Sabotage Explains Flight 587 Crash, Says Expert

Federal investigators still have no evidence indicating that a benign structural failure played a role in the tail breaking off Flight 587 last month, sending the plane tumbling into Queens, N.Y., according to AviationNow.com. But as National Transportation Safety Board and other safety experts wrestle to solve the mystery of the powerful forces that ripped the plane’s fin off and then cast the engines from their mountings, one aviation expert said sabotage of the aircraft’s left engine while still on the ground could explain what shook the aircraft to pieces.

Expert Marshall Smith opined, "A single point failure, the in-flight actuation of the left engine thrust reverser, can account for all three observed phenomena of the clean breaking off of the tail and the failure of both pylons holding the engines.”

"If the left engine thrust reverser had either partially or completely actuated during flight, it would cause the plane to go into a flat spin to the left. The airplane would spin something like a flat Frisbee with the right engine pushing forward and the left engine pushing backwards,” Marshall explained.

"Within a second of the flat spin occurring, the sideways windblast would rip off the tail assembly, since it was never designed to take such a side blast of air.

"As soon as the tail assembly broke off, there is now very little wind resistance to the flat spin. At this point the engines would cause the aircraft to spin even faster with the g-forces away from the center of the spin becoming so great that both engines would be violently ripped off the wings and thrown outward away from the plane,” Marshall said.

Marshall’s opinion is that the spin accounted for why the engines were found so far away from the crash site and why the tail came off first.

The mechanical engineer, aviation ground school instructor and former NASA adviser painted this scenario:

During the night, a terrorist saboteur disguised as a ground crew mechanic reached up in the back of the left jet engine of the American Airlines Airbus and cut the hydraulic line going to the thrust reverser actuator and the control safety sensor lines.

The next morning after the jet engines were started, the hydraulic fluid began dripping from the cut line.

When the aircraft was about 3,000 feet in the air, the sound of an "airframe rattle” was heard in the cockpit voice recorder (CVR) record. Cause: the tampered-with left thrust reverser had started to close, causing the plane to turn to the left.

The pilot compensated by applying right rudder to bring the nose back to straight flight by turning to the right.

The aircraft commenced a "side slip.” During this condition, the burbling air flowing over the extended control surfaces made the plane shake, rattle and roll, accounting for the airframe rattle noise heard on the CVR at 107 seconds into the flight.

The pilot thought he had overcompensated, worried about losing too much airspeed, and returned the controls to normal. The rattling momentarily stopped as indicated on the CVR.

The pilot again tried to compensate for the strong drift of the plane to the left caused by the partially closing thrust reverser by again applying right rudder and opposite aileron. The same rattling sound is heard again at 121 seconds into the flight.

Four seconds later, at 125 seconds into the flight, the first officer calls for "full power,” presumably to compensate for the side slip, which had again slowed the plane down to dangerously slow speed.

As soon as the power went to full, the spinning effect caused by the partially or fully actuated thrust reverser caused the plane to spin out of control in a flat spin.

Two seconds later, at 127 seconds, the CVR indicated the flight crew making a comment about being out of control. No more comments are made after that, and the recording ends 17 seconds later when the plane hits the ground.

Fighting to control the aircraft, the pilot held full right rudder and hard left aileron just as the left thrust reverser came into the full-on position. The application of full power greatly increased the turn to the left, created a huge side force on the tail and rudder assembly, and snapped them off cleanly.

Within another second, without the vertical tail assembly to slow the spin, the plane spun violently to the left about the center of gravity of the airplane. The plane spun horizontally with the full power from both engines increasing the spin faster and faster until both engines broke off.

The flight crew at the front was thrown violently forward with such g-force they were instantly rendered unconscious or killed, explaining why no more comments from the flight crew are heard after applying full power.

With the plane completely out of control and the engines still running at full power, the engines broke away ripping the fuel tanks in both wings and igniting the plane. Wake Turbulence Discounted

Marshall created his saboteur scenario because he concluded early that it is not possible for any type of wake turbulence from a preceding jet to rip off the tail of an airplane. Furthermore, he concluded, even with the vertical stabilizer gone, Flight 587 would not have gone out of control in such a way that both engines would also fall off.

He pointed to 1985 incident where a Japanese Boeing 747 with the vertical tail assembly completely torn away continued to fly in large circles for over half an hour before hitting a mountain.

According to Marshall, Flight 587, an Airbus A300, used a modern "fly-by-wire” computer system and would fly quite easily with complete loss of the vertical fin and rudder.

"Most air accident investigators would easily conclude that the chances of three simultaneous airframe failures all occurring at the same time is not probable. It must be one or the other but not all three. It would be much easier to conclude that something else actually caused all three failures,” Marshall said.

