Posted on 11/16/2001 1:09:52 PM PST by Solson
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.
Compiled By AviationNow.com Staff
12-Nov-2001 1:26 PM U.S. EST
Technical information on the American Airbus A300 that crashed near New York John F. Kennedy Airport on Nov. 12:
Aircraft Type: Airbus A300-605R
Registration: N14053
Manufacturer Fuselage No: 420
Rollout date: December 1986
Delivery date: July 12, 1988 to American Airlines by Airbus
Owner: Chase Manhattan Bank (leased to American Airlines)
Engines: Two General Electric CF6-80C2A5s
Airframe maintenance information
Last A Check: Nov. 11, 2001
Last B Check: Oct. 3, 2001
Last Heavy Maintenance Check: Dec. 9, 1999 (N14053 was scheduled for heavy maintenance visit in July 2002).
Engine Maintenance Information
No. 1 Engine: 694 hours since last overhaul
No. 2 Engine: 9,788 hours since last overhaul; 2,887 hours since last shop inspection. (Overhauls typically done every 10,000 hours).
Notes:
American operated 35 A300-600s, including N14053. Of the remaining 34, 10 are owned by the airline.
N14053 was the oldest of American's 35 A300-600s, although it was the seventh A300-600 to join the carrier's fleet.
Sources: American Airlines, Back Information Services, JP Airline Fleets Int'l.
Author wins the Booby prize for reporting the most obvious fact possible. He must've gone to school for years to be able to find out such facts as these.
"the vertical stabilizer was the first piece of debris found, followed by the rudder about 200 yards further down the flight path."
This seems odd, though. The rudder is attached to the fin; so, it should've come off with the fin. And, if it subsequently separated from the fin, why would it have been found further down the flight path. Significantly so -- since the airframe went down a half mile away, the rudder was a full quarter of the way further down the track.
Is the rudder also separately attached to the tailcone? So that it might have been left "hanging", before it too separated?
What kind of noise did they hear? Why no detail on this?
Perhaps the heavier piece fell more quickly which is why it was the first to hit the water.
This is one thing I find interesting...
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.
Yes. I believe the 'takeoff roll' may indicate a roll maneuver to put the aircraft on its proper heading after takeoff, approximately 253 seconds into the flight. Just a guess.
Which occurred at 144 seconds, 37 seconds after the first "airframe rattle" (a travel distance of, say, a bit more than a mile-and-a-half).
Could the first "airframe rattle" be the vertical stab coming loose, but not separating? Then, could the "wake turbulence" mentioned at 114 seconds be a "weathervaning" effect from the slowly detaching fin? And does the second "airframe rattle" at 121 seconds denote the departure of the vertical stab and rudder some 6 seconds before one of the pilots announces "loss of control" at 127?
Seventeen seconds later, about half a mile away, the plane breaks up and goes straight down.
This chain of events seems to put the vertical stabilizer in its proper place on the flight path, a half mile short of impact.
I found that piece of information disturbing.
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