlocked the canopy and withdrew•the sears from the canopy rocket motor firing units. This caused the rocket motors to ignite, with the rocket efflux rotating the canopy assembly on its hinges away from the fuselage via nozzle assemblies (Figure 8-9).
2.5.7 As the canopy ascended, the hinges rotated around the link assembly hinge bolts until tongues at the centre of the link assembly's contact the rear of the hinge brackets. The canopy continued to rotate and sheared the centre link assembly at a machined slot (designed weak point) which freed the canopy from the hinge bracket and transferred the canopy from the aircraft separation phase to complete jettison.
2.5.8 If either of the CUJ's failed to operate during the jettison phase, the respective sear would not be withdrawn from the rocket motor firing unit, resulting in the CJS operating with only a single rocket motor.
QINETIQ/AT&E/CR00782/1 Page 7 of 70 3 Assessment of Evidence.
3.1 GQ 5000 Parachute and Bladder Inflation System Zero/Zero.
3.1.1 Between October 1998 and June 1999, MBA conducted several trials to verify that the integration of the GQ 5000 parachute and bladder inflation system (Mod 02198) would not adversely affect the survivability of aircrew during a zero/zero ejection sequence. These trials were described in a MBA document [13] and addressed seat installation and performance with differing mass seat occupants. Information on the type of test dummy utilised and the methods of data acquisition are detailed within each of the reports.
3.1.2 All ejections within the MBA zero/zero trials were conducted via a Seat Test Department (STD) 'A' frame, which provided the correct installation angle of 20° back from the vertical, indicative of the Tornado aircraft. The ejection gun utilised in the tests contained the revised primary and secondary cartridges, the assessment of which will be discussed later in this report.
3.1.3 A zero/zero performance trial was conducted and documented by MBA [14] (dummy mass 135kg, total ejected mass 241kg) in late September 1998, which was successful with regard to parachute deployment and parachute inflation characteristics essential to zero/zero ejection sequences.
3.1.4 However, an identical trial conducted in mid October 1998 [15], (dummy mass 135kg, total ejected mass 241kg) resulted in the failure of the main parachute to correctly deploy, allowing the seat and trial dummy to impact the ground at a high velocity. An investigation into the incident concluded that "the orientation of the seat whilst describing its trajectory resulted in the shackle failing to release the drogue in sufficient time for the main parachute to be correctly deployed". Although the Time Release Mechanism (TRM) of the seat fired at the desired point during the ejection sequence, the drogue failed to immediately release due to the orientation of the seat. The seat orientation caused the drogue to be geometrically locked in the open 'scissors' shackle, and it was released only when the seat had obtained sufficient forward pitch.
3.1.5 Due to the failure of the MBA trial in mid October 1998 [15], the 'scissors' shackle mechanism was replaced with a GS drogue bridle release system, incorporating associated modifications to the BTRU and the GFTDU. The GFTDU modification was a replacement for the original BTTDFU. The originally fitted BTTDFU required the removal of a sear pin via the rotation of a shaft in order that the ejection gun primary cartridge fired after a pre-determined time delay. Due to the introduction of the GS drogue bridal release system, there was insufficient space available for the BTTDFU and associated operating system. The GFTDU did not require a rotating shaft or sear pin assembly for activation, it only required a pipe to transfer high pressure ballistic gas to its initiating cartridge [6] (Figure 8-6 and Figure 8-7). Modifications were also made to the Seat Initiation Ballistic Signalling Transmission System (SI BSTS) circuit for the GFTDU. An MBA trial [16], (dummy mass 135kg, total ejected mass 241kg) was carried out incorporating the previously mentioned modifications, and was successful. However, at one point during the trial ejection sequence, the test dummy feet crossed through the parachute rigging lines. This was due to the orientation of the seat relative to the deployed parachute canopy and was recorded as 'momentary', with entanglement being averted once the parachute canopy began to inflate.
Page 8 of 70 QINETIQ/AT&E/CR00782/1 3.1.6 A further trial was conducted by MBA [17], (dummy mass 68kg, total ejected mass 174kg) and was successful, with no re-occurrence of the dummy feet interacting with the parachute rigging lines.
3.1.7 MBA conducted a further trial in mid May 1999 [18] (dummy mass 135kg, total ejected mass 243kg) which was also recorded as a success, with all parameters being met.
3.1.8 A further MBA trial [19], (dummy mass 103kg, total ejected mass 211kg) again produced a successful result with regard to ejection parameters.
3.1.9 A final MBA report [20] highlighted the advantages of the GQ5000 parachute over the earlier GQ1000 design with regard to ejection during a zero speed/zero height scenarios. The GQ5000 decent rates were improved for all dummy mass configurations when compared to those of the GQ1000.
3.1.10 It is unknown if a QinetiQ representative was present at any of the zero/zero trials. However, it is considered that the evidence provided within the reports is sufficient for QinetiQ to support the integration of the GQ5000 parachute and bladder inflation system (Mod 02198) onto the Mk10A ejection seats fitted to the Tornado GR4/4A and F3 aircraft for zero/zero ejection events. The replacement of the 'scissors' shackle mechanism by the GS bridle release system and all other related modifications to the BTRU was considered acceptable. The replacement of the BTTDFU with the GFTDU along with modifications to the SI BSTS, brought about by the introduction of the GS bridle release system, was also considered acceptable. The evidence provided in the reports of the performance of the revised ejection gun, with regard to propelling the ejection seats and occupants (specifically the heavy weight occupant in the rear seat) to a sufficient altitude (with the help of the rocket pack) at zero speed and zero height for all ejection sequence events to be carried out successfully, was found to be acceptable. The improved rates of decent of all seat occupants, due to the characteristics of the GQ5000 parachute [20], in a zero/zero situation were also found acceptable. On the one occasion that the parachute failed to deploy/inflate fully, the cause was found to be due to a geometric lock of the drogue within the 'scissors' shackle. This problem was satisfactorily addressed with the introduction of the GS bridle release system with no re-occurrences of parachute canopy inflation failure during the remainder of the trials.
3.2 GQ 5000 Parachute and Bladder Inflation System 625Kts.
3.2.1 In May 1999, MBA conducted a trial to verify that the integration of the GQ 5000 parachute and bladder inflation system (Mod 02198) onto the Mk10A ejection seat, would not adversely affect the survivability of aircrew during an ejection sequence at 625Kts and zero height. This trial was described in a MBA document [13] with regards to seat incorporation and performance with the maximum and minimum mass occupant. Information on the type of test dummies utilised and the methods of data acquisition are detailed within the MBA trial report.
3.2.2 The MBA trial [21] involved the integration of two ejection seats into a BAES fuselage representative of the Tornado aircraft. This was located on a sled track so that the seats ejection sequence could be initiated at the required forward velocity of 625Kts. The fuselage was also fitted with an aircraft canopy (unpressurised) and an Inter-seat Sequencing System (ISS). The front seat occupant was a 3%ile simulated subject (68kg mass) and the rear seat occupant was a 98%ile simulated subject (135kg mass).
QINETIQ/AT&E/CR00782/1 Page 9 of 70 The ejection gun utilised in the test contained the revised primary and secondary cartridges, the assessment of which will be discussed later in this report.
3.2.3 Canopy Jettison (CJ), utilising rocket motor assistance, was seen to commence at 0.06s after test initiation, with the rear seat first motion being recorded at 0.29s and the front seat at 0.77s. The canopy broke at a release angle of approximately 60°.
3.2.4 The results recorded for the rear seat occupant ejection event (98-percentile) were successful, showing full parachute canopy inflation at 2.82s at a height of 36 feet above ground level. On completion of the trial, the rear seat ejection gun (retained on the aircraft sled) was found to be bent, which resulted in the collar holding one of the secondary cartridges into the gun being split. The magnitude of the loads created during the high-speed test was blamed for the distortion and it was not believed to have had a detrimental effect on the rear seat trajectory.
3.2.5 The results recorded for the front seat occupant ejection event (3-percentile) were also successful, showing full parachute canopy inflation at 2.94s at a height of 78 feet above ground level.
3.2.6 The MBA trial [21] concluded, "The overall performance of the twin seat system was satisfactory. The canopy was jettisoned safely, both seats were ejected with satisfactory trajectories and both dummies were recovered on full parachutes". However, the trial report indicates that the test speed was 608Kts at the time of ejection initiation and not the 625Kts that was originally planned.
3.2.7 The final MBA report [20] highlighted the fact that the GQ5000 parachute design allowed improvements over the GQ1000 parachute with regard to the peak loads experienced by the test dummies during a high speed/zero height ejection scenarios. The peak deceleration at parachute 'lines tight' (heavy weight occupant) for the GQ5000 parachute was 11.54g, compared to the 24.42g of the GQ1000 parachute. The peak inflation load (heavy weight occupant) for the GQ5000 parachute was 16.28g, compared to the 22.12g of the GQ1000 parachute. The peak deceleration at parachute 'lines tight' (lightweight occupant) for the GQ5000 parachute was 16.78g, compared to the 35.2g of the GQ1000 parachute. However, the peak inflation load (lightweight occupant) for the GQ5000 parachute was 19.55g, compared to the 14.52g of the GQ1000 parachute. This was attributed to a lighter weight manikin being used in the GQ1000 test, which was supported by a reduction in the GQ1000 parachute inflation time of approximately 0.2s.
3.2.8 No representative for QinetiQ was present during the 625Kts/zero-height sled test. However, the evidence provided by the report [21] was found to be sufficient for QinetiQ to support the integration of the GQ5000 parachute and bladder inflation system (Mod 02198) onto the Mk10A ejection seats fitted to the Tornado GR4/4A and F3 aircraft for ejection at 608Kts and zero height. The reduction in loads experienced by the seat occupants in all but one instance was found to be acceptable [20]. Where a slight deterioration in performance was noted (lightweight seat occupant inflation load), it was concluded that a lighter dummy had been utilised during the testing of the GQ1000 parachute. The evidence provided in the report [21] of the performance of the revised ejection gun, with regard to propelling the ejection seats and occupants (specifically the heavy weight occupant in the rear seat) to a sufficient altitude at 608Kts and zero height (with the help of the rocket pack) for all ejection sequence events to be carried out successfully, was found to be acceptable.
Page 10 of 70 QINETIQ/AT&E/CR00782/1 R1€014\1... I ad
3.3 GQ 5000 Parachute and Bladder Inflation System Environmental Qualification.
3.3.1 The MBA produced QTR [5], investigated the performance of the headbox fitted with the GQ5000 parachute assembly and inflation system (Mod 02198) with regard to its operational ability after extremes of environmental conditioning. Each of the environmental trials were provided with a test number, with a separate number being issued for the operational test of the BSTS after each of the environmental conditioning phases. The tests were carried out to satisfy the requirements of the Panavia Equipment Specification for Tornado [22] and to demonstrate that the enhanced Mk10A ejection seat complied with the program requirements and qualified the seat and its components for service release in accordance with appropriate standards and specifications.
3.3.1.1 High temperature exposure (ET3237HT). The headbox, whilst fitted with the GQ5000 system, was exposed to +90°C for a period exceeding 48 hours before being returned to ambient temperature conditions [5]. A visual examination was subsequently performed on the assembly. During the post-test visual examination, the headpad was found to be imprinted with marks from the chamber rack on which it had rested. However, there was no other evidence to suggest that the headbox and GQ5000 assembly had suffered any other damage or deterioration during the test. In preparation for the BSTS trial (ET3237B2), the piercer unit of the bladder inflation system was removed for instrumentation and was found not to have been initiated by high temperature exposure. The reassembled headbox was then soaked at +70°C for a period of 2hrs. The following BSTS trial resulted in the packed parachute being 'vigorously ejected' from the headbox well within the specified time period. Post trial investigation found that the bladder was fully inflated and retained its pressure until manually deflated.
3.3.1.2 Low temperature exposure (ET3237LT). The headbox, whilst fitted with the GQ5000 system, was exposed to -60°C for a period exceeding 24 hours before being returned to ambient temperature conditions [5]. A visual examination of the assembly post-test revealed no evidence of damage or deterioration and its appearance was unchanged from pre-test condition. In preparation for the BSTS trial (ET3237B3), the piercer unit of the bladder inflation system was removed for instrumentation and was found not to have been initiated by low temperature exposure. The reassembled headbox was then soaked at -40°C. The following BSTS trial resulted in a failure of the bladder by rupture of the bladder material. Further investigation showed that the bladder had split along a material overlap seam, initiating from a convergence of several crease lines. The failure of the bladder resulted in the bagged parachute being only partially ejected from the headbox. The bladder was returned to the manufacturers, (Beaufort) who examined the component and produced a report [23] stating that the material from which the bladder was manufactured had been utilised outside of the design parameters for a two ply butyl fabric. The material tests encompass a temperature range of -40°C to +70°C. However, MBA had previous experience of the material being utilised at a low temperature of -54°C, where no recorded failures had occurred. Further trials were proposed by MBA at a higher temperature of -54°C with an application for a waiver from the National Design Approval Authority Representatives (NDAAR). All other components comprising the test item, which had been exposed to -60°C, functioned satisfactorily and therefore met the success criteria. MBA conducted a further low temperature exposure BSTS test (ET3237B3/3) on a new item of the same type at a temperature of -54°C, which provided satisfactory evidence of bladder inflation without rupture.
QINETIQ/AT&E/CR00782/1 Page 11 of 70 'RESTRICTED-
3.3.1.3 In a Performance Enhancement Programme Review meeting at the NATO EF2000 and Tornado Development, Production and Logistics Management Agency (NETMA) on 3rd November '99 [24] MBA/BAES recommended that a deviation to the current seat specification be adopted in regards to low temperature exposure. MBA/BAES asked that the temperature limit be raised from -60°C to -50°C to provide margin for the N2 inflation bladder operation, which had been successfully tested at -54°C. It was noted that the Military Aircraft Release (MAR) operating limits for the Tornado aircraft were -25°C. In the NETMA meeting [24] it was agreed that the proposed new higher temperature limit of -50°C could be accepted, as the Release to Service indicated that -25°C was the minimum temperature at which the Tornado aircraft could take off after storage in a hangar or Hardened Aircraft Shelter (HAS).
