vertical stabilizer AA 587

[SaturnV]

http://us.news2.yimg.com/us.yimg.com/p/ap/20011112/capt.1005600133plane_crash_nydd101.jpg

With apologies in advance to CaptPPRune who closed the previous thread on this crash, I thought this picture of the vertical stabilizer as retrieved from Jamaica Bay will be of interest to PPrune members. Jamaica Bay is between JFK and the crash site.

[ 12 November 2001: Message edited for typos by: SaturnV ]

[ 12 November 2001: Message edited by: SaturnV ]

[G.Khan]

http://www.aviationnow.com/ avnow/news/channel_maint.jsp?view=story&id=news/raa41112.xml (http://www.aviationnow.com/avnow/news/channel_maint.jsp?view=story&id=news/raa41112.xml)

This is the URL to the Aviationnow.com website. Looks pretty factual.

[ 13 November 2001: Message edited by: G.Khan ]

[ 13 November 2001: Message edited by: G.Khan ]

[strobes_on]

Does anyone know if there was any debris found on the departure runway after AA 587 become airborne ?

[GlueBall]

Most unusual debris pattern. It's difficult to imagine how an apparent uncontained engine failure might cause the vertical stabilizer to separate. (One of the engines found at the Texaco station had a large hole in the side of the cowling).

[Ranger One]

Agreed glueball... that picture is pretty worrying, possibly the most telling I've seen so far today. I can't see any trace of impact, tearing, or twisting... the tail looks almost as if it had just been unbolted. Loss of stabilizer -> total loss of control -> overstress -> breakup maybe? I can't conceive of any other scenario that would leave the tail so far from the main impact, apparently cleanly removed, with no obvious sign of damage.

Hopefully we'll know pretty quickly, whatever it was it must have been an impossible situation for the crew... RIP folks.

[ 13 November 2001: Message edited by: Ranger One ]

[CaptA320]

Without wanting to contribute in any way to the theorists I have to agree with Ranger One's assesment, very strange. My deepest condolences to the family members of the Crew and Passengers, may they rest in peace.

[Global One]

I recall that in the Mid 1970s a C-141 crashed after straying into a thunderstorm in England. The aircraft had rolled into 30 degrees of right bank in an effort to escape the thunderstorm, adding to the stress on the airframe already induced by the storm. At the crash site, number 4 engine and the vertical stabilizer were found together in an open field, hundreds of yards away from the main wreckage. That showed a historical correlation between engine separation and either stress on the vertical stablizer, or perhaps the engine actually striking the vertical stabilizer as it separated from the wing during. Of course, weather was no factor in the AA crash.

[N380UA]

Global One
A rather unlikely event. A power plant would not be striking the vertical stab, not even the horizontal after a separation. Looking at the picture, it does seem to be a clear "cut", as Ranger One has mentioned, "un-riveted" almost. I can't come up with any plausible scenario causing such a separation myself either. In any case the vertical stab being separated in such way, found in bay can't have anything to do with a possible uncontained blade separation.

[geoffrey thomas]

Beg to differ on the engine failure/tail theory. When the AA DC10 that lost an engine at Chicago in 1979, the engine flew over the wing and just missed the DC10's tail. In this case the blade failure may have been so severe that it caused the engine to separate and at that angle of attack after take-off the engine would have likely ripped off and over the wing. It may have then struck the tail a glancing blow, with various results.

[N380UA]

Golf
Would it not be more likely that the Vertical stab together with the empennage be found in the bay if the engine would have struck the tail?
If indeed the engine came loos at the pylons but be otherwise still intact the DC10 scenario seems plausible. However, in this case, first reports state that the power plant suffered an uncontained blade separation literally shredding its interior. In my opinion, this would present a different outcome of the engine trajectory.

[Kaptin M]

...except, from the photo, the tail appears TOTALLY undamaged (except for the missing rudder!).

[VIKING9]

My sincere condolences to all those involved in yet another tragedy.

Question: Is the A check (performed on this a/c on Sunday) of any relevance ??

[fionan]

Much as I hate to speculate about the manner of a fatal accident such as this I would just like to ask any driver of a large twin the following:

Catostrophic engine failure at take-off power + no rudder (according to above photo)= what?

I accept we don't know when the rudder separated but if it was while airborne ( engine debris? ) they would'nt have a prayer.

Incidently we can't see if there is damage to the other side of the H/Stabilizer.

R.I.P

[ 14 November 2001: Message edited by: westman ]

[SaturnV]

This picture*, which is not as good a perspective as pictures shown on television, is of the fan section of one engine. This engine is located in the yard of a house on 127th St. Another picture of an engine and cowling (or part of this engine?) posted on the closed thread is that of the engine that landed at a petrol station on 129th St. The engine in the yard is slightly to the left of the flight path; the engine at the station is slightly to the right. The main portion of the aircraft impacted at 131st St. (The streets rise in number going from east to west.) The vertical stabilizer was retrieved from the water several hundred yards or more to the northeast from where these engine parts impacted.

