The Wrong Fuel: Three Misfuelling Accidents
The Wrong Fuel: Three Misfuelling Accidents Misfuelling aircraft with kerosene based Jet A-1 rather than Aviation Gasoline (AVGAS) continues to be a source of accidents. We look at three: 1) Misfuelled PA31 Accident: 15 Sept 2015 Manitoba The Canadian Transportation Safety Board (TSB) has recently released their report on the 15 September 2015 accident involving twin engined Keystone Air Service Piper PA31-350 Navajo C-FXLO at Thompson, Manitoba. The TSB say: Shortly after rotation, both engines began to lose power. The crew attempted to return to the airport, but the aircraft was unable to maintain altitude. The landing gear was extended in preparation for a forced landing on a highway southwest of the airport. Due to oncoming traffic, the forced landing was conducted in a forested area adjacent to the highway, approximately 700 metres south of the threshold of Runway 06. The descent angle through the trees to the impact point of the main landing gear was about a 10° descent angle in a nose-high, wings-level attitude. From the initial impact point, the aircraft travelled another 30 m before coming to a stop. The total length of the wreckage trail from the first tree impact was approximately 76 m. The [8] occupants sustained varying serious injuries but were able to assist each other and exit the aircraft. Prior to Flight The refuelling technician, who had been working for the fuelling company for a just over a month, and had no prior aviation experience, had fuelled another aircraft with Jet A1 before the Keystone aircraft arrived and drove the Jet A1 truck to where the PA-31 had parked. The aircraft commander had intended to relay the fuel requirements to the technician, but the Co-Pilot, who was escorting passengers, had noticed that the fuel technician was having trouble with the fuel filler openings. The Co-Pilot assisted the technician and asked for required fuel quantity. The Captain overhead this conversation and so did not talk to the refueller. Neither pilot noticed that the truck was a jet fuel truck. The technician did not spot the aircraft placard specifying aviation gasoline. When the technician couldn’t get the flared fuel filler nozzle to fit, he switched to a narrower nozzle, defeating a defence to prevent Jet A1 being used on a piston engined aircraft, but was sometimes required on aircraft that needed Jet A1. Prior to departure, the Captain returned to the fuel providers office to collect the fuel slip but it was unoccupied The crew then performed an abbreviated check before taking off without the fuel slip. TSB say: The Esso fuel dealer at Thompson Airport was Mara-Tech Aviation Fuels Ltd, which operated the Imperial Oil owned facility and equipment under an aviation dealer agreement. In addition to its day-to-day operation of the facility, Mara-Tech was responsible for staffing the facility and training the employees. Training materials were supplied by Imperial and consisted of a series of CDs or VHS tapes whose content was organized into modules. Each module was accompanied by a corresponding multiple-choice quiz. Aviation dealer agreements require that fuel dealers adhere to Imperial’s operating standards and procedures. Under the aviation dealer agreement, fuel dealers have a licence to use Imperial brand trademarks, such as Esso and Esso Aviation, in marketing their businesses. The [fuel technician’s] training consisted of reading the Imperial training material, viewing the CDs, and completing the corresponding multiple-choice quizzes. Additional certifications, such as Airside Vehicle Operator’s Permit and Transportation of Dangerous Goods, were administered by...