3.3.1.4 Humidity Test (ET3237HU) and Salt Fog Test (ET3237SF). The headbox, whilst fitted with the GQ5000 system, was exposed to the 24 hour humidity cycle described in MIL- STD-810B, Method 507, Procedure 1 for two continuous cycles (48 hours). Following this, the humidity level was increased to a constant 98% Relative Humidity (RH) with the temperature cycle remaining unchanged. This exposure continued for a further 8 continuous cycles (192. hours). On completion of the ten cycles, the test item was extracted from the chamber and allowed to return to ambient temperature and humidity conditions. On visual inspection of the headbox assembly, a small amount of separation of the headpad covering from the lower edge of the headbox aluminium top skin was detected. However, there was no other evidence that the test item had suffered damage or deterioration during the test. The headbox and GQ5000 assembly (Mod 02198) was then introduced into a salt fog chamber where the temperature was raised to +35°C and maintained for 2 hours before the introduction of the salt solution. The salt fog fallout rate and the solution value were recorded every 24 hours at two positions within the chamber. After 48 hours the test item was removed from the chamber and subjected to a visual examination. A period of 48 hours was then allowed for the test item to dry under atmospheric conditions and then a further visual examination was performed. The results of the visual examinations were that the general appearance of the headbox was good, with no evidence of corrosion. It was also noted that the headpad delamination from the headbox was no worse than before the salt fog test began. Slight staining of the piercer locknut and the free end of the piercer manifold hose assembly were found, but it was considered that this was of minor cosmetic implication only and would not affect the function or fit of the test item. During the set up for the BSTS test, examination of the piercer unit showed that neither the humidity nor the salt fog test caused initiation. On completion of the BSTS trial (ET3237E7), the test item functioned correctly with regard to the bladder and inflation equipment. This result concluded that the test item satisfied the success criteria for both the salt fog and humidity tests. A further test sequence was conducted utilising a different adhesive process for bonding the headpad to the aluminium skin, which produced a satisfactory result. With this modification, the entire headbox and GQ5000 parachute system satisfied the test success requirements. It was noted that the humidity test was in fact more aggressive than required by the Equipment Specification [22] with exposure to higher temperature and humidity levels.
3.3.1.5 Sand and dust test (Test House Certificate 9424 — Cape Engineering). The headbox and GQ5000 parachute system (Mod 02198) was exposed to dust in a sand and dust chamber for a period of 12 hours in total, in two separate condition types. During the dust test, it was not possible for the humidity to be controlled to a level specified in MIL- STD-810B Method 510, as there was no UK facility available that could achieve the desired control. The low humidity issue was to reduce the potential for clogging of the dust delivery system, but during the test none was evident and therefore the deviation
Page 12 of 70 QINETIQ/AT&E/CR00782/1 was considered acceptable. After the exposure period was concluded accumulated dust was shaken from the test item and a visual examination took place. There was no evidence of damage or deterioration to the test item as a result of exposure to the dust test. The piercer unit was also inspected and found not to have been initiated. On completion of the BSTS trial (ET3237GS/G8) the unit was found to function satisfactorily and exhibited no degradation attributable to the dust test. The post-test Marginality of Success (MOS) examination was also satisfactory.
3.3.1.6 Vibration and shock tests (Test House Certificate, Report Number ENV/IHC/4522 — MATRA Marconi Space UK LTD). An anthropomorphic dummy, wearing representative AEA was harnessed to a seat throughout the trials. The mass of the occupant for the vibration tests was 103.9kg and for the shock tests, 135kg. Although the entire ejection seat assembly was utilised, the tests were focused on the BSTS and headbox assemblies, with the seat acting as a realistic support and interface. The tests were comprised of resonance search, resonance dwell, and sinusoidal cycling followed by shock testing in three mutually perpendicular axes (designated X, Y and Z). On completion of the vibration tests in the first axis, the shock test was carried out in that axis after replacing the 103.9kg dummy with the 135kg version. The unit was then visually examined prior to testing in the next axis. This procedure was continued until all trials had been completed on all axes. There then followed a final examination of the seat structure with particular reference to the headbox, bladder connection, N2 bottle and piercer assembly, along with a pressure test of the ballistic circuit. The piercer assembly was also removed and subjected to a radiographic examination. The results of the tests showed that there was no structural damage to the seat assembly, other than local deformation of the headpad due to contact with the dummy's head. This damage was due to the fact that the dummy was not sufficiently flexible in the neck region, which resulted in the helmet being forced into hard contact with the headpad for the duration of the tests. This was not however, representative of a live seat occupant. There were other anomalies noted during the post-test examination of the seat assembly, all of which were deemed to have been minor in nature with no further action being required. Details of the other anomalies can be found in the MBA QTR [5] 5.9.6 & 5.9.7. Initiation of the piercer assembly (and therefore inflation of the bladder) had not occurred throughout the tests and the parachute remained in its packed condition with all flaps secured. The BSTS test was scheduled to be completed after acceleration testing. The results of the vibration and shock tests on the seat assembly were deemed to have satisfied the success criteria.
3.3.1.7 Acceleration test (CENT 045). The seat assembly, post vibration and shock test, was then fitted with an anthropomorphic dummy dressed in flying overalls, with a total mass of 135kg, simulating a maximum weight occupant. Although the entire ejection seat assembly was utilised, the tests were focused on the BSTS and headbox assemblies, with the seat acting as a realistic support and interface. The seat was then attached to a centrifuge arm by the upper and lower gun tube attachment points using suitable test fixtures. During the trial, the seat was adjusted to one of six different directions, or axes, with visual examinations being performed after each axis. The centrifuge was accelerated gradually until stable at the required speed, which was maintained for a duration of one minute. The centrifuge speeds were derived from the requirements of SP-72001-OOP and produced (aft) 7.08g, (up) 11.67g, (forward) 2.83g, (down) 5.1g and (port/starboard) 3.9g. On completion of the final axis of testing, the seat structure, with particular reference to the headbox, bladder connection, N2 bottle and piercer assembly was visually examined. The piercer was also removed from the headbox and subjected to radiographic examination. Examinations of the assembly carried out in between each test axis revealed no evidence of structural damage, which was confirmed by the final QINETIQ/AT&E/CR00782/1 Page 13 of 70 inspection. A radiographic examination of the piercer unit found that the piercer piston had remained in position and initiation had not occurred. The headbox had also remained in its 'as-packed' condition. On completion of the BSTS trial (ET3237GSC1) the unit was found to function satisfactorily and exhibited no degradation attributable to the vibration, shock or acceleration tests, with the parachute being ejected from the top of the headbox well within the specified time period. Subsequent examination revealed that the bladder was fully inflated and retained pressure until manually deflated. The test item was deemed to have achieved the success criteria of the tests.
3.3.2 Further environmental trials were required to ensure that any resurgence of the GQ5000 parachute within the headbox assembly (Mod 02198) was not going to compromise the free space between the headbox and the canopy. Although the headbox with GQ5000 parachute had already been fully qualified and reported in MBA QTR [5], further tests were completed and reported in MBA QTR [25]. During the MBA trial, the height of the headbox was obtained by measuring from the lower mounting attachments to the top of the flaps. A tri-square was used to gently push the flaps to the point at which resistance was felt and was repeated across the upper surface, with the maximum dimension of 446mm height of the headbox being recorded. During the measurement of the headbox height by MBA, the lower mounting attachments were included in the overall height. Later measurements carried out by BAES (paragraph 3.4.5 and 3.4.6 of this report) were taken from the base of the headbox container and did not include the mounting attachments. The following tests were then conducted:
3.3.2.1 Altitude cycling (3476 ALT). The test item was introduced into a temperature and altitude chamber. After setting a constant temperature of +20°C and after 30 minutes conditioning, the test item was cycled a total of 75 times from sea level to 40,000 feet. The climb to 40,000 feet was carried out at the maximum chamber climb rate, where the test item remained for 1 hour. At the end of the 75 cycles, the test item was re- measured and a value of 446mm was recorded. The test report concluded that the packed headbox was unaffected by excursions to altitude.
3.3.2.2 High temperature testing (3476 HTE). The test item was introduced into a conditioning chamber and the temperature was increased to +70°C, where it was maintained for a period of 48 hours. After the 48-hour trial period, the chamber was set to ambient conditions and the test item allowed to stabilise. At the end of the high temperature cycle, the test item was re-measured and a value of 448mm was recorded. The test report concluded that the high temperature test had resulted in 2mm resurgence in the direction of the aircrew spinal column.
3.3.2.3 Vibration testing (3476 VIB). The test item was attached to representative vibration test fixture blocks and was subjected to the specified random and gunfire vibration spectra for a period of 12.5 hours in each of the X, Y and Z-axes. The test item was removed from the test fixings after each of the vibration cycles in one of the axes and then re- measured. After the measurement of the headbox height, the test item was refitted to the test fixings and the vibration test was carried out in the next axis. This was continued until vibration tests had been completed in all three of the axes. At the end of the tests it was reported that a further 2mm resurgence had occurred in the Y (or lateral) axis, with no resurgence occurring in the X and Z-axes.
3.3.2.4 The MBA report [25] on the intensive environmental programme for the headbox assembly, with regard to resurgence and the possible loss of clearance between the headbox and aircraft canopy provided evidence that the height of the packed headbox increased by a margin of 4mm in the worst case.
Page 14 of 70 QINETIQAT&E/CR00782/1 3.3.3 The evidence provided in the QTR [5] with regard to the results of tests carried out on the GQ5000 parachute and bladder inflation system (Mod 02198) concerning high/low temperature, sand and dust, shock and acceleration, vibration and humidity exposure were found to be satisfactory. The failure of the two ply butyl fabric bladder during the low temperature trial was not considered significant in relation to the aircraft cold limit of -25°C. The test was successfully repeated at -54°C and a concession of -50°C against the original specification was granted by NETMA. QinetiQ are satisfied with the successful test conducted at -54°C. All anomalies which occurred to the assembly during the trials were deemed to have been purely cosmetic (no effect on form or function) or minor in nature. Resurgence of the GQ5000 parachute from the packed headbox assembly was limited to 4mm after cyclic altitude, high temperature and vibration testing. Therefore QinetiQ supports the integration of the GQ5000 parachute and associated deployment system onto the Mk10A ejection seat fitted to the Tornado GR4/4A and F3 aircraft with regard to environmental conditions and possible packed parachute resurgence.
3.4 GQ 5000 Parachute and Bladder Inflation System Canopy Clearance.
3.4.1 With the introduction of the Phase One GQ1000 Mk2 parachute assembly, concerns were raised with regard to the proximity of the top of the headbox to the underside of the aircraft canopy. Specifically, the distance from the fabric top flap of the headbox and the LCC of the canopy. A BAES trial [26] proved that damage would occur to the top flap of the headbox packed with a GQ5000 parachute (Mod 02198) if touching the LCC during detonation. It should be remembered that initiation of the LCC would only occur in the event of a failure of the rocket motors of the Primary Canopy Jettison System (PCJS) (Figure 8-10). Because of the damage sustained in the trial, the fabric top flap was redesigned to incorporate a kevlar material insert, which was cross-stitched into place below the top surface. This modification was proven to sustain no damage after detonation of the LCC whilst in contact with the GQ5000 parachute fabric top flap in a further test (Figure 8-11).
3.4.2 The BAES report [26] stated that after the required 12mm seat movement (necessary to initiate the LCC if the PCJS failed) there remained a positive clearance of 1-3mm from the top of the headbox to the underside of the aircraft canopy when packed with the larger GQ5000 parachute (Mod 02198). However, this was not considered an adequate clearance. In order that the height of the headbox could be reduced with minimum of change, BAES/MBA reviewed the configuration of the DWL, which sits under the fabric top flap at the centre of the headbox. Minor changes to the stitching pattern and a reduction of the armoured sleeve around the DWL provided a significant reduction in headbox height and thus increase headbox to canopy clearance. The armoured sleeve was originally incorporated to protect the DWL from damage on ejection seats that physically broke through aircraft canopies. This system does not require the top of the ejection seat to physically break through the aircraft canopy, therefore a reduction in the length of the armoured sleeve would not be detrimental to the DWL operation. The fitting of the new fabric top flap and the alterations of the DWL resulted in slight differences to those tested in the MBA QTR [5]. It was therefore deemed necessary to carry out a trial deployment of the newly modified headbox to prove the changes had no effect on operation. The GQ5000 headbox (Mod 02198) was pre-conditioned with a high temperature soak at +70°C followed by deployment firing of the drogue gun and bladder inflation system [26]. The test was successful, with no variation in the deployment in comparison to the initial standard used in the qualification testing.
QINETIQ/AT&E/CR00782/1 Page 15 of 70 3.4.3 Tolerances were then considered between the IDS and ADV type aircraft [26] with regard to dimensional variations in canopy transparencies to supporting frame structure on 12 aircraft canopies and a cockpit structure review by the BAES Design Office. The canopy measurements were taken from the canopy sill structure, via a perpendicular line, to the underside of the canopy above the rear seat position. The results showed that the canopies varied in height by +/- 0.5mm. Tolerance build-up resulting from manufacturing limits of the overall cockpit structure was then considered. A tolerance of +/- 0.25mm was noted for positioning of the rear seat brackets to the rear pressure bulkhead and the Navigators floor. The accuracy in position of the rear pressure bulkhead to the Navigators floor was +/- 1.0mm. This resulted in an accumulated tolerance in the height of the seat in the airframe of +/- 1.25mm. When added to the canopy tolerance, a total tolerance of +/- 1.75mm between the headbox and the aircraft canopy was calculated. The manufacturing tolerance of the headbox was then considered and MBA issued a statement thus, "When packed with a parachute canopy and drogues, in either Phase One (GQ1000 Mk2) or Phase Two (GQ5000) configuration it is considered that the dimensional tolerances will have no impact on the ejection seat to aircraft canopy clearance issue with the exception of the parachute packed height".
3.4.4 In response to a query by the RAF, the BAES Design Office confirmed that the configurations between the IDS and ADV Tornado aircraft were found to be identical with regards to seat mounting to canopy position and all key datum's.
