By Alan Levin
Veteran aviation accident investigators say they have never seen a scenario
like the one that played out in the final moments of American Airlines
They have little doubt about what led the jet to crash Monday in New York
City: Large pieces came loose shortly after it took off.
But that hardly solves the mystery. Investigators are still searching for
what could have caused the Airbus A300 jet to break into pieces and slam
into homes in the Rockaway Beach neighborhood of Queens about 9:17 a.m.
The two General Electric CF6 engines landed separately in the neighborhood,
each several blocks from the fiery main crash site, federal sources say. The
Coast Guard also pulled a part of the A300's tail from Jamaica Bay.
''Right now, to me, it is extremely mysterious. I find the evidence
perplexing,'' says Bernard Loeb, a retired chief aviation investigator with
the National Transportation Safety Board.
NTSB investigators said late Monday that preliminary information from the
cockpit voice recorder suggests that the crash was an accident. Only the
captain and co-pilot can be heard on the recording, said NTSB Chairwoman
But they offered few specifics. They said that the flight lasted less than 2
minutes from takeoff to crash. Investigators have not yet examined radar
data that will provide the precise altitude at which the jet encountered
One of the first things they will try to determine is whether the engines
failed. Such failures occur dozens of times each year. In extraordinary
circumstances, engines shoot damaging shrapnel into an aircraft.
However, it's unheard of that two engines would break loose at or about the
same time, aviation experts say. Jet and engine manufacturers go to great
lengths to ensure that catastrophic engine failures cannot cause a crash.
Similarly, jets are designed with so much strength that even when the wings
or tail fins are damaged, they almost never break loose before crashing,
The part of the tail -- a fin that rises vertically -- that was recovered
had no visible marks indicating it was struck by an object that could have
torn it from the jet.
Even the early evidence about how the jet broke apart puzzled investigators
and others. Some pilots who saw the jet after takeoff said it did not come
apart, while other aviators said they saw pieces coming from it, one source
''It doesn't sound like the typical thing,'' says Kevin Darcy, a former lead
accident investigator at Boeing who is now an aviation consultant.
Loeb says it is possible that the key to the crash could be with the tail
section, which was hauled from the bay Monday afternoon. The vertical fin
keeps the jet pointed straight and allows pilots to turn the jet's nose left
If the small wings on the tail, which raise and lower the nose, also came
loose, Loeb says, that could cause the jet's nose to move downward with
great force. That, in turn, could theoretically shake the engines off the
Loeb cautions that such a scenario is highly speculative. ''I don't really
know exactly. But I think that's possible,'' he says.
Whenever engines break off a jet, investigators focus on possible failures
within the engine. The CF6 engines on American's A300 fleet have recently
drawn the attention of safety regulators.
The NTSB issued a recommendation last December urging that the Federal
Aviation Administration, which regulates the aviation industry, address
safety issues on the CF6 engines.
On Sept. 22, 2000, a CF6 engine on a US Airways Boeing 767 blew up as
mechanics tested it on the ground in Philadelphia. There was a loud
explosion, and a fire broke out under the left wing of the jet, the NTSB
''The incident raises serious safety concerns because, if it had occurred
during flight rather than on the ground during maintenance, the airplane
might not have been able to maintain safe flight,'' the NTSB wrote.
Other incidents involving the engine have also raised concerns among
In April 2000, a Continental DC-10, which had three CF6 engines, had one
engine break apart as it took off from Newark International Airport. Pieces
from that engine damaged a second engine. The crew landed the jet, and no
one was injured.
Since then, the FAA has required additional inspections of all CF6 engines.
''My understanding is that the airplane was in compliance with all
airworthiness directives,'' says Al Becker, a spokesman for American
Birds are another possible cause of engine failure. The marshy area near New
York's John F. Kennedy International Airport is a haven for birds. Several
crashes, though not on A300 jets with GE engines, have been caused by
engines exploding after birds were sucked into them.
However, several accident investigators say it seems unlikely that such
failures struck Flight 587. Major failures on jet engines are often obvious
after a crash, but sources said the engines exhibited little evidence of
such a failure. The sources cautioned that on-scene observations are not
Furthermore, earlier failures of the CF6 engines have not caused them to
break off. On the US Airways 767, for example, the engine remained on the
In fact, one engine specialist who asked not to be identified says modern,
high-power engines such as the CF6 have failed so rarely in flight that
investigators have little idea what would happen to a jet if one came apart.
Investigators also say it seems unlikely that failures violent enough to
shake each engine loose from the aircraft could strike both about the same
Though federal officials went out of their way to say no evidence suggested
sabotage, officials say privately that they cannot rule it out.
Copyright 2001 USA TODAY, a division of Gannett Co. Inc.