Marshall pointed to a statement by New York City Mayor Rudolph Guiliani at a news conference Nov. 14 that the rescue workers recovered 262 bodies including "a man still holding a baby.” "

Certainly no man can be strong enough to hold on to a baby through that force, unless instead the plane was in a flat spin. For the passengers in the center of the plane, the force would have been downward [not forward] as the plane hit the ground, and the baby would be simply forced deeper into the man’s lap as he sat in the passenger seat.

Further clues pointing to his theory, said Marshall: news videos of the crash scene as firemen put out the flames. A large section of the central part of the plane is lying on the ground almost intact but in flames.

If you make pods, how are the modern ones configured to handle compressor surges and resulting bang of re-ignition of the excess fuel? For those that missed the earlier threads in which I mentioned this, a compressor surge is the engine speed suddenly exceeds the ignition speed of the fuel air mixture and snuffs out its own fire. The engine management system goes into auto-ignite and lights off the now excess fuel within the engine, producing a good size bang with a lots of flame. This is what the witnesses probably saw. Usually, nothing happens but I saw pictures of an Alaskan 757 earlier this year that had popped the front cowl off the engine from a compressor surge, badly damaging the engine and parts of the wing. Compressor surges are rare these days with the modern engine management systems but it used to happen often in engines 15 years ago or more. Because of the rarity of these events, are present day engineers putting the needed emphasis into designing the pods to withstand the explosive re-ignition?

On the day of the crash, many of the witnesses were drawn to look at the plane because of popping noises (i.e., the engine noises was unusual). This was followed by many seeing flames between the wing and body (the engine re-igniting?). The crew did not loose control until they commanded throttle up for full power. If one engine was having fuel delivery problems, it may not have put out the required thrust so the plane then slew to one side and that's when the rudder let go (though many witness said they saw parts of the wing hit the rudder after the bang and flames).

As for sabotage, there are easier ways to damage an engine than by cutting through hard titanium tubing to a system that can only deploy with the help of the hydraulics. The above thrust reverser theory doesn't hold water.

It is not quite true that a flat spin was not witnessed: Witenesses did in fact see the plane "stop" in midair. It does not have to spin all the way around.

The main weakness I see is that he starts with a good analysis: that only air load could have torn off the vert stab and engines, but he follows it to a very specific conclusion.

The main contribution of this analysis is that the plane coming apart was a symptom, not a cause. I think this is driven home by the fact that the engines, part of a wing, and the vert stab are so far apart on the plane that their coming off has to be explained by forces like air load that work on all parts of the plane at once. Worst of all, I think thrust reverser deployment would have been discovered very early in the investigation. I think it has been ruled out.

Worst of all, I think thrust reverser deployment would have been discovered very early in the investigation. I think it has been ruled out.

It indeed has been ruled out. Whatever caused the Flt. 587 crash, it wasn't something going wrong with the engines.

Yet it was widely reported right after the crash that "the engines blew themselves apart," etc. You still see people persistently posting that kind of disinformation (reverse thrust deployment) on threads like these (along with the usual sophomoric "tinfoil hat" comments of course).

My conclusion is that there're quite a few people who don't want to know the truth about Flt. 587 and who don't want the rest of us to know either. But...Magna est veritas, et praevalebit. "The Truth is mighty, and will prevail."

Things we know:

There was a specific threat to aviation from bin Laden.

There was as specific rant against the U.N. by bin Laden.

The UNGA and GWB were in town the day 587 crashed.

Eyewitnesses saw explosions/fire at the wing roots. Some were specific this happened before stuff came off the plane. (And nobody had the kevlar cojones to try the "exploding center fuel tank" thing again.)

It wasn't engine trouble.

It would have to have been the worst-ever case of wake turbulence. Several experts say wake turbulence could not rip apart a plane this big.

No other AB300s have vert stab structural problems - all were inspected.

The plane came apart after take-off and after a 180 degree turn. There was no evidence of rudder problems before the vert stab came off.

Dominicans take a lot of stuff (e.g. appliances) with them when they visit relatives back home.

"Airframe rattle" is a term that has never been use before to describe a sound heard on a CVR.

Loss of control happened after hearing these noises.

Numerous bogus mechanical failure theories were floated in the media - all discredited.

The NYT initially reported an "FBI source" said there was an explosion on board. Sounds like subsequent media trial balloons are an attempt to put this toothpaste back in the tube.

All but one passenger has been identified. None are obviously Arab. In fact most are obviously Dominican from their names.