3.4.5 An installation trial was carried out at RAF Marham on an IDS variant aircraft (24th April 2002). The report for this trial is yet to be issued (BAE/WPM/RP/TOR/CRW/1733 Issue 1) but was witnessed by the author. A headbox with GQ5000 parachute (Mod 02198) with the new DWL and top flap (headbox packed height 400mm) was attached to the ejection seat beams and the canopy lowered. During the measurement of the headbox height by BAES, the lower mounting attachments were not included in the overall height. Measurements carried out previously by MBA (paragraph 3.3.2 of this report) included them. In the Marham trial, a much improved canopy clearance of 25mm was recorded.
3.4.6 A further trial was completed at RAF Coningsby on an ADV aircraft (15th May 2002). The same procedure was followed and the GQ5000 headbox (Mod 02198) was found to give 26mm clearance to the aircraft canopy (headbox packed height of 401mm). The results of this trial are also yet to be issued (BAE/VVPM/RPTTOR/CRW/1733 Issue 1) but were witnessed by the author.
3.4.7 The clearance between the front corner rims of the headbox and the aircraft canopy was questioned by the Tornado Integrated Project Team Quality Assurance representatives (IPT QA). The BAES Design Office had shown that there was a clearance of 26mm from the front corners of the headbox and the aircraft canopy inner surface. This was confirmed by the trial at RAF Marham [26].
3.4.8 QinetiQ support the evidence provided by the Marham and Coningsby trials with regard to the clearance between the GQ5000 packed headbox and the underside of the canopy. The evidence produced for the modification to the fabric top flap and the DWL, with the subsequent deployment trial was found to be acceptable. QinetiQ therefore supports the integration of the GQ5000 parachute and bladder inflation system onto the Mk10A ejection seat fitted to the Tornado GR4/4A and F3 aircraft with respect to the available clearance between the headbox fabric top flap and the aircraft canopy (LCC). It had been shown that the fabric top flap was resistant to damage by the LCC even if in direct contact on LCC detonation.
Page 16 of 70 QINETIQ/AT&E/CR00782/1 3.5 Simplified Combined Harness Assembly.
3.5.1 In order that the dynamic loading of the parachute harness, experienced during canopy inflation with the enhanced large occupant mass could be assessed, MBA derived a trial procedure [27].
3.5.1.1 The trial revolved around a 98-percentile dummy, dressed in helmet, boots and flight coveralls seated in a Mk10A Tornado ejection seat. The dummy was ballasted to 135kg to represent a heavy weight occupant and was configured in the parachute harness under test in the appropriate sitting position (with the seat pan at the lowest extent of travel).
3.5.1.2 The seat harness locks were to be released enabling the test subject to be removed from the seat, whilst remaining attached to the parachute harness and Personal Survival Pack (PSP) (ballasted to give a total mass of 16kg). Removal of the dummy, harness and PSP from the seat in this manner ensured the appropriate mass representative test configuration was provided with the dummy and harness held in the correct position.
3.5.1.3 A dynamic tensile load was then transmitted to the test harness through parachute rigging lines attached to a ballistically deployed mass. A peak acceleration of between 20 — 40g in the Z-axis relative to the dummy was desired, although any value over 20g was considered acceptable. Three accelerometers were required to gather data from the X-axis (forward of the test dummy), Y-axis (viewed through the side of the test dummy) and the Z-axis (in line with the spinal column of the test dummy).
3.5.1.4 The trial was conducted by MBA [28] and three sets of results were recorded. The first test (Shot No. 5256A) displayed a peak dummy acceleration of 23.16g (in the Z-axis). The second (Shot No. 5256B) produced a result of 44.93g and the third (Shot No. 5256C) produced a result of 33.16g. Inspection of the harness after each of the tests indicated that no damage had occurred to the assembly.
3.5.1.5 The variations witnessed in the peak G-levels recorded during the tests was associated with the degradation of the system, i.e. stretching of the parachute rigging lines. After the initial test it was thought that the stretching of the lines increased the slack, and therefore the second test showed an increase in resultant acceleration of the test subject. The slack was reduced in the third test by increasing the distance from the subject to the ballistically applied load, thereby reducing the peak acceleration.
3.5.1.6 The results of the trial regarding the maximum acceleration in the Z-axis relative to the test dummy were representative of parachute inflation loading, as required [27]. Load levels achieved during the test were also representative of the required dynamic loading. The trial [28] concluded that there would be no degradation of performance as a result of the introduction of the tested parachute harness configuration.
3.5.2 Not only was it necessary for the harness to be tested for integrity, with regard to the applied dynamic loading of parachute canopy under inflation, it was necessary to ensure that the harness assembly would withstand the loading of a large occupant mass without failure in an aircraft 40g crash scenario. The MBA Stress Office issued a statement [29], which gave the maximum webbing loads and harness lug loads in comparison to loads produced by the occupant mass increase.
QINETIQ/AT&E/CR00782/1 Page 17 of 70 3.5.2.1 The harness webbing (conservatively only assuming a single thickness) had a minimum strength of 2957.4kgf (29002.19N). The load generated for occupant mass increase is 2805.9kgf (27516.48N). This therefore covered the maximum load case.
3.5.2.2 The harness lug (by calculation) with respect to its manufactured material had a failure load of 3612kgf (35421.62N). This was in excess of the 2805.9kgf (27516.48N) generated by the occupant mass increase and therefore also covered the maximum load case.
3.5.3 The evidence provided by MBA [28] was considered to be acceptable. QinetiQ also considered the statement made by the MBA Stress Office [29] with regard to harness integrity as being acceptable. Therefore, QinetiQ has sufficient confidence to support the integration of the revised simplified harness assembly onto the Mk10A ejection seat, fitted to the Tornado GR4/4A and F3 aircraft, in regard to resistance to dynamic forces created by a heavy-weight seat occupant in both crash and parachute canopy inflation scenarios.
3.6 Revised BTRU/MOR Cartridges.
3.6.1 During the environmental testing of the GQ5000 parachute and bladder inflation system (Mod 02198), which investigated the performance of the headbox fitted with the GQ5000 parachute assembly [5], several operational trials were carried out of the BSTS. This system incorporated the BTRU/MOR systems and the associated pipe network.
3.6.2 A seat structure supporting the BTRU/MOR ballistic gas circuit was utilised which was based on Seat and Equipment drawing MBEU 112959-3. A headbox fitted with a bladder, piercer assembly and charged N2 bottle and packed with a GQ5000 parachute and drogue was fitted to the seat structure. Where applicable, the parachute assembly had been environmentally conditioned.
3.6.3 A live cartridge was then placed into the BTRU and/or MOR breech as required for each of the individual test configurations. The seat was attached to a fixture which simulated the loads which would have been applied to harness release locks, drogue shackle and leg restraint lines. After each of the trials, the headbox was refurbished using standard production techniques, a new N2 bottle was attached and the piercer unit was refurbished or replaced as required. Bladders were also re-used, unless they had been pre-conditioned at low temperature. The BSTS system was refurbished by the cleaning of all gas routes and the replacing of all seals, shear pins and pipes as necessary to provide a clean, leak-free circuit.
3.6.4 During this test programme, the original 'scissors' shackle was replaced with GS and associated pipe-work. This required the BTRU to be altered to supply ballistic gas to the GS via a pipe, which replaced the redundant mechanical operating mechanism of the `scissors' shackle. Due to erosion of the MOR breech during trials, a variant was introduced which incorporated an internal steel sleeve within the breech. Further trials were carried out to ensure that the MOR breech erosion resistance had improved.
3.6.4.1 Test 3237B3 — BTRU operation -40°C (minimum pressure). This test failed due to low BSTS ballistic pressure and coincided with the failure of the inflation bladder in the headbox (previously discussed in this report). This resulted in the BTRU/MOR cartridge MBEU62486-1 being replaced with cartridge MBEU98777. Test 3237B3/1 was carried out post cartridge change specifically for the measurement of ballistic performance — there being no parachute assembly in the headbox and an empty N2 bottle fitted. The
Page 18 of 70 QINETIQ/AT&E/CR00782/1 result showed a 'significant performance improvement over the original cartridge', with all system events having taken place successfully. Test 323763/3 was carried out with the headbox, parachute and inflation system fitted and resulted in a successful operation of the BTRU. The revised cartridge standard (MBEU98777) was used on all subsequent tests.
3.6.4.2 Tests for BTRU operation 3237A4 (ambient) and 32376/2 (+70°C, maximum pressure). These tests showed successful operation of the BTRU with all system events occurring with ballistic pressures being above the success criteria (1000psig within the circuit for more than 20ms).
3.6.5 Further trials were carried out after the 'scissors' shackle was replaced with the GS as described in paragraph 3.6.4, due to an increase in the volume of the BSTS [5]. Tests 3237/GS/G8, 3237/GS/G9 and 3237/GS/B3 (BTRU and/or MOR operation -40°C) gave results exceeding the success criteria, with only a small reduction in the system ballistic pressure. Tests 3237/GS/E5 and 3237/GS/A4 (BTRU and/or MOR operation at ambient) gave mixed results as the first test failed to achieve the success criteria due to rupturing of a pipe. The subsequent test did achieve the success criteria, but with a reduction in system pressure of 13% when compared to pre-GS figures. Tests 3237/GS/B2, 3237/GS/D6 and 3237/GS/E7 (BTRU and/or MOR operation +70°C) again gave successful results, which exceeded the success criteria.
3.6.6 During the post-GS tests, failure of pipes within the BSTS occurred on more than one occasion. One of the instances of pipe failure resulted in the system failing to achieve the necessary success criteria (although all system events did take place satisfactorily). Investigation of the system after failure concluded that eroded aluminium from the MOR breech body was responsible for pipe rupture. A steel sleeve was therefore introduced into the MOR breech so that the cartridge efflux was diverted away from the aluminium body. After the modification to the MOR breech was completed, a further set of tests were completed.
3.6.7 Tests 3237/GS/E5-1, 3237/GS/E5-2 and 3237/GS/E5-3 (+70°C), 3237/GS/E5-4 and 3237GS/C1 (ambient), 3237/GS/E5-5 (-40°C) all produced results that were in excess of the success criteria [5]. Furthermore, MOR breech erosion was eliminated and there were no more occurrences of pipe rupture. However, it was noted that the non-initiating cartridge failed to face fire during some tests. As this is not a system design requirement (the system was designed to initiate all events with the ballistic gas from a single cartridge) it was considered acceptable.
3.6.8 The revised cartridge MBEU98777 was constructed utilising the same components and processes as the initial cartridge MBEU 62486-1. However, the mechanical composition of the pyrotechnic charge within the cartridge MBEU 98777 was slightly different to its predecessor. The charge in the revised cartridge was comprised of 10 discs of propellant rather than the original one disc and a tube. To ensure that the dynamic environment to which they will be subjected (detailed in SP.P-72001-00P) would not adversely affect the new cartridges, three were tested against vibration and shock [5]. This period of dynamic testing was followed by performance tests, with the results being compared to cartridges from the same batch previously fired to give proof firing data. All the results from the firing of the cartridges were within the technical specification with regards to Delay Time, Maximum Pressure and Time to Maximum Pressure. There was little variation between the results of the test cartridges and the results of the proof firing data cartridges.
QINETIQ/AT&E/CR00782/1 Page 19 of 70 3.6.9 QinetiQ support the evidence produced from the tests carried out by MBA with respect to the revised BTRU/MOR cartridges [5]. The introduction of the GS into the BTRU/MOR ballistic circuit along with the bladder inflation system had increased the ballistic circuit volume, but the revised cartridges were shown to be able to operate the entire system at the required pressure for the required duration. The results of the tests also show that early erosion problems of the MOR breech have been resolved by the introduction of a steel sleeve into the breech. This also had the effect of preventing pipe ruptures within the ballistic circuit. The results of the environmental testing of the MBEU98777 cartridges were also a success when compared to proof firing data. Therefore QinetiQ supports the use of the revised BTRU/MOR cartridge (MBEU98777) within the revised BSTS of the Mk10A ejection seat fitted to the Tornado GR4/4A and F3 aircraft.
3.7 Ejection Gun Qualification (Revised Primary and Secondary Cartridges).
3.7.1 Tests were conducted with the revised ejection gun (Mod 02197) at three temperatures (+70°C (hot), -40°C (cold) and ambient), with each of the occupant sizes (small, medium and large) [30]. The tests were generally similar to the original ejection gun and cartridges qualification tests and were carried out to fully characterise the performance of the revised ejection gun and cartridges. It must be noted, however, that the original qualification programme for the Mk10A ejection gun only consisted of tests at ambient temperature conditions, resulting in comparisons of the revised and original cartridge sets at extremes of temperature being impossible.
3.7.2 Initially, the revised cartridge designs and fillings (Mod 02197) were optimised with the utilisation of a thermo-mechanical model of the Mk10A ejection gun. This resulted in the determination of the optimum cartridge fillings. Once this had been established, two tests were carried out to verify the predicted performance at ambient temperature (proof of concept tests).
3.7.3 Post proof of concept testing, it was decided to reduce the nitro-cellulose filling of the primary cartridge from 630 grains to 570 grains and increase each of the secondary cartridge fillings from 680 grains to 730 grains. This was so that the DRI of the primary cartridge phase of ejection gun operation (where the risk of injury was at its highest) could be reduced, but still allow an acceptable seat exit velocity. Two development tests were then completed to further assess the performance of the cartridges at ambient temperatures.
3.7.4 Once the proof of concept and development phases of the programme were completed (with the performance of the revised cartridges being determined and found acceptable) fourteen further tests were carried out. All trials were carried out utilising a Mk10A ejection seat representative of the standard seat with regard to mass and inertial properties. A dressed manikin was strapped into the seat and the centre of gravity of the test assembly was determined. The seat was mounted at its correct installation angle on a rigid 'A' frame with a net placed over the top in order to catch the ejected seat. The tests required the initialisation of the ejection gun only therefore all other systems were inert. As there was no rocket assistance, the manikin and seat remained together, as without the rocket pack insufficient height and therefore time was available for separation. This was considered acceptable, as the operation of the ejection gun performance was the only factor being assessed. The primary cartridge of the ejection gun was initiated via gasses from an Ejection Gun Initiator (EGI), which was itself fired electrically by a squib. Exact test equipment set ups and procedures for each of the specific temperatures in the programme could be found in report B198 [30].