read moreBusiness Aviation Compliance With Pre Take-off Flight Control Checks
Business Aviation Compliance With Pre Take-off Flight Control Checks The US National Transportation Safety Board (NTSB) highlighted a number of important human performance issues in after a fatal Gulfstream G-IV N121JM business aircraft accident which occurred on 31 May 2014 at the joint civil/military Hanscom Field (BED) in Bedford, Massachusetts (final report). Aerossurance has discussed that accident previously: Gulfstream G-IV Take Off Accident & Human Factors This NTSB video illustrates the G-IV take off: The NTSB determined that the probable cause of this accident was: … the flight crewmembers’ failure to perform the flight control check before takeoff, their attempt to take off with the gust lock system engaged, and their delayed execution of a rejected takeoff after they became aware that the controls were locked. Contributing to the accident were the flight crew’s habitual noncompliance with checklists, Gulfstream Aerospace Corporation’s failure to ensure that the G-IV gust lock/throttle lever interlock system would prevent an attempted takeoff with the gust lock engaged, and the Federal Aviation Administration’s failure to detect this inadequacy during the G-IV’s certification. Aerossurance subsequently analysed a US Air Force (USAF) Lockheed Martin C-130J accident were a control check was omitted: C-130J Control Restriction Accident, Jalalabad It is noteworthy that when the NTSB reviewed flight data from the aircraft’s Quick Access Recorder (QAR), they discovered that this flight crew had failed to perform complete flight control checks before 98% of their previous 175 take offs. To the NTSB this indicated that this omission was “habitual”. The NTSB describe this a procedural drift (a topic we have discussed in our recent article: ‘Procedural Drift’: Lynx CFIT in Afghanistan). Among the NTSB recommendations was a recommendation to the National Business Aviation Association (NBAA): Work with existing business aviation flight operational quality assurance groups, such as the Corporate Flight Operational Quality Assurance Centerline Steering Committee [a Flight Safety Foundation initiated initiative], to analyze existing data for non-compliance with manufacturer-required routine flight control checks before takeoff and provide the results of this analysis to your members as part of your data-driven safety agenda for business aviation. The NBAA has now published their analysis report: Business Aviation Compliance With Manufacturer-Required Flight-Control Checks Before Takeoff The [FDM] data [analysed] shows that out of 143,756 flights conducted during the 2013 to 2015 time period, flight crews [only] conducted a partial flight-control check before takeoff (caution event) during 22,458 flights (15.62 percent). There was no flight-control check before takeoff (warning event) conducted on 2,923 flights (2.03 percent). For the three-year period covering 2013, 2014 and 2015, the overall noncompliance rate for manufacturer-required routine flight-control checks before takeoff was 17.66 percent, reflecting 25,381 events. After the accident on May 31, 2014, and the release of the preliminary report on June 13, 2014, the average warning event rate was reduced to 1.47 percent, a drop of 50 percent. That may indicate there was a positive reaction to the preliminary report finding that the Bedford crew did not perform any flight-control check before takeoff. The caution events are more variable, and there is not a significant difference in caution event rates between pre- and post-accident percentages. This report to the NBAA membership is not only intended to provide closure action to the NTSB recommendation, but also to raise awareness to the broader business aviation community that complacency and lack of procedural discipline have no place in our profession. NBAA President and CEO Ed Bolen said: As perplexing...
read moreUK CAA CAP1145: 2nd Update on North Sea Helicopter Safety (CAP1386)
UK CAA CAP 1145: 2nd Update on North Sea Helicopter Safety (CAP 1386) The UK Civil Aviation Authority (UK CAA) have issued CAP1386, their second update to their CAP1145 report (‘Safety review of offshore public transport helicopter operations in support of the exploitation of oil and gas’), issued in 20 February 2014. The first update, CAP1243, had provided an update on the 10 months to 31 Dec 2014. CAP 1386: Introduction In his introduction, Mark Swan, UK CAA Group Director Safety and Airspace Regulation, comments: We are pleased that there continues to be a strong collective commitment…evidenced by the co-operation received from all parties… …we have continued to work closely with industry and the European Aviation Safety Agency (EASA)… We are pleased to be participating in the work currently undertaken by EASA as part of their Safety Risk Portfolio – Offshore Helicopter Operations. It is clear that EASA is devoting significant energy, time and expert resources into this activity. This work provides an opportunity for real and lasting progress in this area. The majority of the actions and recommendations are now completed and we have identified a number of ongoing workstreams to ensure that we continue to see improvements in offshore helicopter safety. Swan states “The ultimate aim is for rotary wing safety performance to be on a par with large commercial fixed wing operations”. To achieve this ambitious goal: …the focus needs to be on prevention, as opposed to survival, through helicopter design improvements. In this