Why we can't stop birds downing aircraft

http://www.newscientist.com/article/dn16438-comment-why-we-cant-stop-birds-downing-aircraft.html?DCMP=OTC-rss&nsref=online-news

by alexandros • 18 years ago

24 53 18 years ago

newscientist.com

biohacker422• 18 years ago

I recall very, very old news footage of raptor eye like structures being attached to jet engines.

I guess those didn't work.

What about doing a good job of keeping the airports and areas around them free or large flocks?

How much would it cost to have trained hawks patrol the area.

NY already has wild raptors living in the city.

mattmaroon2• 18 years ago

I don't think the problem are flocks of large geese living in the area, it's them migrating through. Hawks probably couldn't solve that problem, and if you have any ideas as to how to keep Canada Geese away, you should consider doing it as a startup. They're a common pest in my area of the country.

biohacker422• 18 years ago

That's actually a good idea.

I bet even migrating flocks would scatter if a raptor buzzes them.

So perhaps I should get into falconry and charge airports to have my falcon fly through any migrating flocks.

It would be almost like being a super villain.

mindviews• 18 years ago

I know of some folks in NYC who do this for a living - they use trained dogs to scare flocks of geese away from parks, courtyards, etc. Mostly for "aesthetic" reasons (read: geese poop a lot). I'm not sure how long the geese stay away after, though. In any event, it's full time work and they get to play with dogs all day. Not bad, eh?

dag2• 18 years ago

Big money there, definitely. They're a common pest in every area I've been in Canada.

josefresco• 18 years ago

Logan has a staff of people with shotguns to scare away flocks/birds. All bird sightings are reported to the tower and to pilots of incoming aircraft.

laut• 18 years ago

At the CPH airport they shoot more than a thousand birds a year.

If there was a hawk, could you be sure that it would stay out of the way of the aircraft? The hawk itself would be a risk of bird strike.

oconnor0• 18 years ago

Sure, but a hit from single bird is supposed to be survivable. A hit from a flock of birds isn't.

daniel-cussen• 18 years ago

You could train crows to mob the geese.

nuclear_eclipse• 18 years ago

"Interestingly, the Smithsonian Institution's Feather Identification Laboratory has worked out which species causes the most costly birdstrike damage. It's the turkey vulture - the bird that originally inspired the Wright brothers."

Irony strikes again!

yan2• 18 years ago

Irony is coincidentally the name of the turkey vulture.

ryanwaggoner2• 18 years ago

Why don't we just outfit aircraft with a miniature Phalanx system that calculates the trajectory of an incoming bird and the probability of an engine strike and then fires up a Gatling gun to neutralize the threat :)

http://en.wikipedia.org/wiki/Phalanx_CIWS

In all seriousness, I wonder if some kind of laser-based defense system could be used as a last resort.

jm42• 18 years ago

I'd say it's a ways off considering how many years they've spent trying to shoot down much larger missiles with lasers. A missile moves much faster than a bird, but the small size of a bird is going to make it extremely difficult. There's also the issue of how to deal with a flock of birds. This, of course, is assuming you've figured out how to cost-effectively equip hundreds of passenger jets with lasers and the necessary tracking systems given the space constraints. I understand power is also an issue when shooting down missiles. I'm not sure how significantly this requirement is reduced when shooting down birds.

There's also the issue of using a weapon over heavily populated areas and at low altitude. Shooting down a missile will probably take place at high altitude. It's also possible, or even likely, that it will take place over a sparsely populated area or war zone. It could even be over an ocean. The laser might even be fired upwards. If you're shooting down birds from a plane there's a good chance you're going to be firing a laser outward or downward. What if you miss and start blasting holes through nearby buildings?

Bird strikes tend to be a problem most often during takeoff and landing-- usually at either end of the runway. Planes gain altitude so quickly that it's rarely a problem outside of a couple short windows as the plane is approaching or leaving the runway area. I remember reading about an airport with an especially bad bird problem that had success using dogs to keep birds away from the runways.

I think there is a simple solution to this. It might even be possible to put plants or grass around the runway that birds don't like. What about something with thorns that will be difficult for a bird to perch on? Or maybe something with a particular scent that birds will stay away from?

dag2• 18 years ago

I suggest using predator birds and (directable) loud noise, either high-pitched or predator birdcalls.

rtra2• 18 years ago

Yes, it would probably be too costly, require too much energy, and would not effectively neutralize flocks. I wonder if a small cannon wouldn't be acceptable.

mechanical_fish• 18 years ago

This should do wonders for property values near airports. ;)

Eliezer• 18 years ago

How about air-to-bird missiles?

bd• 18 years ago

You could crowd source the targeting - make it arcade game for passengers. Winners get frequent flyer points.

bprater• 18 years ago

Cool, I was wondering that exact thing yesterday: why no jet engine grill? Not all engineering problems are solvable! (Or should be solved.)