Page 20 of 70 QINETIQ/AT&E/CR00782/1 3.7.4.1 The cold tests (-40°C) of the ejection gun (shot numbers 5348, 5349, 5350, 5351, 5352 and 5359) were to examine cartridge efficiency in a worst case velocity situation (Mod 02197). The efficiency of the cartridges reduces as the temperature is lowered and therefore detrimentally affected the seat/ejection gun separation velocity. This result would be more problematic with greater ejected masses, i.e. with the maximum weight occupant. All tests where data was captured were successful, but only one successful test was completed with the maximum weight occupant. The velocity at separation was 15.1m/s for the maximum weight occupant, which was considered acceptable.
3.7.4.2 The hot tests (+70°C) of the ejection gun (shot numbers 5343, 5344, 5345, 5346 and 5347) were to examine cartridge efficiency in a worst case DRI situation (Mod 02197). The cartridges were more energetic at high temperatures, which resulted in higher pressures and greater acceleration. This result would be more problematic with lower ejected masses, i.e. with the minimum weight occupant. All tests in this phase of the programme were successful, but only one test was carried out for the minimum weight occupant. The maximum DRI during the hot test was 20.44, but this was nearly two units below the limit of 22.2 [31] for the hot tests. This equates to halving the risk of spinal injury to the lightweight seat occupant (approximately 17% compared to 40% at a DRI value of 22.2) (Figure 8-12).
3.7.4.3 All ambient tests (5240, 5339, 5340, 5341 and 5342) were successful and provided very consistent DRI results below the limit of 19, which were all an improvement on the results of the original Mk10A ejection gun qualification programme. The document [31] states the maximum DRI (the mean DRI plus three standard deviations) shall not exceed 21. This only related to the 50-percentile manikin, therefore was more challenging for the lightweight occupant. This was, however, achieved satisfactorily.
3.7.5 On successful completion of the trials, the revised ejection gun (Mod 02197) was found to provide improved performance in regards to both velocity at separation and the DRI value experienced by the seat occupant within the increased weight range. The original ejection gun separation velocity for the original maximum mass (seat and occupant) was 19.5 m/s (ambient temperature). The separation velocity of the revised ejection gun (modified cartridges) with the original maximum mass was increased to 19.8 m/s (ambient temperature). For the enhanced maximum mass, an ejection velocity of 18.22 m/s was reported for the separation velocity of the revised ejection gun in ambient conditions. The report [30] considered that the revised ejection gun results were successful and the revised cartridges should be qualified for service in accordance with the fin clearance at high-speed report [32].
3.7.6 QinetiQ supports the evidence provided in the MBA report [30]. The optimised primary and secondary cartridge fillings of the revised ejection gun were able to offer improved performance in velocity at separation when compared to the test conditions of the original ejection gun and produced only a slight loss of performance for the revised maximum mass (at ambient temperature). The DRI results of the revised ejection gun were also considered acceptable. QinetiQ therefore supports the incorporation of the revised primary and secondary ejection gun cartridges into the ejection gun, and the integration of the revised ejection gun onto the Mk10A ejection seat fitted to the Tornado GR4/4A and F3 aircraft with respect to DRI and velocity at separation.
3.8 Revised Primary and Secondary Gun Cartridges (Lot Acceptance Test Limits).
3.8.1 The improved cartridge set (Mod 02197) was based on the original design of cartridge with the same propellant constituent, but with different filling quantities [5]. Due to this,
QINETIQ/AT&E/CR00782/1 Page 21 of 70 there were no structural changes to either the primary or the secondary cartridges. This resulted in the qualification of the original cartridge set being valid for the improved set, however, a programme was derived for setting the Lot Acceptance Test limits for the improved cartridges [5].
3.8.1.1 A primary and secondary cartridge (Mod 02197) were fired together in a proof chamber, and then fifteen sets were tested with regard to pressure/time characteristics at three specific environmental temperature conditions (five each at +70°C (hot), -40°C (cold) and ambient). The environmental conditioning involved the cartridges being exposed to their specified temperatures for a minimum of 4 hours after chamber temperature stabilisation (but not longer than 24 hours).
3.8.1.2 All sets were fired in the proof chamber within three minutes of being removed from the conditioning chamber and the results were recorded. Initiation was via a sear withdrawal mechanism operating a spring-loaded firing pin, which struck directly onto the primary cartridge percussion cap. The secondary cartridge was then face fired by the ballistic gas from the primary cartridge.
3.8.2 The results from the tests with regard to cartridge pressure/time characteristics were all successful, with post firing visual examination confirming correct operation.
3.8.3 In an effort to reduce the lead-time from manufacture to test, the primary cartridges were rushed into use with the previous cartridge part marking. The 15 primary cartridges were marked with two part numbers. The previous cartridge part marking MBEU 62377- 1 was engraved on the bases of the cartridges and the correct improved part number, MBEU 62377-2 printed on the side's [33]. The concern was that the cartridges with these part numbers are interchangeable and if the number on the side of the cartridge were to be removed, the cartridge would be identified incorrectly. The report stated that the production cartridges would be correctly marked and that the raised TIPR3134 [33] could be closed.
3.8.4 QinetiQ supports the evidence provided in the MBA report [5] for the Lot Acceptance tests for the primary and secondary ejection gun cartridges. The revised primary and secondary ejection gun cartridges were all found to operate within specific parameters for pressure and time, after environmental conditioning. QinetiQ therefore supports the incorporation of the revised primary and secondary ejection gun cartridges into the ejection gun, and the integration of the revised ejection gun onto the Mk10A ejection seat fitted to the Tornado GR4/4A and F3 aircraft with respect to cartridge Lot Acceptance tests. However, it is essential that the correct revised primary cartridge (MBEU 62377-2) is fitted to the ejection gun and that the cartridge is correctly part numbered. A check should be carried out on fitment, due to the possibility of fitting the wrong, pre-modification type primary cartridge (MBEU 62377-1). This is also .true of the secondary cartridge [Maintenance Warning].
3.9 Aircraft Tail Fin Clearance.
3.9.1 MBA produced a report [34], which identified the fact that, the clearance between the CofG of the ejected seat/occupant and the aircraft fin at high speed was close to the minimum 1.2m distance (BAES do not know from where this stated 1.2m is referenced, as it is not an aircraft design/specification requirement). The report quoted 'For the maximum boarding mass considered of 135kg the maximum safe ejection velocity (as defined by fin clearance only) reduces to 600 KCAS from 625 KCAS'.
Page 22 of 70 QINETIQ/AT&E/CR00782/1
iiirrehrp)(sTali? 3.9.2 A report by MBA [32] addressed the issue of the fin clearance performance. The results from the sled ejection test (paragraph 3.2) were analysed from film recorded at the time. In addition, a mathematical model was developed by MBA with 6 Degree-of-Freedom (DoF).
3.9.3 The primary model analysis was conducted with a heavyweight 135kg seat occupant at an aircraft velocity of 610 knots. These values were chosen so that the model results could be compared to the actual results obtained from the high-speed ejection sled trial [21] where 608 knots was achieved. The plotted result of the model analysis and the plot from the film analysis of the actual test were then overlaid on a graph with the outline of a Tornado IDS aircraft (Figure 8-13). The model also produced an animation of the resulting ejection event, from which still images could be gathered. The red line above the aircraft fin shows the 1.2m clearance profile (Figure 8-14, Figure 8-15 and Figure 8-16).
3.9.3.1 The resultant actual and modelled plots differed from each other only slightly. The simulation animation still images clearly showed that the seat/occupant CofG is much closer to the aircraft fin than the minimum specified 1.2m. However, the seat/occupant combination was shown not to make hard contact with the fin.
3.9.4 A second model analysis was then conducted with a configuration of the originally qualified Mk10A ejection seat and qualified maximum 112kg occupant ejecting at 625 knots. As the original qualification tests were carried out on the ejection system some 20 — 25 years ago, there was no reliable retrievable test data available with which to compare the modelled results. Although the currently cleared maximum seat occupant is 107.9kg in the MAR documents, the seat has gained 4.5kg during its service life up until the Phase One and Two modifications. The addition of this extra mass (4.5kg) to the MAR clearance (107.9kg) results in a total mass of 112.4kg. A pessimistic assumption was therefore made that the rear seat CofG trajectory just achieved the specified 1.2m clearance from the extremities of the aircraft fin.
3.9.4.1 The resultant modelled plot showed the CofG trajectory of the seat/occupant clearing the aircraft fin at a distance just greater than the specified 1.2m. The still images from the simulation animation confirmed the resultant plot.
3.9.5 Further simulations were conducted by use of the two matched models and interpolation. These were carried out to determine the fin clearance achieved with the rear seat occupied by either the 135kg or current 112kg occupant, as a function of ejection speed. The two criteria for fin clearance were that the seat/occupant combination CofG clears the fin by the minimum 1.2m or the seat/occupant combination just clears the fin (assessed by the simulation animation). The simulations were also conducted to determine the maximum ejection speed to achieve fin clearance as a function of crew mass, with the same two criteria being considered.
3.9.5.1 The results of the simulations were plotted on a graph of total ejected mass against maximum aircraft speed (on ejection) to achieve fin clearance. It was found that the 135kg occupant/seat CofG would clear the fin with the specified 1.2m distance at a maximum aircraft speed of 560 knots. If the relaxed criterion is used (occupant/seat just clears fin extremities) then the maximum ejection speed increases to 620 knots. Again the still images from the simulation animation supported the plots.
QINETIQ/AT&E/CR00782/1 Page 23 of 70 3.9.6 The results of the simulated ejection events [32] produced the following additional information:
3.9.6.1 1.2m clearance between the occupant/seat CofG and the fin was achieved at 625 knots ejection speed for all crew below 105kg (This was less than the current qualified maximum aircrew mass due to the increase in seat mass during its service life and should be considered as a conservative estimate).
3.9.6.2 Actual clearance between the occupant/seat and the fin was achieved at 625 knots ejection speed for all crew below 130kg.
3.9.7 The initial simulation analyses were considered for the Tornado IDS type aircraft with regard to fin clearance at high ejection speeds, as the fin is more adverse than that of the Tornado ADV. The reduced length of the IDS fuselage when compared to the ADV fuselage resulted in the fin being closer to the rear seat position. For completeness, BAES requested that the same analyses be conducted for the Tornado ADV [32] Corollary 1.
3.9.8 As was expected, the results of the simulation analyses for the ADV aircraft [32] Corollary 1 showed a slight improvement in performance of the enhanced Mk10A seat. The results produced the following summary:
3.9.8.1 1.2m clearance between the occupant/seat CofG and the fin was achieved at ejection speeds at or below 562 knots when the 135kg crew occupied the seat.
3.9.8.2 1.2m clearance between the occupant/seat CofG and the fin was achieved at 625 knots ejection speed for all crew below 107kg (This was less than the current qualified maximum aircrew mass due to the increase in seat mass during its service life and should be considered as a conservative estimate).
3.9.8.3 Actual clearance between the occupant/seat and the fin was achieved at 625 knots ejection speed for all crew below 135kg.
3.9.9 Due to modifications to the design of the seat during the course of the Mk10A seat test programme (principally the GS modification) the seat increased in mass from its original pre-programme level. At the start of the programme, the mass of the seat and new maximum weight occupant was recorded as 240kg (135kg for the occupant and 105kg for the seat). Towards the end of the programme the mass of the seat and occupant had increased to 242.6kg (135kg for the occupant and 107.6kg for the seat). Therefore, the maximum ejected mass was now 242.6kg, which was an increase of 2.6kg on the originally analysed seat/occupant combination [35].
3.9.10 With the correct value of maximum ejected mass, the analyses were re-conducted and figures for the ADV and IDS aircraft were amended for maximum ejection speed to achieve fin clearance as a function of crew mass (Figure 8-17 and Figure 8-18). The result produced the following summaries:
3.9.10.1 The 1.2m clearance between the seat/occupant CofG and the fin was achieved at ejection speeds at or below 556 KCAS when the seat was occupied by the 135kg crew for the IDS aircraft and 559 KCAS for the ADV aircraft.
3.9.10.2 Actual clearance between the seat/occupant and the fin was achieved at or below 617 KCAS when the seat was occupied by the 135kg crew for the IDS aircraft and 622 KCAS for the ADV aircraft. Page 24 of 70 QINETIQ/AT&E/CR00782/1 3.9.10.3 1.2m clearance between the seat/occupant CofG and the fin was achieved at 625 KCAS for all crew below 101kg for the IDS aircraft and 104kg for the ADV aircraft (This was less than the current qualified maximum aircrew mass due to the increase in seat mass during its service life and should be considered as a conservative estimate).
3.9.10.4 Actual clearance between the seat/occupant and the fin is achieved at 625 KCAS for all crewmembers below 127kg for IDS aircraft and below 132kg for ADV aircraft.
3.9.11 BAES advised that the 1.2m clearance between the CofG of the seat/occupant and the tail fin, which was previously used for the Tornado aircraft, be replaced with the seat/occupant achieving actual clearance. This would result in a greater ejection envelope for the higher mass aircrew in the rear seat position, whilst still ensuring that no hard contact will occur between ejectee and airframe.
3.9.12 QinetiQ supports the evidence provided in MBA report [35]. BAES have stated that the 1.2m clearance of the tail is not even shown in the DDP, which is written against the specification requirements (it is not an aircraft design/specification requirement). With this information in mind BAES recommended that the 1.2m clearance from the tail fin be replaced with the ejectee just clearing the fin (no hard contact). Therefore, the limits for the speed at which a 135kg seat occupant (total ejected mass of 242.6kg) would clear the aircraft tail fin are 617 KCAS or below for the IDS aircraft and 622 KCAS or below for the ADV aircraft. However, QinetiQ recommend that 617 KCAS be adopted as the maximum safe ejection speed for both aircraft types (IDS and ADV). This would incorporate a much-reduced risk of confusion between the two aircraft types with regard to documentation and operating procedures. Providing the maximum safe ejection speed of 617 KCAS was incorporated on the operational limitations of the Mk10A ejection seat, QinetiQ supports the use of the revised ejection gun on the Mk10A ejection seat fitted to the Tornado F3 and GR4/4A aircraft.
