News & Comment

ValuJet Flight 592: 11 May 1996

Posted by on 4:48 pm in Accidents & Incidents, Fixed Wing, Human Factors / Performance, Maintenance / Continuing Airworthiness / CAMOs, Regulation, Safety Culture, Safety Management

ValuJet Flight 592: 11 May 1996 On 11 May 1996 a ValuJet DC-9-32 N904VJ crashed in flames into the Florida Everglades while trying to return to Miami, killing all 110 occupants.  ValuJet was an Atlanta, Georgia based low cost carrier which started operations 26 October 1993.  ValuJet Flight 592 was a scheduled flight from Miami (MIA) to Atlanta (ATL).  The DC-9 was also carrying a small amount of cargo, including mail and ‘company-owned material’ (COMAT).  The COMAT was items being returned to the airline in Atlanta by SabreTech, a sub-contracted maintenance organisation in Miami.  It consisted of three tyres and wheels, and five boxes of cabin emergency oxygen generators, labeled as “Oxy Cannisters – ‘Empty’”, stored in the forward Class D Cargo Compartment.  Seven minutes after take-off the crew identified there was an aircraft fire, but although they attempted to return to MIA, just over 2 minutes later the aircraft impacted the ground. The Investigation During wreckage recovery from the swamp it became evident that there had been an intense fire in the forward cargo compartment.  During the investigation the NTSB discovered that the 5 boxes of chemical oxygen generators contained more than 100 time expired, but still active, oxygen generators. They say: The expired oxygen generators had been removed from three ValuJet MD-80 aircraft undergoing maintenance at SabreTech. The Board’s investigation revealed that, although many of the SabreTech mechanics who removed the generators understood the danger they could pose, the generators were nevertheless delivered to SabreTech’s shipping and receiving department without communicating what the items were, or that they were hazardous. Rather than dispose of the generators properly or at least fit them with safety caps designed to prevent their accidental activation, they were boxed up and sent to ValuJet in order to clean up the maintenance area in preparation for a visit by a prospective customer. In addition, they were incorrectly labelled… The NTSB determined that one or more of the oxygen generators activated. This created both the heat (as a by-product of the chemical reaction) and the oxygen to initiating a fire (fuelled by the tyres) that eventually brought the aircraft down. The NTSB concluded that: …the lack of a formal system in SabreTech’s shipping and receiving department, including procedures for tracking the handling and disposition of hazardous materials, contributed to the improper transportation of the generators aboard flight 592. ValuJet did not adequately oversee SabreTech: Had it ensured that SabreTech’s employees were trained on the company’s lack of authority to transport hazardous materials and had received hazardous materials recognition training, SabreTech might not have mishandled the packaging and shipment of the oxygen generators. In their investigation report the US National Transportation Safety Board (NTSB) determined that: …the probable causes of the accident, which resulted from a fire in the airplane’s class D cargo compartment that was initiated by the actuation of one or more oxygen generators being improperly carried as cargo, were: (1) the failure of SabreTech to properly prepare, package, and identify unexpected chemical oxygen generators before presenting them to ValuJet for carriage; (2) the failure of ValuJet to properly oversee its contract maintenance program to ensure compliance with maintenance, maintenance training, and hazardous materials requirements and practices; and (3) the failure of the Federal Aviation Administration (FAA) to require smoke detection and fire suppression systems in class D cargo compartments. Contributing to the accident was the failure of...

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Bell 412 Cross Tube Failure Case Study

Posted by on 9:42 pm in Accidents & Incidents, Design & Certification, Helicopters, Maintenance / Continuing Airworthiness / CAMOs, Safety Management, Special Mission Aircraft