The plane flew in from Boston that morning. So while JFK has serious security problems, there was not much time for sabotage at JFK.

Sorry for the delay in responding to your questions. I was late getting home from work.

The pods (nacelles) are designed to handle compressor stalls and engine surges (which don't destroy the engine, only cause damage internally to the engine, and often thrust is nearly fully recoverable by the restarting of the engine) without damage to the nacelle structure. If what you opine is correct (and it is certainly a plausible hypothesis) that one or both engines stalled or surged (and emitted a bang, and then restarted with some flame out the nozzle), this could explain the reports of explosions and flames.

Your other comment buried in the previous one concerned compressor blade failures. When this happens (either to the fan blades, the low rotor compressor blades, or the high rotor compressor blades), the engine essentially blows apart. If the fan blades depart, the engine and nacelle are designed to contain the fan blades within the nacelle structure, but the nacelle and engine are badly damaged and scrapped. More rare is when the high rotor compressor blades fail - nothing stops them except gravity and the ground, and the engine is irreparably damaged.

In both these cases, the aircraft loses the power in the affected engine, resulting in a yaw (the nose turns) toward the failed engine (since the other engine continues to produce thrust). If there was a stall followed by a restart, there should have been some indication of it on the flight data recorder, and the pilots would have commented on it on AA587. I don't recall hearing about that on the recorder data.

It is possible that the engines stalled (and banged, and flamed out) after the tail came off, and the recorders stopped running (10-12 seconds before impact) due to the high yaw angle of the flow entering the engine inlet. It would be interesting to know when the witnesses saw the explosions - before the tail came off, or after. If the latter, then your hypothesis may be a good explanation for the witness reports.

My earlier posts pondered the possibility of a tire exploding after stowage (my experience is in secondary hydraulics and landing gear). The eyewitness accounts seem to indicate an explosion in the landing gear bay between the wing and body. Newer aircraft don't seem to provide shrapnel protection against tire/wheel failure as older designs (lessons lost). My original impression of the accident was a repeat of the 727 that went down in Mexico in late 60s. A main tire blew, taking out fuel feed lines and some hydraulics. I flew back from Europe recently on a A320 and noted that the spin down of the wheels didn't stop until after they were stowed (badly out of balance wheels at that). The autobrake of the wheels should work before or during stowage. I know the flight recorder didn't pick up any bang but the MLG is remote from the cabin microphones and such an explosion might not be noted. A tread separation is another possibility that whipped around, damaging surrounding hardware. My original thought was that a main tire blew, taking out the fuel feed pump. The engine surge or stall followed, throwing the plane into the sideways slew that ripped the tail off. All of this is conjecture. Hopefully, the NSTB investigators will not rule out all the possibilities. They have the hard evidence. We'll know in year after they have kicked this one around.

Get with the conspiracy, man. Rationality has NO place when a juicy opportunity to gin up a cover-up presents itself.

Which cover-up are you referring to -- defective aircraft or sabotage?

Once you answer this question why don't you explain to all of us why would refer to one "conspiracy" over another? Oh, and why would you choose the word "conspiracy" in this context. We are basically dealing with unknown factors leading to a crash, *not* a supression of evidence. *If* there was strong evidence for sabotage and yet the NTSB continued pushing an implausable explanation for the crash we might term that a "conspiracy" -- otherwise you're just throwing out the term in some mindless manner.

You theory of a tire exploding after the landing gear was retracted is the only mechanical failure theory I have ever heard that does not contradict what was witnessed and the information (like no engine trouble) that has been released so far.

There is also a precedent for failed tires causing planes to crash: a quick search reveals that in 1991 a DC-8 crashed in Saudi due to an undetected firecaused by failed tires. The plane lost control due to the spread of the fire after the gear was in the gear well.

This can probably be checked, however: Tire pressure is part of routine pre-flight checking and the logs on these tires have probably been examined already.

I personally have no use for spiritualistic Mumbo-Jumbo.

Then disregard the Christian message at your own peril.

I know you're not saying that the Christian message is spiritualistic
Mumbo-Jumbo but that is what your reply seems to say.

How can you believe in mysticism if you think it is Christian
but not also believe the opposite?

How can you tell the difference.

You don't think that evil people could post to "Elijah List?"

I chose not to believe in spiritualistic mysticism.

The new testament never admonished anyone to find a believer
with a "gift of dreams" to find out if the WTC is about to be
destroyed by Moslem Terrorists. Jesus never sent anyone
to the "Oracle at Delphi" or "Miss Cleo" to see what the future
held for them.

I chose not to believe in spiritualistic mysticism.

With all due respect, I can't understand why you would want
to be looking there for answers either.

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