3.10 Ejection Seat/Aircraft Canopy Collision.
3.10.1 The introduction of lightweight female aircrew into the role of pilot and navigator on the Tornado aircraft, had made it necessary for the seat to be able to eject a lightweight occupant with a reduced possibility of back injury (reduced DRI discussed previously in this report). With this emerged the risk that a lightweight seat occupant in the rear seat position could strike the departing canopy of the aircraft during an ejection sequence, especially if the sequence was initiated with the aircraft at zero speed. Added to this was the possibility of a single canopy rocket motor failing thereby moving the canopy away from the aircraft at the slowest speed.
3.10.2 This potential for collision of the ejection seat with the aircraft canopy was considered in a BAES report [10]. The investigation primarily centred on the relative motion of the occupied rear seat and the aircraft canopy during the ejection sequence. The worse case scenario for this event was ejection at zero speed, with a single canopy rocket motor failure (canopy moving away from the aircraft at the slowest speed) with an occupant of the lightest mass (seat/occupant travelling at the highest velocity) in the rear seat position (the seat nearest to the departing canopy).
3.10.3 The worst case scenario was quoted in the report [10] as:
Single canopy jettison rocket motor failure.
QINETIQ/AT&E/CR00782/1 Page 25 of 70 Zero altitude.
Zero air speed.
Minimum weight aircrew
Minimum seat clock delay (the time delay between canopy and rear seat movement)
Minimum Declaration of Design Performance (DDP) canopy jettison rocket motor performance.
3.10.4 The trajectory of a jettisoned canopy was modelled using computer software (program N78A0001) and compared to data gathered from actual crew escape system trials. The program was found to give a close correlation when compared to the gathered data, especially over the initial stages of canopy release.
3.10.5 The machined slot in the centre link assembly (designed weak point) of the rear hinge was designed to fail when the canopy reaches 43° from the Canopy Datum Line (CDL) and allow the canopy to separate from the aircraft fuselage (Figure 8-19 and Figure 8- 20). Examination of a film captured during a zero airspeed test (with single rocket motor failure) showed that the angle was approximately 85° before the canopy was seen to release. However, this was thought to be beneficial, as the canopy was thrown further back (towards the aircraft tail fin) rather than upwards away from the fuselage. This resulted in the canopy clearing the ejection seat path more quickly.
3.10.6 Several factors were stated which could account for the late release angle, but for the purpose of the report [10], the canopy release angle was taken to be the designed 43°, as this angle gave the most pessimistic results for clearance of the ejection seat path.
3.10.7 The 140.8kg value for the canopy mass utilised in the simulations was known to be less than some canopies actually in service. It was stated that "A canopy from a Saudi ADV aircraft has been assessed that had a mass of 145kg". A further simulation was carried out to evaluate the effects of increased canopy mass on the jettison system performance. The results of this simulation showed that a canopy of 145kg would reduce the level of clearance between the rear seat and the aircraft canopy by approximately 5mm at a time 0.5s after escape system initiation in the worst case ejection scenario. It was felt that a 5mm reduction in clearance would not represent any increased risk to aircrew in this particular case.
3.10.8 The ejection seat trajectory data was gathered from an actual test carried out with the modified ejection gun containing the revised primary and secondary cartridges (test shot 5226, discussed earlier in this report) [17].
3.10.9 The results of the worst case scenario examined in the BAES report [10] for canopy and ejection seat trajectory with the modified ejection gun (revised primary and secondary cartridges) showed that there was a marginal reduction in the level of dynamic clearance when compared to the level of clearance obtained with an unmodified ejection gun.
3.10.10 The level of dynamic clearance between the ejection seat and the jettisoned canopy (worst case scenario) reduced to a minimum at approximately 0.5s after system initiation, but after this the distance between the rear ejection seat and the canopy rapidly increased.
Page 26 of 70 QINETIQ/AT&E/CR00782/1 3.10.11 The report [10] also stated that "Additionally, the probability of a worse case ejection as defined within this report has been calculated to be so remote that it can be considered to be impossible". However, the results obtained show that even in a worse case scenario, the rear ejection seat and aircraft canopy do not collide.
3.10.12 Although no representative from QinetiQ was present during the creation of the simulations for this report [10], the evidence provided was considered sufficient, with regard to- aiiiiip seat and canop mic clearance, for QinetiQ to support the fitting of the revs section gun to the A ejection seats utilised by the Tornado F3 and GR4/4A aircraft.
3.11 Ejection Seat Mounting to Aircraft (40g Crash Scenario).
3.11.1 In a NETMA meeting, the subject was raised regarding the increased mass of the new heavy weight seat occupant imposing higher loads on the supporting bracket of the ejection seat to the aircraft structure, in the event of an aircraft impact [24]. The specification for the system was that it was to be able to withstand 40g (pilot facing forward direction). The brackets and bulkhead attachment points as they stood were only able to absorb the crash energy of a 34g impact. It was noted that it would be necessary to strengthen the seat attachment brackets and stiffen the bulkhead mounting points for the 40g-impact survivability of the system to be restored.
3.11.2 The stiffening of 'the bulkhead and the strengthening of the mounting brackets would require a significant amount of modification, which would be required to be run as a parallel task, with many implications. The modifications would also lead to addition of weight to the aircraft.
3.11.3 It was suggested that the specification for the system crash survivability be reduced to 34g in line with the systems survivability by theoretical calculation. It was also stated that most other aircraft programmes requires a survivability of only 30g (EF2000 is 30g), as well as the pre-Tornado European standard being only 25g.
3.11.4 In the NETMA meeting [24] it was stated that the 40g-impact survivability of the Tornado Specification was excessively stringent. The fact that the crash case survivability of a human was in the region of only 20g was also discussed. The meeting came to the conclusion that the deviation, from 40g-impact survivability to 34g, was acceptable.
3.11.5 QinetiQ support the lowering of the crash survivability of the ejection seat mounting points to the aircraft structure from 40g to 34g due to the points raised in the NETMA meeting [24]. The revised Mk10A ejection seat fitted to the GR4/4A and F3 Tornado aircraft should be integrated with a reduced crash case survivability specification of 34g.
3.12 GQ5000 Parachute and Harness Suspension.
3.12.1 A trial was organised by BAES [36] whereby two test subjects of different functional reaches ( and employees of BAES) were suspended by a modified combined harness, attached to risers from the GQ5000 parachute, which were in turn attached to a crane held jig (Figure 8-21). The jig splayed the parachute risers into a configuration replicating that which a fully inflated GQ5000 canopy would produce. QinetiQ were represented during the trial by the author of this report.
3.12.2 The functional reaches of the two test subjects were; one-percentile at 695mm 1111 1St and thirty-percentile at 779mm (111/1111.) [37]. The subjects were chosen due to
QINETIQ/AT&E/CR00782/1 Page 27 of 70 araaluawaiim the low percentile functional reach, which gave a worse case scenario for reaching of the GQ5000 parachute steering control lines.
3.12.3 The two subjects were dressed in bulky Winter Sea Nuclear, Chemical and Biological (NBC) AEA [38], which gave the worse case for restriction of movement of the test subjects whilst suspended. Items included in this AEA were immersion suit (Mk1), coveralls (Mk15B), life preserver (Mk31), external anti-g trousers (Mk4), water-resistant gloves, aircrew helmet (Mk1OB for #111111111.and Alpha for /AM as a Mk1OB small enough could not be located) and oxygen mask.
3.12.4 A BAES report [39] was produced on completion of the suspension trial which highlighted difficulties of the test subjects in accessing the GQ5000 parachute steering lines and checking of the canopy.
3.12.4.1 The one-percentile test subject (subject 1) was lifted clear of the ground and then asked to check the field of view. View forwards and down was unhindered, but the subject was unable to inspect the canopy due to restriction in rearward head movement. The subject was also unable to see the parachute steering handles and therefore had to feel his way up the parachute risers and locate by touch, which was carried out successfully (Figure 8-22).
3.12.4.2 After inflation of the life preserver, conditions deteriorated with the field of view being reduced to a downward direction only. This was due to the inflated life preserver applying pressure onto the rear of the aircrew helmet forcing the head forward (Figure 8- 23 and Figure 8-24). Location of the parachute steering handles by feeling up the risers was more difficult, although eventually successfully completed.
3.12.4.3 A high level of discomfort was reported by subject 1 due to the pressure being exerted by the inflated life preserver, forcing the head down and forward, but as was stated in the report [39] that this situation was no different to the pre modified harness.
3.12.4.4 The thirty-percentile test subject (subject 2) was also lifted from the ground and asked to check the field of view. Again, viewing of the canopy was not possible, but downward and forward vision was not obstructed. No difficulty was noted in location of the parachute steering handles, although again they were found by feeling up the parachute risers, as no view of them was possible.
3.12.4.5 After inflation of the life preserver, the field of view was again restricted to the downward direction only, due to pressure on the back of the aircrew helmet. The parachute steering handles were located by touch with more difficulty than before life preserver inflation. The use of NBC gloves by subject 2 did not appear to increase difficulty in accessing or operating the steering handles.
3.12.4.6 A high level of discomfort was also felt with subject 2 due to the pressure exerted on the back of the flying helmet by t fe, pres-Tt_orgLig i he head forward and downward. Niumipin •••7,;i
3.12.5 Inspection of the canopy was not possible by either of the test subjects, pre or post life preserver inflation (Figure 8-25). Location of the GQ5000 parachute steering handles was possible by feeling up the parachute risers with or without the inflated life preserver, but after inflation the task was considerably harder, especially for subject 1. 111. 3.12.6 It was noted that the position *MPoint at which the subjects were Atlited by the combined harness to the parachute risers was directly above the shoulders (Figure 8- Page 28 of 70 Q INETIQ/AT&E/C R00782/1 26). This had the effect of suspending the subject forward of the parachute canopy vertical centreline (canopy and subject viewed sideways) which compounded the difficulties of a canopy check. If the attachment points to the harness were moved forwards (towards the chest of the subject) then improved views of the canopy could result.
3.12.7 The report [39] also stated that the tests were carried out in ideal environmental conditions, with no wind, rain or fog and in strong daylight. Neither of the test subjects were suffering from trauma either sustained pre, during or post ejection sequence. The effects of harsher environmental conditions and/or personal trauma could all increase the difficulties highlighted in operating the parachute steering facility. However, the test subjects were not experiencing the potential benefit of adrenaline (conceivably present in an ejectee).
3.12.8 Subject 2 was able to view the entire parachute canopy with a non-inflated life preserver by pulling up and back with his arms on the parachute risers and leaning back (rather than just hanging in the harness), however this was not possible when the life preserver was inflated.
3.12.9 The report [39] concluded that the parachute steering system improved the chances of survival of aircrew post ejection, by allowing manoeuvrability of the aircrew/parachute combination away from such hazards as burning aircraft wreckage and other obstacles. However, the configuration of the harness and parachute risers with regard to the point of suspension made it difficult to locate the parachute steering line handles (needing to be located by touch). It also made observation of the canopy very difficult with a non- inflated life preserver and impossible once life preserver inflation had occurred. The bulk of the AEA contributed to these difficulties, with higher bulk resulting in increasingly difficult accessibility. The functional reach of the aircrew would further compound aircrew accessibility and operation of the system, with reducing functional reach again resulting in increased difficulty. The worse case was considered to be a harness occupant with a small functional reach wearing bulky AEA and the life preserver inflated. It was also stated that the tests occurred in a controlled environment free from climatic influences and pre/post ejection trauma. Addition of any adverse weather conditions and injury to the ejectee would again increase the difficulty of access and operation of the parachute steering facility.
3.12.10 The BAES report [39] recommended that improvements to the parachute steering handles be considered to aid aircrew with location by touch, to make them easier to locate in an emergency situation. The harness to parachute riser interface should also be reviewed with regard to the point of suspension, allowing the ejectee an improved field of view, specifically for inspection of the parachute canopy. BAES also recommended that all aircrew that are likely to be involved in the use of the new parachute/harness combination be trained in the location and operation of the parachute steering handles.
3.12.11 QinetiQ were represented during the course of the suspension trials (author of this report) and supports BAES observations and recommendations. The parachute steering system is accessible and can be used with aircrew of limited functional reach whilst wearing bulky AEA. However, location of the steering handles is by 'feel' alone and it is necessary that the handles themselves be considered for modification to make them easier to locate. It would be advantageous to relocate them further down the parachute risers so that reach is improved, especially in the case of reduced functional reach ejectee and bulky AEA. All of the tests were carried out in ideal environmental
QINETIQ/AT&E/CR00782/1 Page 29 of 70 conditions with the test subjects not having any form of trauma. Degraded environmental conditions and injury to the ejectee could all add to the difficulties experienced by the test subjects during the suspension trials with regard to location and operation of the parachute steering facility. Aircrew should be trained on location and operation of the GQ5000 parachute steering facility [further work].
Page 30 of 70 QINETIQ/AT&E/CR00782/1 4 Conclusions.
4.1 GQ 5000 Parachute and Bladder Inflation System.
4.1.1 The investigation by MBA regarding the zero/zero performance of the seat and the GQ5000 parachute and bladder inflation system provided sufficient proof of desired performance with seat occupants of differing masses. The occurrence of failure of the main parachute to deploy, due to a geometric lock of the 'scissors' shackle and the drogue created by the orientation of the seat, was successfully eradicated by the introduction of the GS drogue bridle release system and associated system modifications. Since the modification and in later trials, there were found to be no re- occurrences of failed deployment. Therefore, the modification to the drogue release system was found to be acceptable. The instance of the dummy's feet crossing through the parachute rigging lines in a later trial was momentary and entanglement was averted once the main parachute canopy began to inflate. This event was not repeated throughout the remainder of the trials (or previous trials) and is thought to have been a rogue occurrence. Decent rates of the GQ5000 parachute were found to be improved when compared to the GQ1000 for all ejected masses.
4.1.2 The trial of the 625kts/zero-height performance of the front and rear seats incorporating the GQ5000 parachute and bladder inflation system was found to give satisfactory results. The aircraft canopy was successfully jettisoned and the seats both ejected with satisfactory trajectories resulting in both dummies being recovered on full parachutes. However, the ejection sequence was initiated at a forward velocity of 608kts, this being 17kts below the intended target velocity. The evidence produced by the 625kts/zero- height sled test was found to give sufficient confidence in the revised ejection gun and GQ5000 parachute system with an ejection event occurring with the aircraft having a maximum forward velocity of 608 knots. Acceleration forces produced by the GQ5000 parachute were found to be improved when compared to the GQ1000 parachute in all but one case. The case where a slight deterioration in performance was noted (lightweight inflation load) was attributed to a lighter mass manikin being used during the testing of the GQ1000 parachute.