Bell 412 Cross Tube Failure Case Study Earlier this year the German accident investigation agency, the BFU, published their report into Helicopter Emergency Medical Service (HEMS) Bell 412HP that suffered a rear cross tube failure during start up at a hospital in Berlin on 6 September 2010. The helicopter was fitted with ‘high’ skids manufactured by Aeronautical Accessories Inc (AAI) and certified under Supplementary Type Certificate (STC) SR01052AT.  The skids are supported by forward and after cross tubes.  The rear cross tube is mounted to the underside of the fuselage by way of a single central bracket made of two ‘half shells’ (the earlier Bell 205 and Bell 212 had two attachment points). The high aft cross tube was fractured on the right edge of the half shell.  The fractured cross tube damaged the right fuselage bottom side. The damaged tail boom rested on the filling station [sic i.e. the helideck fuel facility] and the wall of the landing platform behind the helicopter. …the area of the two half shells is more rigid than the rest of the [cross tube] pipe resulting in change of stiffness at the ends. Furthermore,…where the U-bolts clamp the half shells…a rigid clamping situation exists. Therefore, the area of the half shells is to be viewed as a highly stressed area… During the manufacturing process the [cross tube] pipe which is made of a high-strength aluminium alloy is shot blasted [i.e. shot peened]. The fatigue life of material shall be increased by shot blasting inserting residual compressive stress. The rear cross tube had first been installed new (on another helicopter) ten years earlier. On the day of the accident the [rear] cross tube had 6,245:08 flight hours and 17,690 flight cycles. After the last inspection [in May 2008] 1,410:34 hours and 4,120 cycles [landings]. In 2007 at the same operator a fracture of an aft cross tube occurred with an identical landing skid. The fracture surface was almost identical with the one of 2010. The cross tube of 2007 had 3,820 flight hours and 10,732 cycles. At that time the US Federal Aviation Administration (FAA) reported in a Special Airworthiness Information Bulletin that: Three reports from the field of failed aft crosstubes have been reported to AAI. Two of those failures occurred during landing. The other failure occurred during transport of the aircraft on ground handling platform equipment. Also, in one case during landing, the aft crosstube failed and subsequently the front cross tube failed causing the helicopter to lean severely on the failed right skid One was the 2007 German case.  The other two involved failures at 11894 and 15336 cycles. In the 2010 Berlin case, laboratory analysis confirmed a facture propagated by fatigue with final failure by overload.  There was no evidence of a hard landing. After the initial failures: In April 2008 Aeronautical Accessories published the Alert Service Bulletin (ASB) No. AA-07109 because of the incidents with the high aft cross tube. The Bulletin stipulated the operating limitations for the cross tube to be 20,000 cycles. Various inspections for crack detection on the surface of the cross tube and detection of permanent deformations were described… Essentially these are to check the pipe surface for crack development. During these checks the areas of the central half shells, which have failed verifiably at least twice, were omitted. BFU Analysis The BFU is of the opinion that...

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EC225 Main Rotor Head and Main Gear Box Design

Posted by on 7:45 pm in Accidents & Incidents, Design & Certification, Helicopters, HUMS / VHM / UMS / IVHM, Maintenance / Continuing Airworthiness / CAMOs, News, Offshore, Oil & Gas / IOGP / Energy, Safety Management

