Private, or general aviation, flights are 82 times
riskier than commercial airline trips and represent the
overwhelming majority of aviation crashes and casualties in
the United States. The safety of private flights can and
should be addressed, according to researchers from the
Johns Hopkins Bloomberg
School of Public Health and Johns Hopkins
School of Medicine, who identified major factors
influencing crash involvement and crash survival and
examined possible approaches for improving the safety of
private flights. The commentary is published in the April
11 issue of the Journal of the American Medical
Association.
General aviation includes all noncommercial flights,
such as emergency medical services, sightseeing, flight
training, traffic reporting, aerial surveys, search and
rescue, crop dusting and firefighting, as well as
recreational and business use. General aviation aircraft
range from small private airplanes and business jets to
helicopters, hot-air balloons and gliders.
"Commercial airlines are the safest mode of
transportation, but general aviation is a serious safety
concern. Fatal crash risk per-person-mile of travel for
general aviation flights is comparable to riding
motorcycles," said Guohua Li, lead author of the study and
professor of
emergency medicine at the Johns Hopkins School of
Medicine.
In an examination of the crash risk of private
flights, the researchers found that general aviation
flights averaged 1,685 crashes and 583 deaths each year
from 2002 to 2005, accounting for 91 percent of all
aviation crashes and 94 percent of all aviation deaths.
Small aircraft flying at low altitudes make general
aviation flights especially vulnerable to adverse weather
conditions. For general aviation pilots who have not
obtained an instrument rating, flying out of "see and
avoid" conditions into conditions that require them to fly
using their instruments is the most perilous scenario.
Additional risk factors include pilots flying while
intoxicated, sudden incapacitation (heart attack or other
health issue), older age, being male, having a
nonconformist flying style (e.g., being a daredevil) and
having a prior record of an aviation crash or violation.
Physician pilots are also found to crash at a higher rate
per-flight-hour than other pilots.
Most aviation crashes do not result in fatalities.
However, when crashes occur, aircraft fire is the most
important determinant of survival. Fire is involved in 13
percent of general aviation crashes but contributes to 40
percent of fatalities. Additional negative influences on
crash survival are bad weather, landing at an off-airport
location and failure to use safety restraints. Overall,
about 20 percent of general aviation crashes result in one
or more deaths, compared with 6 percent of commercial
airline crashes. The additional deaths related to general
aviation crashes may be partially explained by the inferior
crashworthiness — the ability to withstand impact
forces and protect occupants from injury — of general
aviation aircraft.
Major airlines have improved the crashworthiness of
their aircraft, but little has been changed in general
aviation, partly because federal regulations that govern
design changes apply only when entirely new aircraft models
are certified. Installation and use of restraint systems
that include airbags could greatly reduce general aviation
deaths, according to the study authors.
Susan P. Baker, co-author of the study and a professor
in the Bloomberg School of Public Health's Department
of Health Policy and Management and Center
for Injury Research and Policy, said, "General aviation
crashes are a public safety problem that needs to be
addressed. The Federal Aviation Administration and National
Transportation Safety Board should prioritize and
financially support interventions to improve safety of
small aircraft."
The Johns Hopkins researchers have published
extensively in the field of aviation safety. Recently, they
reported that post-crash fires, darkness or bad weather
greatly decrease the likelihood of surviving an emergency
medical service helicopter crash. They recommended
improving crashworthiness of EMS helicopters and reducing
trips during hazardous conditions.
Li and Baker co-authored the study, which was
supported by grants from the National Institutes of Health
and the Centers for Disease Control and Prevention.