Helicopter safety, in a state of stagnation for decades until recently, finally appears to be responding to treatment, says the International Helicopter Safety Team (IHST).
In 2006, the IHST was launched at a meeting in Montreal, Canada to see if it could do something about the fact that helicopter accidents were not reducing while the airline sector was witnessing huge safety improvements. In the 1990s, the US airline sector had set up the Commercial Aviation Safety Team (CAST) to extract data from years of accident and incident reports, identify problems and prioritise solutions. It worked, and not just in the USA, because regional safety teams such as CAST were gradually set up all over the world.
Today, reflecting the work of the IHST and its regional offshoots, beneficial results are showing in the rotary wing sector. The improvement was faltering at first and has seen setbacks, but now seems to be gathering pace.
Last year, US civil-helicopter accident numbers reduced to the lowest level since the early 1980s, according to the IHST, and that improvement appears to be continuing strongly into 2015. During 2014, the US rotary wing industry experienced 3.64 accidents per 100,000 flight hours, a 26% reduction compared with 2013 and a 54% reduction compared with the 2001-05 ‘baseline accident rate’. This ‘baseline’ rate was the industry accident rate measured in the five years before the IHST began its work. According to the IHST, before 2006 the number of worldwide civil-helicopter accidents was rising at a rate of 2.5% per year, but since 2006 the number of accidents worldwide has been decreasing by an annual rate of 2%.
The US rotary wing fatal accident rate also reduced. During 2014, there were 0.59 fatal helicopter accidents per 100,000 flight hours compared with 1.02 fatal accidents per 100,000 flight hours in 2013 – a 42% decrease year-on-year, and a 55% reduction compared with the 2001-05 baseline fatal accident rate of 1.31 (see chart). The IHST attributes this to United States Helicopter Safety Team (USHST) safety education and communication efforts, where safety solutions derived from years of helicopter accident and incident data analysis were successfully shared with the operators.
According to preliminary USHST data, the dip in the accident rate during 2014 came after two consecutive years of increases, giving rise to nervousness about the resilience of the long-term improvement. But the 2014 rate was the lowest in the past 15 years of collected data. In addition, the team notes, the fatal accident rate has been below 0.70 per 100,000 flight hours in four out of the past six years.
Meanwhile the IHST has noted that US civil helicopter safety is continuing to improve rapidly this year. Figures for January-June 2015 show there were 46 civil helicopter accidents occurring in the USA compared with 64 total accidents during the same months of 2014. During the first half of 2015, there were 10 fatal helicopter accidents. This compares with nine fatal accidents during early 2014 and 17 fatal accidents in the first half of 2013.
When the IHST began, the target was to reduce helicopter accident rates by 80% by 2016. Barring a miracle that will not be achieved but, in the USA at least, it looks as if an improvement of 50% may well be consolidated, and that is a remarkable change for the better. But the US improvement in fatal, rather than overall, accident statistics has been, it says, “less consistent”, with a ‘good-year, bad-year’ pattern, even if it is showing a slow downward trend in the long term. The USHST’s reaction has been – since fatal accidents are only reducing slowly – to search for ways of improving passenger and crew survivability, by researching and implementing improvements in cockpit, cabin and seat design.
Meanwhile in Europe, the EASA works with the IHST’s regional counterpart, European Helicopter Safety Team (EHEST) and its data analysis team European Helicopter Safety Analysis Team (EHSAT). Its accident figures are not so easy to interpret because gathering data from nearly 30 states – not all of which conduct detailed analytical investigations of light helicopter accidents – and amalgamating it accurately is not so simple. There is a visible improvement in certain sectors of the European rotary wing industry, but not as much as in the USA. Arguably, however, there was more room for improvement in the USA – and more ‘low-hanging fruit’.
DATA-DRIVEN
About three years ago, EHSAT published its first analysis based on the examination of accidents that occurred during the ‘baseline period’ (2000-06) before the IHST’s global exercise in improving helicopter safety began. This year, the EHSAT published its second analysis of accidents, this time during the post-IHST period of 2006-10, looking for developments or simple comparisons with the baseline period. The study said that “the issues identified in the [2000-05] period continue to be of concern, and that the safety improvement actions decided and developed based on the first analysis period [are] therefore still valid”.
Meanwhile the European figures for rotary wing accident numbers show a decline from 2008 onwards in accidents involving commercial air transport (CAT) helicopters (see graph), but no significant change in accidents involving general aviation and airwork rotary wing operations.
EHSAT’s work, like that of other IHST regional studies, was purely data driven, and the data was analysed using strictly defined criteria agreed at the IHST. The analysis goes far beyond counting the numbers of accidents and identifying the accident rates: it delves deep into the technical, operational and human factors behind each accident, then presents these ‘standard problem statements’ (SPS) in order of significance as contributory factors.
One of the significant discoveries, in the USA, Europe and elsewhere since these regional analyses have been done, is that, with very minor variations, the causes and contributory factors leading to helicopter accidents were much the same, wherever in the world they occurred.