regard, our ambition is to have a defined certification strategy where rotary wing can realistically approach commercial fixed wing safety and reliability performance. …we will continue to work closely with EASA and support all necessary EASA working groups to assist in this objective. In many ways the last comment demonstrates the critical importance to UK helicopter safety of remaining an EASA member State post-Brexit, 13 years since the UK CAA were last a ‘Competent Authority’ able to certify an offshore helicopter. CAP 1386: Passenger Safety and Survivability The UK CAA discuss a number of measures previously report in CAP 1243, and subsequently mandated by CAA Safety Directive SD-2014/001 (issued on 21 May 2014). Since then, significant progress has been made in introducing new requirements relating to the compatibility of passenger body size and underwater escape exit (window) size. Further work has also been performed in the areas of EBS [Emergency Breathing Systems] training and extending EBS to flight crew on offshore helicopters. The current Safety Directive (SD-2015/005 issued on 8 December 2015) introduced cover for support to Lighthouse Authorities and, in response to concerns raised by the industry, also introduced alleviation for the carriage of EBS for medically incapacitated passengers. An additional alleviation has been provided against the operating rules for such passengers in respect of life jackets and survival suits. They go on to discuss the activity to ensure passengers were seated next to windows compatible with their body size: From 1 April 2015, all passengers are now seated next to exits large enough for their body size and are checked by the helicopter flight and ground crews before takeoff as part of standard pre-flight procedures. They go on to say: Since 1 January 2015, all passengers have been required to wear suitable Cat A EBS (CAP 1034 Category A). In our previous progress report, we described how this had been introduced ahead of schedule for all passengers on 1 September 2014, and how the oil and...
read moreAAIB: Human Factors and the Identification of Saab 2000 Flight Control Malfunctions
AAIB: Human Factors and the Identification of Saab 2000 Flight Control Malfunctions The UK Air Accidents Investigation Branch (AAIB) has recently issued its report on a loss of control in flight incident, near Sumburgh Airport, on 15 December 2014 involving Saab 2000 G-LGNO: The aircraft was inbound to land on Runway 27 at Sumburgh when the pilots discontinued the approach because of weather to the west of the airport. As the aircraft established on a southerly heading, it was struck by lightning. When the commander made nose-up pitch inputs the aircraft did not respond as he expected. After reaching 4,000 ft amsl the aircraft pitched to a minimum of 19° nose down and exceeded the applicable maximum operating speed (VMO) by 80 kt, with a peak descent rate of 9,500 ft/min. The aircraft started to climb after reaching a minimum height of 1,100 ft above sea level. Recorded data showed that the autopilot had remained engaged, contrary to the pilots’ understanding, and the pilots’ nose-up pitch inputs were countered by the autopilot pitch trim function, which made a nose-down pitch trim input in order to regain the selected altitude. What the investigators found was that out of 22 airliner types examined, only the Saab 2000 had an autopilot which, when engaged: Applies an override force to the control column that will move the elevator but will not cause the autopilot to disengage Can trim in the opposite direction to the pilot applied control column input Has main pitch trim switches that will not cause the autopilot to disengage While the whole report is worthy of study but the AAIB discuss the identification of flight control malfunctions in a section that we feel is worth highlighting: In an aircraft with purely mechanical flying controls, a jammed flight control can be identified by resistance to movement of the control wheel or column. Failure of a control linkage will be apparent as the control will move without the usual resistance. In either case, the absence of the usual aircraft response to an input will be apparent. In this control system, the ‘loop’ from pilot input, to response felt through the controls, to aircraft response, is complete. In an aircraft with powered or fly-by-wire controls, and without any physical feedback, it may be harder to determine a malfunction because effect of control inputs can only be assessed from aircraft response. In manoeuvring flight or turbulence, this assessment may be more difficult. In the Saab 2000, the forces required to achieve particular control column displacement are greater when the autopilot is engaged, but this is not a usual mode of operation and pilots are unlikely to be familiar with it. A pilot feeling abnormal control resistance may not readily determine that the reason for the unusual forces is that the autopilot is engaged. Mental models are developed by experience and/or training, and more experience leads to more detailed mental models. Mental models guide interaction with systems: an accurate mental model can facilitate good performance, but poor mental models can lead to misunderstanding of system functioning, increasing the risk of error. AAIB note that: Designers can promote good mental models by optimising feedback, for example by providing indicators of system status and performance which are easily assimilated, even under stress. Automation surprise* can occur if the autopilot does not behave...
