Pilots of Doomed Jet Unaware Tail Fin Fell Off

Reuters | 10/29/02 | John Crawley

[kattracks]

WASHINGTON (Reuters) - The crew of a doomed American Airlines jetliner apparently was unaware the tail fin had fallen off as they struggled to control the plane before it crashed last year into a New York neighborhood, killing 265 in the second-worst U.S. aviation disaster.

Cockpit voice recordings released by the National Transportation Safety Board at the start of public hearings into the crash shed little light on the cause of the disaster. But they established a critical time line for events and illustrated the dramatic final seconds of Flight 587, an Airbus A300-600. Safety board investigators are probing a number of factors -- including actions of the crew, rudder movements, and the possible role of turbulence generated by a bigger plane -- in the crash that occurred 103 seconds after takeoff on Nov. 12, 2001, from John F. Kennedy airport en route to Santo Domingo, Dominican Republic.

The crash took place just two months after the catastrophic Sept. 11 hijackings, and immediately raised concerns it might have been another attack. But the safety board said then, and again on Tuesday, that the crash appeared to be an accident.

"There is no indication to date of any criminal activity associated with this crash," Carol Carmody, the acting safety board chairman, said at the hearing.

Investigators also said weather, which was clear at the time of the ill-fated flight, maintenance, air traffic control procedures, and engine performance were not factors in the accident.

There were also no apparent problems with the rudder before the flight, which is a critical finding.

Investigators believe a series of aggressive rudder swings a little more than a minute into the flight created substantial aerodynamic stresses on the tail fin, or vertical stabilizer, and caused it to break off the fuselage.

The safety board believes the crew was in full command of the flight controls, including the rudder movements. There have been some reports of rudders on other Airbus planes moving on their own without a pilot stepping on the pedals.

The voice recordings, which can provide a wealth of information for investigators, included comments from the pilot, Capt. Edward States, and the co-pilot, Sten Molin, who was flying the plane, as well as sounds heard by the crew.

The flight recorder captured routine conversation before takeoff, and the clipped jargon of cockpit procedures during the first minute of the flight, which was normal.

But then the plane encountered two wakes, similar to horizontal tornadoes, generated by a Japan Airlines 747 that took off from the same JFK runway two minutes before Flight 587 and was flying about 5 miles ahead.

The first, according to documents released at the hearing, was little more than a bump as the American jet crossed over it.

"Little wake turbulence, huh?" asked States.

"Yeah," Molin said.

Flight 587 hit the second wake seconds later as it began to turn left and climb to 2,400 feet. The cockpit recorder noted one "thump," followed by two more, and then a call by Molin in a "strained voice" for "max power."

While boosting the engines, the crew initiated a series of rapid back-and-forth rudder swings.

"You all right?" States asked.

"Yea, I'm fine," Molin replied.

"Hang onto it. Hang onto it," States called out.

There was a snap, another thump and then a loud bang, which investigators believe was the tail fin falling off the aircraft traveling at roughly 240 knots.

A roaring noise filled the cockpit and then two chimes sounded seconds apart, indicating the engines had fallen off. Engines are designed to break off when a plane spirals violently.

There were no indications from the recordings that the crew was aware the tail fin had fallen off the plane, as the pilots frantically struggled to determine what went wrong.

"What the hell are we into? We're stuck in it," Molin said after the tail fin had separated.

"Get out of it, get out of it," States said.

The transcript ended two seconds later at impact.

American is a unit of AMR Corp . Airbus, owned by European Aeronautic Defense & Space Co NV and Britain's BAE Systems Plc., which has defended its rudder system throughout the investigation.

[Bobby777]

I believe this was the first shoe bomber

I hope no tin foil is required but this is my belief too ... since the eyewitnesses reported the fire you mentioned ... it's only necessary to fracture the fuselage of an aircraft and then speed and airflow will do the rest ... perhaps the *bang* they heard was the show bomber going off ... I'd like to see a seating chart, the point of initial breakup, and the name/country of origin of every passenger in that area of the aircraft ... it was too dang close to 9/11 and the next shoe bomber ... coincidences do happen but this seems strange ...

