More plane info:
From WSJ (interactive)
Investigators examining one of the separated engines from American Airlines Flight 587 found foreign debris inside, indicating that the engine may have ingested a flock of birds and then caught on fire.
The engine burned internally, people close to the investigation said. But its parts appeared intact, except for the damage from what is known in aviation as ``foreign object debris,'' or ``FOD.'' That would suggest that the engine didn't suffer a catastrophic failure from some mechanical breakdown, but from sucking in birds, these people said.
Bird strikes aren't uncommon, especially at seaside airports like New York's Kennedy International Airport. Airports, including Kennedy, have programs trying to keep birds clear of runway areas. But typically even if ingesting birds causes an engine to fail, a twin-engine plane like the A300 can fly on its remaining engine. In simulators, pilots repeatedly practice the tricky maneuvers to keep planes under control when they lose an engine at takeoff, the most critical time for an engine failure.
In this case, people close to the investigation see the finding of foreign debris in the engine as the start of a chain of events. Most likely, the burning, damaged engine somehow caused damage to other parts of the plane. Because debris has been found at various locations in Queens, it's clear that pieces of the plane came apart in flight. Another possibility, these people suggested, is that both engines possibly suffered bird strikes.
Witnesses reported seeing the plane's left engine on fire, then fall off the plane. The wing appeared to be on fire as well, witnesses said, most likely because of ruptured fuel lines or fuel tanks. Engines are designed to shear off a plane if forces on them become great so that they break away before tearing the wing off. But an engine breaking away can itself damage a plane if pieces hit the fuselage, wing or tail.
The National Transportation Safety Board says the cockpit voice recorder recovered from the wreckage shows that the pilots encountered an aviation-related problem, and not some act of terrorism. The NTSB has yet to say what problem the pilots were talking about, however.
And:
US officials concluded a month ago that there was an unsafe condition in the type of engine that powered the Airbus that crashed in New York yesterday, killing more than 260 people.
They had started moving toward tougher inspections of the US-manufactured engines.
Investigators were treating the crash of American Airlines Flight 578 as an accident, with early evidence pointing to mechanical failure in the twin-engine Airbus A300.
A Federal Aviation Administration’s safety notice on October 5 followed months of increased scrutiny of the CF6-80C2 engine that powered the ill-fated American plane and is used on more than 1,000 aircraft worldwide, including the presidential jet, Air Force One.
The engines have drawn close scrutiny by federal safety officials since the spring of 2000 after planes reported engine failures that sent metal fragments flying.
After extensive review, the FAA published its notice in the Federal Register last month stating there was a ‘‘need for mandatory inspections’’ of the engine because ‘‘an unsafe condition has been identified.’’
It gave the public 60 days, until December 4, to comment before ordering the more extensive and more frequent inspections.
General Electric, the parent company for the engine maker, said it complied with all the government’s repair orders and believed the engine was ‘‘phenomenally reliable.’’
GE has built 2,954 of these engines - first introduced in 1984 - and they are among the best-selling for wide-bodied aircraft.
The left engine that apparently failed in yesterday’s crash had been overhauled recently, while the right engine was due for an overhaul soon.
Mindful of the September 11 suicide hijackings of four airliners, investigators looking at the crash in the borough of Queens said the voice cockpit recorder, debris patterns and eyewitness reports all pointed toward an accident, not terrorism.
‘‘All indications are it’s an accident,’’ National Transportation Safety Board Chairwoman Marion Blakey said.
With the holiday travel season approaching, officials in Washington sought to manage renewed anxiety about the safety and financial health of airlines already badly shaken by the events of September 11.
Top administration officials were quick to stress that an initial review of intelligence data had found no evidence that terrorism was involved in the crash, and that the NTSB, which investigates transportation accidents, was in charge. The FBI assisted, looking for any evidence of a crime.
‘‘If we find out it is a tragic accident, everybody will give a collective sigh of relief, which really shows how much stress we’re under since September 11,’’ said Darryl Jenkins, director of George Washington University’s Aviation Institute.
Investigators, nonetheless, scoured records of who had access recently to the plane, which had routine maintenance the night before it departed New York’s John F Kennedy International Airport en route to the Dominican Republic.
One mystery was the discovery of the completely intact tail of the plane in the waters of Jamaica Bay.
Investigators also had extensive descriptions from eyewitnesses, including a commercial pilot on the ground who reported one of the plane’s engines caught fire during take off and eventually broke from the wing.
‘‘When you see an engine separate like that and be visibly intact, it seems to point to mechanical failure,’’ said aviation lawyer Don Nolan, whose firm represented victims of United Airlines Flight 232, which crashed in 1989 in Iowa, after an earlier version of General Electric’s CF6 engine came apart in flight.
The October 5 FAA order came after the FAA had told airlines in June to begin other inspections of the same engines for cracks in certain rotor disks, a component within the engines.
A month earlier, a problem with the same type of engine forced the emergency landing of a Monarch Airlines passenger jet in Portugal.
Documents from the British Air Accidents Investigation Branch said a rotor blade had snapped, puncturing the engine’s housing with a three inch hole and causing minor damage to the wing.
The pilots reported dramatic vibration, and British officials reported there had been ‘‘several similar failures prior to this event.’’
In September 2000, part of a GE CF6 series engine was ejected and penetrated the left wing of a US Airways jet undergoing a maintenance run on the ground at Philadelphia International Airport. A loud explosion was heard, following by a fire. ‘‘This 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 said in December. Last year, the FAA ordered airlines to replace a fuel tube within these engines to prevent high-pressure leaks that investigators warned could result in an engine fire and damage to the airplane. Also last year, the FAA ordered carriers to replace certain fan shafts earlier than planned to prevent possible catastrophic failure.
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I got the above off the freep site, so no direct links sorry. |
