Insights from Bristow CEO at Helitech
Insights from Bristow CEO Jonathan Baliff at Helitech On 14t October 2014 at Helitech in Amsterdam, Jonathan Baliff, discussed an objective of reducing the range of types in the company fleet and an approach of increasing risk sharing with more availability focused contracts with the helicopter manufacturers: We will purchase our aircraft in larger numbers, so we will have fewer types, and we will buy aircraft where there is sharing of availability risk. We will pay for this and there are hundreds of millions of dollars of profit for OEMs that execute this risk sharing through life of the asset. OEMs realise that the real value is in selling razor blades rather than razors. This reflects both the problems in recent years with certain aircraft types being temporarily restricted from operations due to airworthiness problems and the logistic support challenges for other manufacturers as usage of their fleets has increased to cope. However he also commented that the helicopter industry needs to have the equity to cope with any future rise in interest rates or toughening economic conditions. The reason we have $700 million in cash is both to reassure clients that we can survive in tough conditions and so we can take advantage of opportunities in the market. This is particularly relevant as oil prices fall an oil majors look to cut costs. One wonders if this will put pressure on some of the smaller operators and result in more mergers and takeovers (NHV recently merged with Blueway) even though demand remains high. In fact some smaller operators may suffer because demand is high and the larger, better financed operators have big, long term order books, restricting the remaining supply. In the last 5 years Bristow has increased its use of leased helicopters, at a time when the helicopter leasing industry has started to expand rapidly with a host of new players. In turn the big players, such as GECAS, have taken an interest in the sector (GECAS have just announced the purchase of Milestone, having been hinting at interest in the sector before the Singapore Airshow at the start of the year). At the same time as Baliff addressed Helitech, Bristow released a technical financial paper advocating a move from a focus on return on capital to a value added metric which better accounts for the use of leasing and encourages efficient operation with the equity reserve to weather financial storms. UPDATE: Baliff’s full presentation is now here, which started with comments on the Joint Operators Review and the formation of HeliOffshore, (whose foundation Aerossurance discussed in June). Baliff also recently described to Rotor and Wing a way forward he described as the 4 Cs: Clients: the need to be even more focused on their strategic needs Culture: both in relation to the company’s Target Zero culture and its core values Continuity: specifically maintaining the continuity with his predecessor from July 2004 to July 2014, Bill Chiles and what Baliff terms Chiles’ Target Zero “legacy of safety” and also in terms of business continuity in the face of threats such as Ebola Communication: two-way communication internally and externally UPDATE 13 January 2015: Bristow World published an interview with Baliff. UPDATE 22 January 2015: In this article John Briscoe, Bristow’s Senior Vice President and Chief Financial Officer, comments on the financial outlook: Bristow Takes Long View of Oil Price Slide. Briscoe says: We are not deferring deliveries...
