The Tech Behind Preventing Airplane Bird Strikes 242
the4thdimension writes "CNN is running an article covering the technology used at Sea-Tac for preventing airplane bird strikes, like the one that occurred weeks ago to the now famous Flight 1549. The hardware used ranges from low-tech pyrotechnics, to netting, to lasers, to avian radar. Using a combination of all these technologies, Sea-Tac believes they save hundreds of thousands of dollars per year in avoiding dangerous bird strikes."
falconers (Score:5, Informative)
This seems to be about that, though I'm not sure if it was the article I saw: http://www.nydailynews.com/ny_local/2009/02/01/2009-02-01_untitled__falcon01m.html [nydailynews.com]
Re:falconers (Score:1, Informative)
This method has been used at the Toronto airport for years.
http://www.gtaa.com/en/news/torontopearson_today/details/7499a896-f358-436e-b3f4-f9fbc69bccb9
Re:What about (Score:5, Informative)
Then you get birds stuck in the titanium chicken wire, and the engine has a good shot of now sucking in both the bird and the chicken wire. On top of that, even if that doesn't happen, you're still seriously impeding air flow into the engine which is needed to make the engine function.
And according to Wikipedia [wikipedia.org] at least, a typical modern jet engine shunts dead bird parts through a bypass rather than through the engine.
Falcons (Score:5, Informative)
Re:Another idea? (Score:3, Informative)
A couple issues with putting a cone over the inlet of a subsonic engine.
1) If you restrict airflow to only entering from the sides, you're going to have massive separation bubbles as that flow has to turn 90 degrees to enter an axial engine. That results in a loss of efficiency and significantly reduces engine performance.
2) The added weight of this would kill the proposal for any aircraft manufacturer out there.
And not to be pedantic, but the inlet and thrust has a lot to do with whether something flies or not. If you can't get sufficient airflow over the wings to begin with your aircraft isn't going to achieve takeoff.
Re:Indiana Jones (Score:2, Informative)
Re:Obligitory Joke (Score:2, Informative)
Re:What about (Score:3, Informative)
Not quite. What they're talking about there is the difference between a turbojet and a turbofan.
People seem to assume that "the engine" is the entire thing you see hanging off the wing. Really, the engine is a fraction of the diameter of what you're seeing - a lot of the rest is plumbing and bypass ducts. The big fan you see on the front does the same job as a propeller, forcing large quantities of air back at relatively low speeds. On a large turbofan engine, the majority of that air will bypass the actual engine and get shunted out the back end. So depending on which part of the fan is hit, you could end up with bird parts going out with the bypass air instead of getting sucked into the engine. That way you just get damage to the fan, which is much safer and a relatively cheap fix. It's not really something that was designed to make bird-strikes less dangerous, though, it's just an inherent property of large turbofans. The bigger your bypass ratio, the more likely it is that the bird bypasses the engine.
Re:Not that hard. (Score:5, Informative)
Re:What about (Score:3, Informative)
Major point they're missing (Score:5, Informative)
The techniques they use are valuable because they reduce the bird density right around the airfield, and having a multi-engine failure like what happened with 1549 had would be MUCH less survivable if it occurred immediately after takeoff.
Re:What about (Score:3, Informative)
You're a bit off here. It is NOT a requirement that an engine survive a bird ingestion, only that it shut down safely, i.e. without any of the fans coming apart. And engines do tend to take some significant damage [wikipedia.org] when they ingest birds.
To make things worse, the tests are done assuming a 4 lb. bird, but Canada Geese like the ones involved in the recent incident average 7-14 lbs.
And the tests aren't actually done with chickens anymore. They use a block of gelatin now; much easier to clean up.
Re:Pointless (Score:5, Informative)
Airlines would love to save gas by going right up to the point where they can cut the engines to idle and then coast in to the airport. But since everyone wants to do that it would create a traffic nightmare. They need a way to line everyone up on the same runway so they can space them out properly. And if it's cloudy, you need a way to make sure you can be lined up on your runway when you come out of the clouds. So they make instrument approaches that use navigation aids on the ground or GPS.
This works well at small airports, but busy ones have too many planes coming in so they make these things called a Standard Terminal Arrival Route (STAR). Everyone flies to one of these routes and then they join up to an instrument approach to land.
Airlines would love nothing more than to save gas by doing exactly what you suggest, and people on the ground would also like to not have airplanes buzzing their house at all hours of the day, but it's not even close to practicable.
Re:What about (Score:5, Informative)
Bird bones are not the concern; they're hollow, lightweight, and brittle. It's the weighty mass of muscle that causes the damage.