read moreOil Spill Response Boeing 727s
Oil Spill Response Boeing 727s UK company Oil Spill Response Limited (OSRL) provide a global aviation aerial dispersant service. OSRL has commissioned two Doncaster, UK based 727 dispersant aircraft with the 15,000 litre TERSUS dispersant system. Both OSRL 727s, operated by 2Excel Aviation, were in action for an exercise off the Isle of Wight today. OSRL say: The aircraft, two Boeing 727-2S2F(RE), are now central to OSRL’s aerial dispersant capability… Fitted with internal tanks, pumps and a spray boom to deliver dispersant liquid, the specially adapted Boeing 727-2S2F (RE) aircraft are truly a first-of-a-kind capability for the oil and gas industry. The Valsan engined 727-2S2F(RE) proved to be an ideal aircraft for OSRL: Because of their age the choice of the 727-2S2F(RE) aircraft offered a relatively low capital cost… Furthermore, the aircraft’s JT8D-217C Valsan high bypass ratio engines reduce the 727’s noise outputs to comply with Stage 3 noise levels, while offering between six and seven per cent reduction in fuel consumption. The tri-engine design of the 727-2S2F(RE) offers an important level of redundancy and if one were to lose an engine, the asymmetric effect is reduced and it can still climb away rapidly. Spraying is done at 150ft. Operator 2Excel Aviation explain: In 2014, EASA ruled that for an aircraft spraying system, oil spill dispersant liquids are to be classified as ‘flammable fluids’. The FAA soon aligned with EASA, and as a result any system entering service now has to meet the stringent regulation set out by these agencies. TERSUS, the system on the B727, was designed and built from scratch by 2Excel’s EASA Part21J & G design and production organization Leading Edge. Awarded an EASA STC in 2016, TERSUS is the only aerial dispersant system in the world that complies with the new EASA and FAA regulations. ORSRL video. It has since been joined by G-OSRB. both were built as cargo aircraft for FedEx. UPDATE 21 January 2017: A new 10 minute mini-documentary on the 727s and their capability: For details of another special mission conversion see our article: BAe 146 & Avro RJ85 Fire Bombers UPDATE 28 April 2017: The 2Excel operation for OSRL features in the article ‘Ready to Respond’ in the May 2017 issue of AIR International. UPDATE 5 June 2017: A further exercise is announced: Oil spill company OSRL to run test flight over the Solent UPDATE 16 July 2018: OSRL extend the contract 10 years as the 727 is displayed all week at Farnborough 2018. UPDATE 17 August 2020: OSRL and 2Excel sign a contract with the MCA. UPDATE 18 August 2020: 2Excel have modified the 727s to enable flight in known icing conditions with spray booms fitted. For practical expert advice you can trust on contracting for, design & conversion of and operation of special mission aircraft, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest...
