The European helicopter safety team (Ehest) released the preliminary results of the first European-wide helicopter accident study on October 13, during a conference in Cascais, Portugal. The Ehest is now transitioning from analysis to the development of an action plan. Ultimately, the goal is to reduce the helicopter accident rate by 80 percent by 2016, consistent with the goals of the international helicopter safety team (IHST).
The 186 accidents analyzed for the period between 2000 and 2005 period account for 58 percent of all the final reports available to the analysis team, dubbed EHSat. “This is why we call these results preliminary; however, statistically, they already [indicate clearly] what the final results will be,” EASA safety action coordinator Michel Masson told AIN. About 130 more reports are being analyzed.
The EHSat’s regional teams bring together representatives from the national aviation authorities, accident investigation boards, civil operators, helicopter equipment manufacturers or type certificate holders, pilot associations, the general aviation community and, in some cases, military organizations. The EHSat has representatives from the UK, France, Germany, Hungary, Ireland, Italy, Spain and Switzerland as well as from a Nordic team representing Norway, Sweden and Finland. “The EASA is supposed to gather accident data but it still depends on member states’ reporting promptly,” noted consultancy firm AviateQ’s Andy Evans, who co-chaired the analysis team. It is for this reason that regional teams are useful.
According to the team, the general aviation category accounts for the largest percentage of accidents (39 percent). Next comes aerial work (35 percent), followed by commercial air transport (22 percent) and state flights (4 percent). The aircraft was destroyed in 49 percent of the accidents. It suffered substantial damage in 46 percent of the occurrences, minor damage in 3 percent and no damage in 2 percent. There was no injury to the occupants in 43 percent of the accidents, while fatal, serious and minor injuries accounted for 25, 17 and 16 percent, respectively.
The Ehest’s analysis is the most exhaustive study of helicopter safety ever conducted in Europe, and it confirms a major distinction between fixed- and rotary-wing aircraft: helicopters encounter much more trouble en route, a phase of flight that accounted for 64 of the 186 accidents. Next in the top three phases are the approach and landing (47 accidents) and maneuvering (38 accidents).
The en route phase accounts for the greatest number of fatal accidents (32). “This is the phase of flight during which the helicopter has the highest energy,” explained Gilles Bruniaux, Eurocopter’s operational v-p for fleet safety.
The analysis team used two methods to classify accident factors. One is the standard problem statement (SPS) that the U.S. joint helicopter safety team uses. The European team benefits from using this method in that it allows comparison of the two teams’ results. According to the preliminary results, the European and U.S. results correspond within 11 percent overall, which the Ehest regards as good agreement.
Accident Analysis
The SPS method uses codes–more than 400 of them–to classify accidents according to maintenance, pilot judgment and actions, part or system failure, safety management and so on. The accidents are then divided further to define the various factors more accurately. For example, if one contributing factor reads “the pilot inadvertently entered IMC and probably became spatially disoriented,” the level-one area is pilot situational awareness. Getting into deeper detail, the SPS level-two category in that example is visibility/weather. At the third level, the sub-category is inadvertent entry into IMC.
The other method focuses on human factors. It is called the human factor analysis and classification system (HFACS), developed by the U.S. Department of Transportation’s Douglas Wiegmann and Scott Shappell. The system, also known as the Swiss cheese theory, compares vulnerable points in an organization to holes in layers of organization levels and introduces the concept of latent failure.
The four main areas of study are organizational influences, supervision, preconditions and unsafe acts. Using the same inadvertent flight into IMC as an example, this system would label the first category “supervision,” the second “inadequate supervision” and the third “local training issue.”
EASA safety analyst Marieke Van Hijum said, “Human factors are going to become more and more important, as the latest-generation helicopters have more sophisticated man-machine interfaces.”
The safety team used a combination of HFACS and SPS to produce recommendations, and the two types of analysis yielded similar results. Under SPS analysis, pilot judgment/actions was identified as the cause in 68 percent of accidents. Next in the top three were safety culture/management (48 percent) and situational awareness (38 percent).
With HFACS, it appeared judgment and decision-making errors were a factor in 60 percent of accidents. At the supervision level, inadequate operation planning accounted for 59 percent of the accidents. At the “organizational influences” level, process problems were found in 64 percent of cases. Climate, with for example the owner exerting pressure on the pilot, was determined to be a factor in 24 percent of accidents.
In commercial air transport, the SPS method shows that the top issue (at level three, the most specific one in analysis) is decision making. The HFACS provides a different perspective, showing brownout/whiteout as the top level-three issue.
In aerial work, according to the SPS method, the highest-ranking factor was the proximity of hazards such as obstacles, including wires. The HFACS method highlighted poor risk assessment during operation. Aerial work includes agricultural, firefighting, construction/sling load, aerial observation and logging.
In general aviation, pilot decision making was found as the top issue under the SPS method. The other study, HFACS, again found risk assessment during operation as the first problem.
From the factors identified in the analysis, the Ehest developed a number of intervention recommendations. The top three categories are training; flight operations and safety management/culture; and regulatory. The last category is not necessarily about additional rules. These “regulatory” recommendations also include encouragement to use best practices.
While the top three categories above reflect the ranking for the commercial air transport sector, the findings are similar for aerial work and general aviation. For aerial work, flight operations and safety management/culture accounts for the largest number of recommendations. For general aviation, training is the most pressing category, followed by regulatory and flight operations and safety management/culture.
There are 945 intervention recommendations. Van Hijum gave a number of examples. One is improved training for mountain operations, specifically for landing on snow-covered surfaces. Also, instructors and examiners should be updated more regularly by type-rating training organizations.
In terms of flight operations and safety management/culture, the Ehest wants to fight the “get the job done regardless” attitude. It also wants to investigate the user-unfriendliness of checklists. Another recommendation is increased oversight of new pilots.
In the regulatory category, the Ehest recommends a review of VFR criteria and license privileges to reduce the risk from flight in degraded visual conditions. Also, it would like to promote inexpensive flight data and voice recorders for small helicopters.
The team has assigned each recommendation a score from zero to 4 denoting confidence that a recommendation can mitigate an event and that it will be used and will perform as expected.
The analysis team (EHSat) is handing over the keys to the still-to-be-formed implementation team (EHSit). In doing so, Europeans are about 18 months behind their U.S. counterparts in a similar effort.
Unlike the U.S., Europe lacks a homogeneous spread of field representatives for civil aviation authorities. “A major challenge will be to find a way to [persuade] small operators to be more safety-driven,” John-Pierre Dedieu, Eurocopter’s senior v-p for fleet safety and Ehest co-chairman told AIN.
Another challenge is to calculate an accurate accident rate, which requires a firm grasp on the number of flight hours. As Dedieu told AIN, there is a lack of data on the number of hours flown by small operators. “We at Eurocopter believe we have a good database and yet we think we have a 10- to 15-percent margin of error,” he said. Information is hard to come by, as it is scattered among the manufacturers, national aviation authorities and the operators themselves.