BOSTON – Birds like those believed to have crippled a US Airways jetliner in New York have been a danger to aviation since the days of Orville and Wilbur Wright, so airports use everything from hawks and snarling dogs to screaming fireworks and shotguns to kill or scare off the intruders.
Federal aviation officials require airports to have programs to prevent collisions between birds and planes.
"It gets as simple as banging pots and pans and getting out of your vehicle to just shoo them away," said John Ostrom, a Minneapolis airport executive and chairman of the Bird Strike Committee-USA, a volunteer group of airline, government and wildlife experts formed in 1991 to share information.
The airport in Fort Myers, Fla., lets a border collie roam its turf. In Orlando, Fla., airport officials strain fish out of stormwater runoff pools to eliminate a food source for birds. At the Sea-Tac Airport in Washington, officials have filled a pond with black floating balls to discourage waterfowl. They also developed a grass seed mix containing a fungus that makes it less appetizing to some birds and insects.
Airports also routinely keep the grass cut short to make their grounds less attractive to wildlife.
At Boston's Logan Airport and many other U.S. airports, they startle birds with propane cannons or other noisemakers.
When that doesn't work, marksmen pull out a shotgun and kill birds — sometimes to the chagrin of conservationists.
In 2007, California officials stopped killing birds with shotguns at the Sacramento airport over concerns the practice violated state wildlife protection laws. The airport last week gained temporary permission to kill birds as a last resort until state law can be changed, said Hardy Acree, director of the Sacramento Airport System.
"We exist in an area that is rich in habitat, so it's always a delicate balance between managing the safety of the public with the habitat that we're part of," he said.
The agency that operates New York City's major airports said it has a multimillion- dollar program to chase birds off its property, but can only do so much to protect planes once they are in the air.
The Port Authority of New York and New Jersey said it kills thousands of birds every year in the marshes and tidal flats around its two major airports in Queens, and uses guns, pyrotechnics and hunting hawks to drive away seagulls and other birds.
The work has special meaning in Boston. In 1960, an Eastern Airlines plane crashed into Boston Harbor after hitting a flock of starlings on takeoff from Logan, killing 62 people. It remains the deadliest bird-collision accident in U.S. history and was a catalyst for the modern-day collision-avoidance and engine improvement programs.
"We try to make the airfield as unwelcoming to birds as possible," said Edward Freni, aviation director for the Massachusetts Port Authority, which runs Logan. "We don't want to ring the dinner bell for birds."
From 1990 to 2007, there were nearly 80,000 reported incidents of birds striking nonmilitary aircraft, or about one collision for every 10,000 flights, according to the Federal Aviation Administration and the Department of Agriculture.
Alexis Higgins, a spokeswoman for the Tulsa, Okla., airport, said Thursday's crash reinforces the importance of keeping birds away from runways.
"If anything, it brings awareness to the public," Higgins said. "For instance, when we are out using pyrotechnics to scare birds, that could startle passengers and they don't always understand what we are doing."
Birds can get sucked into jet engines, wrecking them, or can crash through cockpit windows. The FAA requires airliners to withstand collisions with birds weighing as much as 8 pounds at particularly vulnerable points along the aircraft.
The plane that ditched in New York's Hudson River on Thursday was powered by two CFM engines certified to withstand sucking in five 1.5-pound birds or a single 4-pound bird. Jet engines are tested with freshly killed birds or a gelatin substitute with similar properties.
The Wright brothers learned the risk of a bird strike in 1905, according to their diaries. The men who built the first airplane wrote of flying four loops in Dayton, Ohio — twice over a cornfield — and hitting a bird with the top wing of their biplane.
Today the Navy, Marine Corps and Air Force have BASH, or Bird Aircraft Strike Hazard, programs. Their importance was underscored after 24 people were killed in the 1995 crash of an Air Force plane whose engines sucked in several Canada geese shortly after takeoff from Elmendorf Air Force Base in Alaska.
Military pilots are especially vulnerable because they often fly in clusters, practice low-level flying and make repeated takeoffs and landings that mimic the precision approach to aircraft carriers.
The lesson the armed forces have learned is to constantly reevaluate their tactics, said Matthew Klope, a biologist at the Whidbey Island Naval Air Station in Washington who helps administer the BASH program. Collies may work against waterfowl but not raptors, he said, while noisemakers scare away wildlife for only a limited period.
"You have to change your toolbox constantly," Klope said. "It's up to the biologist on the base to change that recipe. And the specifics of birds change with migration, so you have to change your techniques as the seasons change."