They strike, but often cause no major damage to aircraft
Airplane collisions with birds are a danger at any airport, and Logan International Airport is no exception. In 2008, there were 61 recorded collisions between birds and planes at Logan, out of 390,000 flights.
But the vast majority of bird strikes do not cause major damage, much less a crash like the one this week in New York City.
Last year, only one bird strike at Logan caused damage. A bird collided with a departing Jet Blue flight in November, and the plane, which was only slightly damaged, landed safely, officials said.
Logan is particularly vulnerable to strikes because it sits on a migratory bird pathway along Boston Harbor. Efforts are focused on making Logan "as unwelcoming to birds as possible," Edward Freni, director of aviation for the Massachusetts Port Authority, said yesterday. "We don't want to ring the dinner bell for birds."
Thursday's accident in New York - a terrifying spectacle with a happy ending, as all passengers emerged safe - cast a light on a little-known part of airport security and safety, the wildlife team, which is responsible for keeping birds away.
At Logan, wildlife technicians employ a variety of tactics to scare birds off, blaring horns, shooting off propane cannons, using pyrotechnics, and, if necessary, a shotgun.
"In the same way that there's lots of air traffic, there are lots of birds that similarly concentrate," said Wayne Petersen, director of the Important Bird Areas program for the Massachusetts Audubon Society.
"Boston Harbor is a rich bird area. It's definitely a case where you have two completely different communities using it, airplanes and birdlife."
Added Petersen: "Arctic birds see a place like Logan, and they say, 'This is home away from home.' "
The upland sandpiper, a bird on the state's endangered species list, breeds there, Petersen said. Snowy owls are trapped and removed. Peregrine falcons hunt around Logan, and American oystercatchers nest nearby.
All of which makes occasional collisions between birds and aircraft all but inevitable.
"Crashes are very, very, very uncommon, but strikes themselves are fairly common," said John Ostrum, chairman of the Bird Strike Committee-USA, a national group of private industry and federal agencies devoted to reducing wildlife hazards.
"It's no different than hitting bugs with your car," he said. ". . . You hit all kinds of bugs, you use windshield wipers," but occasionally there may be a rock.
The deadliest bird strike collision in the United States occurred at Logan in 1960, when an Eastern Airlines flight collided with a flock of birds shortly after taking off and plunged wing-first into Boston Harbor. There were 72 people aboard, and all but 10 died.
Nationally, more than 219 people died and more than 200 aircraft have been destroyed by accidents related to bird strikes since 1988.
But the number of routine collisions is far higher. Between 1990 and 2007, there were 82,057 wildlife strikes, including porcupines, alligators, turtles, and birds, according to a Federal Aviation Administration report published last June.
Ostrum, who is also manager of airside operations at the Minneapolis-St. Paul International Airport, says it is difficult to quantify which airports are most prone to strikes, because the rate of reporting, as well as habitats, can vary widely. While a place like Logan would be prone to accidents with migratory birds and sea birds, an airport surrounded by farmlands could have a different set of wildlife problems.
Though very few collisions cause serious damage or dramatic crashes, the trend has been on the rise because of the increasing number of wildlife species adapted to living in urban environments and because of increasing air traffic.
Engines are tested to make sure they can withstand bird ingestion, but manufacturers do not affix screens or grilles to the engine intake for several reasons.
"Jet engines are very powerful, and you would not want to risk sucking in a screen; this would be catastrophic," Mary Cummings, who teaches a class at MIT that examines aircraft accidents, said in an e-mail. A screen would also hinder air intake and reduce the efficiency of the engine.
That means airports work vigorously to keep wildlife away. At Logan, officials plant a special type of grass and let it grow long, making it less attractive to birds. Four wildlife technicians patrol the perimeter of the airport, and pilots are regularly warned not only about weather but also about bird activity.
Petersen pointed out that with the number of planes taking off and landing everyday and the small number of incidents, "it's just not something people should worry about."
Bird strikes are as old as aviation itself, with the first recorded bird strike in 1905 by aviation pioneer Orville Wright.
Carolyn Y. Johnson can be reached at cjohnson@globe.com. 