Helicopter Ditching Limitations
Helicopter Ditching Limitations The European Aviation Safety Agency (EASA) is proposing introducing Emergency Floatation System ditching limitations into Rotorcraft Flight Manuals (RFMs) and that these are then a limitation for operations. This is in broad alignment with a UK CAA Safety Directive effective 1 September 2014. On 30 May 2014 EASA issued a Proposed Airworthiness Directive (PAD) for public comment. That PAD (14-089) focused on EU helicopter Type Certificate Holders (TCHs). On 4 August 2014 EASA issued a PAD (14-130) to address non-EU TCHs. These will support European rulemaking on offshore helicopter operations (on which EASA published the Comment Response Document on 15 August 2014). EASA note that in accordance with “Paragraph 4.a of the Essential Requirements for air operations, aircraft must be operated within their certification limits”. UPDATE 28 August 2014: Airworthiness Directives have now been issued for EU and non-EU designed helicopters. The ADs introduce a limitation in the RFMs based on the Sea State that the ditching performance (i.e. the water entry and floatation stability) the helicopter has been certified to. Some more recent helicopters do include this information, but the ADs ensure consistent data in all RFMs. EFS are certificated against airworthiness standards (for large helicopters EASA CS-29 and US FAA FAR-29) that require demonstrating helicopter ditching performance under “reasonably probable water conditions”. What is “reasonably probable” of course depends on the operating environment. With the growth of offshore helicopter operations in hostile environments, such as the North Sea, Norwegian Sea and North Atlantic, increasingly what is “reasonably probable” is more severe than assumed when this rule was first drafted. Unfortunately, the advisory material defined “reasonably probable” as “at least sea state 4” and in a number of cases Sea State 4 is all the EFS has been substantiated to. More recent designs have tended to have demonstrated higher performance levels, mindful that the oil and gas market for large helicopters is substantial. EASA have chosen to continue to use the World Meteorological Organisation (WMO) scale of Sea State, although also stating the associated wave height range. According to the WMO: The sea state basically specifies wave height. Wave height depends on local winds but on remote winds also (swell). As far as weather observation is concerned, while sea state reporting remains a legal international practice, with modern in situ observing techniques we try to avoid using sea state or Beaufort scale as we prefer direct readings from appropriate instruments… Swell is created by winds as much as a hundred miles away or more, is relatively unidirectional and results in wavelengths of a hundred meters or more and wave periods of 9 seconds or more. The distance the winds travelled to create swell is known as the fetch. Local winds create more varied waves, with shorter wavelengths and periods. Depending on the local geography and weather conditions, waves can be created by different combinations of local winds and swell. So for example in the Southern North Sea, fetch is limited by the adjacent land masses and waves are predominately driven by local winds. West of Shetland, in the Atlantic, the fetch is great and swell predominates. The WMO Sea State definitions are as follows (Sea State / Description / Wave Height in metres): 0 Calm (glassy) 0 1 Calm (rippled) 0 – 0.1 2 Smooth (wavelets) 0.1 – 0.5 3 Slight 0.5 – 1.25 4 Moderate 1.25 – 2.5 5 Rough 2.5 – 4 6 Very rough 4 – 6 7 High 6...
