vertical stabilizer AA 587
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Re the C-141 accident - actuallytwo C-141's were lost within minutes or a few hours of each other, the second in Sonderstrom. Both 'accidents' had very similiar wing separations. Both aircraft parked side-by-side on the ramp at McGuire AFB before departures. One accident investigator I spoke with swears these were not mechanicl failures. Re AA 587, I don't think I've ever heard the NTSB make any comments within the first 24 hours of an accident ruling anything out. Why this time?
Do a Hover - it avoids G
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When trying to work back from ground wreckage patterns to establish the order of break-up in flight, it has to be remembered that something relatively light and very aerodynamic (like a vertical stabiliser) can slow down very quickly after it leaves the aircraft and can also “fly” some distance in any direction depending on how it rotates as it falls. On the other hand a heavy small mass (like an engine) will behave very differently. Lockerbie gave several instances of this. Expert interpretation of debris fields way beyond plain common sense is required.
With so many bits being recovered I am sure the investigation will be able to establish a likely series of events more quickly than in some other tragedies.
But all of the bits of the jigsaw must fit – not just some of them – in order to get the perfect picture and patience will be required by LATEST and others. A holding piece about such investigation issues rather than an attempt at a quick answer would go down very well with the professionals and, I suspect, a lot of the public. Might not be easy to convert the news editor to such an approach though.
With so many bits being recovered I am sure the investigation will be able to establish a likely series of events more quickly than in some other tragedies.
But all of the bits of the jigsaw must fit – not just some of them – in order to get the perfect picture and patience will be required by LATEST and others. A holding piece about such investigation issues rather than an attempt at a quick answer would go down very well with the professionals and, I suspect, a lot of the public. Might not be easy to convert the news editor to such an approach though.
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E-cam I seriously doubt the likelihood of either of your propositions. The rudder/stabiliser is designed to be used to keep the aeroplane straight if an engine fails or separates, and should therefore be up to the job.
If the engine mountings can secure the engine at full power, then a bit of yaw is highly unlikely to cause it to separate.
As both John Farley and I have said, we will have to wait.
John - I loved that photo of you hovering a Harrier with the gear up - it looked really smooth. Did you ever work with Mike Laughlin, RAF TP on the Harrier develpoment? He flew the P1127 quite a bit and said it scared the you-know-what out of him!
If the engine mountings can secure the engine at full power, then a bit of yaw is highly unlikely to cause it to separate.
As both John Farley and I have said, we will have to wait.
John - I loved that photo of you hovering a Harrier with the gear up - it looked really smooth. Did you ever work with Mike Laughlin, RAF TP on the Harrier develpoment? He flew the P1127 quite a bit and said it scared the you-know-what out of him!
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If a high power engine is stopped rapidly (say by swallowing a line of migrating Snow Geese) then the resultant rapid yaw, added to the violent torque may well exceed the fuse pin design strength - and lead to a detached engine striking the vertical fin and carrying it away.
Takes a bit of imagination, but cannot think of any other chain of events that would fit.
Takes a bit of imagination, but cannot think of any other chain of events that would fit.
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John Farley:
Well said. The only reason I got into this was the 'obsession' in local media here in New York with the 'engine fell off and it crashed' theory (if one can dignify that with the term 'theory').
E cam:
That's what I found worrying about the image - there is no evidence whatever of damage to the stab. One might expect considerable impact damage if another part had hit it, causing the separation. If it failed from aerodynamic forces, one might expect twisting, buckling, skin damage, or midspan failure.
None of this is seen, it is *as if* the loss of the stab was *perhaps* the first stage in the accident, with the engine separation etc. occuring as a consequence of the overstress and breakup that would follow.
LATEST: *everything* you read here - my own posts NOT excluded - is worth precisely what you've paid for it. Just don't make the 'engine failed/fell off' assumption and go with it - this needs MUCH more investigation.
Well said. The only reason I got into this was the 'obsession' in local media here in New York with the 'engine fell off and it crashed' theory (if one can dignify that with the term 'theory').
E cam:
That's what I found worrying about the image - there is no evidence whatever of damage to the stab. One might expect considerable impact damage if another part had hit it, causing the separation. If it failed from aerodynamic forces, one might expect twisting, buckling, skin damage, or midspan failure.
None of this is seen, it is *as if* the loss of the stab was *perhaps* the first stage in the accident, with the engine separation etc. occuring as a consequence of the overstress and breakup that would follow.
LATEST: *everything* you read here - my own posts NOT excluded - is worth precisely what you've paid for it. Just don't make the 'engine failed/fell off' assumption and go with it - this needs MUCH more investigation.
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Ranger One - point taken - yes its all a bit rudimentary the press speculation at the moment.