read moreMaintenance Check Flights: Safety Lessons
Maintenance Check Flights: Safety Lessons We look at the safety lessons from three UK Air Accidents Investigation Branch (AAIB) reports into serious incidents during maintenance test flights (the most recent published this month). CL600 N664D ADG Check Flight March 2014 In March 2014 the US registered Bombardier CL600-2B16 required a post-maintenance check flight at Biggin Hill, UK. The check involved deploying the aircraft’s air-driven generator (ADG) and therefore placing the aircraft in an emergency electrical configuration. During the flight, with two crew accompanied by an engineer as an observer, the required check was successfully completed. However, the aircraft was not returned to the normal electrical configuration. As a result the flaps, ground spoilers, anti-skid and nosewheel steering remained disabled. Consequently, on landing, with difficulty the aircraft was stopped approximately 120m from end of the runway (the Landing Distance Available was 1,550m). All four main tyres deflated, causing damage to the left hand wheel and brakes. The AAIB note that the CVR were not promptly deactivated to preserve the recording. The AAIB report highlights a difference in understanding between the flight crew and engineering personnel: The commander observed that the roles of the pilots and the engineer had not been clearly established before takeoff, and the pilots assumed that the engineer would ‘talk through’ what he needed to see once airborne. The commander also observed that the crew should have referred to the Quick Reference Handbook (QRH) for the situation rather than rely on the engineer to guide them. The commander later discovered that the engineer was not expecting to make decisions or inputs during the flight, so a misunderstanding had existed. The engineer described his role as primarily that of an observer, although with the intention of noting any defects or abnormalities that might arise during the flight test. The maintenance organisation internal investigation made several recommendations including: …the requirement for a full briefing to be given to flight crews undertaking a maintenance check flight, irrespective of whether or not the crew declared themselves to be familiar with the procedure. Falcon 2000 CS-DFE Brake Fault Finding November 2009 In November 2009, flight crew were requested by maintenance to carry out high speed taxi trials of a Portuguese registered Dassault Falcon 2000 as part of the troubleshooting process of a braking defect, also at Biggin Hill, UK. Seven accelerate/stop runs were conducted along the main runway, at gradually increasing reject speeds. At the start of the eighth run, the crew felt that a tyre had deflated and brought the aircraft to a stop. ATC radioed that there was a fire under the left wing and all six persons on board safely abandoned the aircraft via the airstair door. The Airport Fire and Rescue Service (AFRS) extinguished the fire. The fire was caused by damage to the brakes from the excessive temperature of the repeated runs, this released hydraulic fluid under pressure, which then ignited. AAIB note that: There were numerous systemic factors relating to the manner in which the operator conducted this test activity which contributed to the incident. Many of these, such as appropriate crew selection, the need for an approved test schedule and a detailed brief and debrief of the test activity with all involved personnel, are common to other recent incidents and accidents involving operators conducting maintenance or customer demonstration check flights. These issues have been highlighted and analysed in detail in the AAIB report...
read moreHow To Develop Your Organisation’s Safety Culture
How To Develop Your Organisation’s Safety Culture Last week we highlighted how mindless management actions can destroy an organisation’s safety culture and we explained that building a strong, positive safety culture takes deliberate, concerted and continual effort. But what sort of effort? This week the annual European helicopter expo and conference, Helitech, is being held in Amsterdam. Three years ago we presented on this very topic at the safety seminar at Helitech 2011 in Duxford, UK. Safety Culture – the Key to Safety Performance The term ‘safety culture’ was initially used in the report on the 1986 Chernobyl nuclear accident. While there are many definitions of ‘culture’ and an associated concept of ‘climate’, a safety culture can be conveniently considered to be the product of an organisation’s collective, safety related: values, attitudes, perceptions, social norms and ultimately… patterns of behaviour We think that those patterns behaviours are the most important as they are observable and therefore the strongest manifestation to influence others. As such an organisation’s culture can not evolve simply by management edict but in response to a whole range of factors including: local conditions, past events, the character of leadership and the mood of the workforce Prof. James L. Heskett of Harvard Business School wrote in his 2011 book The Culture Cycle, that effective culture can account for 20-30% of the differential in corporate performance when compared with “culturally unremarkable” competitors. A safety culture reflects the organisation’s actual collective, shared commitment to safety. It not simply what is said about safety but the commitment to safety that is demonstrated by normal behaviour, crucially when problems emerge or hazards are identified. Weaknesses in safety culture are increasingly being identified in accident investigation reports as a critical precursor to accidents. This not because there is necessarily a widespread decline in organisational safety cultures, but because investigators are now looking more closely at organisations, how they function and how the shared culture is influencing individual and team behaviour. One example is the Columbia Accident Investigation Board (CAIB) report on the loss of a Space Shuttle in 2003. It has been written that: Safety Culture can have a direct impact on safe performance. If someone believes that safety is not really important, even temporarily, then workarounds, cutting corners, or making unsafe decisions or judgements will be the result, especially when there is a small perceived risk rather than an obvious danger. The UK Health & Safety Executive (HSE), the occupational health and safety regulator, issue specific guidance on the consideration of safety culture during inspections. Safety Leadership – the Key to Safety Culture Leadership is a powerful influence on culture. The term ‘leadership’ is sometimes misused. Sometimes as a trendy alternative for ‘senior management’ and occasionally in the Orwellian term ‘thought leadership’ (which was recently labelled “grossly indulgent” in the Forbes list of ‘most annoying business slang’). Leadership is not the same as managing resources and schedules. Here we use leadership to represent an activity that involves: Being visible, Focusing on people, Building trust and ultimately… Influencing other people’s behaviour It is this deliberate, concerted and continual activity that can influence culture, though as we have showed previously, that can be unravelled far more rapidly by poor leadership. Excellent safety leaders realise that safety leadership is not an alternative to safety management but an essential complement. They also have a vision for safety in their organisation. It perhaps goes without saying that safety leaders therefore have a passion for safety. Safety Leaders...
