Test and Evaluation:
Reducing Risks to Military Aircraft From Bird Collisions
NSIAD-89-127, Jul 13, 1989
Pursuant to a congressional request, GAO reviewed the services': (1) testing of military aircraft to reduce losses and damages resulting from bird collisions; and (2) development and use of nonflammable hydraulic fluid to reduce fire risks.
GAO found that: (1) between 1983 and 1987, military aircraft collided with birds over 16,000 times, causing the loss of 9 aircraft, 6 crew member fatalities, and $318 million in damage; (2) the services' specifications for testing jet engines against bird collisions served as guidance, rather than as requirements, resulting in the services not always requiring testing or using analytical methods which fully tested against known bird hazards; (3) jet engine testing methods did not always reflect the sizes and numbers of birds that could be ingested; (4) the services did not test airframes to identify and minimize vulnerability to bird collisions; (5) military oversight of engine testing against bird collisions was typically limited to monitoring; and (6) little documentation existed to evaluate the effectiveness of tests against bird collisions. GAO also found that: (1) between 1965 and 1986, hydraulic fluid fires during aircraft accidents have caused at least 5 crew member fatalities, 19 injuries, and $237 million in lost aircraft; (2) the Air Force has developed a nonflammable hydraulic fluid that is not compatible with existing aircraft hydraulic systems; and (3) costs of the Air Force's attempts to develop the nonflammable fluid and new components for hydraulic systems exceeded $21 million through September 1988.