Dagger Dirk - I read on the NBC and CBS websites that there were reports of very high bird activity in the area prior to the plane taking off. Maybe that fits with what you said ?
Dagger Dirk - I read on the NBC and CBS websites that there were reports of very high bird activity in the area prior to the plane taking off. Maybe that fits with what you said ?
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Here is another image of a piece of wreckage that fell from the plane into a parking lot, taken from a BBC article. It too looks like it came from some kind of aerodynamic failure, rather than being dislodged by impact from a stray engine, or stray engine part. What part of the plane is it?
This is the most perplexing crash. At first I thought that this crash may have been a replica of the American Airlines DC10 crash at Chicago, where the engine pylon failed because of improper pylon attachment. That engine rotated over the wing and hit the top of the wing, causing all the hydraulic problems that made the plane uncontrollable.
In this case I first thought that the engine may have broken off and flipped up over the wing with sufficient force to cause the wing to fail, or to somehow subsequently hit the tail assembly.
But the problem with this kind of conjecture is that both the engines appear to be near the fuselage on the ground, while the nearly undamaged stabiliser appears to have left the aircraft at some point in flight before the subsequent trajectory of the debris found on land.
The pictures of the engine at the service station are also unusual, in that to my untrained eye the only damage to that engine is ground impact damage. Did it also come off because of aerodynamic forces rather than because of some internal failure?
I too am of the mind that there may be some some structural cause of this crash other than engine failure. Where is the rest of the rudder? It should also be out in Jamaica Bay somewhere, should it not?
This is the most perplexing crash. At first I thought that this crash may have been a replica of the American Airlines DC10 crash at Chicago, where the engine pylon failed because of improper pylon attachment. That engine rotated over the wing and hit the top of the wing, causing all the hydraulic problems that made the plane uncontrollable.
In this case I first thought that the engine may have broken off and flipped up over the wing with sufficient force to cause the wing to fail, or to somehow subsequently hit the tail assembly.
But the problem with this kind of conjecture is that both the engines appear to be near the fuselage on the ground, while the nearly undamaged stabiliser appears to have left the aircraft at some point in flight before the subsequent trajectory of the debris found on land.
The pictures of the engine at the service station are also unusual, in that to my untrained eye the only damage to that engine is ground impact damage. Did it also come off because of aerodynamic forces rather than because of some internal failure?
I too am of the mind that there may be some some structural cause of this crash other than engine failure. Where is the rest of the rudder? It should also be out in Jamaica Bay somewhere, should it not?
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I cant help feeling that things probably happened the other way round. JAL123 (1985) flew (erratically) for over half an hour without a tail fin.
I'm no big engineer, but if the engine seperated through some sort of fatigue or shock surely the drag on that wing could cause severe shock loading on the fin also, could this also be enough to rip off the rudder from the fin?
Could the loss of hydraulics and the fin under severe yaw put the aircraft in to an uncontrolable dive more quickly than normal, maybe ripping the other engine (still under heavy thrust) fom its mount?
Thoughts and prayers are with all the families involved.
I'm no big engineer, but if the engine seperated through some sort of fatigue or shock surely the drag on that wing could cause severe shock loading on the fin also, could this also be enough to rip off the rudder from the fin?
Could the loss of hydraulics and the fin under severe yaw put the aircraft in to an uncontrolable dive more quickly than normal, maybe ripping the other engine (still under heavy thrust) fom its mount?
Thoughts and prayers are with all the families involved.
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McGinty.
The photograph shows one of the wingtips of the airbus. It's impossible (for a non-expert like myself!) to say whether it is from the port or starboard side, as it is more or less symmetrical about the plane of the wing. Also, the port/starboard wingtip indicator seems to be broken/missing, so unforunately no clue can be gleaned from that either.
The photograph shows one of the wingtips of the airbus. It's impossible (for a non-expert like myself!) to say whether it is from the port or starboard side, as it is more or less symmetrical about the plane of the wing. Also, the port/starboard wingtip indicator seems to be broken/missing, so unforunately no clue can be gleaned from that either.
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The top of the fin (Vertical Stab.) is generally where the FDR is located on most aircraft.
Mayor Guilianni and others have stated thet CVR was recovered, but NOT the FDR, which makes no sense to me.
Can anyone tell me where the FDR on this aircraft is located?
Mayor Guilianni and others have stated thet CVR was recovered, but NOT the FDR, which makes no sense to me.
Can anyone tell me where the FDR on this aircraft is located?
I think you'll find the FDR is located on most modern aircraft behind the pressure bulkhead, never yet seen one on the vertical fin, but am willing to accept that some may have it there 
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Actually I'm reluctant to speculate about the possible cause. But such an inflight break-up reminds me of the Lauda Air 767, on which the thrust-reverser suddenly deployed.