read moreEHEST: New Publications on Technology & SMS
European Helicopter Safety Team (EHEST) Issues New Publications on Technology & SMS EHEST have released two new publications, one on accident reducing technologies and the other on SMS for non-complex operators: The Potential of Technologies to Mitigate Helicopter Accident Factors – An EHEST Study EHEST created a Specialist Team Technology (ST Technology) to assess the potential of existing and emerging technologies to mitigate the top 20 helicopter safety issues identified from EHEST helicopter accident analyses. The team has created a technology matrix that includes 145 technologies, of which 93 have been rated to determine their Technology Readiness Level (TRL) and has published its results in a new report. EHEST report that: There are 15 ‘highly promising’ technologies (that jointly can potentially mitigate 11 of the top 20 safety issues), and 50 that are ‘moderately promising’. Five technologies are highly promising for three or more safety issues. The industry is highly recommended to channel their technological development in line with the results of the study. The regulatory side should find ways to improve safety by adopting the technologies. Researchers and universities are encouraged to concentrate their efforts on developing the lacking technologies and the technologies which have a low Technology Readiness Level. Safety Management Toolkit for Non-Complex Operators EHEST have released the second edition of their Safety Management Toolkit for Non-Complex Operators. It consists of a Safety Management Manual (SMM), a Guidance Document and an Emergency Response Plan. This manual for non-complex helicopter operators is derived from the more comprehensive SMM for complex operators. Although reduced in complexity the non-complex SMM is still fully compliant to the EU and EASA requirements. EHEST Background Launched in November 2006, EHEST brings together helicopter manufacturers, operators, research organisations, regulators, accident investigators and a few military operators from across Europe. EHEST is the helicopter arm of the European Strategic Safety Initiative (ESSI), and also the European component of the International Helicopter Safety Team (IHST). If you want to support the EHEST’s work and learn more about helicopter safety join the EHEST LinkedIn Group. Aerossurance has extensive safety, helicopter design, flight operations, airworthiness and safety analysis experience. For aviation advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest...