For example, the top SPS factor identified in more accidents than any other is “pilot judgement and actions”, which is present as a primary factor in nearly 70% of all accidents. This was the same in the analysis of both 2000-05 and 2006-10, and shows up in a similarly dominant way on both sides of the Atlantic. Failures in safety management, ground duties (including flight preparation) and pilot situational awareness are also high on the primary SPS list, with “parts or system failure” further down.
Announcing a new downloadable leaflet on threat and error management (TEM) for pilots earlier this year, EHEST had this to say: “Data analysis confirms that a continuing significant number of helicopter accidents occur due to poor decision making and human performance made both prior and during flight. The aim of this new… leaflet is to introduce and illustrate the concept of TEM to flight crews and training organizations.”
Unlike the experience in fixed wing aviation, most European helicopter accidents across all industry sectors occur in the en-route phase (27% of rotary wing accidents). The next most risky flight phase is “manoeuvring flight” (23%), so those two would account for half of all accidents. The manoeuvring phase involves “intentional low-level, low-speed flying in the vicinity of obstacles” – but not the approach and landing or the take-off and departure phases, and is the phase where most of the aerial-work accidents occurred (39%).
Also noteworthy, says the report, is that 61% of all fatal rotary wing accidents occurred in the en-route phase, while most accidents causing serious injuries occurred in the manoeuvring phase (25%).
The EHSAT 2006-10 analysis found the CAT helicopter sector often suffered poor management of operations and the assignment of inexperienced pilots to difficult missions. In accidents where ground preparation was a factor, poor mission planning dominated. Among those in which pilot situational awareness was an issue, lack of alertness regarding the external environment, weather and visibility stand out.
Since the 2000-05 analysis report was published, the European Helicopter Safety Implementation Team (EHSIT) specialist teams in Training, Ops & SMS and Technology have produced a number of safety-promotion deliverables in the form of leaflets, videos, toolkits, manuals and reports. That material addresses, and provides ways to mitigate, the top safety issues and intervention recommendations identified.
Now the results of the analysis of the 2006-10 accidents will contribute to shaping the future priorities and further actions of the EHSIT specialist teams, but since studies of the two periods largely validated each other’s findings, this will probably be more about refining recommendations than making radically new ones.
EASA says results will also be shared within the agency and contribute to defining the helicopter Safety Risk Portfolio, which will serve as a basis to develop the helicopter section of the European Aviation Safety plan (EASp).
BACK TO SCHOOL
The IHST states its strategy for today includes these elements: operator safety management systems; training; systems and equipment – including flight-data monitoring and health and usage monitoring systems; and maintenance. If that looks like a ‘back to school’ summary of what’s needed, so be it. Maybe ‘back to school’ is what’s required.
The products aimed at refreshing operators’ knowledge and awareness include IHST, or regionally produced, fact sheets, safety toolkits, safety bulletins, safety leaflets and videos, manuals and guides.
The EHEST products certainly have a ‘back-to-school’ flavour, consisting of handbooks entitled: Safety Considerations; Helicopter Airmanship; Off-Airfield Landing Site Operations; and Decision-Making. On more advanced themes, EHEST offers Threat And Error Management for Helicopter Pilots, Instructors and Training Organizations and Helicopter Automation Management. It offers a video on Degraded Visual Environment and Loss Of Control and Passenger Management. Just published is a comprehensive Helicopter Flight Instructor Manual.
This barrage of information for helicopter operators and pilots is so comprehensive it looks like an indictment of existing training, both ab initio and recurrent. But it has been compiled as a result of analysing hard accident and incident data and identifying training and operational needs, so it does not merely look like an indictment – it actually is one.
EHSAT’s analysis of SPS indicators demonstrated that human factors are consistently top of the causal list for helicopter accidents, in the form of “pilot judgement and actions” and other regions have found the same. In the airline safety world, advanced technology is recognised as being the single largest component in air-safety performance improvement over the last 30 years or more. So EHEST commissioned the Dutch research organisation NLR to carry out a study of what technology could do to enhance helicopter safety. Entitled The Potential of Technologies to Mitigate Helicopter Accident Factors, the first sentence in the introduction makes a clear case for the study: “Technology is not high on the list of accident/incident factors, as it is merely the lack of technology that may have led to an accident.” On an allied subject, EHEST has also published a safety promotion leaflet entitled Advantages of Simulators in Helicopter Flight Training – an under-used resource in most of the helicopter industry.
The technology study looked at several different areas: emerging technologies; existing technologies not yet used on helicopters; and existing technologies used on large helicopters, but not yet on small ones.
Among these, 145 technologies were “identified”, 93 have been “rated”, 50 declared “moderately promising” and 15 declared” highly promising”. Among the latter, five technologies have been identified as highly effective for mitigating three or more safety issues. These include: a terrain awareness and warning system (TAWS); a laser radar obstacle and terrain avoidance system; digital-range image algorithms for flight guidance aids for helicopters in low-level flight; digital maps; and, finally, a voice and flight data recorder – ideally deployable.
Again, the plethora of advice EHEST and the USHST have seen fit to prepare for the industry makes the task look like a ‘back to the drawing board’ exercise. Maybe the lack of a fundamental review of the industry’s way of operating has been the problem all along, and will remain a problem until operators and trainers start taking some of the IHST’s data-driven advice on board.
Source: FlightGlobal.com
