Bird Causes Helicopter Crash - Tilted Forum Project Discussion Community

genuinegirly · 02-23-2009, 12:33 PM

A single hawk can make a Sikorsky helicopter topple?

Quote:

Bird strike may have preceded fatal helicopter crash(CNN) -- The National Transportation Safety Board said Monday that a bird strike may have preceded the January 4 crash of a Sikorsky helicopter near Morgan City, Louisiana.

The crash killed eight of the nine people aboard.

Though a bird specialist's initial visual examination found no evidence of a bird strike, DNA testing of a swab taken from the windscreen on the pilot's side of the Sikorsky S-76C++ helicopter found microscopic remains of a hawk, the NTSB said.

"The swab was taken from an area of the windscreen that exhibited concentric ring fractures," the NTSB said in a written statement. "Similar concentric rings were visible in the gel coat of the fuselage area just above the windscreen."

Last week, in a second examination of the wreckage, small feather parts were also found "under a right-side windscreen seal and in the folds of the right-side engine inlet filter," the statement said.

More swabs for bird remains were taken from other parts of the helicopter, which was operated by PHI Inc., it said.

The craft's original windscreens had been replaced by PHI about two years ago "as part of their normal procedures," the statement said.

They had been replaced for a second time about a year before the accident with a lighter-weight, acrylic windscreen that is approved by the Federal Aviation Administration, the statement said.

Further investigations into possible scenarios that could have led to the crash are planned, it said.

Birds are a known hazard to flyers. The NTSB reported two weeks ago that it was Canada geese in both engines that forced US Airways Flight 1549 to ditch into the Hudson River last month.

The flight crew of the Airbus A320 put the plane down gently on the river after the bird ingestion caused both engines to lose power. All 155 people aboard survived.

Investigators said bird remains -- called snarge -- were found in both turbofan engines, which were certified in 1996 as able to withstand bird ingestion up to 4 pounds. Almost all adult Canada geese weigh more.

Investigators have not determined how many birds hit the jet's engines.

Ack! Another big thing falling from the sky causing all sorts of havok. I feel like chicken little this month.

What have you heard about this crash?
Was the bird the equivalent of a straw on the camel's back?
Perhaps an indication of an even greater underlying design flaw?
____________
My thoughts:

Again I find myself reading about a crash that doesn't make any sense to me. How hard would a hawk need to hit a helicopter - and where - to make it fall? Hawks are large birds and they've undergone generations upon generations of evolution to perfect flying and to maintain their place in the sky - but is that helicopter truly that poorly designed? I'm glad I wasn't on it. I feel bad for the families of those 8 passengers who died in the crash.

Willravel · 02-23-2009, 12:54 PM

It might be a good idea to put carbon fiber cages in the form of a dome over the intakes on aircraft and to use metal netting inside the windscreens, but the best way to avoid this is altitude, an area where helicopters eventually have trouble. Glass can always be made stronger, but there are serious weight considerations in aeronautics. Short of developing lighter and stronger materials, we may just have to assume the calculated risk of avian collision.

PonyPotato · 02-23-2009, 01:44 PM

Quote:

Originally Posted by Willravel

It might be a good idea to put carbon fiber cages in the form of a dome over the intakes on aircraft and to use metal netting inside the windscreens, but the best way to avoid this is altitude, an area where helicopters eventually have trouble. Glass can always be made stronger, but there are serious weight considerations in aeronautics. Short of developing lighter and stronger materials, we may just have to assume the calculated risk of avian collision.

We already use some extremely light, strong, non-magnetic materials in aeronautical construction.

My dad was part of the team at GE working with the NTSB to investigate the engines of flight 1549. I've seen photos (and once, for real) of tests during which they test the engines constructed for bird collisions. Sometimes it's disturbing, but it's not like these engines aren't tested and tested again to conform to realistic regulations and design goals. I'm not sure about helicopters - my dad doesn't work on them or test them - but I know that jet engines go through a long, detailed design and testing process before they ever end up on a plane. Once, a guy my dad worked with dropped a bolt inside a GE90 engine while in the final steps of assembly. Because the materials are non-magnetic and designed not to stick to anything other than what they're supposed to, they couldn't get the bolt out of the engine even by un-doing the assembly process they had started when the engine arrived from Japan for completion. They had to send the engine BACK to Japan so an earlier step of assembly could be undone, the bolt removed, and everything put back together again. It cost millions.

I don't believe that the last couple of crashes caused by birds are evidence of underlying design flaws - I believe they are evidence of accidents and just happen to have occurred within a short time of one another. When else have you heard of a crash caused only by birds?

Willravel · 02-23-2009, 01:47 PM

Oh, I absolutely agree we use some pretty amazing stuff in the construction of aircraft. I was simply saying that we can't prevent ALL collisions and such until we get maybe the next generation of materials.

02-23-2009, 12:54 PM	#2 (permalink)
Willravel ... a sort of licensed troubleshooter.	It might be a good idea to put carbon fiber cages in the form of a dome over the intakes on aircraft and to use metal netting inside the windscreens, but the best way to avoid this is altitude, an area where helicopters eventually have trouble. Glass can always be made stronger, but there are serious weight considerations in aeronautics. Short of developing lighter and stronger materials, we may just have to assume the calculated risk of avian collision.

02-23-2009, 01:47 PM	#4 (permalink)
Willravel ... a sort of licensed troubleshooter.	Oh, I absolutely agree we use some pretty amazing stuff in the construction of aircraft. I was simply saying that we can't prevent ALL collisions and such until we get maybe the next generation of materials.