JOHNS HOPKINS (US)—The number of sightseeing helicopter crashes in Hawaii has dropped by 47 percent since an emergency FAA rule was adopted in 1994 following a spate of accidents. However, a new study finds the remaining crashes have become more deadly.
Researchers from Johns Hopkins University report the proportion of crashes that resulted in lives lost actually increased after the rule change due to an increase in crashes that resulted from poor visibility, which tend to be exceptionally fatal. The report is published in the July issue of Aviation, Space, and Environmental Medicine.
“Our findings indicate that the 1994 rule was followed by a reduction of almost half in the crash rate. On the other hand, crashes that occurred as a result of low visibility—often because of rain, fog, or clouds—increased from 5 percent to 32 percent of all air tour helicopter crashes in the 14 years after the new regulation,” says senior author Wren L. Haaland, a 2009 graduate of Johns Hopkins University who conducted the study as an undergraduate research assistant with the Bloomberg School’s Center for Injury Research and Policy.
The Federal Aviation Administration issued Special Federal Aviation Regulation 71 to establish minimum flight altitudes and clearances from terrain, to emphasize passenger safety precautions, to mandate performance plans prior to each flight, and to require flotation equipment or life preservers on flights beyond the shoreline.
“Our data suggest the FAA should reconsider the rule’s clause that established a minimum flying altitude of 1,500 feet, as we know higher altitudes are associated with more cloud cover,” says Susan P. Baker, the study’s research director and a professor with the Injury Center.
Clouds obscuring mountain peaks and passes are particularly common in Hawaii. The Hawaii Helicopter Operators Association appealed the rule on the basis that the 1,500-feet above-ground-level minimum flying altitude would lead to crashes due to the prevalence of clouds at or above that altitude. The appeal was rejected by the U.S. Ninth Circuit Court of Appeals.
The research team analyzed data collected from the National Transportation Safety Board’s Aviation Accident Database, identifying 59 crashes of helicopter air tour flights in Hawaii from 1981 through 2008. Crashes in 1995 to 2008 were compared with those in 1981 to 1994. The greatest decreases occurred in crashes into the ocean, crashes not involving malfunctions, and nonfatal crashes. Aircraft malfunctions were the most common precipitating factor throughout the study period, occurring at similar frequencies pre- and post-regulations. The most common malfunction was loss of power, most often caused by improper maintenance. Forty-six tourists and nine pilots died in 16 fatal crashes during the 28-year study period.
“The persistence of mechanical problems and malfunctions is noteworthy, since they were related to the majority of crashes and not addressed by the FAA’s 1994 rule,” says Dennis F. Shanahan, a coauthor of the study. “This is an oversight, as many of these problems could be prevented through better mechanic training, closer FAA oversight, and increased emphasis from management on proper and thorough maintenance procedures. Helicopter tourism is popular in other areas such as Alaska and the Grand Canyon, and every precaution should be taken to save lives.”
The research was funded by grants from the Centers for Disease Control and Prevention to the Johns Hopkins Center for Injury Research and Policy.
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