Just watched this show on terrible plane landings. Featured the Hudson landing which resulted from the jet flying into a flock of gulls.  My question is, why don’t they just put high strength conical screens of some sort in front of the engine inlets?  Air gets through, but birds bounce off to the side.  Just seems so utterly obvious.

The air is coming sufficiently fast that all you could hope for from a “screen” (it’d have to be something very solid and substantial to withstand the thrust) is that it would dice up the bird before the carcass reached the fins. But even then you would still have the same mass of bird in the engine.

Also, I’m sure such screens would significantly reduce the efficiency of the engines. (Basically they’d act like baffles). If they were far enough out to be thin screens, they would cause an enormous amount of drag.

The main reason they wouldn’t do such a thing is that bird strikes are so uncommon, and most of them are survivable. What made the Hudson plane so unusual is that birds struck both engines at the same time while the plane was still too low to do a restart. How many times has that happened in history? I’m pretty sure the cost/benefit in this case would be prohibitive.

Ya that makes sense. The situations I saw in this show were when the plane hadn’t even left the runway, so it seems like the speed wouldn’t be that much yet.  Even if it was something retractable after take off, you’d think they’d address it.  Cost-benefit like you said is probably the main factor (although it seems the benefit of saving lives would be pretty high ).

CuthbertJ - 11 October 2012 10:44 AM

(although it seems the benefit of saving lives would be pretty high ).

Well ... that’s always what people say when they want to do something to increase safety or security. Think of the one terrorist that could get through and kill everyone!

Problem is that every dollar you make plane transport more expensive, you make more people decide to drive, and that also causes excess fatalities. Driving is significantly more dangerous than flying. So any decision on safety really is a tradeoff, and it’s generally not a good idea to allow freak accidents to drive design decisions.

On this matter, I recall hearing that all the excess security precautions instituted in airports after 9/11 have caused significantly more traffic fatalities than actually died on 9/11.