AA Flight 587

[scottkin]

Not to beat a dead horse, but after some research I have a few questions. I dont have a conspiracy theory mindset but i'm very curious as to why the NTSB and the FBI discounted so many of the eyewitness reports of an explosion on board before the vert stab seperation? Over 349 witnesses interviewed and 95% claimed to of seen an explosion before the seperation. http://hometown.aol.com/missiletwa800/aa587.htm

[TriStar-MiStar]

I have asked this same question over and over and never got an answer that made any sense / had any logic. There seems to be lots of oddities surrounding the ArrowAir DC-8 crash at Gander, Nfld, too.

[chrisburns]

None of the wreckage had any signs of an explosion before impact and the data recorder also showed what was going on.

[Dmmoore]

Not to beat a dead horse, but after some research I have a few questions. I dont have a conspiracy theory mindset but i'm very curious as to why the NTSB and the FBI discounted so many of the eyewitness reports of an explosion on board before the vert stab seperation? Over 349 witnesses interviewed and 95% claimed to of seen an explosion before the seperation. http://hometown.aol.com/missiletwa800/aa587.htm

The eye witnesses saw and heard engine compressor stalls due to air flow disruptions in the inlet caused be the yaw motion set up by the rudder input. A compressor stall (engine surge) can cause visible flames from both ends of the engine.

Yaw an A300 30 degrees and the nose of the aircraft blocks ram air from entering the engine inlet cleanly. A 20 degree cant on the inlet is enough to disrupt air flow into the engine.

[Cam]

Eyewitness account can be notoriously inaccurate.

[scottkin]

Don a quick question. During tear down of the engine would investigators be able to tell if there was any pre-impact malfunctions including a compressor stall?

[Dmmoore]

Don a quick question. During tear down of the engine would investigators be able to tell if there was any pre-impact malfunctions including a compressor stall?

If the stall was caused by an internal failure the answer is very likely. A stall caused by unstable air followed by an impact with earth, not likely. The damage from the collision would hide or destroy any evidence of a stall.

Many stalls leave no indication at all. I've borescoped many post stall engines looking for tip clang on the compressor blades. The tips bend forward and clang on the non rotating stator. It's about 50/50 on finding damage, however "IF" I heard the stall, I've been 100% in predicting the outcome. Tip clang = engine change.

[scottkin]

Don just one more question and i'll go back to my corner. Is it possible that investigators would be able to detect any scarring on the engine or possibly the fueslage or wings from the stall? Such as scorch marks. I read a snipet where the inspectors found no evidence in either engine of pre crash failure. Thanks again.

[Dmmoore]

Don just one more question and i'll go back to my corner. Is it possible that investigators would be able to detect any scarring on the engine or possibly the fueslage or wings from the stall? Such as scorch marks. I read a snipet where the inspectors found no evidence in either engine of pre crash failure. Thanks again.

It's not likely. A stall caused by airflow disruption is not an engine failure, so the report of no pre-existing engine defects would be valid assuming engine stalls are involved. Flames from an engine surge (Stall) are in free air and a long way from the fuselage. They are of very short duration and would not leave much (if any) evidence on the aircraft.

The bigger picture is there is no indication on any explosion anywhere on board the aircraft. It's impossible to have an explosion anywhere in the aircraft and not have a trail of evidence.

[Gabriel]

Don, wouldn't a compressor stall or other type of engine stall / surge, specially those that "cause visible flames from both ends of the engine" and are seen or heard by 300 witnesses, leave an audible record in the CVR? Was there such evince in the CVR.

I don't remember so (but hey!, I don't remember that there was a bomb explosion recorded either).

[alanh]

People are likely to describe any loud bang as "it sounded like an explosion". Couple that with something like this.

[Dmmoore]

Don, wouldn't a compressor stall or other type of engine stall / surge, specially those that "cause visible flames from both ends of the engine" and are seen or heard by 300 witnesses, leave an audible record in the CVR? Was there such evince in the CVR.

I don't remember so (but hey!, I don't remember that there was a bomb explosion recorded either).

The sound may be recorded on the DCVR but it will be recorded on the DFDR if power was present at the time of the event. The stalls would have been after tail separation.

[Gabriel]

The sound may be recorded on the DCVR but it will be recorded on the DFDR if power was present at the time of the event. The stalls would have been after tail separation.

I don't understand the implications of what you are saying. The DFDR kept recording after the fin separation, didn't it?

Please do it fool-proof: Was there any evidence of the engine stalls recorded in the CVR or DFDR? If there was none, Why there was none? If the answer to that last question is "there was no power", Why there was no power?

[alanh]

The NTSB says about sounds:

The CVR group examined all of the CVR channels to document any unknown or unusual cockpit or airplane sounds. The sound of a brief squeak and rattle at 0915:37.3 and the sound of two thumps at 0915:52.9 were associated with movement of cockpit items in response to the airplane’s encounter with wake turbulence. The CVR group identified no specific events or noises on the CVR that, by themselves, could be positively associated with the departure of the vertical stabilizer. Also, the Board did not determine the sources of sounds after the airplane was believed to have started its uncontrolled descent.

The rudder separated at 09:15:58 and the CVR quit recording at 09:16:15, at the time of crash. Later in the report they show that the "loud bang" at 09:15:58 corresponded to the time the rudder separated -- the CVR group couldn't identify it on their own because they didn't have a reference for "sound of rudder falling off".

The main thing is, they found the rudder in the bay with an overstress fracture. It wasn't cut and it didn't blow up. The rudder didn't separate as part of an in-flight breakup because the jet was in one piece before it fell off.

[Uncle Jay]

The Eyewitnesses

After successfully observing TWA 800 arising from the ocean in flames and ascending to 11,000 feet, the eyewitnesses were packed into a bus and ferried to Queens in time to observe AA 587 explode in mid-air.