read moreRegulatory Reflections & Resisting the Seduction of the Risk Management Process
Regulatory Reflections & Resisting the Seduction of the Risk Management Process In 2014 the UK Military Aviation Authority (MAA) Head of Regulation and Certification, Commodore Malcolm Toy presented reflections five years on from the Haddon-Cave Report, issued in October 2009, following the loss of Royal Air Force (RAF) Nimrod XV230, that resulted in a revolution in UK military aviation regulation and safety, including the formation of the MAA UK Military Aviation Authority (MAA). Reflections The seven reflections have resonance for other regulators and organisations managing risk: You cannot be world class unless you know what the world is up to. Regulatory (safety) decisions must be evidence based and proportionate to the Risk to Life. Learn from near misses. Scarcity [of personnel, time and capacity] is a challenge and cannot be overcome without a plan. Do not be seduced by the process of managing risk. Regulators (Safety Organizations) do not play to win, they play not to lose. Put those organizations that have Risk to Life exposure at the centre of managing that risk. The Process of Risk Management Perhaps the most interesting are the comments on avoiding the allure of the process of managing risk. Toy warns that simply ‘measuring’ risk is not actually the same as actively managing risk. Managing risk needs actions to be planned and executed but some times it may seem easier to ‘tinker with’ risk than actually engineer solutions. Commodore Toy’s full presentation can be found on the European Defence Agency website or here. The MAA’s vision and mission for 2016 to 2021 has been published. Haddon-Cave Nimrod Report Background Haddon-Cave himself presented at a UK CAA event in 2010 and to the Piper 25 conference (marking the 25th anniversary of Piper Alpha offshore disaster in the North Sea, in which 167 workers died). His paper was entitled “Leadership and Culture, Principles and Professionalism, Simplicity and Safety – Lessons from the Nimrod Review”: Piper 25: Presentation Transcript UPDATE 2 September 2016: 10 Year Anniversary: Loss of RAF Nimrod MR2 XV230 UPDATE 19 September 2016: It’s worth listening to Todd Conklin’s podcast interview with Prof Ed Schein. UPDATE 22 September 2016: NTSB Board Member Robert L. Sumwalt presented Lessons from the Ashes: The Critical Role of Safety Leadership to an audience in Houston, TX. Its worth noting the emphasis made of safety as a ‘value’ and of alignment across an organisation. UPDATE 1 September 2017: See also: Audits Highlighted Risk Assessment Weaknesses Prior to Ro-Ro Fatality, which goes on to discuss two marine accidents while towing that also involved risk assement failures. For advice and support you can trust on air safety, risk management, safety leadership development and regulation (civil or military) contact us at enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest...
read moreNew Helicopter Cargo Loading System
New Helicopter Cargo Loading System Dutch engineering company VRR is working with AgustaWestland to design a helicopter Cabin Cargo Container and Restraint System for the AW139 helicopter, anticipating it will be of interest in the offshore oil and gas industry for transport of spares and equipment. Certainly with a large drillship costing $500k per day to charter and the largest production platforms producing more than $10mn per day, there can be times when key equipment really does need to be delivered by helicopter. The company explains: The solution will come in two parts: the AW139 Restraint System and the AW139 Cabin Cargo Container. The restraint system can easily be installed by just two people. The restraint system is designed to hold the cargo container which has two side doors (left and right) and a lid for convenient loading and unloading. The side doors will allow access to the container while it is still in the helicopter. The base will have fork pockets, so it can be handled by a forklift truck. …we’re constructing this container from fire resistant materials. We’re also equipping it with a smoke detector, a fire indicator light and a switch, plus a quick release connection to connect a fire extinguisher. Both the lid and the doors will be equipped with rubber seals to prevent leakages of chemicals used in fire suppression systems. The door locks will also have custom sealing provisions to prevent unauthorised access to the container. http://vimeo.com/106564780 It is not yet clear what tie downs will be available inside the container to secure heavy loads such as valves and motors. Rotterdam based VRR, founded in 1946, specialises in designing and manufacturing air cargo equipment such as Unit Load Devices (ULDs). The company has previously designed a pallet system for the AW101. For advice on the design and certification of helicopter equipment and helicopter logistics, contact us at enquiries@aerossurance.com Follow us on LinkedIn for our latest...
