Study reveals bird threat to U.S. military helicopters

Rotary-wing aircraft, such as Apache and Chinook helicopters, play vital combat and logistical roles across the U.S. military services, but new research in the Wildlife Society Bulletin reveals how vulnerable these aircraft are to wildlife strikes.

Many types of aircraft are vulnerable to strikes, estimated to cost the aviation industry $1.2 billion worldwide per year; however, to date no assessment of strikes to military rotary-wing aircraft has been conducted.

A research team led by Dr. Brian Washburn from the Wildlife Research Center used records from the Army, Navy, U.S. Air force and the Coast Guard to identify statistical trends in wildlife strikes.

2,511 strikes were identified across the services. While strikes were recorded in almost all states, Florida, New Mexico and Georgia had the highest number of incidents with 617, 204 and 192 respectively.

812 of the records included the type of animals involved, with birds accounting for 91%. The species involved in the collisions varied between services which operate across different habitats. Warblers (16.8%), bats (11..5%), and perching birds (12.0%) were the wildlife groups most commonly struck by the air force, whereas gulls (18.2%), seabirds (14.9%), shorebirds (13.4%), and raptors and vultures (12.6%) were most frequently struck by naval aircraft.

Further analysis revealed that strikes were most common between September and November, which accounted for 41.6% of all strikes. In contrast December and February, claimed 10.4%.

Economically, each strike costs the military between $12,184 and $337,281; however, there is also a human cost. Wildlife strikes resulted in eight injuries and two fatalities from eight identified strikes, each of which occurred during flight operations within the United States.

"This study is part of the first formal evaluation of the impact of wildlife-rotary wing aircraft collisions to be conducted," said Dr. Washburn. "Findings from this research are being used by the U.S. Department of Defense to increase the awareness of this issue, mitigate the problem, and increase the safety of pilots and aircrews."