Could a large bird bring down a whole Airliner?

Factual Questions
21

Chickens and Gulls are damaging enough it seems, through reading some of the articles posted on this thread. BUt what about a Canada Goose, or a Barnacle Goose? Heaven forbid a Swan gets caught up in an engine. I do believe these birds are rather bulky, in upwards of 20+ pounds. I have to say a 20lb bird ramming into an airliner engine syatem is bound to do damage. Maybe not the carnage we saw today but definitely a signifcant amount of damage.

Also has anyone seen those large flying V’s in the air?? Yes the ones that flap and kackle, those are the ones. In the Jamaca Bay estuary I would assume that is a nice little place to land a large flock for a bit of a drink and graze. I would not completely rule out birds as of yet, but my sense is it is going to turn out to be a missed maintenance or something along those lines. Looks to me like the engines are sitting in various peoples yards and in front of a gas station. Everything is right there in front of them…I sincerley hope it was a bird or such and not a bomb. NO crash is a good one, but after the fact, I’d rather blam a goose than a terrorist bent on carnage.

22

I’d also like to point out that a full-grown Canada Goose or migrating hawk such as are seen in Jamaica Bay this time of year weigh a f*** of a lot more than 4 lbs.

There aren’t many unpopulated areas in which to crash if the pilot was unable to circle. There’s Prospect Park or Greenwood cemetary, but the results of a miss would be pretty steep, since they are both densely populated on all sides. Breezy Point, at the very end of Rockaway, could have been an intentional choice, since alot of it is beach. AP reported:

“Six people, all adults, were reported missing on the ground, the mayor said. Four houses were destroyed, four were seriously damaged,”

I can’t think of anyplace nearby that could absorb a jetliner with the loss of only 8 houses and 6 people on the ground.

23

Cecil Adams on Is a “chicken gun” used to test jet engines?

24

Removing wildlife - particularly birds - from an airport is a continuing problem and please, someone come up with a viable solution. I just love flying into Gary, Indiana’s airport while hearing the perennial “Warning - bird, deer, and coyote activity in vicinity of airport” over the radio. During bow-hunting season this fall my home airport invited some hunters to take care of some of the deer munching grass around the runway. We’ve got blue herons, an endangered species, nesting nearby along with the usual assortment of Canadian geese and various duck species. We had a pair of ospreys raising a family this summer in one of the main maintenance hangars, which at least kept the rodent population at bay. I won’t mention the skunk incident, beyond pointing out that a spinning propellor can fling skunk-stink an amazing distance. It’s amazing how many critters set up housekeeping at airports. I’m beginning to think that humans are the only species that are bothered by engine noise.

The problem is, airports cover a fairly large amount of space that tends to not have a lot of people on it. There’s usually a greenbelt of some sort around them as well, and if not that, various buildings and fences to hide behind. It’s a great spot for wildlife that are trying to escape suburbia and roving bands of juvenile humans.

T’ain’t necessarily so. Eyewitness account here - I was one a commercial airline flight about, oh, 13 years ago now that sucked up a gull (or so it was believed) into the right engine just after the wheels lifted off. Totally destroyed the engine, smoke and fire pluming off the wing, the whole plane jerked to one side… obviously, I survived because I’m sitting here typing. It was not fun, let me tell you, but the pilot did maintain control, the fire was controlled (probably by shutting down the fuel line), and we landed safely with no one hurt (other than the bird). Major differences between that incident and today’s accident: on my flight, although the engine was destroyed parts were contained within the engine cowling and did not fly about slicing up airplane and people, and my airplane did not break up. Clearly, there is an element of luck in some of the these circumstances.

WHY the engine fell off is just not known at this time. Heck, who would have thought a small scrap of metal could bring down the Concorde? It could be a bird, it could be random debris sucked into an engine, it could be a mechanical failure, a problem with the fuel system, or even, god help us, sabotage. We just don’t know.

