As summer fades into fall, birds begin to migrate south to their wintering grounds. That migration means one thing to pilots and airfield managers: a dramatic increase in the risk of bird strikes.
Monthly trends recorded from 1995 - 2010 by the Air Force Safety Center Aviation Safety Division indicate the number of strikes typically increase from about 6,500 in July to more than 9,000 in September and October.
For the period 1995 - 2010, the Air Force reported 64,946 strikes costing a total of more than $527 million, according to Dan Sullivan, the acting chief of the AFSC Bird/Wildlife Aircraft Safety Hazard (BASH) Team. In 2010, 4,723 reported bird strikes resulted in $22.5 million in damages, including $10 million to an F-15E Strike Eagle following engine ingestion of a Black Vulture.
"Flocking birds are especially dangerous," said Ted Wilkens, a BASH Program initiatives specialist, "because that can lead to multiple strikes or impacts."
While large-bodied birds generally create significantly more damage, smaller birds are responsible for the majority of strikes, officials said. For example, perching birds, Horned Larks and American Mourning Doves were responsible for 6,473 strikes between 1995 and 2010, costing the Air Force more than $5.5 million. By comparison, Canada Geese were responsible for 52 strikes, costing more than $80 million.
Most bird strikes occur below 3,000 feet during aircraft initial climbs or airfield approaches, Sullivan said. "Airfield strikes account for about 45 percent of all reported strikes and 50 percent of all damage costs."
As bird populations increase due to adaptation to their surroundings and conservation efforts, so have Air Force efforts expanded to educate aircrews about tracking migratory patterns and activity and to ensure base-level managers maintain robust mitigation programs.
"Better land use management of areas on and adjacent to airfields, improved bird identification processes, use of bird detection radar and easily accessible systems to track migratory activity and report strikes are all valuable tools in reducing the number of incidents," Wilkens said.
Air Force installation safety offices are responsible for managing base-level BASH programs with cross-functional participation. The AFSC BASH Team is available to provide local managers technical assistance in control techniques, habitat management, coordination with outside agencies as well as objective bird strike data analysis.
Article by Darlene Y. Cowsert, Air Force Safety Center