4.1.3 The environmental trials conducted by MBA with regard to the operational and durability performance of the headbox and GQ5000 parachute and inflation system provided sufficient evidence that the system was satisfactory. The system satisfied the test success requirements of the high temperature, humidity/salt fog, sand and dust and vibration/shock tests suffering very little or no damage and on all counts parachute deployment was as specified. However, the low temperature test resulted in failure of the deployment system (rupture of the inflation bladder) after a temperature soak of -60°C. Due to previous experience of the bladder material by MBA, a further trial at a slightly higher temperature of -54°C provided a successful result, with deployment of the parachute occurring as specified. MBA/BAES then recommended a reduction in the current release specification for the lower temperature and this was agreed at a NETMA meeting. This resulted in the lower temperature (soak) limit being raised to -50°C. Thereafter, the headbox and GQ5000 parachute and inflation system was found to operate satisfactorily and within the amended specification throughout all environmental trials.
4.1.4 The environmental trials conducted by MBA with regards to the possibility of resurgence of the GQ5000 parachute from the top of the headbox concluded that altitude cycling
QINETIQ/AT&E/CR00782/1 Page 31 of 70
IRC40140TOIN had no affect. However, the high temperature soak produced 2mm resurgence. Vibration testing in the X-axis and Z-axis produced zero parachute resurgence, but another 2mm of resurgence occurred after vibration testing in the Y-axis. Therefore the overall resurgence of the packed GQ5000 parachute assembly from the headbox after MBA trials was 4mm.
4.1.5 Concerns regarding the proximity of the headbox to the underside of the aircraft canopy, specifically the LCC, resulted in a BAES trial providing evidence that top flap damage would occur. Although the damage was limited to the upper surface of the fabric top flap and the plastic insert and the chance of both rocket motors failing on the PCJS being very remote, a decision was made to redesign the fabric top flap. The modification entailed the introduction of a kevlar insert, which was cross-stitched into place within the fabric top flap. A further trial completed by BAES post-modification, produced no damage, even whilst in physical contact with the LCC on detonation. The results of the trial for the fabric top flap's resistance to LCC detonation damage were found to be acceptable.
4.1.6 The concerns raised over the clearance of the GQ5000 packed headbox assembly from the aircraft canopy, resulted in a reconfiguration of the DWL with regard to a reduction in the armoured sleeve and minor changes to the stitching pattern, as well as a new fabric top flap. These modifications produced a significant reduction in the headbox packed height. An operational trial conducted on the modified headbox and GQ5000 parachute system, due to it now being altered from its original test state, produced a satisfactory result. The parachute was ejected from the top of the headbox successfully with no variation from the initial standard utilised in the original qualification testing. The result of the test for the GQ5000 parachute deployment, post modification of the DWL and fabric top flap was considered acceptable.
4.1.7 Trial installations of the headbox and the GQ5000 parachute and inflation system within ADV and IDS variant Tornado aircraft was successful, with headbox to aircraft canopy clearances of 25mm and 26mm in the rear seat position. The clearance between the front corner rims of the headbox and the inner surface of the aircraft canopy were given as 26mm. Build dimensional tolerances of the headbox were considered to have no impact on the clearance between the ejection seat and the aircraft canopy, other than the parachute packed height. Tolerances between 12 canopies of the IDS and ADV variant aircraft, with respect to dimensional variations in canopy transparencies to supporting frame structure were found to be +/- 1.75mm. The resulting proximity of the parachute top flap to the aircraft canopy, due to the canopy packed height, ensured that a clearance would still be maintained on LCC detonation. This was the case even when the tolerances given for both the aircraft and headbox dimensional variations and the 4mm resurgence noted during MBA trials were considered, along with the 12mm movement of the seat necessary for LCC initiation. The evidence produced with respect to the available clearance between the top of the headbox (packed with the GQ5000 parachute) and the underside of the aircraft canopy was found to be acceptable.
4.2 Simplified Combined Harness Parachute Inflation Loading.
4.2.1 The three tests carried out by MBA on the harness were all successful, with no damage being evident. The harness was exposed to a maximum peak acceleration of 44.93g, which was in excess of the intended loading due to stretch in the rigging lines from the initial test. The conclusion from these tests was that there would be no degradation of system performance with the introduction of the tested parachute harness configuration.
Page 32 of 70 QINETIQ/AT&E/CR00782/1 4.3 Simplified Combined Harness Crash Loading.
4.3.1 The statement produced by the MBA Stress Office concluded that the harness and harness lug were capable of withstanding the load generated by the occupant mass increase. The occupant mass increase generated a load of 2805.9kgf (27516.48N). The harness had a minimum strength of 2957.4kgf (29002.19N) and the harness lug had a calculated failure load of 3612kgf (35421.62N). Both items are therefore capable of retaining the heavy weight occupant in a 40g crash scenario. This is backed up by the fact that during the parachute inflation loading trials, the harness was subjected to a peak acceleration of 44.93g and showed no sign of degradation.
4.4 Revised BTRU/MOR Cartridges.
4.4.1 The environmental trials [5] carried out by MBA with regard to the introduction of revised BTRU/MOR cartridges in support of the GQ5000 parachute and deployment system (Mod 02198) were found to be a success. Early problems of MOR breech erosion were combated with the introduction of a MOR breech with an integral steel sleeve. The evidence produced from the trials is thought to give sufficient confidence in the BTRU/MOR system, specifically with the cessation of breech erosion resulting in a much-reduced risk of ballistic system pipe failure.
4.4.2 Initial tests at low temperature (-40°C) produced a failure of the BSTS system due to low ballistic pressure. Replacement of the original BTRU/MOR cartridge (MBEU62486-1) with BTRU/MOR cartridge (MBEU98777) resulted in a significant performance improvement, regarding ballistic pressure, over the original system. The replacement of the original BTRU/MOR cartridge with the revised type was found to be acceptable with regard to the BSTS system.
4.4.3 The replacement of the original 'scissors' shackle by the GS and its associated pipe- work (which included alteration to the BTRU/MOR system, so that ballistic gas could be supplied to the GS) during the course of the BTRU/MOR trials was found to cause no detrimental effect to the operation of the BSTS. All ballistic pressures were found to be above the minimum success criteria. Therefore, the introduction of the GS and associated pipe-work into the BSTS was found to be acceptable.
4.4.4 The testing of the three revised BTRU/MOR cartridges (MBEU98777) with regard to vibration spectra and shock was also found satisfactory. All the cartridges produced firing results within technical specification for Delay Time, Maximum Pressure and Time to Maximum Pressure, with little inter-variation. The revised cartridges were therefore unaffected by the environmental tests and operated satisfactorily.
4.5 Ejection Gun Qualification with Revised Primary and Secondary Cartridges.
4.5.1 The results of the cold tests (-40°C), which simulated a worst case velocity situation, were successful, with the maximum weight seat/occupant combination being within limits for seat/ejection gun separation velocity. The revised ejection gun's ability to eject a seat containing a heavyweight occupant in a worst case 'separation velocity' situation was therefore found acceptable.
4.5.2 The results of the hot tests (+70°C), which simulated a worst case DRI situation, were successful, with the minimum weight seat/occupant combination being within limits for the permissible DRI. The DRI value was 20.44, which resulted in a reduction in the risk of spinal injury of the minimum weight occupant to 17%. This is comparable to the
QINETIQ/AT&E/CR00782/1 Page 33 of 70 maximum allowable DRI value for hot tests of 22.2, which gives a 40% chance of spinal injury. The DRI result for the hot test was therefore found to be acceptable.
4.5.3 The results of the ambient tests provided consistent DRI values below 19. All results acquired were much improved over the original Mk10A ejection seat qualification programme in regards to DRI values. The maximum DRI value of 21 was not exceeded for the minimum weight seat occupant and therefore the test results for ambient conditions were found to be acceptable. The ambient results for the velocity at separation showed a small improvement with the originally cleared maximum mass (112kg) of the revised ejection gun (19.8m/s) compared with the pre-modification gun (19.5m/s). However, the velocity at separation of new maximum mass (135kg) with the revised ejection gun was 18.22m/s. This is shown in the reduced ejection envelope maximum speed (617 knots) for tail fin clearance (paragraph 3.9 of this report).
4.5.4 The revised ejection gun was found to provide improved performance for DRI values when compared to the original ejection gun. The velocity at separation was found to be improved at ambient conditions with the originally cleared 112kg seat occupant and the revised ejection gun. However, a marginal drop in velocity at separation was noted with the 135kg seat occupant and the revised ejection gun. Due to the findings of the report [30], the ejection gun fitted with the revised cartridges, was found to be acceptable.
4.6 Revised Primary and Secondary Gun Cartridges (Lot Acceptance Test Limits).
4.6.1 As there were no structural changes made to the revised cartridges, the qualification for the original cartridges was valid. However lot acceptance tests were carried out, with the results for the three environmental conditions (-40°C, +70°C and ambient) giving successful results [5]. Post firing examination of the cartridges showed that the operation had been satisfactory. The results for the lot acceptance tests for the revised primary and secondary gun cartridges were found to be acceptable.
4.7 Aircraft Tail Fin Clearance.,
4.7.1 During assessment of the tail fin clearance (paragraph 3.9 of this report) the MBA document [35] provided evidence that the originally cleared seat was able to achieve a 1.2m fin clearance from the GofG of the seat/ejectee combination at 625 knots for a maximum mass seat occupant of 112kg (paragraph 3.9.4 of this report). The modified seat (post Phase Two modification) was shown to achieve a 1.2m clearance at the same speed, but for a maximum seat occupant mass of only 101kg. There was concern that the ejection seat had actually reduced in performance after the Phase One and Two modifications. However, the originally cleared seat performance figures did not take into account the fact that the seat itself had increased in mass during its service life (total ejected mass with the modified seat is now 240kg, compared to the original 210kg) and it is highly possible that the currently cleared seat (pre Phase Two modification) is not able to achieve the 1.2m clearance from the fin with the currently cleared (112kg) maximum mass seat occupant.
4.7.2 Due to insufficient/non-existent test data being available from the original clearance of the seat, MBA had very little to work with when comparing the original seat performance with the Phase Two modified seat performance. This resulted in the reported maximum ejected masses (1.2m clearance at 625 knots) for the Phase Two modified seat being a conservative estimate. This means that the 101kg mass limit of the Phase Two modified seat could be greater than 101kg, but would not be less.
Page 34 of 70 QINETIQ/AT&E/CR00782/1
ResTRTUrrb IIECT.RIOTED
4.7.3 When the originally cleared seat capability (112kg maximum occupant mass clearing the fin by 1.2m at 625 knots) is compared to the modified seat (101kg maximum occupant mass clearing the fin by 1.2m at 625 knots) it can be seen as to why the seat would have appeared to have lost performance (paragraphs 4.7.1 and 4.7.2 of this report refers). However, this is not the case, as the ejection gun qualification (paragraph 3.7 of this report) shows that the original mass of explosive within the primary and secondary cartridges has increased by 100 grains. Although the primary cartridge charge was reduced to 570 grains from 630 grains, each of the secondary cartridges increased from 680 grains to 760 grains. This has resulted in the revised ejection gun storing more energy than the original gun, therefore making it more powerful (increased performance).
4.7.4 The 1.2m clearance from the CofG of the seat/ejectee combination and the fin has been reduced to the seat/ejectee combination just clearing the fin, to give the greatest possible escape envelope. BAES are unsure as to where the clearance limit of 1.2m for the original seat was referenced from, as it is not an aircraft design/specification requirement. This has resulted in the maximum speeds for ejection of a heavy weight occupant (135kg) from the rear seat position as 617 KCAS for the IDS and 622 KCAS for the ADV type aircraft, to just clear the aircraft tail fin, eroding the previous safety margin.
4.7.5 The MBA report [35] provided sufficient evidence that the heavy weight occupant in the rear ejection seat would clear the tail fin at a maximum of 617 KCAS for the IDS aircraft and a maximum of 622 KCAS for the ADV aircraft. QinetiQ supports the revised ejection gun for use on the Mk10A ejection seat, with regard to tail fin clearance, for a maximum air speed of 617 KCAS for both aircraft types. However, a warning should be made to aircrew that the 617 KCAS limit is based on achieving clearance from the fin under stable conditions. Clearance, and the risks associated with this, improves with a reduction in speed.
4.8 Ejection Seat/Aircraft Canopy Collision.
4.8.1 The report [10] concluded that the clearance levels between the Tornado canopy and the rear ejection seat during a 'worst case' ejection are marginally reduced due to the introduction of the modified ejection gun with the revised primary and secondary cartridges, in conjunction with a minimum mass seat occupant. The evidence produced for this reduction in clearance was considered acceptable.
4.8.2 When using the modified ejection gun with a minimum weight crew member in the rear seat position, the Tornado aircraft canopy and rear ejection seat/occupant had been shown not to collide, in a virtually impossible 'worst case' scenario. In all more probable ejection scenarios the dynamic clearance between the canopy and rear ejection seat would be much greater. The evidence that an ejected minimum weight crew member would miss the jettisoned canopy in a worse case ejection scenario is considered acceptable. It was also considered acceptable that there would be a greater clearance between the minimum mass ejectee and the canopy for all other ejection events. QinetiQ therefore supports the ejection gun for use with regard to ejection seat and canopy dynamic clearance.
4.9 Ejection Seat Mounting to Aircraft (40g Crash Scenario).
4.9.1 The Tornado Specification for the crash case survivability of the Mk10A ejection seat, with the introduction of heavy weight aircrew, was reduced from its original value of 40g
QINETIQ/AT&E/CR00782/1 Page 35 of 70
IirsperTOWei to 34g. The original specification for Tornado was considered excessively stringent and it was stated that the human body was resistant to a maximum of 20g only. QinetiQ supports the new lower limit of impact survivability of the revised Mk10A ejection seat due to increased mass aircrew.