read moreAlaska B1900C Accident – Contributory ATC Errors
Alaska B1900C Accident – Contributory ATC Errors The US National Transportation Safety Board (NTSB) identified contributory ATC errors when they issued their probable cause of a fatal Beechcraft B1900C Controlled Flight Into Terrain (CFIT) accident in instrument meteorological conditions at Aleknagik, Alaska on 8 March 2013. The aircraft, N116AX, was operated by Alaska Central Express (Ace) Air Cargo. The air traffic controller cleared the airplane to fly directly to ‘ZEDAG’ the initial approach fix, stating, “maintain at or above 2,000” feet until established on a published segment of the approach. This was ambiguous and should have stated the aircraft should enter the terminal arrival area at or above 5,400 feet. The flight crewmembers repeated the clearance back to the controller as “maintain 2,000” feet until established, and they began descending. The controller did not notice the pilot’s incorrect readback. Shortly after, when at 2,200 feet, the pilot requested to enter the holding pattern while they checked on runway conditions on another frequency, and the controller cleared them to hold “as published.” The published minimum altitude for the hold in that location was 4,300 feet msl. The air traffic system did generate aural visual minimum safe altitude warnings for the controller but he did not intervene. The aircraft collided with rising terrain at 2,000 feet msl while flying in a wings-level attitude on the outbound leg of the holding pattern. The aircraft had three pieces of navigation equipment that should have provided visual and aural terrain warnings to the flight crew, but these were so damaged on impact their functionality could not be examined. The NTSB probable cause was determined to be: The flight crew’s failure to maintain terrain clearance, which resulted in controlled flight into terrain in instrument meteorological conditions. Contributing to the accident were the flight crew’s failure to correctly read back and interpret clearance altitudes issued by the air traffic controller, their failure to adhere to minimum altitudes depicted on the published instrument approach chart, and their failure to adhere to company checklists. Also contributing to the accident were the air traffic controller’s issuance of an ambiguous clearance to the flight crew, which resulted in the airplane’s premature descent, his failure to address the pilot’s incorrect read back of the assigned clearance altitudes, and his failure to monitor the flight and address the altitude violations and issue terrain-based safety alerts. Ace Air Cargo operate less than a handful of Beech 1900Cs. On 21 January 2010, one of their other Beech 1900Cs, N112AX, crashed in the ocean shortly after takeoff from Sand Point Airport, Alaska with the loss of its two crew. Only part of the wreckage was recovered and the probable cause was: An in-flight loss of control for an undetermined reason, which resulted in an uncontrolled descent. These aircraft were not fitted with cockpit voice recorders (CVRs) of flight data recorders (FDRs). Clint Johnson, the NTSB’s chief investigator in Alaska, says much about the crash that could be known never will be, due to their absence: One of the most frustrating things is that we don’t know what was going on in that cockpit. After the earlier accident the NTSB report that: According to Alaska Central Express management personnel, at the conclusion of the Sand Point accident investigation, the board of directors opted to voluntarily install cockpit image recording systems in all company-owned and operated aircraft; however, the airplane involved...
read moreExtreme Latitudes – Extra CFIT Risk
Extreme Latitudes – Extra CFIT Risk (RNoAF C-130J 5630 in Sweden and Kenn Borek Twin Otter C-GKBC in Antarctic) Two recent accident reports have highlighted a potential higher risk of Controlled Flight Into Terrain (CFIT) at the extreme latitudes of the Arctic & Antarctic regions. That increased risk is not to do with the geography but with database limitations of some Terrain Awareness and Warning Systems (TAWS). The Accidents Lockheed Martin C-13oJ, 5630, operated by the Royal Norwegian Air Force, Mount Kebnekaise, Sweden, 15 March 2012: SHV Accident Report (ASN Database Entry) Viking DHC-6-300 Twin Otter, C-GKBC, operated by Kenn Borek Air, Mount Elizabeth, Antarctica, 23 January 2013: TSB Accident Report (ASN Database Entry) Arctic In the case of the Norwegian military C-130J that crashed in Sweden with the loss of 5 lives, the aircraft had two terrain databases. A commercial Honeywell database is used in ‘normal’ mode. However, ‘tactical’ mode can be selected for low flying. The tactical database uses higher resolution terrain data from the US National Geospatial Intelligence Agency. It however does not include data north of 60˚ N or south of 56˚ S. The Swedish Accident Investigation Authority (SHK) reported that at previous training: …information was given about the fact that they thus did not have coverage north of 60 degrees North, something which evoked a response as they normally flew in this area. This inconvenient limitation may also help to explain why: …the tactical databases in the Norwegian Air Force’s C-130Js have not been updated since the aircraft were delivered. For reasons that aren’t clear, the tactical mode was selected during the accident flight, a relatively high level transit to Sweden for an exercise. Consequently a “TAWS Void” caution was displayed, but these appears to have been mistaken as indicating the fact the aircraft was at the time considerably above the local terrain, rather than being outside database coverage. Unfortunately the route took the aircraft over the highest mountain in Sweden, which they struck just below the summit. The accident investigators comment: SHK cannot however eliminate the possibility that the pilots’ reliance on the automation of the J model’s “glass cockpit” in any way instilled the pilots an unconscious faith in the system’s capability to consistently provide the pilots with visual or audible feedback when e.g., flying above mountainous terrain, irrespective of their knowledge of the system. Similar issues of over-reliance on, over-confidence in, or misunderstanding of automated systems were discussed at a recent RAeS conference on automation in offshore helicopters. SHK go on: Overall, SHK finds that inadequate procedures adopted by the operator and lack of clarity in the system documentation and training have entailed potential short-comings in the crew’s knowledge of the system for ground collision avoidance. This coupled with the inadequacies in the system design may explain the crew’s use of TAWS Tactical despite the limitations north of 60° N. Antarctic In the case of an accident to a Canadian civil aircraft and loss of 3 lives while supporting scientific missions in Antarctica, the aircraft was equipped with a Sandel ST3400 TAWS and two Garmin GNS 430W navigation receivers. The Transport Safety Board (TSB) of Canada notes: The Sandel ST3400 TAWS unit [fitted] was certified to meet the new regulations’ Class B requirements, which include a forward-looking terrain avoidance (FLTA) mode. However: The database available for the ST3400 unit did not cover the area beyond 70°S latitude which meant that...