Radar trace information is as follows:
9:14.34 takeoff
9:15.02 1300 feet, 200 mph
9:15.36 "plane begins to climb more rapidly"
9:16.01 2800 feet, 306 mph (last trace)

(The above information courtesy of the New York Times.)

http://dailynews.yahoo.com/h/p/nm/20011113/ts/mdf84430.html

* The image will not post for some reason. Here is the URL address: http://dailynews.yahoo.com/h/p/nm/20011113/ts/mdf84430. html (http://dailynews.yahoo.com/h/p/nm/20011113/ts/mdf84430.html)

[ 13 November 2001: Message edited by: SaturnV ]

[ 13 November 2001: Message edited by: SaturnV ]

[RogerTangoFoxtrotIndigo]

the mayor said that a wing was also in the water north of the main debries, wouldnt that have had to depart the aircraft in flight too?

what are the coast guard saying, they must have had a cutter in jamaica bay, seemed to have no trouble finding wing and vertical stabiliser

incidently does anyone know anything about the investigation into the cause of the A310 crash off of the ivory coast in jan 2000. we are coming up for 2 years since that incident with no word.

[captainkilner]

If the wing was found in the bay also couldn't it have been this that struck the tail , correct the photo does make the tail look undamaged but the rudder is missing , could something striking just the rudder cause the whole tail to be torn off , also we don't know what the damage was to the rear of the aircraft below the tail , apparantly it nose dived into the ground suggesting maybe the whole of the tail may have been damaged.
Deepest sympathy to all the relatives

[SaturnV]

Reports of a wing having come off are apparently in error, with the vertical stabilizer being mistaken for a wing. Jamaica Bay is relatively shallow and I'm quite sure a wing would be easily spotted and recovered by now.

There are edge-on pictures of the stabilizer, and both sides look smooth and relatively undamaged.

[LATEST]

Sorry to ask for simple explanation - but could someone tell me in layman's terms what is the significance of the vertical stabliser being detached so cleanly - what does this suggest about the reasons for the crash. Pardon my ignorance

[moggie]

Latest - if the vertical stabiliser had been hit I (as non-engineer, I hasten to add) would expect there to be evidence of impact damage from whatever had struck it (such as an engine). Also, again as a non-engineer, I mught expect there to be tearing and buckling of the surface where it had ripped free. However, I do not know how the tail surface is attached to the fuselage and so it may be feasible that high enough stress could cause the fasteners (bolt, rivets etc.) to fail and if the vertical stabiliser is strong enough this may leave little or no damage on the stabiliser itself.

Bear in mind that an aeroplane that suffers catastrophic failures may display evidence of damage that simply does not look feasible to the non-engineer but which is actually quite expected as far as the accident investigators are concerned.

So, in answer to your question, I feel that there is non significance yet - the separation has to be taken as one part of a complex sequence of events which will require much more information (such as ADR and CVR info) to explain.

[LATEST]

thank you very much - that really helps me. I'm trying to unravel all the conflicting reports and scraps of information that are floating around. Much appreciated. xx

[Turtlenest]

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?

[John Farley]

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.

[E cam]

Could the fin have been detatched by yaw or side-slip forces? Alternativly, could the loss of the fin cause the seperation of an engine? Cause or effect?

[moggie]

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!

[Dagger Dirk]

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.

[Ranger One]

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.

[LATEST]

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 ?

[McGinty]

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?

http://news.bbc.co.uk/olmedia/1650000/images/_1653291_fincar300megan.jpg

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?

[buck-rogers]

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.

[quaerereverum]

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.

[I. M. Esperto]

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?

[EGGW]

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 :)

[JBravo]

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.

[Dagger Dirk]

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.

[Al Weaver]

Absolutely ridiculous speculation!!

Time to close this thread as well

[wideman]

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 (http://www.mostnewyork.com/today/News_and_Views/City_Beat/a-131935.asp)

[Eff Oh]

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.

[John Farley]

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

[brain fade]

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.

[EI - E I - O]

Does anybody know how may hours/cycles were on the Airframe/Engines since the A check?

[broadreach]

McGinty,

That's one of the wingtip "winglets".

broadreach

[The Guvnor]

I'm surprised that no-one has brought up the case of the Dan Air 707F in Lusaka where the vertical stabiliser also separated. I recall that was due to fatigue damage and resulted in ADs and eventually in the USAF buying a large proportion of the world's civil 707 fleet for their fins to extend the lives of their 135 fleets.

[Viscount Sussex]

Danny,
Please put this one also to bed!!
The 'experts' had a good go at it already. There is so much bull$... being thrown around. :rolleyes: :mad:

[Captain Numpty]

EI EI O.......

Don't know how accurate this is....but I heard a so called "expert" in the know claim that that one engine had 10,000 operating hours, while the other had 640. He then went onto say that he would have "trusted the older one more"??????? !!!!!!!!

DON'T ASK!

(On UK telly this morning, however I don't know what channel it was, sorry)

Terrible terrible events whatever the circs!

Kind regards to all,
C.N

[Not Invented Here]

Guv - wasn't the Dan Air 707 a Horiz Stab?

[MajorMadMax]

A tragic accident, regardless of the circumstances behind it. The following item really tore me up:

"According to police, the bodies included a man found holding a baby."

My wife and two young sons just flew to Baltimore on Saturday...

My thoughts and prayers go out to all the families and friends of the souls lost aboard the plane and on the ground.

M2

[PAXboy]

EI EI O: The following is taken from CNN today but credited as from Airbus and 'aircraftmuseum.com'. However, the 'wire' diagram that was displayed showed an A300 without winglets.

