How a Tiny Bird Can Take Down a Massive Plane: What We're Doing to Prevent Crashes
Airplane crashes are very unlikely in the grand scheme of things. And bird strikes that cause airplanes to go down are even less likely. But what causes a massive plane to go down after striking a few birds while a car, for example, can keep going after hitting a bird?
Birds actually fly into airplanes every day without causing damage. In fact, bird strikes usually don't even register as turbulence. But some bird strikes can be deadly; more than 200 people have been killed since 1988 due to airborne collisions with birds.
"There have been instances where birds the size of robins bring a plane down, all the way up to Canada geese," said John Ostrom, who chairs the Bird Strike Committee USA, formed to analyze bird strike data, in an interview with ABC News.
So how does a bird bring down a plane? It isn't from colliding into the side of a plane. Instead, it's largely due to a large bird colliding with an engine.
FFA regulations require that an engine be able to survive the impact of a four-pound bird. In other words, the engine has to be able to be safely shut down without exploding or disintegrating. Unfortunately, while the engine may survive, this doesn't mean it's in perfect working order; and without an engine, a plane is going down one way or another.
For example, on Nov. 10, 2007, a pilot of a Rayanair flight made an emergency landing in Rome after multiple bird strikes killed both engines. It's these multiple bird strikes, in particular, that can be a huge problem. While an engine may survive one bird, a flock of birds is another matter entirely.
There's also the fact that geese can be about eight pounds. This makes it a lot larger than the four pounds that engines are supposed to be able to handle. Even so, it might seem strange that an eight-pound animal can take down something as big as an airplane.
The real issue here is physics. Energy is proportional to mass times velocity squared. This means that the velocity of the aircraft allows for the impact of a bird to generate enough force to cause an engine to malfunction. For example, a bullet is smaller in comparison to a human, but can still cause a lot of damage if it hits the person in the right location with enough velocity.
Airplanes, in particular, speed through the air and several hundred miles per hour. Its engine fan planes are going 3,000 to 4,000 rotations per minute, and the tips of the turbofan blades are at the speed of sound or greater at 700 to 800 mph. This means that when a bird hits it, there's tremendous energy, which can down a plane by causing serious damage to the engine.
Bird strikes are actually on the rise. The Bird Strike Committee USA has found that the number of reported strikes for all aircraft and aircraft types increased 6.2 fold from 1,851 in 1990 to a record 11,399 in 2013. The number of strikes that damaged an aircraft increased from 340 in 1990 to 764 in 2000. Since then, it's declined to 605 in 2013.
Bird strikes are, indeed, a serious issue. And while efforts to bring down excess bird populations may help, the true leader in this particular issue will be new technologies installed in aircraft that may help prevent bird strikes-or create more robust engines.
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