read moreObituary: Offshore Survival Pioneer Dr Joe Cross OBE
A pioneer in offshore survival, Dr Joe Cross OBE, died in Aberdeenshire on 27 July 2014. Dr Cross started as a naval safety equipment fitter in 1953 before rising to be a commissioned Royal Navy Officer. However it was in 1975 that he became Managing Director of the Robert Gordon’s Institute of Technology (RGIT) Survival Centre in Aberdeen. RGIT (the forerunner of the Robert Gordon University) started the centre with just two people at a crucial moment in the history of the North Sea oil industry. North Sea exploration has been steadily revealling large fields during the early part of the 1970s. These finds were in a harsh and demanding environment. However, the 1973 oil crisis and subsequent oil price increases, coupled with their location in a political stable region, made these fields suddenly practical. The first production was already starting in the UK sector in 1975 and construction of massive offshore installations was underway. Today, the ‘topside’ of installations are usually built and fitted out onshore and lifted into place nearly complete, but in the 1970s a vast workforce of construction workers were needed to assemble and fit out the superstructure on site. Consequently in the mid 1970s the use of helicopters to support the oil and gas industry was accelerating rapidly. As The Scotsman reported in their obituary: The centre developed a major training facility in Aberdeen with the first simulator teaching trainees how to escape from a helicopter under water. There was also a freefall lifeboat training facility in Dundee. In 1980 he founded the IASST, to share best practice in maritime survival training around the world. It was in 1978 that RGIT’s own School of Mechanical and Offshore Engineering designed the pioneering Helicopter Underwater Escape Training (HUET) simulator to give realistic training for Survival Centre. The Survival Centre was eventually spun-off and became part of Petrofac Training in 2004. Cross, who also served on the Defence Services Lifesaving Committee, was made an OBE in 1986, received an honorary MSc from the Council for National Academic Awards in 1991 and was made an honorary Doctor of Technology by Robert Gordon University in 1995, the year before he retired. The IASST (International Association for Safety and Survival Training) commented: Joe was the pioneer in safety training in UK that lead to the founding of IASST as he found many trainers world wide in need for assistance in starting safety training. For all those who knew Joe they will remember his fighting spirit and enthusiastic for safety training and trainers. He was also the centre of the attention with his good humour, jokes and inspiration. Dr Joe Coss OBE: Born: 9 November, 1934, in Liverpool. Died: 27 July, 2014, in Ballater, aged 79. Dr Cross moved home from Inverurie to Ballater just two days before he died and is survived by his wife Desna, children Martin, Greig, Desna and Samantha, 11 grandchildren and three great-grandchildren. Follow us on LinkedIn for our latest...
read moreFAA Impose Fines After Maintenance Errors – Just Culture?