EC225/H225 Main Rotor Head and Main Gear Box Design (CHC LN-OJF Fatal Accident 2016) Following the recent tragic accident at Turøy near Bergen, Norway involving CHC Airbus EC225/H225 LN-OJF there is a lot of interest in the Main Rotor (MR) and Main Gear Box (MGB) design of the EC225.  Here we provide some background information on the design. The EC225/H225 MRH/MGB Design Unlike some other types, the 11t+ lift load from the Main Rotor is not imposed on the casing of the MGB, but is instead transferred via a Double Taper Bearing to the Lift Housing (see the diagram below).  When static the Double Taper Bearing also transmits the weight of the MR assembly to the Lift Housing. The Lift Housing is connected to the fuselage via three Suspension Bars (which connect to fittings secured to the fuselage by 4 bolts).  The Lift Housing also takes the suspended weight of the MGB via the Flared Housing.  The MGB is supported underneath by the flexible titanium Barbeque Plate which absorbs the MR torque, longitudinal and transverse loads and damps out vibrations. The EC225 has a integral Main Rotor Head (MRH) and MR shaft, which mates with output of the MGB Epicyclic Module via a spline.  The five Blade Sleeves (and their associated Blade Dampers) are attached to the MRH.  The composite Main Rotor Blades (MRBs) are fitted to the Blade Sleeves. As is conventional on a helicopter, the pitch of the MRBs is controlled by Pitch Change Rods connecting the Rotating Swashplate to the Blade Sleeves.  The Rotating Swashplate follows the position of the Non-Rotating Swashplate, which is moved by three flying control Servo Units (not shown above), in responses to movement of the pilot’s Cyclic and Collective Controls.  The Rotating Swashplate oscillates around a ball joint which can also slide up and down a Guide Tube that surrounds the MR Shaft.  Each part of the Swashplate has a two part articulating Scissor.  The one connected to the MRH drives the Rotating Swashplate, while the one connected to the Lift Housing prevents the Non-Rotating Swashplate from rotating. The MGB is modular, with a main module which drives an epicyclic module and two accessory modules.  Drive from the two 2101 shp Turbomeca Makila 2A engines enters the front of the MGB via two high speed (22962 rpm) shafts (known as Bendix shafts). The MGB Main Module and the 2 stage Epicyclic Module reduce the speed to the nominal Main Rotor speed of 265 rpm.  The Main Module also drives various accessories and the Tail Rotor Drive Shaft (TRDS). The LN-OJF Investigation The independent Accident Investigation Board Norway (AIBN – the Statens Havarikommisjon for Transport [SHT] in Norwegian) is leading the LN-OJF accident investigation in accordance with the International Civil Aviation Organisation (ICAO) Annex 13 on air accident investigation. The AIBN have issued the following press releases: 1 May 2016 The Helicopter Accident: The work continues 2 May 2016 The Helicopter Accident: Data from the combined FDR and CVR retrieved. Data is of good quality 6 May 2016 The Helicopter Accident: The search for components is resumed UPDATE 13 May 2016: The AIBN issue their preliminary report (see below). UPDATE 27 May 2016: A second preliminary report is issued (see below). UPDATE 31 May 2016: Airbus Helicopters clarifies an earlier press release (see below). UPDATE 1 June 2016: A third preliminary report is issued (see below). UPDATE 28 June 2016: A fourth preliminary report is issued (see below) UPDATE 3...

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Night Offshore Windfarm HEMS Winch Training CFIT (BK117C1 D-HDRJ)

Posted by on 9:59 am in Accidents & Incidents, Crises / Emergency Response / SAR, Helicopters, Human Factors / Performance, Offshore, Regulation, Safety Management, Special Mission Aircraft, Survivability / Ditching

Night Offshore Windfarm HEMS Winch Training CFIT (BK117C1 D-HDRJ) During night-time offshore helicopter hoist training Airbus Helicopters BK117C1 D-HDRJ, operated by Helicopter Emergency Medical Service (HEMS) operator DRF, impacted the Baltic on 28 Feb 2014 in a Controlled Flight Into Terrain / Water (CFIT).  Three of the four crew died.  The helicopter, on emergency stand-by for a windfarm complex, had been approaching a small vessel for night winch training.  The German accident investigation agency, the BFU, has recently published their report. The Accident Flight The crew of four, Pilot in Command (PIC), co-pilot, one winch operator or Helicopter Hoist Operation Crew Member (HHO-CM), who was also paramedic, and an emergency physician, intended to conduct helicopter hoist training above a sea rescue vessel over sea at night. A night-VFR flight plan had been filed. …the sky was overcast, there neither was moonshine nor starlight, humidity was high, and there was slight precipitation. The visibility of light was considerably reduced. There neither were any illuminated ships in the vicinity nor could light sources at shore be seen. The sea was also described as “almost wave-less” further reducing the visual clues.  The aircraft departed Rugen at 17:52. After take-off the crew flew to wind park [i.e. Windfarm] Baltic 1 supported by the flight director [i.e. autopilot] and subsequently to the prearranged meeting point with the [23m] sea rescue vessel. Prior to reaching the vessel and the visual identification the approach was flown manually without the support of the flight director.  The first direct approach had to be terminated due to the low visibility and the late identification of the sea rescue vessel. Another attempt, with the co-pilot flying a left-hand circuit was successful. His reference point and possible reference concerning the flight attitude was the illuminated ship which was in his field of vision. Then three hoist manoeuvres were conducted. The PIC in the right-hand seat took over controls after the subsequent departure from the ship. He too manually conducted a left-hand traffic pattern without support of the flight director…. Except for the final approach the ship was always left of the helicopter, in an area the PIC for the most part could not see since he was in the right-hand seat. …there were no other illuminated ships in the vicinity, nor could the close shore be seen. Therefore he had to control the helicopter solely with the flight instruments in low altitude, comparatively low airspeed, and no visible external references. The aircraft was fitted with only one radar altimeter (RADALT). It was located on the instrument panel of the PIC in the right-hand seat and was therefore outside the normal field of vision of the co-pilot in the left-hand seat. During the next approach the crew discussed the previous hoisting and the problems with the Hi-line, radio calls were also made to the vessel and ATC. These communications increased [the PIC’s] workload and it is highly likely that they distracted him from focusing on manually controlling the helicopter purely according to the instruments. The descent commenced in the downwind leg. During the base leg [between the downwind leg and the approach into wind] the search light was switched on in addition to the already illuminated landing lights. As a result the high humidity surrounding the helicopter must have been very milky and bright which would have made it more difficult to see the sea rescue vessel...

