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PARIS (AFP) - For centuries man dreamt of flying like a bird - but for the pilots of planes like the Airbus that crashed into New York's Hudson River, birds can be the enemy.
Since 1988, more than 200 people have been killed in air accidents caused by bird strikes and the US Air Force reported 5,000 collisions in 2007 alone, according to the US air safety committee that tracks them.
Between 1912, when man was first taking to the skies in wire and canvas contraptions, and last year, when the A380 super jumbo lumbered skywards, 90 civilian planes have been lost to birds, French aviation officials say.
Thursday's US Airways crash has been blamed on geese, but birds of all sizes have been known to be sucked into jets, smash through cockpit windows or damage vital avionics in fast moving aircraft.
"The inside of a turbine engine is like a large blender. If you throw a bird or flock of birds into it, it will disintegrate the birds," said Joy Finnegan, editor of Aviation Maintenance magazine.
"But because there's such high speed there will be damage, and if there's enough damage, the blades will loosen and can shred the engine. The engine can be damaged throughout and lose all power."
This appears to have been what happened on Thursday, when the experienced pilot was able through skill and luck to bring the plane down intact onto the water despite losing both engines - a very rare accident.
"There's pretty extensive testing when they certify these engines: they actually throw birds into the engine," said Finnegan. "They all have their standard bird. I've heard they use a frozen turkey."
Prior to this week, the last serious accident was recorded on November 8, last year, when a Ryanair Boeing 737 airliner made an emergency landing in Rome after its engines swallowed a flock of starlings.
Ten of the 172 people on board needed treatment.
On April 2, 2001 an American Airlines Boeing 767 hit a flock of ducks as it left Paris's Charles de Gaulle airport. Weighing a kilo (2.2 pounds) each, the birds punctured the fuselage and burst the cockpit, depressurising the plane.
The jet was forced to circle and return to land.
"Birds are a constant danger, and incidents are quite common," said Patrick Magisson, who pilots an Air France A320. "Whenever we see them near the runway we call for a team to scare them off. It happens a lot."
Most bird strikes come on or shortly after take off or land, when the jets are working their hardest and sucking in lots of air. This is also the most dangerous time for the pilot and passengers.
Modern jets engines have been designed to cope with all but the most powerful of strikes, and teams patrol most airports to drive off large flocks of migrating birds. Some use cannons or falcons to panic them.
Nevertheless, they remain a risk, although some animals can pose a more surprising threat than even a flock of geese.
In July 2005, an Air France A330 airliner landing in the Nigerian city of Port Harcourt with 196 people on board hit a herd of cows. Seven cattle were killed, but the passengers and crew had a lucky escape.
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