read moreDelta MD-88 Accident at La Guardia 5 March 2015
Delta MD-88 Accident at La Guardia 5 March 2015 (Delta Flight 1086, MD88 N909DL) The US National Transportation Safety Board (NTSB) have meet to discuss the accident to Delta Airlines Flight 1086, MD-88 N909DL, that suffered a runway excursion on a snow covered runway at New York La Guardia on 5 March 2015 (Final Report). The use of excessive reverse thrust resulted in loss of direction control, but noticeably there was a significant delay to the evacuation (which took 17 minutes to complete). The aircraft broke the perimeter fence and came to rest on an embankment adjacent to Flushing Bay. The left wing was damaged by the fence, causing a fuel leak. The fuselage and interior were also damaged as were the main batteries. The 2 pilots, 3 cabin crew and 98 of the 127 passengers were uninjured. The remaining 29 passengers received only minor injuries. The Landing The NTSB say: The captain and the first officer were highly experienced MD-88 pilots. The captain had accumulated about 11,000 hours, and the first officer had accumulated about 3,000 hours, on the MD-88/-90. In addition, the captain was previously based at LGA and had made many landings there in winter weather conditions. The NTSB found that: The flight crew was well prepared for the approach and established landing requirements that were consistent with company policies. The flight crew was concerned about the available landing distance on runway 13 and, while en route to LGA, spent considerable time analyzing the airplane’s stopping performance. The flight crew also requested braking action reports about 45 and 35 minutes before landing, but none were available at those times because of runway snow clearing operations. The unavailability of braking actions reports and the uncertainty about the runway’s condition created some situational stress for the captain, the Pilot Flying. …the flight crews of two preceding airplanes (which landed on the runway about 16 and 8 minutes before the accident landing) reported good braking action on the runway, so the flight crew expected to see at least some of the runway’s surface after the airplane broke out of the clouds. Even though…observations of snow on the runway were inconsistent with the expectations…their decision to continue the approach was appropriate because the landing criteria had been met. …postaccident simulations showed that the braking action at the time that the accident airplane touched down was consistent with medium (or better) braking action. Although the runway was contaminated with snow, runway friction when the accident airplane landed was sufficient for stopping on the available runway length. …the snowier-than-expected runway, short runway length, and body of water off the departure end of the runway, likely exacerbated the captain’s situational stress and prompted him to make an aggressive input on the thrust reversers. When in reverse thrust, buckets deploy behind the rear-mounted engines of the MD-88 to deflect thrust forward. This reduces the airflow over the vertical stabilizer and rudder and reduces aerodynamic directional control, a phenomenon known as ‘rudder blanking’. Consequently, Boeing recommend limiting the Engine Pressure Ratio (EPR), a measure of engine thrust, to a maximum of 1.3 on contaminated runways, where direction control from nose steering is least effective. Delta’s Flight Crew Training Manual and MD-88/90 fleet bulletins issued in November 2014 and February 2015 however referred to this as a target. In this case, EPR reached 2.07 on the left hand engines and 1.91 on the right. The NTSB sampled data from 80 Delta MD-88 landings. Boeing’s recommended maximum of 1.6 EPR on dry runways was exceeded...