Tail Number: N14053
Owner: Wilmington Trust Company as Trustee
Leased by: American Airlines
Initial service date: July 12 1988
Passenger capacity: 266
Cockpit crew: 2

Maintenance dates:
November 11 2001 - A check
October 3 2001 - B check
December 9 1999 - D check
Next scheduled D - July 2002

Engines: GE CF6-80C-2A5
Left engine - 694 hrs since last overhaul
Right engine - 9.788 hrs since last overhaul

[ 13 November 2001: Message edited by: PAXboy ]

[Kaptin M]

This thread is reminiscent of a car accident when crowds gather around to "Ooh, and ahhh...isn't it shocking." Some of the posters obviously have NO aviation experience, yet insist om making stupid[b] and [b]ludicrously innacurate statements, thus cluttering what started out as an informative posting.

Would the "idiots" please DESIST!

[bluecrane]

Regarding brainfade`s question about the vertical fin structure: Yes, it is made of CFC (Carbon Fibre Composite).
In the news there have also been suggestions that the pilots tried to dump fuel. There is no fuel dump function on the A300-600, it is not necessary, you can land at any weight.

[Airbubba]

>>Don't know how accurate this is....but I heard a so called "expert" in the know claim that that one engine had 10,000 operating hours, while the other had 640. He then went onto say that he would have "trusted the older one more"??????? !!!!!!!!<<

I remember early in my career an oldtimer told me "Son, there's two things I don't trust. One's old airplanes. The other is new airplanes..." Good advice.

[Turtlenest]

Best talking head comments, not: 1-"Engine was due it's $10,000 check". 2- "Suprising that the fireball was contained so quickly as there was 100,000 gallons of fuel on the A-300."

[EI - E I - O]

I asked How many hours since the "A" check?

Facts please or pull the Fire Handles on this one as well!

[SaturnV]

The NTSB reports no bird or foreign object damage to either engine, and no obvious sign of catastrophic engine failure in either engine. The vertical stabilizer was found one half mile east of the fuselage. The rudder was also found today in Jamaica Bay, and the flight data recorder recovered as well and flown to Washington for analysis. Both engines separated from the aircraft before impact.

From the Cockpit Voice Recorder as reported by the NTSB:

107 seconds after takeoff roll: airframe rattle sound.

114 seconds: pilot remark of 'wake encounter'. (Apparently in reference to a Japan Airlines 747 8 miles ahead.)

121 seconds: airframe rattle sound.

125 seconds: call for "maximum power"

127 seconds: a remark about 'losing control'

144 seconds: end of recording.

Speculation is now turning to thinking that the vertical stabilizer separated first from the fuselage. If indeed such separation was the proximate cause of the accident, what caused this to happen is unknown.

In my post above on the radar trace (assuming the radar trace values are accurate), both the rate of climb and the acceleration in speed seems to be more consistent with normally functioning engines than what might be expected if an engine had experienced a major failure. However, a company pilot on the ground at JFK is reported as supposedly saying he saw smoke from one of the engines as the airplane took off.

In any event, the flight data recorder should provide some answers very soon. As Air Force One has these engines, I am certain that both the Air Force and the Secret Service want answers quickly.

[ 14 November 2001: Message edited by: SaturnV ]

[QAVION]

"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"

Don't you mean in front of the rear pressure bulkhead? If behind the bulkhead or on the top of the tail, then an Airbus is indeed a strange bird... and nothing like any of the Boeings and MD's I've worked on (and changed DFDR's or CVR's on). I am more inclined to believe that these boxes will be warm and cosy somewhere inside a pressurized area.

If you need to know exactly where it is, post this question on the Tech Log or Engineers forums on this site ;)

Q.

[jugofpropwash]

A question from someone who admittedly knows little on these matters: What would be the result if the rudder suddenly and unexpectly deflected to it's maximum deflection during a fairly steep climb? Could this (and perhaps the pilot's efforts to correct) have overstressed the stablizer and torn it off?

[411A]

Quite right, Level 1 or better, it indeed was the horiz stab on the B707 (port side actually, forward attach fitting))and it separated when the flaps were selected to 50...and resulted in an FAA (and CAA) airworthiness directive in short order.

[knackered]

EI-EI-O,

Last 'A' check was the day before.

[N380UA]

jugofpropwash
I regard it as unlikely that the vertical fin would be overstressed during that phase of flight. Bare in mind the inertia of the mass, with exception of a running engine of course is not high enough to cause anything to go beyond it's design stress limit. In addition, the actual point of failure is at 150% of design.

The news this morning mentioned an unidentifiable clicking sound for a short period of time twice before any reaction of the crew was noted. Any A300 driver out thee able to shed some light on the sound?

And on the byby folks, this forum is for professionals of this industry, what ever their opinions or believes, to discuss and speculate about such events. Should anyone feel the need for hard facts and noting else consult www.faa.gov (http://www.faa.gov) or www.ntsb.gov. (http://www.ntsb.gov.)

[The_Cutest_of_Borg]

Vertical stabiliser separates due wake turbulence encounter and perhaps other factors..(maintenance?) causing loss of directional control. Aircraft enters stall/spin and sheds engines due to high rotational forces.

Speculation? Yes. But possible and fits the facts as they are reported.