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5000-1 Safety Lesson: Communication

Posted by on 8:10 pm in Human Factors / Performance, Safety Culture, Safety Management

5000-1 Safety Lesson: Communication After their spectacular season, starting as 5000-1 underdogs but ultimately winning the English Football Premiership, a number of commentators have been discussing the success of Leicester City FC and their manager, Claudio Ranieri. In one article, the Guardian observes (emphasis added): They use technology that is more commonplace at the highest level…, regularly issue electronic questionnaires to gauge everything from energy levels to sleep patterns but, perhaps most importantly of all, strive to create an environment where everybody talks to each other. Isn’t odd that it is conventional safety ‘wisdom’ workers (‘workers’ in an us and them sense) are expected communicate their concerns by formal safety reports or by making database entries? ‘Culture’ is often mentioned, but mostly judged with a heavy emphasis on formal reporting, sometimes even against arbitrary ‘best practice’ quotas of reports per person. Some accident reports have even expressed dissatisfaction that issues were reported via the ‘wrong’ method. Some have argued that the bureaucratization of safety is a out-dated Taylorism, with an over emphasis on hierarchy, command and control, division of labour, rigid application of formalised rules and an unhealthy obsession with determining culpability.  We think that interpretation is a little extreme!  Reporting, investigating, analysing and acting on occurrence and hazard reports are still essential, as is clearly expressing behavioural expectations. However, if we want to build a championship safety team do we not need a trusting “environment where everybody talks to each other about the real safety issues” and works together to address them, rather than an environment of blind form filling and hoping ‘someone else’ will do ‘something’?  In other words, more ‘connect and collaborate’ than ‘command and control’. As this article discusses: Safety Differently @ Laing O’Rourke: Are people placed at the centre of the solution or are they seen as the problem? Do you measure safety as the presence of positives or the absence of negatives? Has safety become a bureaucratic activity or an ethical responsibility? Elsewhere, Malcolm Brinded discusses leadership, communication and how good safety performance and good business performance go hand in hand: https://youtu.be/kTHtUvgmi78 UPDATE 11 May 2016:  Who do we trust in times of change? UPDATE 1 August 2016: We also recommend this article: Leicester’s lesson in leadership, published in The Psychologist. UPDATE 3 August 2016: We further recommend this article on the importance of dialogue: People value dialogue and conversation. It takes much longer…but is infinitely more effective. It is through dialogue, as opposed to monologue, that leaders and managers can understand what people are thinking and feeling about change so that they are in a better position to gain their commitment to it and address their concerns. Three factors drive successful dialogue during organizational change: Firstly: an organization must encourage dialogue early, frequently and consistently. There must be an ongoing strategic approach to dialogue before, during and after any organizational transformation. Dialogue is, and must be, a constant. Secondly: the greater the value an organization has for its dialogue, the greater the likelihood for success. Thirdly: leaders and managers need to encourage dialogue with care. Dialogue with care means choosing the channels for dialogue strategically, tailoring the approach to the aims of the change initiative, authentically engaging in conversation and being sensitive to the pace and timing of dialogue. This means bringing together the right people to offer meaningful input and support. So successful dialogue allows more people to contribute, generating not only wisdom and a wealth of ideas but also commitment and engagement to change. UPDATE 19 September 2016: Disruptive HR discuss: Engagement –...