read moreHow To Destroy Your Organisation’s Safety Culture
How To Destroy Your Organisation’s Safety Culture The term ‘safety culture’ was initially used in the report on the 1986 Chernobyl nuclear accident. Building a strong, positive safety culture takes deliberate, concerted and continual effort. Destroying a safety culture is a lot easier… Bad Safety Leadership The following is the text of a real e-mail, spotted pinned to the wall of the flight planning room of an onshore helicopter operator (but with expletives deleted!): Gentlemen, I have been flying multiengine airplanes and helicopters for over 40 years and 20,000+ hours, and have yet to see two gauges match perfectly!!!!!! Please don’t waste your time and my email space reporting this $&*@!!! It’s not even worth writing about!!! The Captain of the aircraft makes the decision if he wants something looked at, at which time he will tell the crew chief and it will get fixed. If the Co-pilot sees something that he is concerned about, he tells the captain. Only the Captain!!! His job is to do what the Captain asks him to do. If the Captain has concerns, he is to ask me. SIGNED – Director of Ops Dated: December 2008 As well as discouraging safety reporting and communication, there is an underlying tone of ‘you will be blamed if you don’t conform to previously undisclosed expectations’ and ‘I know best’ contrary to the principles of a just culture or that of a questioning/learning culture. This was a powerful sign that this operator had a pathological safety culture. Prof Patrick Hudson proposed the following model, developed from earlier work by Ron Westrum: When discussing this model, Hudson wittily explains why brown was chosen as the colour for the pathological to whom bad things just happen… Operational Control However in this case, the situation is even worse as the very existence of the memo also subverted the management of the operator. The context is that the Director of Operations worked for a North American operator who leased aircraft and support services (including captains), to a South American operator. The aircraft were actually legally being flown under the AOC of the South American operators (who provided co-pilots). Just a few months earlier a Bell 412EP, operated under a similar basis, supporting a remote copper mine was, lost in a fatal accident. The Peruvian Comisión de Investigación de Accidentes de Aviación (CIAA) commented in that case on the effect on operational control of having a ‘Field Manager’ from a US organisation with a satellite link back to his US HQ, controlling operations at the forward operating base, rather than the actual operator. UPDATE 14 October 2014: A legal action after this accident is still on-going and the case will be heard in the US. Downeast Airlines In another example of a pathological culture, the US National Transportation Safety Board (NTSB) reported on the 30 May 1979 Downeast Airlines DHC-6-200 Twin Otter N68DE Controlled Flight Into Terrain (CFIT) accident in which 17 people died. The NTSB report stated: The Safety Board’s investigation determined that past and present company personnel perceived the company president as a particularly strong-wilted individual who dominated the course of lay-to-day operations of the company and who was the final authority in all matters. These same company personnel stated that employees who did not unquestioningly accept the president’s decisions were often subjected to various types of coercion ranging from ridicule and verbal abuse to films, seasonal layoffs, and, In some cases,...
read morePDG Helicopters Win UK & Eire Lighthouse Support Contract
PDG Helicopters Win UK & Eire Lighthouse Support Contract The three lighthouse authorities in the UK and Eire have joined together to award a contract for helicopter support. The three General Lighthouse Authorities (GLAs) awarded the £13mn contract to Inverness, Scotland based, PDG Helicopters. PDG will use two new Airbus Helicopters EC135s on the contract which runs from 1 December 2015 for 7 years with three optional one year extensions. This contract supports maritime navigation aids, mostly in remote locations, includes considerable HESLO / underslung load work (the requirement was for an aircraft that could move individual loads >500kg over 50nm to support construction projects), operation with GLA’s fleet of ships (four are ‘helicopter capable’), as well as passenger movements. The contract is expected to involve around 1000 flying hours per annum. The three contracting GLAs are: The Commissioners of Northern Lighthouses, known as the Northern Lighthouse Board (Scotland and the Isle of Man) whose history goes back to 1768 The Corporation of Trinity House, known as Trinity House (England, Wales, Channel Islands and Gibraltar), the oldest of the three, granted a royal charter in 1514 The Commissioners of Irish Lights, known as Irish Lights (the Republic of Ireland and Northern Ireland) dating to only(!) 