FAA Impose Fines After Maintenance Errors – Just Culture? The Federal Aviation Administration (FAA) have proposed fining two helicopter emergency medical service (HEMS) operators and one airline a total of $12.4 million for allegedly operating non-compliant aircraft after various maintenance errors. However does this encourage a just, open reporting culture? The Cases In each case it should be noted that the FAA have publically proposed these fines but the organisations can appeal or negotiate for a lower penalty. Firstly, the FAA propose fining Southwest Airlines of Dallas, Texas $12 million, alleging: …that beginning in 2006, Southwest conducted so-called “extreme makeover” alterations to eliminate potential cracking of the aluminum skin on 44 jetliners. The FAA conducted an investigation that included both the airline and its contractor, Aviation Technical Services, Inc., (ATS) of Everett, Wash. Investigators determined that ATS failed to follow proper procedures for replacing the fuselage skins on these aircraft… All of the work was done under the supervision of Southwest Airlines, which was responsible for ensuring that procedures were properly followed. It is interesting that the FAA do not also propose fining the FAA approved Part 145 Repair Station who are alleged to have not followed proper procedures. Southwest returned the jetliners to service and operated them when they were not in compliance with Federal Aviation Regulations, the FAA alleges. The regulatory violations charged involve numerous flights that occurred in 2009 after the FAA put the airline on notice that these aircraft were not in compliance with either FAA Airworthiness Directives or alternate, FAA-approved methods of complying with the directives. Retrospectively Southwest submitted data that allowed the FAA to approve the alternative procedures used. Also: During its investigation, the FAA found that ATS workers applied sealant beneath the new skin panels but did not install fasteners in all of the rivet holes during the timeframe for the sealant to be effective. This could have resulted in gaps between the skin and the surface to which it was being mounted. Such gaps could allow moisture to penetrate the skin and lead to corrosion. As a result of the improper repairs, these airplanes did not comply with Federal Aviation Regulations. The FAA also alleges that ATS personnel failed to follow requirements to properly place these airplanes on jacks and shore them up while the work was being performed. If a plane is shored improperly during skin replacement, the airframe could shift and lead to subsequent problems with the new skin. Corrective maintenance action is only mentioned in the final allegation: …the FAA alleges that Southwest Airlines failed to properly install a ground wire on water drain masts on two of its Boeing 737s in response to an FAA Airworthiness Directive addressing lightning strikes on these components. As a result, the aircraft were not in compliance with Federal Aviation Regulations. The airplanes were each operated on more than 20 passenger flights after Southwest Airlines became aware of the discrepancies but before the airline corrected the problem. These allegations highlight the importance of: Conducting all maintenance in accordance with approved maintenance data Seeking approval for justified alternative data in advance Ensuring that data is referred to and followed Promptly responding when maintenance errors are detached Ensuring maintenance organisations/continuing airworthiness management organisations have effective assurance processes to monitor actual maintenance standards According to Southwest: Having fully resolved the repair issues...
read moreEASA Launch Helicopter Gearbox Lubrication Rule Making
EASA Launch Helicopter Gearbox Lubrication Rule Making The first meeting was held last week of a new European Aviation Safety Agency (EASA) Rule Making Team (RMT.0608) on helicopter gearbox lubrication. The Terms of Reference (ToR) and Group Composition (GC) are here. This activity follows European/US/Canadian dialogue after the loss of Cougar Sikorsky S-92A C-GZCH Flight 491 off Newfoundland, Canada on 12 March 2009 in which 17 people died, although one passenger, Robert Decker, survived. The Canadian Transportation Safety Board (TSB) reported on that accident in 2011. TSB state: On 06 August 2002, Sikorsky carried out its initial certification loss of lubricant test by draining the MGB and using only the remaining residual oil (approximately 1.3 gallons) then continuing operation in accordance with the requirements of AC 29-2C. The purpose of this test, outlined in the test documentation, was to demonstrate that the S-92A transmission could provide, “continued safe operation for a minimum of 30 minutes following a complete loss of lubricating oil in accordance with the requirements of FAR 29.927(c)(1).” … Sikorsky and the FAA expected that, based on the similarities between the S-92A’s MGB and the Sikorsky S-60 [sic: H-60 / S-70] Black Hawk‘s MGB, the S-92A’s MGB would successfully operate for 30 minutes after draining the lubricating oil. The FAA indicated that the initial test was thought to be a low risk test, and Sikorsky scheduled it very late in the overall S-92A certification program. This original S-92A test matched the way other manufacturers conducted such a loss of lubrication test. TSB explain that: EASA indicated that applicants in its jurisdiction normally complied with Part 29.927(c)(1) by draining the MGB and continuing operation with only residual oil. Prior to the S-92A certification validation it had already tested and certified at least four helicopters using this criterion. Aerossurance is aware that Canadian manufacturers also followed the same interpretation as the European manufacturers. Unfortunately with just 1.3 gallons of oil the S-92A MGB: …suffered a catastrophic failure about 11 minutes after the test was started. TSB go on: Following the loss of lubricant test resulting in catastrophic failure, instead of taking steps to redesign the transmission to provide a 30 minute run dry capability [sic: this term is not used in regulation] for the MGB, Sikorsky re-visited the requirements of Part 29.927(c)(1). Relying on guidance from AC 29-2C and the FAA [Federal Aviation Administration] Rotorcraft Directorate, Sikorsky and the FAA concluded that, except for a potential failure of the oil cooler and its exterior plumbing, all other MGB failures leading to a total loss of oil were extremely remote. …the MGB lubrication system was redesigned to incorporate a bypass valve. The loss of lubricant test was repeated on 16 November 2002 with the bypass system installed. This test was carried out by draining oil from a leak in the oil cooler system. The leak was isolated and further oil loss was prevented when the bypass valve was activated. About 4.3 gallons or 40% of the maximum oil quantity remained in the MGB. The S-92 was certified by the FAA on 17 December 2002, one month after the second test and in time to be awarded the prestigious Collier Trophy for “the greatest achievement in aeronautics or astronautics in America” of 2002. Just one day before that certification, another Sikorsky product, an S-61N C-FHHD, was involved in an accident in Canada after a loss of main gear box oil, which should...
