Features Safety & Training Standards & Regulations
NTSB adopts air bag study

Airbags are designed to mitigate head and upper body injuries and are
installed in the lap belt or shoulder harness portions of the restraint
system. They were first approved for use in the pilot and co-pilot
seats in GA aircraft in 2003. Currently, there are nearly 18,000
airbag-equipped seats in over 7,000 of the 224,000 GA aircraft in the
United States.

"Although airbags have been mandated in automobiles for over a
decade, the aviation industry has no such requirement for small
aircraft," said NTSB Chairman Deborah A.P. Hersman. "The good news is
that over 30 manufacturers have stepped up to the plate and offer
airbags as standard or optional equipment."

The study, which examined 88 accidents involving airbag-equipped
airplanes that occurred between 2006 and 2009, found no instances where
the airbag caused harm in properly restrained occupants. In addition,
the study found 10 survivable accidents in which the crash forces were
severe enough to cause injury and/or to deploy the airbag.

Within the group of 10 accidents, 12 occupants experienced airbag
deployments, and the study found that the airbag likely mitigated
injuries for two of the occupants.

The study also noted that there were no negative consequences as a
result of airbag deployments. For instance, there were no cases in which
the airbags were expected to deploy but did not. Nor were there any
cases that involved airbags deploying under unexpected circumstances,
hindering egress, fueling post-crash fires or interfering with rescue
attempts. Yet investigators did uncover some safety issues with
restraint systems.

One such issue involved the incorrect usage or adjustment of seat
belts. In certain aircraft types, the seat belts in the left and right
seats can become reversed, which could result in the wrong airbag being
activated if only one of the seats is occupied.

There were also concerns with optimal airbag protection for occupants
whose body mass indexes (BMI) classified them as either overweight or
obese (BMIs of 25 or higher). The NTSB questions whether the
airbag-equipped restraints were designed and tested with the high-BMI
population in mind.

An additional finding of this study was the strong affirmation that
correctly installed shoulder harness/lap belt combinations provide
significantly greater protection in GA accidents than that offered by a
lap belt alone. Based on an analysis of over 37,000 GA accidents, the
Board concluded that the risk of fatal or serious injury was 50 percent
higher when an occupant was only restrained by a lap belt as compared to
the combination lap belt and shoulder harness.

"The simplest and cheapest improvement to the safety of general
aviation aircraft occupants is the mandatory installation of shoulder
harnesses," said Hersman.

The five-Member Board voted to adopt six safety recommendations, all directed to the Federal Aviation Administration:

1. Require manufacturers to modify restraint systems vulnerable to
   being used incorrectly in newly built GA airplanes and to modify
   restraints in existing airplanes.
2. Revise the guidance and certification standards for restraint systems to reduce the likelihood of misuse.
3. Modify the guidance to GA airbag manufacturers as to how they
   should demonstrate that an airbag design provides adequate protection
   for a greater range of body sizes, including very small and very large
   individuals.
4. Require the retrofitting of shoulder harnesses on all general
   aviation airplanes that are not currently equipped with such restraints.
5. Evaluate the feasibility of requiring airbag-equipped aircraft to
   capture and record crash dynamics data to determine whether the system
   performed as designed.
6. Develop a system to track safety equipment, such as restraint
   systems, airbags, and aircraft parachutes, designed to improve crash
   outcomes.

The complete safety study will be available on the NTSB website in several weeks.