read moreHelideck Safety Alerts: Refuelling Hoses and Obstructions
Helideck Safety Alerts: Refuelling Hoses and Obstructions Helideck safety alerts have recently been released by the Helideck Certification Agency (HCA) and the US Bureau of Safety and Environmental Enforcement (BSEE). Refuelling Hoses Left Out on the Helideck The HCA say in a safety alert, further distributed by Step Change in Safety: The hose winding mechanism on fuel cabinets can breakdown which makes it difficult to rewind the hose back into the cabinet after a refuelling operation. Consequently helideck teams are leaving the hose laying out around the perimeter of the helideck. This practise MAY be acceptable for a short term pending rectification of the system, PROVIDING an adequate & robust risk assessment is in place and the hose is PROPERLY MANAGED for EVERY helicopter movement. In a recent near miss, a helideck team had left the hose out on deck from a previous refuelling operation. A day or two later when the next helicopter arrived, the hose was left on the downwind side of the helideck which resulted it being under the tail rotor after the helicopter had landed. The helideck team attempted to retrieve the hose but came perilously close to the tail rotor in doing so! The safety concerns stated by the HCA are: When the pump is switched off the hose remains full of fuel so leaving 20-30m of hose out on deck can contribute around 200l of fuel to any incident on the helideck. The hose obscures the green perimeter lights which affects night operations. The hose suffers increased UV degradation & wear dragging across the deck. The hose can end up under the tail rotor putting the helideck team at risk of a rotor strike. HCA comment: Because of this near miss and the increasing tendency for installations to leave the hose out on deck; HCA are minded to take a much harder line on instances where the duty holder does not have a satisfactory risk assessment or a suitable rectification plan in place to bring the system back in to compliance promptly, say within 6-months. Upon notification that the system is not operating correctly, HCA will register the system as ‘Non-Compliant’ and issue a Temporary Limitation Notice (TLN) to helicopter Operators advising them of the situation and requiring them not to land with the hose laid downwind. Pilots will be asked to report all such occurrences. Where a suitable rectification plan is not available, refuelling operations will be suspended until the system is returned to full serviceability. Helideck Obstructions and Procedural Errors Contribute to Five Near Misses in US In 4 months over the summer there were “at least 5 near misses involving helideck hazards” on US oil and gas installations according to BSEE: 26 May 2016. A helicopter landed to a helideck that the Operator had closed by Notice to Airmen (NOTAM) but had not marked as closed…. 6 July 2016. After landing to the edge of a helideck (rather than to the aiming circle), the pilot saw a vent pipe sticking up two feet above and three feet beyond the edge of the helideck. The pipe was four feet from the tail rotor. The Operator had not issued a NOTAM or marked the obstruction. After the landing, the Operator removed the pipe. 19 July 2016. During an unannounced inspection, a pilot landed on the helideck before noticing the flashing red light indicating that...
read more‘Uncontained’ CFM56-7 FBO Failures: Southwest B737-700s 27 Aug 2016 & 17 Apr 2018
‘Uncontained’ CFM56-7 FBO Failures: Southwest B737-700s 27 August 2016 & 17 April 2018 (UPDATED) The US National Transportation Safety Board (NTSB) has issued a press release, in advance of a preliminary report, on a fan blade off (FBO) occurrence to Boeing 737-700 N766SW operating Southwest Airlines Flight 3472, from New Orleans, Louisiana to Orlando, Florida on 27 August 2016. A second, seemingly very similar FBO event occurred to N772SW operating Flight 1380 from New York-La Guardia, NY to Dallas-Love Field, Texas on 17 April 2018. In that case debris penetrated a cabin window aft of the wing and one passenger is confirmed to have died (early reports suggest they had been partly sucked through the window). This was Southwest’s first passenger fatality ever and the first Part 121 passenger airline fatality since February 2009 (although all 7 crew died in a B747F crash at Bagram, Afghanistan in April 2013). The NTSB originally called these uncontained failures, though the fan blades did not exit radially (the true definition of uncontained) but instead axially (i.e. forward). The out of balance forces resulted in failure of the inlet structure. The First Accident Flight 27 August 2016: N766SW (Pensacola) One fan blade of the left hand CFM International CFM56-7B engine separated from the fan disc during the cruise. The root of that blade remained in the fan disc hub but the blade was not recovered. Consequently the entire left engine inlet separated from the engine, with debris damaged the fuselage, wing and empennage. A 5 x 16 inch hole was made in the fuselage just above the left wing and the cabin depressurised (though no engine debris penetrated the cabin). The aircraft diverted to Pensacola, Florida and made a safe landing, 18 minutes later. None of the 99 passengers and 5 crew onboard were injured Investigation Findings The CFM56 fan blades are