Aluminum birds and those of the feathered variety just don’t mix. In July, images circulating on the Internet provided a head-on look at a massive hole in a United Airlines Boeing 737 nose. What caused this gash? Flight 1475 had collided with a bird during its descent to Denver International Airport. The aircraft with 151 people onboard landed safely but the event served as a reminder that the public, government and industry cannot relax bird/wildlife strike mitigation efforts.
In January 2009, US Airways Flight 1549’s collision with Canada geese on climbout from New York LaGuardia Airport first heightened awareness of the hazards of strikes. “Hit birds. We’ve lost thrust on both engines,” came the chilling words from the cockpit. The flight crew glided the Airbus A320-200 to a controlled ditching on the Hudson River without causing a single fatality among the 155 people onboard.
But not all strikes have such happy endings. Since 1975, birdstrikes have been a “significant” factor in major accidents involving nine airlines, and since 1988, have caused the deaths of 221 people worldwide, according to Bird Strike Committee-USA data.
The Bird Strike Committee USA met Aug. 13-16 in Memphis, Tenn. The annual meeting gathers together wildlife experts and airport officials from the United States, Canada and abroad. The committee, formed in 1991, like similarly named organizations worldwide, aims to share strike information, reduce wildlife hazards and find ways to best manage wildlife while protecting the environment. FAA is co-sponsor of the committee.
Damages from bird and wildlife strikes — such as fan blade and hull repairs are staggering. Bird/wildlife strikes have cost U.S. civil aviation more than $650 million per year in the 1990-2011 period.
Reference to “other wildlife” strikes can mean collisions with animals in the airport environment. From 1990-2011, 1,000 civil aircraft collisions with deer and 375 with coyotes were reported in the United States. According to Birdstrike.org data, from 1990-2011, 460 different species of birds and 37 species of terrestrial animals were involved in strikes that occurred in the United States.
In 2009, FAA made its National Wildlife Strike Database available to the public (http://wildlife.faa.gov). Reports can be made either online or from personal data devices. The site provides guidance on handling and reporting strikes, and offers wildlife resources and mining from 94 fields of data, including the type of aircraft, engine type, bird and airline involved in the strike, as well as the extent of damage.
In 2009, 9,539 strikes were reported; in 2010, 9,919 and in 2011, 10,090. The U.S. Air Force reported 4,500 bird strikes in 2011. Most of the strikes occur when aircraft are operating at altitudes less than 500 feet.
The hazards are increasing due to conservation and environmental programs in North America, as well as the growth of bird populations. Birdstrike.org notes that non-migratory Canada geese, for example, have quadrupled their number in 1985-2008, from 1 million to more than 3.5 million. And the cormorant population on the Great Lakes has increased 1,000-fold, from 200 nesting adults in 1970 to more than 100,000 in 2011.
Commercial jet aircraft (hulls) are built to withstand impact with a 4-pound bird and continue flying even if substantial damage occurs and if one engine has to be shut down, according to Birdstrike.org. The problem is about 36 species of birds in North America weigh more than 4 pounds and travel in flocks. As for powerplants, bird ingestion certification standards vary with engine type. Look what happened to US Airways Flight 1549 — both engines sustained hits from multiple Canada geese weighing 6 to 10 pounds beyond the size the engine was designed to handle. FAA noted the GE CFM56-5 engines met single-birdstrike criteria: the engines closed down safety after ingesting one 4-pound bird.
Civil aviation authorities, airport and wildlife management employ several mitigation strategies. Bird radar technologies, such as those offered by Panama City, Fla.-based DeTect, provide bird alerts to airports, which in turn broadcast information to pilots. Studies using on-aircraft technologies indicate that birds are frightened away by flashing aircraft lights.
Another “scare” tactic is to make the environment unattractive to birds. For example, spikes were installed on New York Long Island’s North Shore Marine Transfer Station to discourage birds from “landing” there. The station is located about 2,000 ft. from LaGuardia airport’s Runway 31 and has engendered blistering controversy.
Supporters of the station, which is scheduled to open next year, claim the waste will be transferred from trucks to containers in an enclosed area. FAA has claimed the station would not create a bird strike hazard.
Opponents of the transfer station, including advocacy group Friends of LaGuardia Airport and Flight 1549 Capt. Chesley “Sully” Sullenberger, claimed the garbage will attract birds and increase the risk of strikes.
Culling of bird populations is usually a last resort. According to Birdstrike.org, 90 percent of all strikes in the United States are by species protected under the Migratory Bird Treaty. In early July, the U.S. Department of Agriculture culled more than 700 Canada geese from the Jamaica Bay Wildlife Refuge and bird sanctuary near New York JFK International Airport. Government officials claimed the birds were a hazard to aircraft operating at JFK and nearby LaGuardia.
So let’s keep working to strike out bird/wildlife strikes, and do it safely and humanely.
Frances Fiorino, a Washington D.C.-based freelance writer, has more than 20 years’ experience as an aviation journalist with major publications. She holds a private pilot license and covers air safety and simulation/training issues in the transport and general aviation sectors.