[Slicksadick]

The ratio L/D is sometimes called glide number, or glide ratio, or finesse.
Boeing B707-320 19.4
Douglas DC-8 17.9
Airbus A320 17.
Boeing 767-200 19.
Boeing 747-100 17.7
Douglas DC-10 17.7
Lockeed Tristar L1011 17.0
Douglas DC-9 (1966) 16.5
Boeing B727-200 16.4
Fokker 50 (1966) 16
Douglas DC-3 (1935) 14.7
Ford Trimotor (1927) 12.
Wright Flyer I (1903) 8.3


Table 3: L/D of Some Birds Bird L/D
House Sparrow (passer domesticus) 4.
Herring Gull (larus argentatus ) 10.
Common Tern (sterna hirundo ) 12.
Albatross (diomeda exulans ) 20.

[banjo joe]

Pilots always strike me as brave and professional all the way to their last breath.

You always hope to pull it out and recover. What they don't tell you in these transcripts are the last two words, just when it's realized that you're out of altitude (and options)...

[eno_]

The tail fell off. But was that the initiating event? Another good question. This account ignores the fact that three widely separated parts of the plane came off. The only common cause for that would be air load, and the only way that could happen is if the plane is already out of control.

Google up "unusual attitude." It isn't uncommon for planes to come apart AFTER they cannot be controlled.

And, as you point out, ignoring th eeyewitnesses makes this a pretty blatant propaganda piece.

[KellyAdmirer]

Interesting facts, but I would prefer to have the possibility of regaining control rather than the almost utter certainty of a horrendous crash. Doesn't it make a difference to those numbers whether the plane is fully loaded?

[Doctor Stochastic]

You left out the Death of Wellstone Incident.

[eno_]

In the ABSENCE of any turbulence that would do more than make a drink slosh, the plane made two fairly violent sideways movements. Two loud noises were heard on the CVR. The shoe bomber that was thwarted had two separate bombs.

Moreover, while the tail and engines coming off are something of a mystery by themselves, it is pretty much the result that one would expect if a shoe bomber succeeded in taking out the plane's controls (this was NOT an FBW AB, which would have more redundancy and survivability).

[Bobby777]

Lucky for Canada that the 767 has that high glide ratio ... it's important when you don't carry enough fuel to make the trip ... ah that darn metric conversion ...

I figured the 727 would be nearly as high as the 707 ... did the 707 have longer wings (more wing area)?

[Bobby777]

hmmm ... I wonder how much time elapsed between those loud noises? ... bomb then tail ripping off, perhaps?

[Willie Green]

Makes me wonder if the media is going to campaign for installation of a "your-tail-fell-off" warning light.

[Trust but Verify]

I guess I don't want to hear their last words, you know? That just seems too personal.

[Alice in Wonderland]

... I wonder how much time elapsed between those loud noises? ... bomb then tail ripping off...

09:15:40 (66 seconds after liftoff) Airframe rattling noises recorded on the Cockpit Voice Recorder

09:15:54 (80 seconds after liftoff) 2nd airframe rattling noises on CVR

09:16:04.5 (90.5 seconds after liftoff ) The vertical stabilizer separates from the craft.

09:16:17 (103 seconds after liftoff) Plane crashes

Complete timeline and a wealth of other information can be found at www.usread.com

[spald]

your post #14. I'm with you.

[Bobby777]

interesting ... around 10 - 14 seconds or so between noise indicators ...

[The_Victor]

Actually, the component name you want is "vertical stabilizer." The rudder is the control surface (the part that moves) in the vertical stabilizer. But, you are right in that the author has chosen his words poorly with regard to the actual aircraft part definitions.

[willyone]

I was on a Southwest 737 which flew through wake turbulence from a wide body. If you want to check out your max heart rate that is a good way to do it. Have someone put you inside a metal garbage can and then hit it with a bat. And slide sideways out of control. That is sort of what goes on.

[willyone]

Rudder and tail fin are not the same thing. Check it out. And actually it is called the vertical stabilizer of which the rudder is a part.

[Lobbyist]

A roaring noise filled the cockpit and then two chimes sounded seconds apart, indicating the engines had fallen off.

What was the "roaring noise" that filled the cockpit? If the engines had fallen off where was the noise coming from?

[agincourt1415]

Wing Tip Vortex - or WAKE TURBULENCE

Normally, wake turbulence will extend backward and downward from the aircraft wingtip, like a horizontal Tornando.

Wind also will blow the vortex's, but sometimes they will hang, in calm wind and stay in or at an altitude, then the next plane in line runs into them.

I think there have been crashes caused by them, the Colorado 737 Crash into the school yard, and the Pittsburg Crash of a 737.

This one could be another example.