ryanwaggoner2• 18 years ago

I wonder if anyone has looked at doing a cone-shaped grill that extends forward some distance beyond the front of the engine. It would look goofy as hell, but it would only have to be strong enough to survive a glancing impact, rather than a direct hit like a flat grill. Air resistance might be an issue though...

ph0rque• 18 years ago

I was just thinking about that same thing.

pmjordan• 18 years ago

I think that sort of geometry would encourage the air to flow around the engine, reducing pressure & density of the air actually propelling the aircraft. This would seriously impact the efficiency of the engines, and I suspect this is what the article is referring to. A flat grille would be crazy as it would just collect the birds, held in place by the extreme pressure conditions.

anewaccountname• 18 years ago

Are we playing 20 questions or something? Just come out with it; the name you are looking for is cow catcher.

aeroevan• 18 years ago

Aerodynamics and weight. Both are very important for all aerospace vehicles. Something like that would also decrease engine efficiency.

Supersonic aircraft engines usually have an aerospike, which could impale a bird... that would be a bloody sight.

sokoloff5• 18 years ago

I wonder if selectable inertial separator would work on turbofans. (They are installed on single-engine PT-6 turboprops.) Imagine a system that requires air to make a sharp turn, but anything with significant mass (water, ice, birds) would pass through, or get ground up against something other fan blades. I couldn't find a good diagram online.

You would want them to be selectable (engaged during low-altitude flight, stowed during cruise flight) so as to hopefully not unduly hurt range, other than via the increased weight.

The problem though is that there are significant one-engine-out climb performance targets that must be met for Part 21 certification, and inertial separators have power penalties on top of the weight penalty. Taking performance away from a one-engine-out scenario would further restrict max take-off weights, increase balanced field lengths (meaning some airports would need to make improvements to serve some aircraft, etc), increase the time from roll to V1 (the takeoff commit speed) and at the end of the day, taking performance away may represent a higher risk than birds currently represent.

In 700 hours or so of single-engine piston flight, I've struck two (small) birds, and had close calls with half-dozen more. I've never had a close call with a bird over 2000 feet AGL, so cruise flight could surely be done without brid protection.

stcredzero3• 18 years ago

Taking performance away also directly impacts the bottom line of airlines and airplane manufacturers, so highly unlikely.

sokoloff5• 18 years ago

So does dunking a $60mm jet in the Hudson River. :)

thomasmallen• 18 years ago

If I were any kind of ornithologist, I'd devise a sensory device (human-inaudible sound, most likely) that would frighten the birds away, possible via mimicry of a predator.

Note that this is an excerpt of a comment I made on the news article page.

spolsky• 18 years ago

they do this at JFK all the time

amichail• 18 years ago

I thought the a380 has flexible engine blades that bend temporarily upon a bird strike. I wonder if its engines would have shut down with a similar bird strike as the one that occurred yesterday.

endtime• 18 years ago

>International Civil Aviation Organisation regulations say that jet engines must be able to ingest a small bird without problems. But for large birds, the rules say only that the engine must not explode.

This is probably the best passage I've read all week.

furyg3• 18 years ago

Do we need to list all the contingencies when an engine must not explode? Can't that be just a general requirement of engines?

Edit: On second thought, I suppose jet engines are generally in a constant state of exploding. Maybe the rule should be "Upon ingestion of a large bird, keep exploding".

paul7986• 18 years ago

This makes me extremely weary of flying, as you can deter birds on take off through sound deterrents on the ground, but not while in the sky. Birds may have even become conditioned to the sound of our noisy flight, thus not deterring them away from airplanes.

There is a entrepreneurial/engineer solution needed here! They rule out adding grilles due to fuel inefficiency, but what about rigging airplanes with the sound deterrents used on the ground - bird radar triggers these sounds? Just a thought...they'd probably have to be crazy insane loud.

I hope someone creates a solution soon! I dont want to land my next flight in the Hudson (chances are slim but still)!

yan2• 18 years ago

Talk about misplacing your fears.. Airplanes typically cruise at around 33,000 feet; there are no birds that high. All bird-related accidents happen upon take-off and landing, but even then they are barely a threat. The numbers I heard, in the last twenty years or so, there have been about two hundred deaths world-wide due to birds colliding with airplanes and I'm not sure what percentage of that is for commercial airliners versus general aviation. Birds hitting airplanes is probably the least-likely way you can perish.

I'll even bet $5,000 of my own money that neither you, nor anyone you personally know will be killed by a bird colliding with an aircraft, ever.

tome• 18 years ago

I'll take that bet, please.

raamdev• 18 years ago

I don't know much about the engineering stuff behind this, but if fuel inefficiency is the only real reason they don't want to add grills, then why not have a mechanical system that removes the grill after they pass a particular altitude (where flocks of birds don't exist) and then add the grill again for landing?

ivankirigin• 18 years ago

The US and Israelis are working on lasers to take out mortars. They are radar based, which would make hitting birds harder. But a vision system tied to the lasers could probably drop a bird before it gets sucked into the turbines.

Why we can't stop birds downing aircraft

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