25

I only know about the damage small birds can cause to an aircraft. I was handed some pictures of a 757 (IIRC, it may have been a DC8, but you get the idea, a mid/large-size aircraft) that had flown through a flock of small birds. Holes in the wings, holes in the fuselage, a hole in the front of the plane where a bird had smashed all the way through and actually impacted one of the pilots legs (a bloody mess of feathers in the cockpit.)

Didn’t come close to bringing the airship down, but it did de-pressurize it in a hurry, which is usually bad.

26

It is not unheard of for geese and swans to fly at over 20,000’. A 20-30lb bird striking a Jet traveling at M .70+ would make a terrible mess and surely shake up the crew and everyone on board, and quite possibly put the jet in jeprody.

I still have doubts as to if a birdstrike at sub 10,000’ could rip an engine and nacelle off in addition to an almost entire wing. Just doesn’t make sense to me… I just can’t wrap my head around that.

27

It’s unlikely that a birdstrike by itself could bring down a big jet, but the damage caused by the impact may lead to other problems that might eventually cause a crash. Or, if there is some hidden damage the bird impact may trigger at catastrophic failure that would have eventually happened anyway.

28

How come no one has said anything about having a screen on the intake of the jet engine. A large fitted screen to keep out birds and debris?? Would this simply not work, I have seen nothing about this so I should assume there is a big reason against it…

29

Philosphr I’m guessing that at the speeds aircraft travel, this would cause the inflowing air to be turbulent resulting in a significant loss of thrust.

30

Bingo, Broomstick! This is my suspicion as well, if a bird-strike is involved.

Phlosphr, I think that Balduran has nailed the reason that screens aren’t used on jet engine. A screen that has a fine enough mesh to stop birds is going to block a significant amount of airflow, and is still subject to tearing loose under extreme conditions (excerbating the mess in the fans with wire). I once suggested razor sharp and extremely fine wires to slice ‘n’ dice in-bound organics (not a nice thing to think about), but someone who’s opinion I respect opined that it would be very difficult to get right.

31

The more I think of a birdstrike, IMHO they most likely way it would have happened is by making it a damn big bird getting ingested causing turbine blades to come shooting out, puncturing fuel tanks and then thats all she wrote.

Then again, I am just guessing this…

32

Question for the Materiels Engineeres / Aircraft Types:
While the fragments and shrapnel resulting from a 4-lb bird-strike should be contained by the engine casing, would hte engine casing retain material cast-off from, say, a 12-lb bird? Would ingesting, say, a mid-sized Canadian goose cause fragments to penetrate the casing, and possibly, could those hypothetical fragments cause sufficient damage to cause the engine to fall off, or even compromise the integrity of the wing?

33

This bird “accident” thing still conjecture. For me, it’s still way too much of a coincidence: the war, new york, American Airlines, veteran’s day, threats of “airliners raining down on your cities”…

so when I read of a possible bird strike, all I could think was,

“oh great, now we gotta worry about suicidal terrorist water fowl”
[sub]and no, you may not use that for a band name[/sub]

34

It depends upon when its used. The Soviets figuring that the US forces would bomb the crap out of their runways designed some of their fighters with a moveable grate to be used on take off and landings to lessen amounts of trash sucked into the engines. Why these aren’t used on commercial planes, I can only guess. I imagine that it has to do with the added cost versus pay-off thing.

Can you imagine what would happen if all of those got sucked into an engine at the same time? :eek:

35

The bird strike hypothesis is looking increasing probable, as they have now found “foreign debris” inside one of the engines that apparently caused it to catch on fire.

36

We have a chicken cannon where I work. One (obvious) drawback is the mess they make, so we have been using “synthetic chickens” by default, unless the customer requests the real thing. The synthetic chickens have about the same mass, density, and elasticity as a real chicken.

37

I have always imagined that this is how “chicken nuggets” are produced.

38

a little off the subject, but there’s a documented case of a kangaroo hopping onto a runway and destroying a B-17 bomber trying to take off. Sounds very far fetched, but I read it on one of those Martin Caidin WWII arial histories, though I can’t remember which.