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Chernobyl: 30 Years On – Lessons in Safety Culture

Posted by on 12:01 am in Accidents & Incidents, Human Factors / Performance, Safety Culture, Safety Management

Chernobyl: 30 Years On – Lessons in Safety Culture Late at night on 26 April 1986 in the then USSR, a team of nuclear workers prepared to conduct a test on Reactor 4 of the Chernobyl nuclear power plant as part of an otherwise routine shutdown.  The exercise was to test a modified safety system and determine how long the reactor’s steam turbines would continue to power to the main coolant pumps following a loss of main electrical power supply. In order to achieve the test conditions automatic shutdown devices were inhibited and the emergency core cooling system shut-down.  We the total clarity of hindsight we know this was particularly high risk because the particular RMBK-1000 reactor design is unstable at the low power levels (c7%) being tested.  The test was also to be started by one shift and completed in the early morning by another, with potential shift handover and circadian low factors.  A previous attempt had failed, potentially heightening the pressure to complete it on this shutdown. At 01:24 the reactor was shook by two massive explosions.  Over the coming months many emergency workers were to die and many more members of the off site population exposed to harmful levels of radiation, with widespread environmental effects across many countries. Some reports suggest the operator’s actions were ‘violations‘, however as the World Nuclear Association notes: The 1991 report by the State Committee on the Supervision of Safety in Industry and Nuclear Power on the root cause of the accident looked past the operator actions. It said that while it was certainly true the operators placed their reactor in a dangerously unstable condition (in fact in a condition which virtually guaranteed an accident) it was also true that in doing so they had not in fact violated a number of vital operating policies and principles, since no such policies and principles had been articulated. Additionally, the operating organisation had not been made aware either of the specific vital safety significance of maintaining a minimum operating reactivity margin, or the general reactivity characteristics of the RBMK which made low power operation extremely hazardous. Safety Culture and Chernobyl The Chernobyl accident was analysed by the International Atomic Energy Agency‘s International Nuclear Safety Advisory Group (INSAG): INSAG concluded that the need to create and maintain a ‘safety culture’ is a precondition for ensuring nuclear power plant safety. The concept of ‘safety culture’ relates to a very general concept of dedication and personal responsibility of all those involved in any safety related activity at a nuclear power plant. Inculcation of a safety culture requires that, in training personnel for nuclear plants, particular emphasis be placed on the reasons for the establishment of safety practices and on the consequences in terms of safety of failures on the part of personnel to perform their duties properly. Special emphasis must be placed on the reasons for the establishment of safety limits and the consequences in terms of safety of violating them. Safety culture presupposes total psychological dedication to safety, which is primarily created by the attitude of the administrative staff of the organizations engaged in the development and operation of nuclear power plants. In INSAG publications, the concept of safety culture has been extended beyond the purely operational aspects to cover all types of activities at all stages in the lifetime of a nuclear power plant which...

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UK To Buy “Certifiable Predator B” Protector

Posted by on 7:45 pm in Design & Certification, Military / Defence, News, Special Mission Aircraft