4.10 GQ5000 Parachute and Harness Suspension.
4.10.1 The BAES report [41] concluded that the parachute steering system had improved the chances of survival of aircrew post ejection, by allowing manoeuvrability of the aircrew/parachute combination away from such hazards as burning aircraft wreckage and other obstacles. However, the configuration of the harness and parachute risers with regard to the point of suspension made it difficult to locate the parachute steering line handles (needing to be located by touch). It also made observation of the canopy very difficult with a non-inflated life preserver and impossible once life preserver inflation had occurred. The bulk of the AEA contributed to these difficulties, with higher bulk resulting in increasingly difficult accessibility. The functional reach of the aircrew would further compound aircrew accessibility and operation of the system, with reducing functional reach again resulting in increased difficulty. QinetiQ support the observations and conclusions made during the suspension trials with regard to the difficulties involved with location and use of the GQ5000 parachute steering facility when utilised in conjunction with the revised simplified harness. As a consequence, aircrew should be trained on location of the steering facility and the correct operation of the GQ5000 parachute.
4.11 Mk 10A Ejection Seat Performance.
4.11.1 The escape envelope for the Mk10A ejection seat fitted to the Tornado ADV and IDS aircraft (0-625kts, 0-50,000ft) is now fully. restored for aircrew under 127kg boarding mass. Aircrew over 127kg boarding mass (up to 135kg boarding mass) have a reduced maximum ejection speed of 617kts for the IDS and 622kts for the ADV. However, for simplification the ejection seat escape envelope for the IDS and ADV Tornado aircraft types fitted with the fully modified Mk10A ejection seat should be declared as 0-617kts, 0-50,000ft for all aircrew with boarding masses of between 67.5kg and 135kg (inclusive). The limitations currently shown tabulated in the MAR documents for ejection from Tornado F3 and GR4/4A aircraft with respect to mass, altitude and speed are now invalid due to escape envelope restoration by the GQ5000 parachute and deployment system and the revised primary and secondary ejection gun cartridges.
Page 36 of 70 QINETIQ/AT&E/CR00782/1 5 Recommendations
5.1 Military Aircraft Release (MAR).
5.1.1 The Phase Two changes to the Mk10A ejeCtion seat, with regard to the GQ5000 parachute and associated deployment system (Mod 02198) and the revised primary and secondary ejection gun cartridges (Mod 02197) as well as all other minor modifications have been found satisfactory and are recommended for service release. The amendments to the F3 and GR4/4A MAR documents consist of replacing the previously cleared aircrew boarding masses with the revised aircrew boarding masses (67.5kg to 135kg inclusive), deletion of the escape envelope limitations table, amendment of the maximum ejection speed for all aircrew (617kts) and the deletion of an 'on the ground' forward velocity of 30 KCAS for boarding masses above 107.9kg. The GR4/4A MAR should also have the reference to a minimum seat/occupant ejected mass (165.5kg) and the minimum seat ejected mass (97.5kg) deleted. A warning to aircrew that the 617 KCAS limit is based on achieving clearance from the fin under stable conditions and that clearance, and the risks associated with this, improves with a reduction in speed, should be included in the MAR documents.
5.2 Use of the GQ5000 parachute.
5.2.1 Aircrew must be briefed upon the fundamentals of parachute control, with regard to the utilisation of the GQ5000 parachute, for both day and night operation. This is considered essential for the safe operation of the revised system.
5.3 GQ5000 Parachute Steering Facility.
5.3.1 The GQ5000 parachute steering handles should be considered for modification (for ease of location by touch) and possibly located further down the parachute risers towards the ejectee (for ease of location by aircrew with a restricted functional reach). This is considered to be highly desirable for the efficient operation of the GQ5000 parachute by an ejectee.
5.3.2 The location at which the GQ5000 parachute risers interface with the simplified combined harness should be modified so that when the ejectee is suspended in the harnes, an improved view of the parachute canopy can be achieved. This is considered to be desirable.
5.3.3 Aircrew should be trained on locating the GQ5000 parachute control line handles by use of touch due to restricted view. This is considered to be essential for efficient use of the GQ5000 parachute by an ejectee.
5.4 Maintenance Documentation.
5.4.1 All maintenance documentation relating to the Mk10A ejection seat fitted to the Tornado ADV and IDS aircraft should be amended to take into account the Phase One and Two modifications. The maintenance documentation should also give a warning to fit the correct part number primary and secondary ejection gun cartridges into the ejection gun. This is considered to be essential.
5.5 Seat Limitations Documentation.
QINETIQ/AT&E/CR00782/1 Page 37 of 70
Rernkfrergb 5.5.1 The revised operational limitations of the Mk10A ejection seat with regard to the crash limit of the ejection seat mounting points (34g) and the cold limit of the GQ5000 parachute deployment system (-50°C) should be incorporated into any documentation on system operational ability. This is considered to be essential.
Page 38 of 70 QINETIQAT&E/CR00782/1
1460*Pleagb 6 References
1. Vigirallfaiity,11111111.11111.11111111x Ejection Leg Injuries RAF Experience 1972-1996. Royal Air Force School of Aviation Medicine Report No. 04/96, December 1996.
2. 41.1111.11. Mk10A Ejection Seat Modifications (2`196 & 2200) for Tornado GR4/4A and F3 Aircraft Phase One. QINETIQ/AT&E/CR00653, Issue 1, April 2002.
3. 1111111111110. A General Description of the GQ5000 Parachute as used in Martin Baker Ejection Seats. MBA-SYS-TN-9608, 22nd February 1996.
4. iMMINOW. AIRFRAME ESCAPE SYSTEM EJECTION SEAT SP-P-72001 Introduction of a new GQ5000 Parachute. PONO BAES Proposal Number 02198, 18th November 1998.
5. 1111111111111. Qualification Test Report Mk10A Ejection seat for Tornado Seat Enhancement Programme. MBA/QTR/446, Revision A, 4th May 2000.
6. Unknown Author. Tornado Seat Enhancement Programme. Enclosure 8C to T/33706/GERM/17137/99/NU, 16th June 1999.
7 Unknown Author. WEAPONS COURSE NOTES Aircraft Assisted Escape System. Tornado Maintenance School.
8. flallraik AIRFRAME ESCAPE SYSTEM EJECTION SEAT SP-P-72001 Introduction of Optimised Ejection Gun Cartridges. PONO BAES Proposal Number 02197, 18th November 1998.
9. Tornado Aircraft Publication. AP101B-4104-1ET, Chapter 145-13.
10. MIMONI, Tornado Escape System Analysis of Relative Motion of Ejection Seat & Canopy Jettison System Post Mod 02197. BAE-WPM-R-TOR-CRW-01639, 25th June 2001.
11. Tornado Aircraft Publication. AP101B-4104-1ET, Chapter, 3300.
12. Tornado Aircraft Publication. AP101B-4104-1ET, Chapter 29-20.
13. 1111111.11P. Qualification Test Plan for the System Testing, of the Mk10 Seat for the Tornado Enhancement Programme. TN2375, Issue 2,'Audust 1998.
14. TEST SUMMARY — SHOT 5227 — Mk.10A FOR THE "Tornado" AIRCRAFT As part of the Seat Performance Enhancement Programme ZERO/ZERO SYSTEM TEST. TN2382, Issue 1, 7th October 1998.
15. 1111111111111111k TEST SUMMARY — SHOT 5229 — Mk.10A.FOR THE "Tornado" AIRCRAFT As part of the Seat Performande —Enh6ncement Programme ZERO/ZERO SYSTEM TEST. TN2385, Issue 1, 27th October 1998.
QINETIQ/AT&E/CR00782/1 Page 39 of 70 16. 411111111/0. TEST SUMMARY - SHOT 5302 - Mk.10A FOR THE "Tornado" AIRCRAFT As part of the Seat Performance Enhancement Programme ZERO/ZERO SYSTEM TEST. TN2408, Issue 1, 13th April 1999.
17. 1111111111111. TEST SUA4114,04Apri4110224ioacopi.„_f4DR THE "Tornado" AIRCRAFT As part of the SearPerformance -Eneaiidement Programme ZERO/ZERO SYSTEM TEST. TN2409, Issue 1, 13th April 1999.
18. 111111111.1/. TEST SUMMARY - SHOT 5283 - 14646WR THE "Tornado" AIRCRAFT As part of the Seat Performance Enhancement Programme ZERO/ZERO SYSTEM TEST. TN2422, Issue 1, 30th June 1999.
19. TEST SUMMARY - SHOT 5284 -.4,10A4,0 THE "Tornado" AIRCRAFT As part of the Seat Performance 'Enhancement Programme ZERO/ZERO SYSTEM TEST. TN2423, Issue 1, 30th June 1999.
20. 1.111111111. Mk10A Ejection Seat System Testing for the Tornado Performance Enhancement Programme - Final Report. 8197, Issue 1, June 2000.
21. 101111Millt. TEST SUMMARY - SHOT 5230 - Mkt? THE "Tornado" AIRCRAFT As part of the Seat Performance Enhancement Programme 625 KTS SLED TEST. TN2421, Issue 1, 5th July 1999.
22. Tornado Equipment Specification SP.P-72001-00P Ejection Seat and Command Ejection System. SP.P-72001-00P, 19th February 1996.
23. aamme. Parachute Inflation Bladder. Laboratory Test Report No. 2365 (Beaufort), 18th August 1998. *WOW** 24. NETMA Meeting Minutes. Ejection Seat Enhancement Modification Package - Qualification Programme - Minutes of the Meeting held on the 3rd of November at NETMA. T/33707/ES-PACK/32780/99/NU, 3rd November 1999.
25. 4111101.110. Mk10A Headbox - Environmental Test Report. MBA/QTR/537, Initial Issue, 28th September 2000. • dirirert- • 26. 11111111111111.111. Tornado Seat Enhancement Programme Headbox/Canopy Clearance. BAE-WPM-RP-TOR-CRW-1605, 21st July 2000.
27. iimir PLAN FOR DYNAMIC PARACHUTE HARNESS TESTING FOR THE "Tornado" AIRCRAFT As Part of the Seat Performance Enhancement Programme. TN2386, Issue 1, 29th October 1998.
28. wow RESULTS OF DYNAMIC PARACHUTE HAI-mi S TESTING FOR THE "Tornado" AIRCRAFT As Part of the Seat Performance Enhancement Programme. TN2388, Issue 1, 29th October 1998. ...1; 4.szite+Pre-
29. Martin-Baker Stress Office. Structural Clearance of Mk10A Seat and Harness with Extended Mass Range. TO451, 22hd October 2001.
30. 41.1111aim Mk10A Ejection Gun Qualification Report. B198, Issue 2, 14th September 2000.
31. Unknown Author. Ejection Acceleration Limits. ASCC AIR STD 61/1B Page 40 of 70 QINETIQ/AT&E/CR00782/1 32. low. Tornado Type 10A Seat Performance Enhancement Programme Analysis of Fin Clearance at High Ejection Speed. MBA-SYS-TN-9908, Issue 3, 16th May 2000.
33. 1101.111. Test Incident/Problem Report Primary Ejection Cartridge. TIPR3134, Issue 1, 31st March 1999.
34. 411111olib. RAF Aircraft Ejection Seats Escape Envelope Limits with Increased Crew Weights. MBA-SYS-TN-95-03, 16th August 1995.
35. /41Waraft. Tornado Type 10A Seat Performance Enhancement Programme Analysis of Fin Clearance at High Ejection Speed. MBA-SYS-TN-9908, Issue 4, 9th August 2001.
36. 111111111111111), Crew System Parachute Harness Trial Test Procedure. BAE-WPM- RT-TOR-CRW-00340, Issue A, June 2002.
37. 04111110.11111, 111111111.1pEt Al. An Anthropometric Survey of 2000 Aircrew 1970/1971. IAM Report 531, 1971.
38. Unknown Author. Aircrew Equipment Assemblies General and Technical Information. AP108B-0001-1, 2nd Ed.
39. 4WD* Parachute Harness Qualification Test Report (Post Modification 02196 & 02198). BAE-WPM-RP-TOR-CRW-01741, Issue 1, 18th July 2002.