And in Wisconsin a few years back, the legislature passed a law, so if you hit and kill a deer with your airplane, you get to keep the deer (this was already the case with cars – one sixth of auto accidents in WI are deer-related).

39

I’ve opened this thread a few times to add my 2 cents (I’ve worked on birds strike hazards at Atlantic City International [ACY] and JFK - see the little red house below for a couple of cites) but find myself getting a little rattled. I’m flying out of Newark to LA on Friday and have come close to cancelling several times.
:frowning:

Anyway, I just thought I’d relate a little of what I know about bird strikes, especially as they relate to ACY and JFK airfields. We did a 4-year study at ACY on bird populations, with an emphasis on Laughing Gull (Larus atricilla) habitat use. (Laughing Gulls are THE major bird strike hazard at both airfields, but are not a factor at this time of year as they have migrated south.) We looked at all sorts of factors, including bird densities, foraging behaviors, diet, and the ecology of the airfields and surrounding environment. We were particularly interested in the relationship between airfields and landfills (the two are often sited near each other) as well as open expanses of land that birds often find attractive. A few things to note:

[list][li] At the time of the building of JFK, the Laughing Gull colony in Jamaica Bay was relatively small but has since grown considerably. Also, the resident Canada Goose (Branta canadensis) population has also grown to the extent that local control is an issue. The resident geese, along with the migrants coming through at this time can pose a big problem as they cross the airspace from the bay to inland foraging sites.[/li][li] Because of this, JFK has taken several approaches to wildlife management. I’m not sure which they are doing at this point in time, but in the past, they have oiled Laughing Gull eggs to reduce colony size and have shot birds that pass through the airspace. Despite this, the colony increased in size. (And they shot a lot of birds - we necrospied several thousand to determine diet.) I think, like ACY, they tried using those inflatable screamers. Also, there is a company located on the airfield that uses birds-of-prey to clear the airspace, and from what I gather, they are fairly successful at this.[/li][li] And finally, I’ll just add what we learned from ACY because I think it’s pretty cool: While the diet of Laughing Gulls at JFK was primarily based on anthropogenic food (read inland foraging sites - spaghetti, Wonder bread, hot dogs), the diet of ACY Laughing Gulls and their presence at the airport was related to insects. In particular, Japanese beetles (Popillia japonicus). These beetles would emerge from the short grass areas around the runways and move over to adjacent scrub areas where they could eat their favorite foods. We found that out by catching the beetles, shaking them in bags of fluorescent powders, releasing them in grass or scrub areas, then later finding them at night with a black light. The ones in the grass scattered for the shrubs while the ones released in the shrubs stayed put. Gull numbers at the airport increased as the emerged beetle populations increased. The gulls were feeding the beetles to their kids and the kids peaked at fledging at the same time that the beetle population peaked. We did some bomb calorimetry and found that one beetle represents about 5 calories. Mom and Dad can carry many MANY beetles and stuff Junior to overflowing. The upshot of all of this was that we recommended that the shrub areas be mowed frequently enough to convert them to grasslands. We hoped this would reduce beetle populations by removing their favored food source (and would have the added benefit of increasing grassland bird species, like the Upland Sandpiper and Grasshopper Sparrow - two species that do inhabit ACY and are of a lesser threat in terms of bird strike hazard). Reduce the beetle population, and thus hopefully reduce the attractiveness of the airport to the gulls. Did it work? Well, they began a mowing regime when their focus shifted to…deer. Sigh.[/li]
Sorry for blabbing on so, but this has been oddly cathartic for me. I feel a little calmer about flying now.

40

Having lived on the North Fork for a couple years after college and having been born and raised on the coast. I have never seen a decline in Gulls hanging out around places where people are, especially junk yards and fishing docks. Unless there was a rash of killings of many hundreds of birds in the 10 miles radius around JFK and Laguardia, the threat will continue. Personally I don’t see this happening. There’s just too many birds, and in the fall those numbers are quadrupled with Ducks and Geese and starlings and the like migrating south.

just my two sense !!