[N380UA]

Short of little green man from Mars attacking, everything is possible." :D :rolleyes:

[DoctorA300]

Qavion,
You are quite right, the FDR and CVR are located in the Aft accesory compartment, just in front of the bulkhead.
If the fin, for one reason or another, departed the a/c first, I seriously doubt that it would have had such serious implications so fast, and it certainly wouldn´t have caused any engine to "eject" either. It sould be quite easy to determine anyway, it, the V.Stab, is attachted with 6 rather large "pins" 2 in front and 4 aft. I don´t think that it poses any difficulty to examine and establish weather or not it was propperly attached before takeoff.
On the other hand, the fuel found in Jamacia bay would indicate a large fuel leak, and taking into account the maintenance history, it might be plausible the a incorectly installed, or faulty, LP fuel filter leaked, filled up the cowlings and at one point exploded. I´m not an expert, but I have experinced something similar on a CF6-50.
Brgds
Doc

[sokoyu]

My heart goes out to all those who've lost family and friends in this accident.

As a follow up to an earlier post, does anyone out there know anything about the KQ A310 that went down off Abidjan in Jan 2000? I can find no follow up anywhere almost two years later.

[Middle Marker]

At the 121 seconds after Take-Off did buffetting occur?
As a collegue earlier stated, rupture of the vertical stab is not very likely due to large manual deflections, but what in a case of an actuator-runaway or rupture of the aft-bulkhead (referring to an earlier accident of a JAL 747, this will result in a clean rip-off of the tail..)
The first does not explain engine-involvement, but what if the engine exploded without containment, and debris of that explosion hit the tail of the aircraft just in front of the aft bulkhead, and damaging this bulkhead??

Clearly a large flock of birds -as media state- does not seem to me a cause to this....

My condolances go out to the people involved.

D

[N380UA]

In reffernce to Kenya airways last year I got following link I hope it works, not much info though.
Airline Disaster (http://dnausers.d-n-a.net/dnetGOjg/300100.htm)

[G.Khan]

Middle Marker - I think you will find that in the case of the JAL 747 the aircraft was pressurised and the cabin air then vented through the ruptured rear bulkhead in to the fin. As the fin was not vented it came apart. Subsequent modifications should now prevent this happening. In the case of this A300 I doubt it was sufficiently pressurised after only three minutes of flight to have a significant effect, apart from which, going by the photos', the fin is relatively undamaged. My opinion only.

[ITman]

I found this information on the Airwise web site:

14-Nov-2001 12:56 AM U.S. EST


As work continued into the night on reading the plane's flight data recorder, investigators late Tuesday revealed several new clues about the crash of American Airlines Flight 587, but the information merely deepened the mystery of what caused the accident.


With both of the Airbus A300-600's engines and its vertical stabilizer coming down before the rest of the airplane, early accident-related speculation was on a catastrophic engine failure that triggered collateral structural damage. But investigators have found nothing that backs such a scenario, and the near-pristine condition of the tail pieces indicates that something besides debris caused them to separate from the plane.

Visual inspection of the plane's two engines showed "no physical evidence" of an engine or fan failure, U.S. National Transportation Safety Board (NTSB) Investigator-In-Charge George Black told reporters in the first of two briefings held late Tuesday. Black also confirmed what AviationNow.com reported several hours before the briefing: neither of the General Electric CF6-80C2 engines showed evidence of a bird strike.


"We will have to await tear-down to completely analyze the condition of the engines and any part they might have played in the accident," Black cautioned, adding that both engines will go to American's Tulsa, Okla., maintenance base for disassembly.


While an engine failure seems less remote based on the lack of evidence, other facts clearly indicate that something went suddenly and terribly wrong shortly after Flight 587 left Runway 31 Left at John F. Kennedy Airport Monday morning. All 251 passengers and nine crewmembers were killed when the jet plunged into a residential waterside area of Queens, New York.


In perhaps the most perplexing development Tuesday, the A300-600's vertical stabilizer and rudder were pulled from Jamaica Bay -- about a half-mile from the main debris site -- and both pieces "appear to be complete," Black said. Television images of the tail showed no marks, holes, or other structural damage that would indicate that the tail was knocked off by debris -- such as from a disintegrating engine.


Relying on what Black described as a "second quick look" at the cockpit voice recorder (CVR) tape recovered hours after the accident, investigators have determined the first part of the flight was "normal."


About three minutes into the flight -- or 107 seconds after power was applied to start the A300-600's takeoff roll -- an "airframe rattling noise" was captured on the tape, Black said.


Seven seconds later, one of the pilots mentioned a "wake encounter," but there was no further discussion, Black said.


At 121 seconds, a second rattling sound is heard.


Four seconds later, the first officer called for maximum power to the plane's engines. This could indicate several things, such as setting up engine thrust to help steer the plane -- an option to compensate for a lack of rudder control -- or an effort to climb in preparation for an emergency return to JFK.


At 127 seconds, one of the pilots indicated that control of the plane has been lost.


The recording stopped 144 seconds after takeoff power was first applied.


The vertical stabilizer and rudder were pulled from Jamaica Bay Tuesday, and both of them "appear to be complete," Black said. Television images of the tail showed no marks, holes, or other structural damage that would indicate that the tail was knocked off by debris -- such as from a disintegrating engine.


