Author Topic: Film: Bird Causes Crash (Read 1587 times)

AWwsky · « **Reply #30 on:** August 10, 2005, 06:21:24 PM »

Wolfa, only the brakes contain magnisium and the temperatures have to exceed 700 Deg F to even be concidered as 'HOT BRAKES'. In other words, the brakes will glow bright orange. No where in a turbine engine will you find a magnisium part.

What you call "ITT" is probably better known to US pilots as "FTIT" or Fan Turbine Inlet Temperture and all engines types have a specific limit. It is rare for an engine fire to start in this area of a turbine engine.

Halo, the reason they ejected vs ditching is based on altitude and airspeed. They had very little of both (3,000 ft as indicated on the HUD display, couldn't see airspeed). It would have been unsafe to attempt to ditch due to the lack of airspeed and a safe glidesloop, not to mention there was probably very little to no response to flight control inputs. The pilots also have to follow the flight manual. They did an outstanding job just getting the plane in an area so as to not threaten lives or property other then the aircraft itself. Your question was not dumb btw. Also realize that the approach is one of the most dangerous parts of landing. No room for error in the case of a bird strick that takes out the engine on a single engine fighter.

AWwsky · « **Reply #31 on:** August 10, 2005, 07:11:15 PM »

Repoman, I had to watch and listen to the footage again after reading the article. Something about the article sounded wrong. Naturally they heard a thump, which came from the damage the bird caused, not the bird itself. It's also the reason they would feel some vibrations as the engine was no longer balanced. At that point, the pitch change, which you can hear in the video, is the engine whinding down. I also clearly heard the crew attempt a restart of the engine, which failed.

If you watch the video, you can see that the pitch of the aircraft went nose high right after the bird went bye bye. This was not mentioned in the article. After that, the pilot didn't just sacrafice airspeed for altitude, he did what had to be done to eject at a survivable altitude. Any lower and both the student and the IP would have been in far worse condition then just the broken leg.

I doubt if I can get any indepth engine information for the engine which a Rolls-Royce Mk.871 Adour turbofan, but I'd love to find out what the area's are that the article mentioned (T6NL & ECA), but if I had to guess, T6 would be the combustion section of the engine and the NL stands for No lite. I'm not sure what ECA stands for. Pratt and Whittney engines use different terms and that's what I'm used to working on.

Wolfala · « **Reply #32 on:** August 10, 2005, 11:20:33 PM »

AW,

Magnesium is not in the engine, but in the sections around the tailpipe. I dunno if you've seen what happens when you have an uncontained engine failure and stuff starts burning - thankfully this one didn't blow itself apart. But a few months ago a guy here posted up a Mig29 on airshow practice back in May this year that threw a few blades. Despite going 200 kts, it took less then 45 seconds for the entire empenage to get engulfed. Point being - most SOP's call for punch out if there is any fire. Or goes something to the point "see if fire gets worse, if it does, leave." A 5lb bottle of C02 isn't gonna do much in that case.

Wolf

Stone · « **Reply #33 on:** August 11, 2005, 06:45:06 AM »

The bird is a vulcher right ?

AWwsky · « **Reply #34 on:** August 11, 2005, 07:01:02 AM »

Wolf, do you have experience working on turbine engines? Including this particular Rolls engine, because I'm curious to know what T6NL is. I took a guess, best I could do.

CrzyMonk · « **Reply #35 on:** August 11, 2005, 09:53:52 AM »

Quote

Originally posted by Enduro
I heard the same explanation, BigR.

PETA would say that the plane caused this crash. I'm sure the investigation is underway...

LOL...

In a past life I was a real pilot and sucked in a bird on approach to Rhinelander Wisconsin in a Saab 340. Lost the engine asap over the outer marker with a heavy crosswind....NOT fun

Mustaine · « **Reply #36 on:** August 11, 2005, 09:59:54 AM »

Quote

Originally posted by ~Pyroman~
Hey DaYooper I see you are in Alaska but use the name DaYooper.

Where are you from in the U.P?

Escanaba here!

mom was born and raised in gladstone, father escanaba.

was just there 2 weekends ago visiting mothers grave.

still have an aunt and uncle in esky.

other aunt / uncle and 2 cousins in neguanee.