read moreOGP Safety Performance Indicators 2013
UPDATE: This article has been reviewed and updated since the publication of OGP’s V1.1 reports adding details that our first edition highlighted were missing. Follow us on LinkedIn for our latest updates. The International Association of Oil & Gas Producers (OGP) has published their annual safety performance review. Earlier 2012 data is here. The OGP members who contribute reported details of 80 fatalities worldwide in 2013 (down from 88 the previous year). Of these 47 were onshore and 33 offshore. The fatal accident rate was 11% lower than 2012 and the Total Recordable Injury Rate was 8% lower. For those interest in aviation safety in the OGP domain: there were 17 fatalities in 2 helicopter accidents, making air transport the category of activity with the highest number of fatalities with 21.% of the total (up from 2.3% in 2012 when there were just 2 aviation fatalities when two crew died when a B212 seismic helicopter crashed on its approach to a landing zone in a forested area of Gabon). The detailed list of fatal events describes: the loss of a Mi-8 of Helicópteros del Pacífico OB-1916-P onshore in Peru in April 2013 with the loss 4 crew and 9 passengers the loss of a CHC AS332L2 G-WNSB and 4 passengers off Sumburgh, Scotland in August 2013 In the case of the Peruvian accident two recommendations are reported: a) hire an aviation specialist to monitor audit findings and b) to replace this family of helicopters. It is also stated that 1.7% of lost work day cases (i.e. 27) are related to air transport (20 offshore and 7 onshore), up from just 0.5% in 2012. In the listing of high potential events are basic details of: A ground collision between a taxying B1900 and a parked ATR42 in Yemen that does not seem to have been reported publically elsewhere The loss of a passenger door from an AS365N helicopter in Tunisia UPDATE November 2014: OGP is now IOGP. For advice on aviation safety & contracting for the oil and gas industry and first hand expertise with the IOGP Aviation Management Guidelines (Publication 390), contact: enquiries@aerossurance.com Follow us on LinkedIn for our latest updates...