The CVR information alone doesn't reveal when Flight 587 took off or how long it stayed airborne, Black said. The CVR information will be merged with data from the FDR, air traffic control radar tapes, and other sources to develop a detailed look at the plane's flight profile.


The rattling noises captured on the CVR will surely get significant scrutiny from investigators. Black, who was relaying information from other investigators and has not listed to the tape, could not provide details on the noises.


Aside from the two rattling sounds, Black did not indicate that other unusual noises were captured by the CVR. In the past, onboard explosions -- such as what would occur due to an uncontained engine failure, fuel tank ignition, or bomb detonation -- have often been picked up on recorders.


"Not only are words important on a tape, but sounds are important," Black said.


While no sounds pointing to explosions have been picked up from the CVR analysis sessions, Black said investigators noted "noises" on an air traffic control tower tape of communications between controllers and Flight 587. The noises -- which Black did not describe in detail -- were heard at about the time crew lost control. He did not say what the sounds indicated.


Detailed analysis of the tapes and coordinated timeline of the events will help shed more light on how the clues fit together, Black said. Transcription of the CVR is slated to begin Wednesday, with participation of representatives from France's Bureau Enquêtes-Accidents as well as Airbus.


Flight 587 took off about two minutes and twenty seconds behind a Japan Airlines 747-400, Black said. While investigators will examine that fact in connection with the Flight 587 crew's reference to wake turbulence, Black noted that the separation between the two jets exceeded the two-minute requirement.


Evidence from eyewitnesses has provided some insight on Flight 587's final moments, Black said. Members of two airline crews that witnessed at least part of the American Airlines jet's final flight have been interviewed, and each pilot tells roughly the same story, Black said. Each pilot recounted that Flight 587 "wobbled," spiraled out of control, and went down at a severe nose-first angle, Black said.


Black said a construction worker shot video of Flight 587's takeoff roll, but turned his camera away as the A300-600's gear was retracting. Black did not indicate that the tape showed anything amiss with the plane during the departure, but investigators are hoping to talk with witnesses -- including airline crews -- that were on the ground as Flight 587 taxied out and took off.


Investigators have not determined if any debris was on the runway when Flight 587 took off, but Black said the board hopes to have more definitive information in the coming days.


All major parts of the plane have been recovered, Black said. The vertical stabilizer and rudder were pulled from Jamaica Bay. The rest of the plane, including both engines, came to rest on land.


Flight 587 took off to the northwest and investigators believe it completed about half a turn and was heading southeast when it began to break up. Black said the Airbus stopped sending transponder signals at an altitude of about 3,000 feet, indicating that something -- such as a major structural failure -- cut the unit's power. "Primary" target returns -- indicating aircraft or large pieces of debris without working transponders -- began at that point, Black said.


Tracing the plane's assumed flight path, the vertical stabilizer was the first piece of debris found, followed by the rudder about 200 yards further down the flight path. Both pieces were in the water, about half a mile from the main crash crater.


The plane's No. 1 engine ended up in a gas station parking lot about 700 feet from the crater, while the No. 2 engine came down in about 800 feet from the main crater. All of the debris is "more or less in a line," Black said.


A sweep of a 16-block area around the crash site turned up one additional piece of wreckage, and a helicopter flight over the area indicated that no major pieces remained in the shallow bay waters. Divers made 15 trips into the bay Tuesday and found nothing substantial, Black said.


Examination of the wreckage showed that the plane's flaps were retracted, which would be expected during a climb-out. The horizontal stabilizer jackscrew was in the neutral position, while the rudder trim actuator indicated a 10-degrees left displacement.


Black also released information on Flight 587's two pilots. The captain was a 16-year veteran of American and had 8,050 total flight hours, including 1,723 as the left-seat occupant on an Airbus A300-600. The first officer joined American in 1991 and had 4,400 total flight hours, including 1,835 as an A300-600 first officer.


Tuesday's progress meetings, attended by more than 100 investigators, included updates from most of the subgroups tasked with probing specific aspects of the accident. Progress reports from the maintenance, human factors, flight data recorder, and cockpit voice recorder groups are expected in the next day or two.


The maintenance group has been sent to Tulsa to review the A300-600's records, while the two recorder groups were working to extract detailed information from the plane's CVR and FDR.

:(

[Capt Chambo]

Re: the Kenya Airways A310 that crashed off Abidjan( Ivory Coast).
I believe the accident investigation was to be done by the Canadians. Their accident investigation website can be found on the following URL: www.tsb.gc.ca/ENG/ (http://www.tsb.gc.ca/ENG/)

I have just checked the website and their is no reference there yet to the accident.

[ 14 November 2001: Message edited by: Capt Chambo ]

[Jackonicko]

While drawn to 'Cutest of Borgs' hypothesis, I have to ask whether a half mile difference between wear the engines landed and where the fin landed 'proves' anything about the order of the 'break up'?

Engines will follow a fairly predictable ballistic path, based largely on momentum and gravity whereas a tailfin could 'fly' or 'sycamore leaf' down. I'm inclined to believe that the aircraft broke up after it lost control, rather than before - but then that's speculation, too.

[SaturnV]

Additional details (from today's Washington Post) which hint at a possible composite failure in the tail section.

"One piece of evidence raises the likelihood that the crew thought the right engine had lost power: The rudder trim setting was found in the crash at a hefty 10 degrees to the left, indicating the crew was using
the long, flat, movable panel at the end of the vertical tail fin to compensate.