manufactured of titanium alloy and are coated with a copper-nickel-indium alloy at the root contact face. Initial findings from the NTSB Materials Laboratory metallurgical examination include: The fracture surface of the missing blade showed curving crack arrest lines consistent with fatigue crack growth. The fatigue crack region was 1.14-inches long and 0.217-inch deep, and The center of the fatigue origin area was about 2.1 inches aft of the forward face of the blade root. No surface or material anomalies were noted during an examination of the fatigue crack origin using scanning electron microscopy and energy-dispersive x-ray spectroscopy. The Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR) have been down loaded by the NTSB. The NTSB’s Tim LeBaron is Investigator-in-Charge. The NTSB say: Parties to the investigation include the Federal Aviation Administration, Southwest Airlines, the Southwest Airlines Pilots Association, and CFM International. The French Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile has appointed an accredited representative who is supported by a technical advisor from Safran Aircraft Engines. CFM International is a joint venture between GE Aviation [US] and Safran Aircraft Engines [France]. Future work will include 3-D measurements of the contact areas of all the blades, a non-destructive examination of the blade surfaces for cracks, and a review of the engine maintenance records. UPDATE 25 August 2017: The FAA issued a Notice of Proposed Rule Making for an AD for comment with 15,000 cycles since last shop visit as the applicability criteria. UPDATE 10 October 2017: Southwest was one of a number of respondees to the FAA NPRM consultation. Southwest opposed a CFM proposal to reduce the FAA compliance time. They said...
read moreFinal Report: AS365N3 9M-IGB Fatal Accident
Final Report: AS365N3 9M-IGB Fatal Accident The Malaysian Air Accident Investigation Bureau (AAIB) has issued their final report on the accident to a privately operated Airbus Helicopters AS356N3 Dauphin 9M-IGM on 4 April 2015. The helicopter was carrying VIPs from a wedding luncheon. While in the cruise, the helicopter, with 6 persons on board was seen to dive into the ground. There were no survivors. The Accident Flight The aircraft had earlier taken off with 7 persons on board: The Cockpit Voice Recorder (CVR) information revealed that after getting airborne, one of the passengers was not happy with the weather condition en-route to the destination. On several occasions, he was suggesting to the pilot to proceed direct to Kuala Lumpur. However, after a short discussion, they concurred to off load one of the passengers originally destined for Bandar Tun Razak, at any open field along the way. While flying along the road en-route to Kuala Lumpur, they spotted a football field and executed an approach for a landing. The AAIB report that while landing on the football field, the left main landing gear had sunk into the soft ground approximately 50cm. The helicopter had consequently tilted over 13 degrees to the left. The left hand (LH) horizontal stabiliser vertical fin and the tail section beneath the tail rotor fenestron had contacted the ground causing some damage to the inboard root of the LH horizontal stabiliser. Investigators also found evidence of a leaked hydraulic fluid on the ground. The AAIB state that: Shortly afterward, the helicopter was seen to take off to a high hover and repositioned to approximately 10 meters to the front of its last position. One passenger disembarked the helicopter while both engines and the main rotors were still running and he exited via the right door escorted by the pilot. Shortly afterward at 1625 LT, the helicopter took off from the field. The pilot was seen by a witness to have exited the helicopter and accompanied the disembarked passenger clear of the main rotor area. However, he did not carry out any inspection of the helicopter. The helicopter was flown wheels down. The CVR recorded the pilot commented to a friend on board: “we went all the way to the belly, it’s not good”. He further said “it’s definitely not normal for the wheels go down into the ground that far”. It’s definitely not good to tip like that”. He said “as a matter of fact, I saw hydraulic fluid leaking and that’s why I don’t want to put them up”. The AAIB comment: The most likely reason to press on for the flight was to accommodate the passenger request to arrive at the destination [Kuala Lumpur] without delay and to enable him to attend the formal dinner as planned. Analysis of the Flight Data Recorder (FDR) showed: …the helicopter was flying under auto pilot at 148 kts, the pitch of the helicopter unexpectedly and significantly decreased. The helicopter rapidly went beyond the flight envelop limits without any pilot input. AAIB explain: Inspection on the reconstruction of the wreckage revealed that the main rotor blades had struck the cowling, tail boom, fenestron and the left cabin door while the helicopter was still in the air. This action is considered consequential and there was no indication that the helicopter had struck terrain or any trees in flight prior to the impact. The helicopter decended [sic] almost vertically to the main wreckage area. The main wreckage was concentrated at one area in a ravine. The 4 main rotor blades were found...
