Jim McKenna: What happened to American Airlines Flight 587?

Wreckage of American Airlines Flight 587

Jim McKenna is the Executive Director of the Aviation Safety Alliance, and a former editor on the staff of "Aviation Week & Space Technology" magazine.

CNN: Good morning, Jim McKenna and welcome to CNN.com Newsroom. JIM McKENNA: Hello everyone.

CNN: The NTSB is proceeding with the investigation of the crash of Flight 587 on the premise that it was an accident. What information points to an accident versus sabotage?

McKENNA: The law enforcement officials haven't indicated they were aware of any threat against this flight. The initial audition of the cockpit voice recorder also apparently contains no indications of an attempted hijacking or an explosion. The investigators will continue to analyze the cockpit voice recorder, and they will also examine the wreckage from the airplane for any signs of an explosion that couldn't be explained by something that would normally be on the airplane.

CHAT PARTICIPANT: Was that plane checked before it left the ground?

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McKENNA: The new FAA security procedures require that every airliner be checked the first thing in the morning for signs of tampering or foreign objects. I assume that was done for this airplane. Likewise, the mechanics would have taken a look at the airplane before it left, as would one of the pilots.

CHAT PARTICIPANT: What would have caused the tail fin of the airplane to go down into the bay. I would have thought that it would have gone down with the main section of the aircraft?

McKENNA: The fact that the tail fin ended up in the water is very puzzling. You're right in that normal circumstances would have dictated that it would have been found with the rest of the wreckage. Investigators have to weigh whether the tail fin separated from the airplane in flight. If it did, that would have made the airplane very difficult to control.

CHAT PARTICIPANT: Has the passenger list been reviewed for anyone that fits the same profile as the 911 hijackers?

McKENNA: I have no specific details on that. However, the airlines have been cooperating with the FBI and reviewing their passenger lists for potential suspects or assailants. I assume, again, that that was done in this case.

CHAT PARTICIPANT: What's the safety record like for the A300?

McKENNA: The A300 has a good safety record on par with most other airliners flying today. There have only been a handful of fatal accidents, most of which involved pilot confusion over how the systems on the airplane were functioning. One of the airplanes was shot down over the Persian Gulf by a US Navy ship.

CHAT PARTICIPANT: What is the safety record for this type of GE engine?

McKENNA: The CF6-80 also has a good safety record. It has been known to suffer internal cracking problems in critical parts and therefore has been subjected to great scrutiny by the FAA, the manufacturer and the airlines. There are stringent inspection requirements in place to make sure that this problem of internal cracking doesn't lead to an accident. Investigators will want to confirm that those inspections worked in this case.

CHAT PARTICIPANT: What type of damage would a surface-to-air missile do to a plane - and how does that differ from the damage to the AA 587 flight?

McKENNA: No one knows yet what the damage to this flight is. Investigators are only beginning the process of cataloging the wreckage and examining the damage. Given the large number of eyewitnesses to the event, it's difficult to imagine that someone would not have reported indications of a missile being fired at this airplane. Anti-aircraft missiles generally work on the principle that the guidance system brings them close to the aircraft target and then the warhead detonates, spraying the aircraft with shrapnel. Were they looking for evidence of a missile strike, the investigators would be looking for a large number of small well-defined holes in the airplane and the bodies of the passengers.

CHAT PARTICIPANT: Why did the pilot dump his fuel?

McKENNA: The reports of the pilots dumping fuel are erroneous. There's very little likelihood that any pilot would have had time during such a short flight to dump fuel. Furthermore, my initial information is that the A300 does not have the capability to dump fuel.

CHAT PARTICIPANT: Do you think there's a possibility that the reverse thrusters were engaged during takeoff?

McKENNA: It's not likely that the reverses were engaged. During the takeoff that should have been a detectable problem. Investigators will want to determine whether the thrusters might have deployed during the short flight.

CHAT PARTICIPANT: Is it not unusual that an engine falling off could cause the plane to come apart as it did?

McKENNA: Keep in mind that nobody knows how the airplane came apart yet. That is one of the key challenges before the investigators. However, the failure of any major part forward of the wings always has the potential to strike the wings or the tail as it breaks free and do severe damage to those critical components.

CHAT PARTICIPANT: Mr. McKenna, have you heard whether any amateur video of this plane crash has turned up?

McKENNA: I haven't. I'm sure if there was, some TV network would have bought and aired it.

CHAT PARTICIPANT: If the tail cracked and fell off would that lead to the engines detaching and falling off?

McKENNA: It could. If the vertical fin (which is the piece that we saw recovered from the water yesterday) broke off, the airplane would very likely go into a severe sideslip. That's the equivalent to a skid in an automobile. As it did that it would almost instantly roll over and then nose over in a steep dive. Eyewitnesses have reported that this airplane appeared to have dived into the ground and in fact the debris field is fairly small indicating a high angle of impact. So investigators are going to be looking very closely at the tail of that airplane.

CHAT PARTICIPANT: There were reports of an explosion on board. What are likely causes of that?

McKENNA: First of all, there are almost always reports from eyewitnesses of an explosion before a crash. Such reports must be taken with a grain of salt. An explosion on board could be caused by a failure of one of the engines or a failure of the APU, which is a smaller engine in the tail. An overheated tire that was stowed in the belly and then ruptured might also account for an explosion. That's among a handful of possible causes for an "explosion" on the airplane.

CNN: Can you describe how this investigation will proceed and what other pieces of critical information will investigators be looking for to get answers?

McKENNA: The investigators will divide themselves up into a dozen or so groups, each of which will look at particular aspects of the flight. One group will look at pilots training and their performance. Another will examine the engines. One will look at the maintenance and design of the airplane. Yet another will look at air traffic control issues. The groups will be headed by an NTSB investigator, but made up of investigators from Airbus, GE, American Airlines, it's pilot's union and mechanic's union, among other parties. They will examine the wreckage, they will examine records in the possession of the FAA and American Airlines and spend several months getting a basic understanding of how the airplane was operated, maintained, flown, and damaged before or during the impact. With that information in hand, the NTSB investigators will then work on their own to analyze that data and recommend likely causes to the five members of the National Transportation Safety Board. Those presidential appointees are the only ones under US law who can make the final determination as to the cause of the crash. Typically, that whole process takes a year or more.

CNN: Do you have any final comments for us today?

McKENNA: This looks to be an intriguing and unusual crash. The course of the investigation may take dramatic turns depending on the evidence the investigators retrieve from the "black boxes", the debris field and Jamaica Bay. So, keep an eye on how this investigation develops.

CNN: Thank you for joining us today, Jim McKenna.

McKENNA: Thank you for having me.

Jim McKenna joined CNN.com via telephone from Virginia. CNN provided a typist. This is an edited transcript of the interview