"Yet the left engine appears to have torn off first. And some investigators are beginning to suspect that the vertical tail fin and rudder -- found back along the flight path in Jamaica Bay -- actually left the plane before the engines did.

"Investigators found that the fin's attachment points were intact, and that the failure seemed to lie at the base of the fin, which is made up of composite materials. Manufacturers have described the composites as stronger than metal, and the failure raises the possibility that the composites have been overrated."

Jamaica Bay has been searched along the flight path. Visibility in the water is reported as being very good, e.g., tyres can be seen on the bottom, and no other parts of the plane have been spotted there.

[Airbubba]

I just read this morning's Washington Post article as well. Looks to me like perhaps a rudder trim runaway just after liftoff. The yaw may have been the reason for an engine failure call and then a vertical stab separation.

[InFinRetirement]

Oh dear! Yet more speculation! Have you informed the NTSB of your findings Airbubba?
Perhaps the noise and rattles heard on the CVR 127 seconds after takeoff will support your theory - then again perhaps they won't.

[Eff Oh]

I just can't see how a rudder trim runaway, or rudder hardover could cause it to fall off! The aircraft had just got airborne, therefore I doubt the airspeed could have been high enough for this to happen. If it was in the criuse then maybe....

The CVR tape did not indicate that the crew thought that they had an engine failure. It talks of "Wake" and "Losing control" but no engine failure/fire call!! Perhaps this has just not been released yet. There was also no talk of any Warning noises on the flight deck. ECAM or whatever they have. I think it is strange that this has been ommited from the tape, and that no comment was made as to the nature of the problem. The only call seems to be, as I said, of losing control.

However it was just a preliminary report of the tape. I am sure we will find out more in the coming days.

Also, as someone else mentioned,the aircraft would not have sufficient pressure to blow the tail off!
This just gets stranger as the days go on!!
Eff Oh

[slim_slag]

Here's one where the fin went AWOL first, followed by all the engines...

BOAC 911 (http://www.airsafetyonline.com/indepth/ayers/911.shtml)

Pretty violent turbulence, could a fin really get ripped off by a departing heavy's wake vortices?

[Techman]

Perhaps off topic, but has anyone heard from Wino?

[Middle Marker]

I agree with Mr. Kahn that the fuselage could not be sufficient pressurized at 2800ft to blow the tail of as happenend with the JAL-aircraft...
The sounds might indicate the rupturing of the vertical stab, considering as of that moment no control could be regained.
Fatigue of the materials then?

I disagree with the possibility of wake-turbulence, for 2 minutes behind a departing aircraft won't lead to such an excess in damage...it would be more probable behind an aircraft in landing config, but that's not the point....

Strange situation....somebody blamed martians...may-be??

Cheerz
D

[sky9]

It might be worth putting this on your "favorites" page. http://www.faa.gov/avr/aai/iirform.htm

[SaturnV]

On television this morning, George Black of the NTSB said that the fracture of the vertical stabilizer appeared to be consistent with what might be seen as the result of a side load gust. The television showed close-up video of the stab being hoisted onto the dock and it did appear the fracture was on the left side (the side not visible in the page one photo) in a composite area (the bottom edge of the stab looked rather jagged). A meterials expert is to study the stabilizer in detail today.

The JAL 747 has been reported as being 7 to 8 miles ahead of AA 587. A preliminary analysis indicates that AA 587 was flying within the wake zone of the 747.

The flight data recorder was sufficiently damaged that it is being sent to the manufacturer for readout.

[ 14 November 2001: Message edited by: SaturnV ]

[Drop and Stop]

slim_slag, I remembered reading about BOAC Flt 911 (G-APFE), just re-read it again (Air Disaster Vol.1 Chapter 5, by Macarthur Job).

It states: "The tail fin had fractured at its attachments to the fuselage, the starboard rear attachment fitting having failed at its upper bolt holes in tension....All engine mounting pylons were fractured at their wing mounting points as a result of a predominantly leftward roll (after the separation of the vert. stabiliser)."

All very interesting, I guess we’ll have to wait for the NTSB to complete its investigation to find out the complete chain of events.

[I. M. Esperto]

I've never flown the A-300 but is seem to recall reading about the take-off being mostly under the control of the autopilots 7 (?) computers. Idf so, could this be a factor?

Also, I understand the side "joystick" has no feel or feedback. Is this a possible factor?

Most of my time is in the Boeings.

[Row 12F]

Whenever I buy cigarettes in a small corner shop, walk down the street, cash a cheque at a bank or, hopefully, check in for a flight the video cameras record the event – just in case. Why does this not happen for the expensive and relatively dangerous events of planes taking off and landing? It would surely cut down speculation, help investigators and thus it could help to reduce future risks. Any airport managers have a comment, apart from cost?

[N380UA]

The A 300 is a early model of Airbus and was not equipped with the side stick.

[pete sahut]

This tracic accident reminds me of a discussion we saw here some days back, about cockpit cameras and the likely misusage of the content by others than accident investigators. In this particular accident, I think cockpit cameras would have been of very limited usage (-and yes, I am against them), but recording cameras pointing lenses to specific parts of the aircrafts like the tail, wings, undercarriage etc. would have been of much more value, at least in this case for the investigation of the accident.
I am also sure these outside cameras -if technically advanced, would increase safety and be very useful during many ground operations, e.g. to monitor flight control checks, flaps, ice or snow on wings, closed/open fuel panel, if towbar is disconnected (its often hard to hear the groundman when eng. are running after start), status of landing gear with unsafe cockpit indications in flight etc. etc....