read moreLoss of RAF Nimrod MR2 XV230 and the Haddon-Cave Review
Loss of RAF Nimrod MR2 XV230 and the Haddon-Cave Review The Accident On 2 September 2006 Royal Air Force (RAF) Nimrod XV230, with 14 crew on board, departed for a surveillance mission over Afghanistan, in support of coalition forces engaging the Taliban. The aircraft rendezvoused with an RAF TriStar tanker for air-to-air refuelling (AAR), then turned towards the operational area. Eleven minutes after the AAR, a bomb bay fire warning and underfloor smoke warning were reported. Smoke entered the aircraft’s cabin. Within a minute the aircraft de-pressurised as fire breached the pressure hull. The crew donned their oxygen masks. The aircraft turned towards Kandahar, the crew declared a MAYDAY and began a descent. Last radio contact was 5 minutes after the first warning. Shortly after an RAF Harrier GR7 pilot, who was flying several thousand feet above, reported that the Nimrod had exploded. None of the 14 crew survived. The Investigations and Inquiries The accident resulted in an RAF Board of Inquiry, a Coroner’s Inquest and subsequently an independent review of the broader issues surrounding the loss. The BOI had found that the most probable physical cause of the loss of the aircraft was “the escape of fuel during Air-to-Air Refuelling” after which the fuel was ignited by “contact with an exposed element of the aircraft’s Cross-Feed/Supplementary Cooling Pack (SCP) duct”. Th Independent Review was then ordered by UK Secretary of State for Defence on 4 December 2007 with the following Terms of Reference: In light of the Board of Inquiry report: To examine the arrangements for assuring the airworthiness and safe operation of the Nimrod MR2 in the period from its introduction in 1979 to the accident on 2 September 2006, including hazard analysis, the safety case compiled in 2005, maintenance arrangements, and responses to any earlier incidents which might have highlighted the risk and led to corrective action; To assess where responsibility lies for any failures and what lessons are to be learned; To assess more broadly the process for compiling safety cases, taking account of best practice in the civilian and military world; And to make recommendations to the Secretary of State as soon as practicable, if necessary by way of interim report. The review was to be led by London barrister Charles Haddon-Cave QC, who was widely recognised as a leading UK lawyer in the aviation field, having served on the defence team for the 1985 Manchester air disaster and having also represented survivors in the inquiry into The Herald of Free Enterprise ferry disaster. The Haddon-Cave Report, was published on 28 October 2009 with 90 recommendations. “Nimrod Review: A Failure of Leadership, Culture and Priorities” Haddon-Cave agreed with the Board of Inquiry: …that the ignition source was the Cross-Feed/Supplementary Conditioning Pack (SCP) duct in the starboard No. 7 Tank Dry Bay. As regards the fuel source, new evidence (not available to the Board of Inquiry or other agencies) has come to light which points to an overflow during Air-to-Air Refuelling being the most likely fuel source; although a leak from a fuel coupling remains a realistic possibility. The Review went on: There were a number of previous incidents and warning signs, potentially relevant to XV230, which represented missed opportunities. In particular, the rupture of the SCP duct in Nimrod XV227 in November 2004 should have been a “wake up call”. The Review focused primarily on: The inadequacies of the ‘Nimrod Safety Case’ which was prepared between 2001- 2005...
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