Commercial, Public Service, Regulatory

Rotorcraft Report: IHST Releases Recommendations to Reduce U.S. Helicopter Accidents

By By James Careless | November 1, 2009


U.S. helicopter accidents can be drastically reduced, and we have the fact-based recommendations to do it: That was the message at the International Helicopter Safety Symposium, held from Sept. 29-Oct. 2 in Montreal, Canada. Hosted by the Intl Helicopter Safety Team (IHST)—the global industry-government group committed to reducing accident rates by 80 percent by 2016—IHSS 2009 provided hard research on why and how accidents happen, and solid strategies and tools to prevent them. But the organization is actually “working towards zero accidents,” said Matthew Zuccaro, president of Helicopter Assn Intl (HAI) and IHST co-chair. “Can you imagine an industry that is accident-free?” he challenged delegates as the convention wrapped up. “We would have no loss of life or injuries; revenue or aircraft.”

At IHSS 2009 are (left to right) M.E. Rhett Flater, executive director of AHS Intl; Somen Chowdhury, manager of research for Bell Helicopter Textron Canada and IHST executive committee and IHSS 2009 chair; Mark R. Schilling, acting manager of FAA’s Rotorcraft Directorate (IHST co-chair); Helicopter Association Intl Presicent Matthew Zuccaro (IHST co-chair); Mark Liptak, FAA aerospace engineer (IHST program director); and Jean-Pierre Dedieu, Eurocopter consultant and IHST EHEST representative.James Careless photo

Since IHST was formed in 2005, its members have not been short of ideas. However, what was initially lacking were hard facts about the causes and factors behind accidents. Without such facts to back up its positions, IHST risked having them dismissed. To remedy this, the association’s U.S. Joint Helicopter Safety Analysis Team (JHSAT) has been working through NTSB accident reports. At the 2007 conference, the team released its analysis of the NTSB’s 2000 data. This year, JHSAT unveiled a 210-page analysis of U.S. helicopter accidents for calendar year 2001. The team delivered an oral report to IHSS 2009 delegates, and Rotor & Wing obtained a copy of the full report. Here are its findings: There were 174 U.S.-registered helicopter accidents in 2001, which worked out to 8.0 per 100,000 flight hours. The good news: “This is a decrease of 12.1 percent over the CY2000 accident rate of 9.1 per 100,000 flight hours,” the report states. The bad news: In those accidents, 137 helicopters were “substantially damaged.” That’s 79 percent of the total 174. “Of the remaining, 32 (18 percent) were destroyed, one (0.6 percent) had minor damage and four (2.3 percent) had no damage reported,” it continues.

Only 14 (4 percent) of the helicopters in U.S. 2001 accidents were twin turbines. In contrast, 84 (48 percent) were single-engine turbines and 76 (44 percent) were single-piston helicopters. The majority of CY2001 accidents occurred during personal/private flying, 38 missions (22 percent) and instructional/training, 29 missions (17 percent). The landing phase accounted for 45 (26 percent) of the accidents, hover 30 (17 percent) and maneuvering 29. There was a direct correlation between a higher percentage of accidents and lesser amounts of flying experience in the specific make/model involved in a crash. “For example, the group with the most accidents, personal/private, also has very low median time in rotorcraft,” the report states.

As for casualties: 91 (52 percent) of the CY2001 accidents didn’t result in injuries. “There were 38 accidents (22 percent) with minor injuries, 17 (10 percent) with serious injuries, and 28 accidents (16 percent) that resulted in fatal injuries,” the report continues. The bottom line: of the 174 accident helicopters, there were a total of 373 people on board at the time of the accident with a total of 48 fatalities, or 12.9 percent. Reviewing the statistics, HAI’s Zuccaro noted that “66–75 percent” of the accidents that occurred in 2001 were caused by “human factors.” But he was quick to point out that human factors are not a synonym for ‘pilot error’. Although that is a part of the mix, other elements such as pilot workload, aircraft design, inadequate training for the missions required and technological shortfalls were also to blame.

“We’re not pointing our fingers at pilots,” he said. “They’re just one factor.” In particular, Zuccaro said that many aircraft feature designs that require pilots to do too much. He also chastised managers who send their pilots on night missions without proper tools such as night vision goggles. Still, of the various Standard Problem Statements (SPS) the U.S. JHSAT used to classify accident causes in its CY2001 report, “The SPS, pilot judgment and actions, dominated the problems, appearing in over 80 percent of the accidents analyzed.”