1786 This contract is a good example of three customers, with common specialist requirements, working together to place a cost effective long term contract. Some reports suggest this arrangement could save nearly £8mn. Its is explained that: Deployment of the helicopter will be co-ordinated by the three lighthouse authorities, working in collaboration. The GLAs will consult on PDG Helicopters work plans and align the helicopter services in the most efficient and effective manner to meet their operational requirements. However, by the very nature of the safety critical work of the GLAs, an agreed contingency procedure will be put in place to allow the Authorities to deal with any immediate or short-notice high priority tasking. PDG was formed in 1995 by the amalgamation of PLM Helicopters and Dollar Helicopters. In recent years it was owned by venture capitalists but the management team and the Scottish Laing family and bought out Glasgow-based Maven Capital Partners in 2012 for £1.8mn. The company currently has 17 helicopters in its fleet, which fly a total of 11,000 hours per annum and employs 85 people. PDG subsidiary Irish Helicopters has been operating EC135T2+ EI-ILS for the Irish Lights. This aircraft is float equipped, with an HR Smith ADELT mounted under the tailboom and the usual mirrors for use monitoring external loads. The company started supporting that GLA in 1986. A GLA is an agency tasked with the provision and maintenance of lighthouses, lightvessels, navigational aids and thus has some analogies with the infrastructure service provide by an air navigation service provider (ANSP) in the aviation sector. An example of the remote locations is the Skerryvore, a pillar rock lighthouse marking a extensive and treacherous reef of rocks 11 miles south west of Tiree. Access is only really feasible by helicopter at certain weather/tidal windows to a 1970s helipad. Up to 30 November 2015 the contracts were as follows: Trinity House: MD902 – Specialist Aviation Services NLB: EC135 – Bond Air Services (part of Babcock International) Irish Lights: EC135 – Irish Helicopters (which is owned by PDG Helicopters) UPDATE 6 October 2015: PDG took delivery of a new EC135T2+ G-GLAA, configured for lighthouse support, at Helitech in London. UPDATE 30 November 2015: The UK Civil Aviation Authority...
read morePassive Fire-Retarding Helideck Designs
Passive Fire-Retarding Helideck Designs A number of helideck manufacturers offer aluminium helideck designs with a passive fire-retarding capability. Typically this is achieved by draining fuel through holes in the deck surface, into cavities filled with aluminium mesh. This starves the fire of oxygen and dissipates heat, extinguishing the flames and draining away unburnt fuel for collection. To show the range of providers, and the capabilities of such deck designs compared to steel decks, we highlight videos from three below. Dutch company Bayards, market their self-extinguishing Safedeck design: Aluminium Offshore, the Singapore based manufacturer of helidecks, has release a video that illustrates their XE Enhanced Safety helideck design: UK company NCMP market their Firesafe design: Spanish helideck manufacturer Helitecnica offer the Safe Aludeck design. Each company is keen to point out that the UK Civil Aviation Authority (CAA) Standards for Offshore Helicopter Landing Areas (CAP437) allow passive fire-retarding decks to use seawater instead of foam in any Deck Integrated Fire Fighting System (DIFFS) fitted (see Chapter 5 para 2.11). This gives a reduction in complexity, maintenance and cost (capital and recurring). This combination of a passive fire-retarding deck and DIFFS is particularly effective on Normally Unattended Installations (NUIs). NUI fire-fighting capabilities were the subject of Chapter 10 of CAP1145, which resulted from the CAA Review. The Risk of Helideck Fires One of the helideck manufacturers includes footage of a 2002 helicopter accident resulting in a fire on the helideck of a US Navy destroyer. It is worth noting that this involved an old generation military helicopter (a Sikorsky H-3, a type that entered service in 1959) suffering a loss of tail rotor drive while landing on a naval vessel in the Arabian Gulf. This aircraft type was designed before the advent of crash resistant fuel systems (CRFS), triggered by military experience during the Vietnam War. It is also worth noting that in that case all personnel survived. Historically, the number of post crash fires on helidecks is small. In CAP1145 the CAA had to use a photograph a non-fatal accident that occurred in the South China Sea off Malaysia in 1985 as an illustration as no such fire has occurred on the UK Continental Shelf (UKCS). Aerossurance is aware of a 2009 helideck fire in Saudi Arabia and again there were no fatalities in that fire. There was also a fire on a drilling rig in 2008 after a helicopter collided with one of the jack-up legs, but this look place away from the helideck. In November 1994 a series of CRFS requirements were introduced into FAR-27 Amendment 27-30 for future civil helicopter certifications (and adopted into the next revision of the European JAR-29 [Change 1]). The FAA explained that: The fuel containment and hazard elimination provisions contained in these proposals would, in the majority of cases, give occupants the time necessary to escape a survivable crash before a [Post Crash Fire] PCF could become critical. A crash resistant fuel system, CRFS, would not be expected to prevent all fires; however, a CRFS would, in the majority of impact survivable cases, either prevent a PCF or delay the sudden massive fire, or fireball, long enough to allow the occupants to escape. These proposed standards have been validated by military safety statistics and their adoption would significantly minimize the PCF hazard and its associated fatalities and injuries. Service experience suggests the probability of a fatal helideck accident is relatively low, however passive fire-retarding decks remain a very...