Best wishes to the families of those lost.

[MFALK]

I.M Esperto, you are truly unworthy of your alias. Otherwise, you would have known that unlike the later generation A320 family, the older A300s do not have a side stick but a conventional yoke.

[PAXboy]

I should like to respond to those that call for this thread (and similar ones) to be stopped.

All that is happening in this thread is an extension of what is happening on the ground. If this prang had happened the day before a PRRuNe Bash, then it would have been the subject of conversation for many. People would relay information heard and relate their experience of similar a/c etc.

Some would say, "I'm not going to speculate about this." and go off to chat with others on other topics. Some would avidly discuss it all evening.

It is human nature to try and make sense of the world we live in and the life that we have made for ourselves upon it.
We all know that it will take months for a definitive result but the lives and livelihood of those posting and reading may depend, in part, upon this. Those that do not wish to read the thread, do not have to

As to the charge that journalists may read the thread and then speculate in public, they have always done that! I am sure that when my grandfather was discussing these sorts of topics at Hendon and Croydon airfields in the 1930s, there would have been plenty of journalists ready to buy him a drink and try to get more information.

I can only repeat, discussing this subject is no different to discussing any other, we are being human.

[Eff Oh]

I. M. Esperto
I think what you read with regard to autopilot controlling the take-off, may refere to the autothrottle. As in the Boeing (757 in my case) The autothrottle controls and sets the required EPR or N1 as commanded.

Also the A-300 has no side stick. It has some EFIS and conventional controls. Check out www.!!!!!!!!!!!!!! (http://www.!!!!!!!!!!!!!!) and search for A-300 flightdeck pictures.
Eff Oh.

[Richthofen]

I remember this report ealier this year :


AIR safety experts have ordered urgent inspections of hundreds of jet engines because it is feared they could
disintegrate, blasting shards of metal into passenger cabins.

The alert follows three failures in the CF6 engine made by the American company General Electric (GE). The most commonly used engine in wide-bodied passenger jets, it has been in production for 25 years. More than 5,000 have been made, each costing up to £6m.

The Civil Aviation Authority (CAA) has carried out a risk assessment and identified 42 British planes with the engines. It is liaising with American authorities to ensure that they are inspected and overhauled.

No aircraft have been grounded, although the National Transportation Safety Board in America has given a warning that the faults could cause a "catastrophic accident".

Aircraft engines are supposed to contain any problems; if there is internal damage, failed parts are designed to eject safely out of the rear.

If broken components shoot through the engine's casing in an "uncontained failure", this could cause a plane to crash. If a hole is made in a plane's cabin, passengers could be sucked out by the low air pressure at high altitudes.

More than 5,000 General Electric CF6 engines have been manufactured. It is fitted to airliners such as the Boeing 767 (above), the DC-10 and the Airbus.

The Federal Aviation Administration (FAA) has issued a stream of airworthiness directives requiring immediate scrutiny of the oldest engines.

This follows incidents which have rocked faith in the engine after 200m hours of almost trouble-free flight. They include:

Partial disintegration of the left CF6 engine on a Brussels-bound Continental Airlines McDonnell Douglas DC-10 on takeoff at Newark near New York last April. Fragments of metal ricocheted off the runway and disabled the right engine. The pilot circled for 30 minutes dumping fuel in preparation for an emergency landing. The plane landed safely using its tail engine.

In two other incidents last year Continental had to abort takeoffs at Newark and Amsterdam after engine failures. The problem was blamed on failure of a lock which caused normally stationary nozzles to rotate and cause damage. GE has introduced a metal plug to hold the nozzles in place until a new nozzle lock can be fitted.

The captain of a Varig Airlines Boeing 767 was able to brake and abort a takeoff in Sao Paulo, Brazil, in June after a CF6 engine partly disintegrated. The failure was blamed on metal fatigue inside the compressor.
This caused cracks in the titanium spools, a series of discs which hold the spinning blades that compress incoming air. If the blades come lose they can shoot through the engine casing.

GE has been ordered to increase inspections of the spools and is offering airlines large discounts to replace them with new ones.

A CF6 engine on a US Airways jet undergoing maintenance checks blew apart on a taxiway at Philadelphia in September when a disc failed in the high pressure turbine, showering parts into a nearby river.

GE admits that the cause of this latest incident is still a mystery and experts have called for a review of the design of that part of the engine. Measures to rectify the other two problems will cost the company up to £20m.

Rick Kennedy, spokesman for GE Aircraft Engines, said there was a "real sense of urgency" at the company. It had undertaken an exercise to inspect 300 engines 12 months earlier than had been planned.

He added: "There are 4,000 aircraft takeoffs each day using CF6 engines. Without minimising the seriousness of these failures, the sheer statistics are such that it is pretty rare."

A CAA spokesman said: "We are aware of the problems that have occurred. We are working closely with the FAA and liaising with British airlines to make sure they comply with the airworthiness directives that have been issued. We have not had to ground any planes."