UK To Buy “Certifiable Predator B” Protector The UK MOD has announced in a low key contracts notice that they intend to meet the PROTECTOR Unmanned Aerial System requirement to replace the RAF Reaper MQ-9A fleet, through a £415 million Government-Government Foreign Military Sales (FMS) contract with the US Department of Defence (US DoD).  UPDATE 27 April 2016: This specific contract, that runs to 31 Oct 2023, appears to be £332 million. The contract announcement states the MOD has conducted a “thorough Assessment Phase (AP) which has concluded that the Certifiable Predator B (CPB) (also known as Guardian Eagle) is the only system capable of achieving UK [MAA] Military Type Certification (MTC) and delivering the PROTECTOR requirement within the required timescales”.  This suggests, as expected, that that integration in non-segregated civil airspace is a key factor (the earlier Reapers are limited to ‘in theatre’ operations).  Certification challenges saw the German cancellation of the RQ-4 Global Hawk based Euro Hawk in 2013 (including also lightning protection and icing capability). General Atomics Aeronautical Systems Inc (GA-ASI) says it is developing the CPB variant of the Predator B Remotely Piloted Aircraft (RPA) which will first “meet European airworthiness initial certification standards in 2017, and in cooperation with the FAA will subsequently meet domestic airworthiness certification standards”.  In June 2015 GA-ASI said Certifiable Predator B: …has completed a successful internal Phase 1 Critical Design Review (CDR), along with reviews by two prospective European customers. Development of the system follows international airworthiness standards that include STANAG 4671, UK DEFSTAN 00-970, SAE ARP4754A, MIL HDBK-516C, DO-178, and DO-254, as well as others. GA-ASI is focused on the development and testing of Detect and Avoid (DAA) capabilities for RPA, combining Traffic and Collision Avoidance System (TCAS) II with the company’s Due Regard Radar (DRR) to enable both automatic collision avoidance and the ability to remain well clear of other airspace users. The integrated DAA system will continue to fly aboard NASA‘s Ikhana (Predator B) in 2015 in support of a series of NASA flight tests. These tests will measure the performance of the entire system in a variety of situations to support the ongoing standards development within the RTCA Special Committee 228. The CPB has a 79 foot wingspan, 13 feet greater than Reaper, which gives a greater internal fuel capacity, increasing its endurance from 27 to more than 40 hours.  The first flight of a test vehicle with the longer span wing occurred on 18  February 2016 at GA-ASI’s Grey Butte Flight Test Facility in Palmdale, CA.  The Predator family has now achieved over 3.8 million flying hours. Protector followed on from the earlier MOD Scavenger programme. The Reaper has been operated by the RAF since 2007. The RAF are the only export operator of the type that carry weapons.  Its first armed Reaper sortie was in Afghanistan in May 2008. Reaper is currently being employed as part of the UK contribution to activities against Islamic State / Daesh militants in Iraq and Syria. UPDATE 6 May 2016: Chris Pocock of AINonline suggestes that the other European customer is the Netherlands.  He notes that France, Germany and Italy are teamed on the rival Euro-MALE UAS project. UPDATE 30 May 2016: At the Berlin Airshow GA-ASI and local subsidiary Spezialtechnik Dresden (STD) are positioning to offer CPB / Guardian Eagle to the German government. UPDATE 12 September 2016: Aircraft integration has been completed at the GA-ASI Poway, CA production facility and the prototype has...

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Dim, Negative Transfer Double Flameout

Posted by on 10:12 am in Accidents & Incidents, Design & Certification, Helicopters, Human Factors / Performance, Safety Management, Special Mission Aircraft

Dim, Negative Transfer Double Flameout (Garden City BK117B2 ZK-HJC) A combination of inadvertently leaving cockpit lights dimed after an early morning take off, a compromise when modifying the helicopter for night vision goggles, a type without an aural low fuel warning and negligible recent experience on type all featured in a recent double engine flameout in New Zealand.  While it occurred in different circumstances this incident is interesting to compare against two fatal police helicopter double flameouts (the 2013 Glasgow Clutha accident and the 2005 Shizuoka City accident). The New Zealand Transport Accident Investigation Commission (TAIC) have recently reported on a 5 May 2014 occurrence when Kawasaki BK117B2 helicopter ZK-HJC experienced a double engine power loss during a hospital patient transfer flight from Ashburton to Christchurch. The pilot made an emergency landing onto farmland near Springston.  The 5 occupants were uninjured and the helicopter suffered only minor damage.  The operator, Garden City Helicopters, operated several helicopters and fixed-wing types for a variety activities, including Helicopter Emergency Medical Services (HEMS). The Flight The helicopter departed Christchurch at ~0715.  The pilot shut down the helicopter’s engines after landing in Ashburton. The patient was taken on board, after which the pilot carried out the before-start procedures and started both engines. At 0852 the helicopter departed Ashburton… About 20 minutes later a loud bang was heard by everyone on board and an aural warning sounded in the cockpit. The pilot noticed the right engine low-revolutions-per-minute light had illuminated and that the instrument readings for the right engine were decreasing. Shortly afterwards a similar banging noise was heard and the helicopter started to descend rapidly. The pilot realised that both engines had now lost power and he entered the helicopter into autorotation and…made a firm landing in a paddock near Springston. After the emergency landing the pilot checked the cockpit instruments and switches,.. He found that: The two fuel prime pump switches were ‘on’ (these would normally be off during flight) The two fuel transfer pump switches were ‘off’ (these would normally be on during flight) There was a total of 380 kilograms (kg) of fuel indicated on the fuel quantity gauges The cockpit lighting dimmer switches were ‘on’. The pilot stated these positions had not been changed during the flight. Fuel System The BK117 fuel tanks are located below the cabin floor. Each engine had an engine-driven fuel pump that would draw fuel from its respective supply tank. Both of these supply tanks were connected by transfer tubes to the front main tank. To ensure the supply tanks remained full, two transfer pumps were fitted inside the front main tank. It was therefore important that the transfer pumps were switched on during flight to ensure that an adequate supply of fuel… was maintained. In order to supply fuel to the engines during engine starts, a prime pump was installed in each supply tank to deliver fuel under pressure to the engine until the engine was running. These prime pumps were not needed during flight…. The normal before-start procedure was for the two prime pumps to be switched on for the engine start. Once the engines were up to operating speed, the two transfer pumps would be turned on and the prime pumps would then be turned off. In the case of early model BK117s, the fuel system had symmetric fuel supply tanks. meaning they could...