QINETIQ/AT&E/CR00782/1 Page 41 of 70 7 List of abbreviations
0 Degrees °C Degrees Centigrade
al* ADV Air Defence Variant AEA Aircrew Equipment Assemblies AT&E Aircraft Test and Evaluation AVS Air Vehicle Systems BAES British Aerospace SYSTEMS BSTS Ballistic Signal Transmission System BTRU Barostatic Time Release Unit BTTDFU Breech Type Time Delay Firing Unit CDL Canopy Datum Line CEC Command Ejection Controller CJ Canopy Jettison CJS Canopy Jettison System CUJ's Canopy Unlocking Jacks CofG Centre of Gravity DDP Declaration of Design Performance DoF Degrees of Freedom DRI Dynamic Response Index DWL Drogue Withdrawal Line EGI Ejection Gun Initiator ft Feet g Gravity GFTDU Gas Fired Time Delay Unit GS Gas Shackle HAS Hardened Aircraft Shelter HPRU Harness Power Retraction Unit hrs Hours IDS Indictor Strike IPT QA Integrated Project Team Quality Assurance ISS Inter-seat Sequencing System KCAS Knots Calibrated Air Speed kg Kilogram Page 42 of 70 QINETIQ/AT&E/CR00782/1 kgf Kilograms Force kts Knots LCC Linear Cutting Cord m/s Metres per Second m Metre MBA Martin Baker Aircraft company Mk Mark mm Millimetres Mod Modification MOR Manual Override MOS Marginality of Success ms Milliseconds N Newtons
N2 Nitrogen NBC Nuclear, Biological and Chemical NDAAR National Design Approval Authority Representatives NETMA NATO EF2000 and Tornado Development, Production and Logistics Management Agency PCJS Primary Canopy Jettison System psig Pounds per Square Inch (Gauge) QTR Qualification Test Report RAF Royal Air Force RH Relative Humidity RRI Remote Rocket Initiator s Second SI BSTS Seat Initiation Ballistic Signalling Transmission System STD Seat Test Department TN Technical Note TRM Time Release Mechanism
QINETIQ/AT&E/CR00782/1 Page 43 of 70 8 Figures
NUMBER OF NUMBER OF LOWER LEG AIRCRAFT ACCIDENTS AIRCREW FRACTURES TYPE INVOLVING EJECTED ON EJECTION LANDING Tornado 36 69 7 Hawk 22 30 1 Harrier GR7 4 4 GR5 1 1 GR3 32 32 GR1 9 9 T4 3 6 Jaguar 32 45 2 Total 139 196 10
Figure 8-1 Number of Leg Fractures during Ejections from RAF Accidents 1972-1996
I. Parachute container 2. Bladder (shown inflated) 3. Rigging line links stowage tray 4. Nitrogen bottle 3. Mounting bracket 6. Gas inlet from BTRU 7. Piercer assembly 8. Nitrogen inlet pipe to bladder
Figure 8-2 GQ5000 Bladder Deployment System
Page 44 of 70 QINETIQ/AT&E/CR00782/1
Rermiegreeit 'Scissors' Shackle operating rod
Figure 8-3 Original BTRU with Mechanical 'Scissors' Operating Mechanism
Figure 8-4 Revised BTRU with GS Ballistic Gas Supply Capability
QINETIQ/AT&E/CR00782/1 Page 45 of 70 Figure 8-5 Ejection Gun Assembly
Page 46 of 70 QINETIQ/AT&E/CR00782/1 Figure 8-6 Original BTTDFU
Figure 8-7 GFTDU (replacement of BTTDFU)
QINETIQ/AT&E/CR00782/1 Page 47 of 70 GAS FROM EJECTION SEAT GAS TO CARTRIDGES UNLOCKING SEAR JACKS .004r. CANOPY JETTISON HANDLES INPUT
FIRING LINK
BELL CRANK
SAFETY PIN HOLE
GAS TO CANOPY JACK PISTON UNIT
Figure 8-8 Canopy Jettison Initiator Unit
FIRING CLAMPING UNIT CAP
L14 CANOPY ROCKET MOTOR VA04 04614,
MOUNTING 0 BRACKET
FORWARD CANOPY FAIRING ASSEMBLY
EFFLUX NOZZLE P,
Figure 8-9 Canopy Rocket Motor
Page 48 of 70 QINETIQ/AT&E/CR00782/1 Figure 8-10 GQ5000 Headbox post 'In Contact' with LCC during Detonation showing Damage to Upper Surface of Fabric Top Flap
Figure 8-11 GQ5000 Headbox Kevlar Reinforced Fabric Top Flap showing no Damage Post 'In Contact' with LCC during Detonation
QINETIQ/AT&E/CR00782/1 Page 49 of 70 40
36
30
25 at
20
15
10
14 16 10 20 22 DRI
Figure 8-12 DRI Value Shown against Spinal Injury Risk
8
Actual trajectory (Shot 5230)
-Matched simulation
seatioccupant cg trajectories
2
0
-2 -12 -10 -2 2 (m)
Figure 8-13 Comparison between Measured (608 knots) and Simulated (610 knots) Seat Trajectories (Rear Seat, 135kg Occupant)
Page 50 of 70 QINETIQ/AT&E/CR00782/1 Figure 8-14 Still 1 from Simulation of Test Ejection of Enhanced Seat at 610 knots (Rear Seat, 135kg Occupant)
Figure 8-15 Still 2 from Simulation of Test Ejection of Enhanced Seat at 610 knots (Rear Seat, 135kg Occupant)
QINETIQ/AT&E/CR00782/1 Page 51 of 70 Figure 8-16 Still 3 from Simulation of Test Ejection of Enhanced Seat at 610 knots (Rear Seat, 135kg Occupant)
Maximum ejection speed to achieve On clearance (KCAS) 650
640 beyond escape system speed limit
greater than 625 knots 630
620 to just clear the fin
610
600
590 equivalent to CRw boarding mass of 135 kg 580
570
560
550 210 216 220 226 230 236 240 Total elected mass (kg)
Figure 8-17 Maximum Ejection Speed to achieve Fin Clearance, for the Tornado IDS, as a Function of Crew Mass
Page 52 of 70 QINETIQ/AT&E/CR00782/1 Maximum ejection speed to achieve fln clearance (KCAS)
630
620
610
600
590 equivalent to crew boarding mass of 135 kg
580
570
560
550 210 215 220 225 230 235 240 Total eiected mass (kg)
Figure 8-18 Maximum Ejection Speed to achieve Fin Clearance, for the Tornado ADV, as a Function of Crew Mass
Figure 8-19 Canopy Hinge
QINETIQ/AT&E/CR00782/1 Page 53 of 70 Canopy Closed Normal Canopy Open
Canopy/Aircraft Separation Canopy Jettisoned
Figure 8-20 Canopy Hinge Separation Sequence
Page 54 of 70 QINETIQ/AT&E/CR00782/1 Figure 8-21 Suspended Test Subject (non-inflated life preserver)
QINETIQ/AT&E/CR00782/1 Page 55 of 70 Figure 8-22 Subject One with Parachute Steering Lines Located (by touch)
Page 56 of 70 QINETIQ/AT&E/CR00782/1 Figure 8-23 Subject One with Life Preserver Inflated (frontal)
QINETIQ/AT&E/CR00782/1 Page 57 of 70 Figure 8-24 Subject One with Life Preserver Inflated (side)
Page 58 of 70 QINETIQ/AT&E/CR00782/1 Figure 8-25 Subject Two Attempts Viewing Parachute Canopy (life preserver not inflated)
QINETIQ/AT&E/CR00782/1 Page 59 of 70 Figure 8-26 Attachment Points of Parachute Risers to Combined Harness over Shoulder (Subject Two)
Page 60 of 70 QINETIQ/AT&E/CR00782/1 A Appendix - GR4/4A MAR Change Pages
SECTION 11: ESCAPE SYSTEM INCLUDING CANOPY AND PERSONAL EQUIPMENT
1. Escape System Clearance
The escape system and equipment are cleared for use, subject to the following:
1.1. Flight Envelope
The escape system is cleared for use in both its modes, when initiated from either the front or rear crew position, throughout the flight envelope up to 617 KIAS for aircrew boarding masses between 67.5 kg and 135 kg.
Note: Boarding mass is the aircrew member complete with all Aircrew Equipment Assemblies and equipment but excludes non-ejected items e.g. NVGs.
WARNINGS
1. THE 617 KIAS IS BASED ON ACHIEVING CLEARANCE FROM THE FIN UNDER STABLE CONDITIONS. CLEARANCE, AND THE RISKS ASSOCIATED WITH THIS, IMPROVES WITH A REDUCTION IN SPEED 2. SEE PARAGRAPH 4 OF THIS SECTION, REGARDING THE PERFORMANCE OF AIRCREW EQUIPMENT ASSEMBLIES AT EJECTION SPEEDS ABOVE 450 KIAS. 3. SAFE EJECTION IS ALSO SUBJECT TO THE MINIMUM SAFE HEIGHT/SINK RATE/SPEED/BANK ANGLE ENVELOPE SPECIFIED IN THE AIRCREW MANUAL.
1.1. The Miniature Detonator Cord (MDC) escape path clearance system is cleared for:
1.1.1. In-flight use as an automatic back-up system in the event of canopy jettison failure following initiation of the escape system, and
1.1.2. Ground use for emergency ground egress.
2. Canopy
Following loss of the canopy the aircraft should be recovered as quickly as possible to a speed less than 250 KIAS and the altitude should then be reduced to below 15 000 ft.
3. NVG Auto-Separation System
3.1. The NVG Auto-separation system is cleared for use. QINETIQ/AT&E/CR00782/1 Page 61 of 70 3.2. Limitations
3.2.1. The PS/BIT box must be serviceable for all NVG sorties.
3.2.2. An integrity test of the NVG Auto-separation system must be carried out using the PS/BIT box immediately following the attachment of the NVG to the helmet, and/or whenever the connection between the man-portion PEC and the seat portion PEC has been broken and re-made.
3.3. CAUTION
Where practicable, the NVG should be manually removed prior to ejection, crash/forced landing, RHAG/Barrier engagement, ditching, in the expectation of a heavy landing or before attempting an emergency egress and placed clear of the escape path.
4. Personal Equipment
The UK Aircrew Equipment Assembly (AEA) satisfactorily withstands ejections up to 450 KIAS. There is an increasing risk to aircrew that the blast visor and oxygen mask will be lost as ejection speeds increase above 450 KIAS. The performance of GE and IT AEAs is essentially the same as for UK equipment.
4.1. FPV
The FPV is to be worn at all times when the NVGs are fitted.
CAUTION
At ejections in excess of 450 KIAS there is an increasing risk that the FPV will become detached from the flying helmet thus subjecting aircrew to the effects of air blast and possible eye injury.
4.2. Flying Helmets
Only Mk 4A4 and Mk4D helmets with Modifications HMO 053, HMO 036, HMO 039 and HMO 067 are cleared for use with NVGs.
5. Cockpit
The cockpit and escape system is cleared for the following aircrew anthropometric size ranges:
BODY MINIMUM MAXIMUM MEASUREMENT mm mm (nude) Functional Reach 736 889 Buttock - Knee Length 558 672 Sitting Height 876 1007 Buttock - Heel Length 998 1211 Bideltoid Breadth 427 512 Page 62 of 70 QINETIQ/AT&E/CR00782/1
BASTRICir0i, Note Measurements are taken in accordance with RAE TR 73083.
QINETIQ/AT&E/CR00782/1 Page 63 of 70 THIS PAGE INTENTIONALLY LEFT BLANK
Page 64 of 70 QINETIQ/AT&E/CR00782/1 B Appendix - F3 MAR Change Pages
PART 6
CHAPTER 14 - ESCAPE SYSTEM
1. Escape System
1.1. Flight Envelope
The escape system is cleared for use in both its modes, when initiated from either the front or rear crew position, throughout the flight envelope up to 617 KCAS for aircrew boarding mass between 67.5 kg and 135 kg.
Note: Boarding mass is the aircrew member complete with all Aircrew Equipment Assemblies and equipment.
WARNINGS
1. The 617 KCAS is based on achieving clearance from the fin under stable conditions. Clearance, and the risks associated with this, improves with a reduction in speed. 2. See paragraph 3 below regarding the performance of Aircrew Equipment Assemblies at ejection speeds above 450 KCAS.
3. Safe ejection is also subject to the minimum safe height/sink rate/speed/bank angle envelope specified in the Aircrew Manual.
1.2. Canopy MDC
The canopy MDC escape path clearance system is cleared for:
1.2.1. In-flight use as an automatic back-up system in the event of canopy jettison failure following initiation of the escape system.
1.2.2. Ground use for emergency ground egress.
2. Canopy
Following loss of the canopy the aircraft should be recovered as quickly as possible to within the flight limits detailed at Part 6, Chapter 11, Paragraph 1.4.
3. Personal Equipment
QINETIQ/AT&E/CR00782/1 Page 65 of 70 The Aircrew Equipment Assembly (AEA) satisfactorily withstands ejections up to 450 KCAS. There is an increasing risk to aircrew that the blast visor and oxygen mask will be lost as ejection speeds increase above 450 KCAS.
4. Cockpit
The cockpit and escape system is cleared for the following aircrew anthropometric size range.
Body Measurement Minimum Maximum (Nude) (mm) (mm) Functional Reach 736 889 Buttock - Knee length 558 672 Sitting Height 876 1007 Buttock - Heel Length 998 1211 Biteltoid Breadth 427 512
Note: Measurements are taken in accordance with RAE TR73083.
5. Combat Survival Waistcoat
The aircrew equipment Combat Survival Waistcoat Type 1, (CSW) introduced under AEC Submission No AES.103, is cleared for use in OEC only and subject to the following limitations:
5.1. Prior to flight the individual aircrew are to carry out a full cockpit integration check to ensure that there are no limitations imposed by the CSW or equipment carried therein. If the integration check reveals a deficiency the advice of FS AEES (RAF) is to be sought. If the deficiency is not resolved the following action is to be undertaken:
5.1.1. The specific CSW is to be withdrawn from use and a F760 Defect Report raised, and or
5.1.2. The particular aircrew is not to be cleared to fly whilst wearing the CSW.
5.2. Lap straps are to run under the lower radio pocket.
5.3. The PEC hose is to be routed around the inboard end of the PRC-112 radio pocket.
Note: Use of a fully equipped CSW will increase seat ejection mass by 5.5 kg.
Page 66 of 70 QINETIQ/AT&E/CR00782/1 Ittwerftemireer
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QINETIQ/AT&E/CR00782/1 Page 67 of 70 Distribution list External: ES(Air) Tor9c 101111110111M ES(Air) SAAD IPT 0100011.110111 ampionlar 411111111111. Internal: Trials Officer 411101. Techical Director D/Air Ops (for CTP) OC FJTS (for Tornado GR4 Project Pilot) DSTL Knowledge Services (2 copies) Library AT&E Database Administrator — e-copy
Page 68 of 70 QINETIQ/AT&E/CR00782/1 Report documentation page
1. Originator's report number: 1
2. Originator's Name and Location: WIMP QinetiQ BCE
3. MOD Contract number and period covered: C8FFT/014
4. MOD Sponsor's Name and Location:
5. Report Classification and Caveats in use: 6. Date written: Pagination: References:
RESTRICTED December! 2002 x + 70
7a. Report Title: MK 10A Ejection Seat Modifications (2197 & 2198) for Tornado GR4/4A and F3 Aircraft Phase Two
7b. Translation / Conference details (if translation give foreign title / if part of conference then give conference particulars):
7c. Title classification:
8. Authors: 4111111111.11
9. Descriptors / Key words: TORNADO EJECTION SEAT MBA MARTIN-BAKER BOARDING MASS HEADBOX HEADPAD GQ1000 PARACHUTE GQ5000 PARACHUTE SIMPLIFIED COMBINED HARNESS MOD 02197 02198
10a. Abstract. (An abstract should aim to give an informative and concise summary of the report in up to 300 words).
This customer report was prepared for 4110/11111111110 at Tor 9c (TOR3/09/97BD) in support of the Phase Two Mk10A ejection seat modifications 02197 and 02198.
The modifications to the ejection gun primary and secondary cartridges (02197) and the integration of the GQ5000 parachute and associated deployment system (02198) were found to be acceptable. A revised ejection envelope for aircrew masses between 67.5kg and 135kg has been advised.
10b. Abstract classification: R FORM MEETS DRIC 1000 ISSUE 5
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