For Airplane Safety, Trying To Keep Birds From Planes 368
The Narrative Fallacy writes "Every year pilots in the US report more than 5,000 bird strikes, which cause at least $400 million in damage to commercial and military aircraft. Now safety hearings are beginning on the crash of US Airways Flight 1549, where a flock of eight-pound geese apparently brought down a plane, plunging it and 155 people into the frigid waters of the Hudson River. Despite having experimented with everything from electromagnetics to ultrasonic devices to scarecrows, the Federal Aviation Administration (FAA) has yet to endorse a single solution that will keep birds out of the path of an oncoming aircraft." (More below.)
"The best bet right now is understanding bird behavior, although an intriguing old pilots' tale — that radar can scatter birds — may carry enough truth to ultimately offer a viable technical solution to a deadly problem. 'We need to find out, is that an urban legend or is there some truth to that?' says Robert L. Sumwalt, the vice chairman of the National Transportation Safety Board. The Federal Aviation Administration already has an extensive program in place for 'wildlife hazard mitigation,' but it seems ill suited to the problem that faced the US Airways flight, which struck geese five miles from the runway — too far for the New York airports to take action — at an altitude of 2,900 feet — too high for radars being installed around the country to detect birds. 'There's no silver bullet,' says Richard Dolbeer, a wildlife biologist and expert on bird strikes. 'There's no magic chemical you can spray or sound you can project that is going to scare the birds away.'"
Re:Falcons (Score:3, Informative)
Re:Airbus (Score:3, Informative)
Bull-fucking-shit.
Re:Shoot them (Score:5, Informative)
I wasn't talking about 1549, just general idiocy of establishing "Federally protected wetlands" in drainage basins for the airfield itself, for example.
Like in case of Detroit Metro Airport's runway 9R-27L, almost directly across Middlebelt Rd. from a 650m x 415m wetland/flood basin. Notice all the vegetation.
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Detroit+Metro+Airport+runway+9R-27L&sll=37.579413,-95.712891&sspn=33.830346,56.162109&ie=UTF8&cd=1&ll=42.202423,-83.326921&spn=0.015546,0.027423&t=k&z=15 [google.com]
Scroll north to see more wetlands. Quoting one buddy: Catch a pic at the right time of day, to be determined by the frickin' birds, and there's hundreds/thousands of waterfowl on that thing or browsing the surrounding fields...some of which are directly under the flight path.
This is the same airport that claims it has no deer within the fence, so therefore no danger of deer on the runway, but drive by the sound abatement berms on the south end early some morning and you'll see herds of them at the edge of the woods. There's a 12+ foot fence the airport managers say keeps 'em out, but no one bothered to tell the deer that.
Or look at main Cyprus airfield
http://maps.google.com/maps?hl=en&ie=UTF8&ll=34.879876,33.620825&spn=0.050133,0.061197&t=h&z=14 [google.com]
just to the north-west was a large salt lake and all around were about half-a-dozen smaller salt lakes. These mostly dry up in summer (except for a couple of small ones) but are in various degrees of wetness during the winter, when they are the predilected home for thousands of wading birds, from the size of a moorhen up to swans and flamingos. They are also internationally recognised and protected nature reserves. It is a common sight in winter to see flocks of hundreds of flamingos transiting between the lakes, right across the flight paths of the aircraft and they aren't the size of a sparrow, either. Aircraft are often sitting on the end of the runway waiting for clearance for takeoff while "hostile" birds bugger off. Bird strikes are common in winter with perhaps 2 or 3/year requiring aircraft to return after takeoff either because of engine failure (rare), Pitot tubes spearing birds, cockpit glass cracked, control surfaces damaged, flaps unable to close etc. So far, no major accidents have occurred but it is a catastrophe waiting to happen.
The white areas are dried salt lakes and the greenish-grey and blue-green areas are wet ones. As you can see, the runway has lakes a few metres from it, on either side!
Re:Fly Around Them (Score:2, Informative)
Just to pick a nick, that jet was not going anywhere near 600 mph during climb just 5 miles downrange from the airport. Usually once a jet reaches that speed they're at cruising altitude above the altitude at which almost any bird ever flies. Another nick is they usually cruise much closer to 500 mph, not 600 mph (the latter being about 91% of the speed of sound at cruising altitude, way too fast for any commercial airliner currently flying).
Still, even at the speed it was probably traveling at (perhaps 200-250 mph) it still would be difficult if not impossible to see the birds quickly enough to avoid them.
Re:Shoot them (Score:5, Informative)
I worked on an airport, years ago. At various places around the graded area, we had propane-powered noisemakers that would let off a gunshot-like sound every few minutes. Unfortunately, the birds became accustomed to the sound. The seagulls would still scatter, but only for half a minute. The ravens would merely flutter their feathers and continue doing what they were doing.
Other bird hazard tools included a starter pistol, a pickup truck (to scare them a little more directly), and a rifle.
Then again, this was a very small airport, so the more direct measures were only needed on the occasion that a plane was actually taking off or landing. And, of course, these measures would not have done anything for the Hudson incident, which happened far from the airport.
Re:It's simple (Score:4, Informative)
I like your idea. The issues come into play when you start screwing around with air flow into the engine. I am not sure you could treat it like a turboprop engine. Turbo props use 100% of the air they intake for combustion or whatever bleed air takes their are whereas in a large turbo-fan bypass ratios are starting to hit 11 to 1 and over, interrupting air flow into the engine could give a drastic and very sudden reduction in thrust.
A lot of TurboProp engines use centrifugal rather then axial compressors or a combination of both making air intake much less critical.
You have no idea how fast this comes up. (Score:4, Informative)
Re:Fly Around Them (Score:3, Informative)
The speed of sound changes with pressure and temperature, unless you consider cruising altitude sea level. The speed of sound at FL35 is 660 mph (http://en.wikipedia.org/wiki/Speed_of_sound). 600 mph / 660 mph = 0.909. 660 mph * 0.78 = 514.8 mph (closer to 500 mph than 600 mph as I claimed). Happy now?
I was trained in aerospace engineering, not English, although in this case I blame dyslexia :P.