Post-crash fires, darkness or bad weather greatly
decrease the likelihood of surviving an emergency medical
service helicopter crash, according to a study by
researchers from the Johns Hopkins Bloomberg School of
Public Health's
Center for Injury Research and Policy and the Johns
Hopkins School of Medicine.
Improving crashworthiness of helicopters and reducing
trips during hazardous conditions can decrease EMS
helicopter fatality rates. The study was recently published
online by Annals of Emergency Medicine.
"Crashes of EMS helicopters have increased in recent
years, raising concern for patients as well as pilots,
paramedics and flight nurses," said Susan P. Baker, a
professor in the Bloomberg School's
Department of Health Policy and Management and Center
for Injury Research and Policy. "Our study found that
darkness more than triples the risk of fatalities when EMS
helicopters crash and that bad weather increases the risk
eightfold. Helicopter EMS programs should recognize these
risky conditions and transport patients by air only when
the benefit clearly exceeds the risk of the flight."
The study authors examined National Transportation
Safety Board records of EMS helicopter crashes between Jan.
1, 1983, and April 30, 2005. During the 22-year study
period, 184 occupants died in 182 EMS helicopter crashes. A
majority (77 percent) of crashes occurred when weather
conditions required pilots to fly primarily by referencing
their instruments rather than using outside visual cues. In
darkness, 56 percent of crashes were fatal, as compared
with 24 percent of crashes not in darkness. One in four EMS
helicopters is likely to crash during 15 years of service.
The death rate for EMS flight-crew members is 20 times the
rate of all U.S. workers.
The researchers also found that 76 percent of the
crashes with post-crash fires were fatal. A previous study
by Baker and colleagues, published in the August 2005
edition of Aviation, Space and Environmental Medicine,
revealed that the potential for post-crash fires in
survivable crashes was greater in civilian helicopters than
in their military counterparts because the standards for
civilian fuel systems are not as strict as those for
military helicopters.
According to the authors, additional studies should be
conducted to determine which preventive measures —
such as equipping pilots with night-vision goggles;
reducing night flights by using a protocol to determine
which cases absolutely require helicopter transport; and
using better restraints, energy-absorbing landing gear and
seats and crash-resistant fuel systems — are most
efficient and cost-effective.
Co-authors of the study are Baker, Jurek G. Grabowski,
Robert S. Dodd, Dennis F. Shanahan, Margaret W. Lamb and
Guohua Li.
The study was supported by grants from the Johns
Hopkins Center for Injury Research and Policy, Centers for
Disease Control and Prevention, and National Institutes of
Health.
GO TO