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NASA ASRS at 40 and the Continued Challenge of Timeliness for Safety Reporting

Posted by on 5:46 pm in Accidents & Incidents, Fixed Wing, Human Factors / Performance, Safety Culture, Safety Management

NASA Aviation Safety Reporting System at 40 and the Continued Challenge of Timeliness for Safety Reporting On 16 April 16 2016 the National Aeronautics and Space Administration (NASA) Aviation Safety Reporting System (ASRS) celebrated 40 years of operation.  Its origins highlights one major challenge of safety reporting, learning and action: timeliness. The Purpose and Administration of ASRS The ASRS collects, analyses, and responds to voluntarily submitted aviation safety reports.  ASRS data is used to: Identify deficiencies and discrepancies in the National Aviation System (NAS) so that these can be remedied by appropriate authorities. Support policy formulation and planning for, and improvements to, the NAS. Strengthen the foundation of aviation human factors safety research. This is particularly important since it is generally conceded that over two-thirds of all aviation accidents and incidents have their roots in human performance errors. ASRS was set up under a Memorandum of Agreement between the Federal Aviation Administration (FAA) and NASA in August 1975.  The FAA fund the programme and provide for its immunity provisions.  The NASA set programme policy and administer its operations. Similar programmes now exist elsewhere, such as CHIRP (the Confidential Human Factors Incident Report Programme) in the UK (which we have previously discussed).  With the lack of a mandatory occurrence scheme in the US, such as that required by Regulation (EU) 376/2014 Reporting, Analysis and Follow-up of Occurrences in Civil Aviation (and the earlier UK Mandatory Occurrence Reporting [MOR] scheme, which also commenced in 1976), ASRS also fulfils some of that role in the US. The UK CAA had issued an Aeronautical Information Circular on 2 October 1972 proposing expanded reporting requirements.  Its predecessor, the Air Registration Board (ARB), had introduced defect reporting requirements in 1964 and voluntary reporting of other occurrences had been encouraged in part through the UK Flight Safety Committee (UKFSC).  The CAA proposed expanding this to include mandatory ‘incident’ (i.e. occurrence) reporting. The Origin of ASRS The origins of the scheme are particularly interesting. On 1 December 1974, TWA Flight 514, Boeing 727-231 N54328 was inbound through poor weather to Washington Dulles in Virginia.  The flight was originally destined for Washington National Airport but was diverting to Dulles due to high crosswinds. As NASA relate: The flight crew misunderstood an ATC clearance and descended to 1,800 feet before reaching the approach segment to which that minimum altitude applied. The aircraft collided Mount Weather, near Berryville, Virginia (near a major US government bunker) killing all 92 aboard. The NTSB investigation determined the crew’s decision to descend was “a result of inadequacies and lack of clarity” in air traffic control procedures and a misunderstanding between pilots and controllers regarding each other’s responsibilities during terminal operations and in IMC conditions. The accident is discussed fin the FAA Lessons Learnt Database.  NASA go on: A disturbing finding emerged from the ensuing NTSB accident investigation. Six weeks prior to the TWA accident, a United Airlines flight crew had experienced an identical clearance misunderstanding and narrowly missed hitting the same Virginia mountaintop. The United crew discovered their close call after landing and reported the incident to their company. A cautionary notice was issued to all United pilots. Tragically, there existed no method of sharing the United pilots’ knowledge with TWA and other airlines. Following the TWA accident, it was determined that safety information must be shared with the entire aviation community. Thus was born the...