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Buck Rogers is probably on the right track:
a. Stbd engine swallows a number of large birds and stops very suddenly due to severe rotational imbalance.
b. Side-Torque generated by this seizure slews that engine and its fuse-pin, upon reaching its design limit, lets go. Engine departs cleanly.
c. With the other engine under high power, and now due to great weight, lift and drag disparities, aircraft commences severe yaw (and roll and pitchdown/IAS increase) - imposing side-forces beyond design limit upon the vertical fin (which separates cleanly)
d. Aircraft "winds up" in its spiral dive with rapidly increasing asymmetric g and roll-rate - causing other engine to also depart due to excessive lateral loads on remaining engine pylon.
The key here is the design strength limits of fuse pins and vertical fins, once subjected to severe out-of-axis forces. Not sure why rudder would have detached (if it did). Winglets may have been torn off due to the same lateral aerodynamic load exceedances.
a. Stbd engine swallows a number of large birds and stops very suddenly due to severe rotational imbalance.
b. Side-Torque generated by this seizure slews that engine and its fuse-pin, upon reaching its design limit, lets go. Engine departs cleanly.
c. With the other engine under high power, and now due to great weight, lift and drag disparities, aircraft commences severe yaw (and roll and pitchdown/IAS increase) - imposing side-forces beyond design limit upon the vertical fin (which separates cleanly)
d. Aircraft "winds up" in its spiral dive with rapidly increasing asymmetric g and roll-rate - causing other engine to also depart due to excessive lateral loads on remaining engine pylon.
The key here is the design strength limits of fuse pins and vertical fins, once subjected to severe out-of-axis forces. Not sure why rudder would have detached (if it did). Winglets may have been torn off due to the same lateral aerodynamic load exceedances.
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Gentlemen: Speculation is more interesting when it is consistent with the currently-known facts. The vertical stab was in the drink, roughly along the flight path and between JFK and the spots where the engines landed. The main part of the a/c landed on 133rd st; the two engines wound up at 128th and 129th streets, respectively.
This would seem to indicate a strong likelihood that the fin separated from the craft before the engines did.
Source for engine locations: NY Daily News
This would seem to indicate a strong likelihood that the fin separated from the craft before the engines did.
Source for engine locations: NY Daily News
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As for an engine seizeure causing seperation........ I doubt it. We practice for this in the sim. The aircraft will fly. Only difference is we shut it down earlier than a "normal" engine failure. Lots of vibration.......YES. Lots of noise..YES! However I cannot see how this alone can, or will cause seperation. However I MAY be wrong!
I don't know what caused this accident, no-one does. I do not think that speculation, however well informed it may be, helps the situation!! Lets leave that to the people who are experienced in that field, and have the evidence at hand!
Eff Oh.
I don't know what caused this accident, no-one does. I do not think that speculation, however well informed it may be, helps the situation!! Lets leave that to the people who are experienced in that field, and have the evidence at hand!
Eff Oh.
Do a Hover - it avoids G
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wideman
Good point about speculation needing to be connected with emerging facts.
The facts seem to support a lot of bits coming off the aircraft in flight, way beyond what one might expect with any simple engine failure or even an engine separation that caused other damge (as at Chicago)
JBravo is quite in accord with the facts - an inflight reverse on one side at high power would cause a much higher level of sidslip than any single engine operating case
As a first event to trigger the rest it seems top of the frame
Good point about speculation needing to be connected with emerging facts.
The facts seem to support a lot of bits coming off the aircraft in flight, way beyond what one might expect with any simple engine failure or even an engine separation that caused other damge (as at Chicago)
JBravo is quite in accord with the facts - an inflight reverse on one side at high power would cause a much higher level of sidslip than any single engine operating case
As a first event to trigger the rest it seems top of the frame
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Given that American Airlines prefer to polish their aircraft, can we assune the tailfin of the A-300 is plastic ie. carbon fibre or of some sort of aramid construction?
(in the photo it appears to be painted light grey). If this is the case perhaps it has some bearing on the possible chain of events leading up to this tragic accident. Perhaps may also explain its intact appearence as if its made of this stuff its effectively one big piece. Thoughts anyone? (apologies if its really made of aloominum!) maybe an AI employee knows.
(in the photo it appears to be painted light grey). If this is the case perhaps it has some bearing on the possible chain of events leading up to this tragic accident. Perhaps may also explain its intact appearence as if its made of this stuff its effectively one big piece. Thoughts anyone? (apologies if its really made of aloominum!) maybe an AI employee knows.