read moreEASA Launch Rule Making Team on In-flight Recording for Light Aircraft
EASA Launch Rule Making Team on In-flight Recording for Light Aircraft The European Aviation Safety Agency (EASA) has launched a Rule Making Team (RMT.0271 & 0272 [MDM.073 (a) & (b)]) on in-flight recording for light aircraft. The Terms of Reference (ToR) and Group Composition (GC) are here. By way of definition the ToRs state: …‘in-flight recording’ means recording by an airborne system of data that can be easily used to reconstruct the history of the flight for the purpose of a safety investigation. In-flight recording solutions include, but are not limited to, flight recorders. EASA note that aircraft that aren’t required to carry data recorders include: Aeroplanes <5 700 kg used for commercial air transport (CAT) operations Helicopters <3 175 kg used for CAT Lighter Than Air aircraft used for CAT Light aircraft operated for General Aviation One could argue that this initiative is particularly important now that EASA have issued a notice of proposed amendment on commercial air transport operations at night or in IMC using single-engined turbine aeroplane (NPA2014-18). The likely aircraft types are the Cessna C208 Caravan, Pilatus PC-12 and Socata TBM700/850. Eight safety recommendations have previously been addressed to EASA recommending the introduction of in-flight recording for lighter aircraft (listed below in chronological order of accident date): SPAN-2012-011 Swearingen SA226 registered EC-GDG, 18/02/1998 (accident report); UNKG-2005-101 Bell 206 registered G-BXLI, 22/01/2005 (accident report); FRAN-2009-008 Beech C90 registered F-GVPD, 18/10/2006 (accident report); HUNG-2008-002 Eurocopter EC135 registered HA-ECE, 31/07/2008 (no report online); NETH-2012-001 Pilatus PC12 registered PH-RUL, 16/10/2009 (accident report); FRAN-2013-012 Cessna 208 registered F-OIXZ, 05/09/2010 (accident report); NORW-2012-010 Aerospatiale AS350 registered LN-OXC, 04/07/2011 (accident report); FINL-2014-001 Cessna 206 registered OH-AAA, 08/11/2012 (accident report). Aerossurance has previously reported on recommendations made in other countries (such as Canada). The US National Transportation Safety Board (NTSB) has had wider recorder use on its ‘most wanted list’ too. EASA notes that industry standards for flight recorders for light aircraft are available (e.g. EUROCAE ED155 [Minimum Operational Performance Specification for lightweight flight recording systems] issued in July 2009). In 2006 the UK Civil Aviation Authority (CAA) published a research report on “The Effectiveness of Image Recorder Systems in Accident Investigations (CAP 762). In their conclusions they stated: …the research indicates that image recording systems can, if properly installed and appropriately analysed together with conventional recording systems, provide additional information that would assist in accident investigation. Aerossurance has previously commented on other recorder options that have been successful introduced. EASA also point out that: Other equipment mandated or usually carried on board light aircraft has also some recording capability. Advantage could be taken of this equipment as an alternative solution to a dedicated in-flight recording solution. One example is the Garmin G1000 Flight Data Logging and SD card download capability. The team is tasked with: Assessment of the need for in-flight recording for each combination of aircraft category, aircraft mass or occupancy, and type of operation indicated [above]. This assessment should take into consideration the cost constraints peculiar to light and general aviation; Identification, where in-flight recording is justified, of the recording function(s) needed (flight parameters, or audio, or both); Establishment of a list of in-flight recording solutions that ranges from the cheapest and lightest solution to the conventional crash-protected flight recorder. This list may include alternative solutions, such as using or enhancing airborne equipment designed for other purposes; Proposal of definitions and requirements,...
read moreS-92A Nose Landing Gear Incident – Aberdeen 29 July 2014
S-92A Nose Landing Gear Incident – Aberdeen 29 July 2014 A minor landing gear incident on a CHC Sikorsky S-92A at Aberdeen Airport in Scotland has attracted press interest. The Nose Landing Gear could not be lowered resulting in the need for maintenance intervention while the aircraft was in a low hover with 16 passengers and two crew aboard. Photographs were posted on an oil workers Facebook page. Observations: This neatly demonstrates: The need to be prepared to respond safely to any eventuality Someone will always be prepared to photograph and tweet or Facebook it! One nice positive is that the local press do highlight that the successful efforts of CHC’s maintenance team did get recognised: Users of the social networking site were quick to praise the workers. One commented: “Fair play to the lads that got under and sorted the landing gear! Good effort boys.” On 24 January 2010, a CHC S-92A at Esbjerg in Denmark, OY-HKA suffered a NLG failure. The Danish Havarikommissionen accident investigators explain in their report that the NLG should self centre when unloaded but this can fail to occur if their is too little hydraulic fluid within the strut (due to a leak for example) or the nitrogen pressure is too high. In the Esbjerg incident, which occurred at night, the aircraft landed on a pallet of bags of salt. The investigators say that: As a result of this incident and their investigations, the helicopter manufacturer has changed service procedure in their maintenance manual AMM (Aircraft Maintenance Manual). The operator’s maintenance organization has informed the Havarikommission that they subsequently have reduced service interval from 500 flight hours to 250 flight hours based on the incident. The effectiveness of the actions are suspect following the UK occurrence. The passengers and crew aboard these two S-92As are not the only people to have a helicopter landing gear failure disrupt their arrival. In May 2008 David Cameron, later British Prime Minister, had to jump from a helicopter at Redhill Aerodrome, before the pilot landed on a bed of car tyres. The UK Air Accidents Investigation Branch (AAIB) reported on that incident in 2010. In that case, with an Agusta A109, it is believed that misassembly of the landing gear selector was responsible. UPDATE 9 August 2018: AAIB release their report into another S-92A NLG incident, on G-CHHF of Bristow, 29 January 2018: During a final approach to land at Scatsta the NLG failed to extend despite being recycled and the use of the emergency blowdown system. The crew declared a PAN and the decision was taken for ground crew to lever the NLG down manually. This was successfully carried out and the helicopter landed safely. It was found that the automatic nosewheel self-centring mechanism had not operated, causing the nosewheels to jam the nose leg in its bay. The exact cause of the failure of the NLG to centre the nosewheels during retraction could not be determined. The helicopter manufacturer has investigated six reports of previous events where the NLG was off-centre, jammed in the wheel well and failed to extend either by the primary or secondary means. …low oil or nitrogen charge in the strut results in the self-centring cams not interlocking correctly, allowing the wheels to remain off-centre when the aircraft weight is ‘off-wheels’ prior to retraction. In September 2017 the manufacturer issued a letter...
