In Jet-Bird Collisions, Planes Rarely Losers

Nov. 11--Two airliners were forced to make emergency landings at Bradley International Airport recently after hitting some birds on takeoff, but the problem of bird strikes in aviation didn't start with the jet age.

It began a century ago with Orville Wright.

It was September 1905, two years after the Wright Brothers first achieved powered flight at Kitty Hawk. Orville was cruising over a cornfield near the family home in Dayton, Ohio, when he reported hitting a bird, said Richard Dolbeer, a federal official who heads a bird strike advisory committee for the Federal Aviation Administration.

Wright was doing circles, chasing the birds, and whacked one, according to his diary. It landed dead on the upper wing.

"It was probably a blackbird," Dolbeer said. "So birds have been interacting with aircraft since the beginning."

These days, however, there are thousands of aircraft in the skies and less open space for birds on the ground. Last year, there were 6,360 reported aircraft-vs.-bird incidents, Dolbeer said.

Almost always, the bird or flock of birds is the loser, although on rare occasions bird strikes have caused catastrophic crashes.

For instance, in 1995, an Air Force AWACS plane taking off from a base in Alaska flew into about 36 geese, some of which jammed both of its engines. The plane crashed about a mile from the runway, killing 24.

A federal report released in May said that during a 15-year span ending in 2004, eight people died in six crashes caused by bird strikes in the United States. The listing covered only civil, or non-military, aviation.

Worldwide, collisions between planes and wildlife have killed more than 194 people and destroyed 163 aircraft since 1988, according to the report, done by the FAA and the wildlife services branch of the Department of Agriculture. Dolbeer said those fatalities are split about evenly between civil and military aviation.

The FAA said more than $300 million annually is lost in the United States to "wildlife strikes," about 98 percent of which involve birds, although collisions have been reported between airplanes and deer, cows, horses, alligators, and even a turtle. Dolbeer estimated that losses top $1 billion worldwide.

On Wednesday, when a few small birds were sucked into the right wing engine of a Delta Air Lines Boeing 737 leaving Bradley, it prompted an emergency landing. Delta replaced some fan blades in the engine and put the plane back into service Thursday.

Federal investigators scraped together a few small bits of blood and feather. It wasn't a Canada goose, said Jenny Dickson, a biologist at the state Department of Environmental Protection. To determine the species, the fragments are being shipped to the Smithsonian Institution in Washington, where identification methods include DNA analysis and feather-structure typing.

"That information will help Bradley airport and wildlife services make decisions about how they want to manage wildlife resources at Bradley in the future," Dickson said.

About a month earlier, a small jet operated by Pinnacle Airlines for Northwest Airlines had a similar problem. It hit some birds while taking off at Bradley, circled the airfield to burn away some fuel, then made a safe landing.

Having two incidents in such a short span surprised airport Administrator Barry Pallanck. Bradley, with its almost 2,400 acres of runways and grassy fields, is lucky, he said. It gets the occasional deer, coyote or flock of starlings, but no persistent aggregations of geese or gulls, Pallanck said.

Air traffic controllers using binoculars watch for passing bird flights, particularly during the spring and fall migrations, and warn inbound pilots. Airport operations staff, who roam the airfield in SUVs, sometimes launch explosives or "whistler shells" to scare away nuisance birds, Pallanck said.

Brainard Airport in Hartford, which Pallanck managed before moving to Bradley several years ago, has a bigger problem with gulls because it lies next to the Connecticut River, he said. But the stakes are lower there because Brainard does not handle about 280 jetliner flights a day the way Bradley does.

That's why the larger airport keeps a regularly updated wildlife management plan, striving to accommodate threatened species, such as the horned lark and savannah sparrow, while discouraging nuisance species.

"We have to cohabitate with the wildlife here, and we do the best we can," Pallanck said. "It's a gentle balance that the airport keeps."

Bert Marien, who retired a few years ago after 37 years with the FAA as a controller and supervisor in the Bradley tower, said that in the fall it is routine for the airport to broadcast a "notice to airmen" warning of migrating birds.

"They can make a mess of an engine," he said, "but most of the time, thank God, it's one engine, and they can fly quite well on one engine." The time of greatest hazard is on takeoff, just at the point at which a plane starts to raise its nose to become airborne, Marien said. If an engine ingests a bird and shuts down, the plane can easily lose control.

But engines are made to be tough. For decades, Pratt & Whitney has tested new engine designs by subjecting them to the sloppy bird-strike test. Store-bought chickens and turkeys are flung into the whirling turbofan blades to ensure that they will not cause a failure.

A rigorous test occurred in the skies over Chicago in October 2004, when an American Airlines MD-80 carrying 112 people encountered a flock of double-crested cormorants at about 3,000 feet. Six of the 5-pound birds were sucked into one Pratt & Whitney JT8D engine, causing a fire. But the plane was able to return to O'Hare International Airport and land safely.

"Fortunately, crashes and loss of life are rare due to bird strikes," Dolbeer said. "And I think that's a tribute to the durability of aircraft today."

>

Loading