Details in the U.S. JHSAT Report The JHSAT CY2001 accident report is exhaustive in its specification, examination and recommendations aimed at remedying specific types of helicopter accidents. For instance, 65 (37 percent) of the 174 accidents were a result of an improperly executed autorotative landing, the report states. “The most common characteristic of these accidents is that all occurred in visual meteorological conditions (VMC) with 59 (91 percent) of the 65 occurring during daylight hours.” JHSAT concluded that human error on the part of the pilot was the leading cause of autorotation accidents. “Human error accounts for 251 (64 percent) of the 389 autorotation-related SPSs. Pilot judgment and actions were cited 138 times (35 percent). So what should be done to combat autorotation errors? Pilots should be trained to safely execute autorotations in flight simulators. But that’s not all: Pilots need to develop better autorotation skills during initial and recurrent training; they and their CFIs need better decision-making skills, and operators should establish standard operating procedures (SOPs) “for specific missions and environments” to reduce the chances of autorotations taking place. And when the worst does occur? Hopefully, operators will have already installed flight information recorders in their helicopters “in order to improve the quality of accident investigations,” the report states.
SPS Group (Level 1) Count of All Count of Accidents % of Accidents
Pilot Judgment & Actions 311 147 84.5%
Data Issues 190 139 79.9%
Safety Management 110 79 45.4%
Pilot Situation Awareness 82 64 36.8%
Ground Duties 79 65 37.4%
Mission Risk 63 50 28.7%
Part/System Failure 61 43 24.7%
Maintenance 48 29 16.7%
Post-Crash Survival 35 25 14.4%
Communications 19 16 9.2%
Regulatory 17 17 9.8%
Safety Systems & Equip 12 12 6.9%
Infrastructure 10 10 5.7%
Personnel – Non Crew 7 7 4.0%
IR (Level 1) Count of All Count of Accidents % of Accidents
Training/Instructional 339 139 79.9%
Safety Management 225 114 65.5%
Data/Information 209 143 82.2%
Systems and Equipment 102 66 37.9%
No Recommendation 71 71 40.8%
Regulatory 34 31 17.8%
Maintenance 85 29 16.7%
Infrastructure 18 16 9.2%
Source: US JHSAT CY2001 report

“The dominance of pilot judgment and actions factors is similar to the conclusions of previous studies,” the report states. “The pilot is the last link in the chain of events leading to an accident. He or she is the only one who can affect the outcome once the sequence of event problems has started. If the pilot’s judgment and actions in response to problems, whether pilot-initiated or not, can be improved, there is the potential for more than 80 percent of the accidents to be mitigated, either prevented entirely or reduced from fatal to minor injury.”

The actual breakdown of SPS categories and how they relate to CY2001 accidents is shown in the top chart above. However, of the many SPS examples cited, the pilot judgment and actions SPS is the most used; the second is safety management, with pilot situational awareness third. These three account for nearly a third of all SPSs used, according to the report. Having compiled this data, the US JHSAT has been able to come up with 1,083 fact-based intervention recommendations (IRs). (See chart.)

Of the Top 20 intervention recommendations the report emphasizes, nine are directly related to training. For instance, better simulator training is needed for autorotations and advanced maneuvers such as dynamic roll-overs, emergency procedures, loss of tail rotor effectiveness (LTE), and systems faults and operating limitations. That’s not all: JHSAT says a list of typical helicopter pilot errors should be compiled and impressed upon pilots during initial and recurrent training.

JHSAT says some form of “personal risk management program” should be created to give operators and independent pilots “a usable tool to evaluate hazards and associated risks of the flight and pilots’ fitness for flight.” An operational risk management program should also be developed, to evaluate the risks associated with each mission before flight, and a checklist for use while in-flight for guiding risk-based decisions.

The helicopter training industry should also increase certified flight instructor awareness training to include timely recognition of rotor RPM and airspeed variations. For helicopter operators, the JHSAT report says that operators need to monitor their maintenance operations more closely to eliminate the “culture of non-compliance,” boost quality assurance and improve pre-flight inspections. NTSB is also involved in a Top 20 recommendation. JHSAT is calling for NTSB to improve the detail and quality of its work. “Many accidents are not receiving in-depth, onsite investigation by NTSB investigators,” the report states. “Investigations are being performed by telephone interview or by personnel whose primary function is not accident investigation. The investigations need to provide more information on the human aspects of the accident chain, more personnel information, and assess the extent of operator oversight.”

JHSAT will be reviewing the NTSB’s CY2006 accident statistics next, and analyze accidents from 2002 to 2005 to ensure that those accidents are similar to CY2000 and CY2001, or identify where they are not. For Zuccaro, these are important details, but details nonetheless. His eye is on the big prize; namely creating a safety culture where every helicopter accident is treated as a problem to be resolved once and for all. “As an industry standard, we need to focus at zero accidents and aim in that direction,” he told Rotor & Wing. “There is no accident that is acceptable.”

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