British airlines said that where necessary they were complying with the directives. British Airways, which usually buys Rolls-Royce engines, said it had only one plane, a DC-10, with CF6 engines but it was up for sale and had not flown for several years.

Virgin Atlantic's planes have GE engines built after 1995, which have not suffered any of the problems. The charter airlines Monarch, Britannia and Air 2000 said their CF6 engines had undergone the necessary tests.

Bill Gunston, editor of Jane's Aero-Engines, said the CF6 was an engine designed 30 years ago that had experienced few problems until now. "There are captains of big jets who were not born when it was first undergoing tests, so it shouldn't be doing this sort of thing now," he said.

http://av-info.faa.gov/ad/NPRM/2000ne30.htm

[blended winglet]

apologies if I'm raising a point already covered;

Is it possible perhaps that 1 engine unit detached, which at T/O power, induced a massive yaw (& secondary effect roll) with the remaining unit still attached, depending on when that other unit also detached (?),
this yaw/roll could perhaps have induced a
side load large enough to detach the fin
(if it was in some way weaker than at build,
e.g. perhaps over stressed at some point damaging the composite mat'l...(danger with composites can be that damage is not always visible)

I would EMPHASISE that this is of course only speculation & a question point.

Finally, sincere sympathies to all involved
words do not offer much help, but at least
it helps maybe that people care.

(I was V cross seeing the TV reports that, as usual insisted on showing poor folks
hearing the awful news, TV guys - some advice, please dont show it, it is private
grief for these poor people)

keep safe everyone,

[ 14 November 2001: Message edited by: blended winglet ]

[747FOCAL]

Has anyone heard if they found the "missing" Cessna 172 that was inbound to New York at the time?

[Wino]

Techman,

I am alive and as well as can be expected. I flew that trip on Sat (2 days before). With 9 funerals to go to, I won't be as busy here as usual.

Thanks for your concern
Wino

[I. M. Esperto]

Gentlemen - Thanks for straightening me out on my misconceptions about the A-300 controls.

The BOAC 911 investigation resulted in restricted use of the spoilers on the B-707's. It was felt that using them in descent in turbulent air could induce the sort of structual failure that brought 911 down.

Todays newspapers indicate that the engines were intact (indicating no massive failure?).The CVR came up with a rumbling noise, and a voice said "wake encounter".
http://www.nj.com/news/ledger/index.ssf?/page1/ledger/15024f6.html

At this time, I for one would NOT rule out sabotage.

[ 14 November 2001: Message edited by: I. M. Esperto ]

[N380UA]

What 172? Any details on that? It's new to me.

[Capt H Peacock]

I have to say that I would go along with the overstress theory. If they did suffer a failure and subsequent separation of number one engine, that close to the ground, and an encounter with wake, the temptation not to slam on as much rudder as possible must have been insuperable. The left engine is on the inside of the turn for a Breezy Point or Carnarsie climb, and the sudden loss of power and significant disturbance in roll ensuing a separation would have left controlability marginal to say the least.

I suspect that the sudden application of full rudder coupled with the lateral load due to the thrust assymetry was simply too much for the vertical stabiliser. A truly tragic accident, and one that all of us would have found virtually impossible to counter.

I was crossing the pond at the time, and it sent shivers down my spine as the incident was reported piecemeal over the radio. I feel deeply for the colleagues of the AA flight crew as they heard bit by bit of the demise of their colleagues. The tremble in the voice of the New York controller was palpable as she broadcast 'suggest you utilise all prudent security measures'. You could hear the 'Here we go again' being pondered by everyone involved.

I feel ashamed to say that thank God it seems it was only an accident. For those who have lost loved ones, it is disaster just the same. Deepest sympathy.

[747FOCAL]

I think it is more likely that the first shudder felt was from initial failure of the tail and it "lifting" partially off the fuselage. The second shudder probably came when the fin came off completely. Wake turbulence, they must think we are daft! :mad:

[Al Weaver]

blended winglet

I'm encouraged by someone at least asking a questions, such as yourself, rather than making uninformed point by point statements of their idea of the sequence of events.

I support your kind of discussion following an accident, rather than the latter.


Only by group discussion of experts should anybody attempt to put together a trail of findings/analysis. I know that collectively there are experts on this forum, but I doubt that any one person has sufficient expertise to set forth some of the speculative scenarios I saw on the earlier pages, especially when they are counter to historical facts.

For background material the members might consider previous experience with widebody twin aircraft relative to gust loading tearing off engines and/or tailfins, or engines themselves catastrophically failing and tearing either themselves off or the tailfin off.

The products flying today have immense margins against this type of loading.

[Capt PPRuNe]

Time to put this one to bed as it reaches 100 replies.

Thank you to the experts who have put forward hypothesies which are palusible and goodbye to the 'experts' who obviously have no idea what they are on about but like the way they 'sound'.

One point reference the 'wake' comments heard on the CVR, I would suggest that perhaps the pilots 'thought' the vibration or shuddering he was feeling might be due to wake turbulence as a catastrophic structural failure is not likely to be the first thing that springs to mind.

For the uneducated in flying matters I would just like to point out that in ANY situation we pilots are taught to AVIATE, NAVIGATE and COMMUNICATE in that order and so those of us who fly for a living will have sympathy for the pilots during the horrendous events that overwhelmed them and of course for the rest of the crew, passengers and people on the ground and their families and friends.