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C-130J Control Restriction Accident, Jalalabad

Posted by on 7:34 pm in Accidents & Incidents, Fixed Wing, Human Factors / Performance, Military / Defence, Safety Management

C-130J Control Restriction Accident, Jalalabad The US Air Force (USAF) Air Mobility Command (AMC) has released its accident report into the fatal loss of control (LOC-I) accident involving of Lockheed Martin C-130J 08-3174 during a night-time take-off from Jalalabad Airfield, Afghanistan on 2 October 2015.  The accident was caused by the failure to remove a loose article that had been deliberately placed behind the control column during a night-time engines-running turnaround to aid loading. The Accident All 11 persons on-board died (four crew, two fly-away security team members of the the 66th Security Forces Squadron and five civilian contractor passengers), as did three Afghan Special Reaction Force (ASRF) personnel as the aircraft struck a guard tower.  There was also a post crash fire.  This was the worst USAF C-130 accident in the last 25 years. The aircraft was from the 317th Airlift Group, Dyess Air Force Base, Texas, and operated by the 39th Airlift Squadron, while assigned to the 455th Air Expeditionary Wing at Bagram Airfield, Afghanistan. In an AMC press release they say: While conducting engine running on-load/offload operations at Jalalabad Airfield, the pilot raised the elevators mounted to the horizontal stabilizer by pulling back on the yoke. This provided additional clearance to assist with offloading tall cargo. After a period of time in which the pilot held the yoke by hand, he placed a hard-shell night vision goggle (NVG) case in front of the yoke [or control column] to hold the elevator in a raised position. However, because the pilots were operating in darkened night-time flying conditions and wearing NVGs, neither pilot recognized and removed the NVG case after loading operations were complete or during take-off. Once airborne, the aircraft increased in an excessive upward pitch during the take-off climb. The co-pilot misidentified the flight control problem as a trim malfunction, resulting in improper recovery techniques. The rapid increase in pitch angle resulted in a stall from which the pilots were unable to recover. The aircraft impacted approximately 28 seconds after lift-off, right of the runway, within the confines of Jalalabad Airfield. The investigators say, surprisingly, they could not determine if a flight controls check would have alerted the pilots to the obstruction. Conclusions The accident investigation board identified the following causes: Inadequate Real-Time Risk Assessment (Hard-Shell NVG Case Placement) Distraction Wrong Choice of Action During an Operation (Misidentification of Malfunction) They identified the following contributory factors: Environmental Conditions Affecting Vision (i.e. night-time operations, use of NVGs, and reliance on the Head Up Display [HUD] and Advisory, Caution, and Warning System [ACAWS]) Inaccurate Expectation (in relation to take-off technique applied) Fixation (on a trim failure) Accident Sequence Video and Other Resources A brief 5s animation of the flight: AIB Report – C-130J, TN 08-3174 (Report) AIB Report – C-130J, TN 08-3174 (Tabs A – U) AIB Report – C-130J, TN 08-3174 (Tabs V – EE) UPDATE 24 April 2016: The Air Force Times has now covered this accident.  They quote sources who observe that such a workaround “was not uncommon”, “there’s no official way to do that other than holding it up by hand” and sometimes items would be used to “prop up yokes”: It wasn’t sanctioned, it was just something you did.  Not always, just sometimes. It’s the end of a long day and you’re tired. Someone wants to stand up and walk around, you’d use something artificial to hold that up. During an engine running turnaround:...

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