The location of an airport, along with the level of provided protection, can heighten or decrease the chances of a bird air strike, like the two strikes thought to have forced U.S. Airways flight 1549 into New York's Hudson River yesterday, suggest federal officials.
Largely due to the skillful maneuvering of the pilot, who founded his own safety systems firm, all 155 passengers and crew survived Thursday's event. The Airbus 320 is believed to have collided with a flock of geese seconds after takeoff.
The emergency water landing, however, highlights at least three risk factors for bird air strikes that likely will receive more attention in the future. Questions that may be asked include: Do flight paths at particular airports cross with bird migratory paths? Can improved technologies prevent birds from being sucked into engines? Does the airport have a trained biologist present to help mitigate the problem?
“If you look outside your plane window before takeoff and see an individual in a vehicle scanning the runway, there's a good chance he's a biologist monitoring the airport for birds,” USDA spokesman Larry Hawkins told Discovery News.
Hawkins is a member of the federal government's Animal and Plant Health Inspection Service, which performs assessment management plans for airports that then have the option of contracting with them to bring in a biologist and support staff.
California-based Hawkins wasn't certain what level of protection was present at LaGuardia, but he said 323 people nationwide currently meet the requirements necessary to serve as an airport biologist.
“Our prevention tactics include habitat modification, removal of wildlife, if necessary, and hazing,” he said, explaining that hazing can involve everything from setting up brightly colored scarecrow-type balloons that frighten birds to audible scaring. The latter involves “setting off a device that's like a 4th of July screamer-type firecracker” whenever flocks of birds are spotted.
An airport's location can also increase the chances of a bird strike, Hawkins suggests, with airports near water being at greater risk, along with airports that intersect “bird flyways.”
“These are flight paths followed by migrating birds,” he explained. “Some California airports, for example, cross the Pacific Flyway.”
Planes are at greatest risk for a bird strike during takeoffs and landings, since above this “risk zone” they fly higher than birds. According to Bird Strike Committee USA, an organization that strives to reduce bird and other wildlife hazards to aircraft, three types of birds represent 75 percent of all reported bird strikes. These are waterfowl (31 percent), gulls (26 percent) and raptors (18 percent).
“Imagine driving your car and a bee hits your windshield. You may not even notice,” Hawkins said. “If a pigeon collides with your windshield, you may suffer cracked glass. But if you hit a turkey, the entire front grill of your car could be destroyed.”
Bird collisions with aircraft are similar, in that minor strikes occur on a regular basis. It is only when the strike affects passengers, or leads to costly damage, that such events come to light.
“In 2008, a single bird was ingested (sucked into) an airplane engine at LAX,” Hawkins said. “The aircraft landed safely and there were no fatalities, but the damage cost $1.9 million.”
Dale Oderman, associate professor of aviation technology at Purdue University, said that birds sometimes get near a plane engine's intake, which consists of multiple compressor blades. If the bird impact leads to a blade breaking, it can turn a blade into a dangerous piece of shrapnel, potentially causing other damage.
Both Hawkins and Oderman agree that even smaller birds, such as starlings, can damage planes, especially if the aircraft collides with a flock. Bird Strike Committee USA even refers to starlings as “feathered bullets,” since they say these birds possess “a body density 27 percent higher than herring gulls.”
Better technologies are being sought to make plane engines less vulnerable to bird air strikes, but airplane improvements ironically may now be increasing avian/aviator collisions.
“Fan jets are quieter and more efficient,” Hawkins said, “but birds can't hear them as well, so the planes themselves are less of a deterrent.”