REP0MAN · « **Reply #37 on:** August 11, 2005, 11:57:28 AM »

AW,

I just pasted a link from another site where I saw the crash video. I know nothing of turbine engines except to keep my Cessna away from them on the ground and in the air. I have seen whet a bird can do to a prop so I can imagine what kinda mayhem it caused inside that engine. Sorry I am no more help.....

Wolfala · « **Reply #38 on:** August 11, 2005, 12:17:39 PM »

Quote

Originally posted by AWwsky
Wolf, do you have experience working on turbine engines? Including this particular Rolls engine, because I'm curious to know what T6NL is. I took a guess, best I could do.

I don't have experience on RR engines, short of an Allison V1710-35 on a P39D, but my uncle works for GE and troubleshoots their turbines (i.e. why they've gone through 4 hydro pumps in 700 hours - kinda thing). He knows RR pretty well from his time in the Navy - i'll drop him an email.

Wolf

Tarmac · « **Reply #39 on:** August 11, 2005, 12:30:16 PM »

What kinds of design specs do they have regarding birdstrikes on those things? I know that when my dad worked for GE Aircraft Engines, one of his tasks was to fire dead birds out of a pneumatic cannon into F-15 and B-1 engines to be sure they could take the impact. I'll show him this next time I see him and see what he's got to say.

Are those Hawk engines not rated for birdstrikes, or was this just a fluke?

grmrpr · « **Reply #40 on:** August 11, 2005, 12:48:06 PM »

Bird!!!!!

DUCK!!!!!!!!!!!!!!

AWwsky · « **Reply #41 on:** August 11, 2005, 05:45:28 PM »

Tarmac, it's all dependent on the size of the bird that goes up the intake then into the engine. Small birds might cause a few knicks in the blades, but large birds like Hawks, Eagles, Turkey Vultures or even chickens cause a lot of damage and in most cases will cause a compressor stall or flameout. The engines found in the F-15 (also in the F-16) are F100-PW series turbines. This includes the 200, 220, 220E, and 229, but there may be newer engines since the 229 came out. But unlike the F-15, the F-16 also uses the GE engines. These engines turn at higher RPM's then what commercial airliners engines do and are more likely to be damaged by a large bird impacting the blades. Not all the blades turn. There are rotar and stator blades in both the compresor and the exhaust sections and are usually refered to as stages (i.e. first set of blades would stage one). Engines are not gauged by RPM's, but by Percent. Idle engine power is between 68 - 72% while full military power is 100% (this includes after burner as well).

I'd love to go into more detail, but I don't know if you'd just get more confused or just bored from the reading, so I'll stop there. Also, note that I stated the F-15 has the PW engines. The F-15 was designed to use both the GE and PW, but cost and fuel consumption made the PW more ideal. The F-16 uses both.

Wolfala · « **Reply #42 on:** August 11, 2005, 11:39:02 PM »

Quote

Originally posted by Tarmac
What kinds of design specs do they have regarding birdstrikes on those things? I know that when my dad worked for GE Aircraft Engines, one of his tasks was to fire dead birds out of a pneumatic cannon into F-15 and B-1 engines to be sure they could take the impact. I'll show him this next time I see him and see what he's got to say.

Are those Hawk engines not rated for birdstrikes, or was this just a fluke?

Its not so much a fluke as it is bad luck. Just because something is tolorent of a bird strike doesn't mean its going to keep on operating like there is nothing wrong. Also, keep in mind they were operating at a high power setting, right after rotation, and that wasn't a sparrow or a pidgeon, but a fairly good size seagull which weigh's a few kilos atleast. The RR doesn't have much if any bypass like the F100X on the F15 or even the motor on the B1. The other thing is the design of the engine - 1 axial and 1 centrifugal compressor. A pure axial design that you see on most airliners atleast affords some margin for the bird effluent to pass through. But a centfugal design gurantee's it goes through the entire thing.

When you take into account the significant amount of energy in K-joules imparted by the bird, and the small space the engine affords and the tolerences and clearences it has to operate within - it doesn't surprise me in the least bit.

On a different but similar note - many years ago while I was training we had a Kingair 200 come into Danbury connecticut. On short final it took out 21 geese, trashed both engines - and was generally miraculous it got down. If you had seen what happened to this bird, it looked like a massacar through a blood ridden hailstorm - literally it was shot to ****. If these guys were taking off, Danbury has no bailout areas to ditch. They were good as dead. So these guys are lucky they had Martin Baker on their side, even if it was only for 1 bird.