read moreFatal $16 Million Maintenance Errors
Fatal $16 Million Maintenance Errors (Sundance Helicopters AS350B2 N37SH) A jury in Las Vegas awarded $16 million to the families of 4 passengers killed in a December 2011 helicopter sightseeing accident, caused by a series of maintenance errors. The National Transportation Safety Board (NTSB) made safety recommendations on maintenance human factors and fatigue after this accident. The Accident Airbus Helicopters AS350B2 N37SH, operated by Sundance Helicopters, suffered a Loss of Control (LOC) accident in mountainous terrain east of Las Vegas on 7 December 2011. The helicopter, en route to overfly the Hoover Dam, was destroyed by the impact forces and post-crash fire. The pilot and four passengers were killed. The day before the accident a team of three mechanics and one inspector had completed a 100 hour inspection on the aircraft, along with replacement of the engine, the tail rotor servo and the main rotor fore/aft servo. In their report the NTSB state: During examination of the wreckage, the main rotor fore/aft servo, one of the three hydraulic servos that provide inputs to the main rotor, was found with its flight control input rod not connected. The bolt, washer, self-locking nut, and split pin (sometimes referred to as a “cotter pin” or “cotter key”) that normally secure the input rod to the main rotor fore/aft servo were not found. The investigation revealed that the hardware was improperly secured during maintenance that had been conducted the day before the accident. Probable Cause The NTSB determines that the probable cause of this accident was Sundance Helicopters’ inadequate maintenance of the helicopter, including: (1) the improper reuse of a degraded self-locking nut, (2) the improper or lack of installation of a split pin, and (3) inadequate post-maintenance inspections, which resulted in the in-flight separation of the servo control input rod from the fore/aft servo and rendered the helicopter uncontrollable. Contributing to the improper or lack of installation of the split pin was the mechanic’s fatigue and the lack of clearly delineated maintenance task steps to follow. Contributing to the inadequate post-maintenance inspection was the inspector’s fatigue and the lack of clearly delineated inspection steps to follow. Maintenance Safety Issues The NSTB specifically highlighted four maintenance safety issues. Issue 1: Improper reuse of degraded self-locking nuts Certification requirements FAR 27.607 and CS-27.607 state that “Each removable bolt, screw, nut, pin, or other fastener whose loss could jeopardize the safe operation of the rotorcraft must incorporate two separate locking devices”. This requirement is designed to give redundancy. In this case the first locking feature is provided by using a self-locking nut and the second by use of the split pin. The NTSB found during their interviews and inspection of a sample of the operator’s aircraft that during maintenance nuts were being routinely re-used that did not meet the published criteria for re-use. That meant the nuts were no longer self-locking and one line of defence was eliminated. Issue 2: Maintenance personnel fatigue / alertness The NTSB concluded that both the mechanic and the inspector, who worked on the helicopter the day before the accident, were likely fatigued, with a consequential reduction in alertness. This was in part, because they had insufficient time to adjust to returning to work earlier than normal. Both were on a 4 days-on, 3 days-off shift pattern, from 12:00 to 23:00. They were due to be off 4-6 December, but were both called on the afternoon of 5 December and asked to...
read more
Recent Comments