read moreLiving Near Zero – New Challenges for Air Safety
Living Near Zero – New Challenges for Air Safety Between 17 July 2014 and 24 July 2014 the aviation industry has been rocked by three loses of commercial passenger aircraft and 462 lives: 17 July 2014 Malaysia Airlines Boeing 777-200ER 9M-MRD (flight MH17) overflying Ukraine after what appears to have been a surface to air missile attack (see Aviation Safety Network database entry here). 23 July 2014 TransAsia Airways ATR42 B-22810 (flight GE222) on approach to Magong, Taiwan in poor weather (see the ASN entry here). 24 July 2014 Swiftair MD83 EC-LTV on charter to Air Algerie (flight AH5017) in the cruise over Mali in poor weather (see the ASN entry here). In this article we will separate deliberate violent/terrorist/military actions from ‘accidents’. However, the MH17 loss certainly raises questions about operational route planning, regulation, risk assessment and the value of defensive aids. The International Civil Aviation Organisation (ICAO) will be hosting a special high-level meeting on 29 July 204 with the Directors General of the International Air Transport Association (IATA), Airports Council International (ACI) and the Civil Air Navigation Services Organisation (CANSO). The subject is how to “more effectively mitigate potential risks to civil aviation arising from conflict zones”. Harro Ranter of the Aviation Safety Network has analysed the losses in 2014 to date and July 2014 in particular and produced a historic comparison. Statistically it is not unusual for clustering of accidents, as discussed in a recent BBC article. While no consolations to the bereaved families of the victims of these recent events, with an estimated 36 million commercial flights per annum worldwide, the risk of dying in a commercial airline accident remains remarkably remote. Nearly 20 years ago years ago there was alarm that unless commercial airliner safety improved we would be averaging a airliner accident every week globally, as air traffic increased. Flight International correspondent David Learmount recently looked back at the 1970s and in particular the first half of 1974. He found: …that there had been 25 fatal accidents involving passenger flights in that period… So we’d been at the weekly accident stage before! Of course the 1990s safety performance was itself a product of two decades of hard work reducing the accident rate faster than the increase in total traffic. The fear two decades ago was that traffic would outpace our ability to improve. This triggered a number of safety initiatives (such as the Commercial Air Safety Team, [CAST]), which coupled with increasing understanding of organisational accidents and the introduction of more modern aircraft have allowed improvements to continue. Aerossurance recently discussed data from Airbus that illustrates the improvements with newer technology aircraft. Aerossurance also recently highlighted positive performance in the European Union discussed in the European Aviation Safety Agency’s Annual Safety Review. For the first half of 2014, Learmount points out: …a preliminary estimate of airline fatal accidents in the first six months of 2014 shows six, and the total number of resultant deaths is 267. But those numbers for the first half of 2014 include the missing Malaysia Airlines Boeing 777-200ER flight MH370, which may turn out to have been due to criminal acts and 4 accidents which did not involve passengers. In fact, there was just one confirmed fatal accident with passengers, a Nepal Airlines Viking DHC-6 Twin Otter, which flew into a mountain side in poor visibility killing 18 people (see the Aviation Safety Network database entry here and footage of the accident site here). Bottom...
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