February 1, 2000
Web posted at: 4:00 p.m. EDT

(CNN) -- Charles Feldman joined CNN.com to discuss the crash of Alaska Airlines Flight 261.

Charles Feldman is a general assignment correspondent for CNN, based in the network's Los Angeles bureau.

Feldman joined the chat on February 1, 2000 by phone from the CNN Los Angeles bureau and CNN.com provided a typist.

Chat Moderator: Thank you for joining us today Charles Feldman and welcome to chat!

Charles Feldman: Thank you for inviting me to this chat. I look forward to answering as best I can any questions our CNN Web site visitors may have.

Chat Moderator: Can you update us on the Alaska Airlines crash?

Charles Feldman: Right now the search is still on for any potential survivors from the crash of Alaska Airlines flight 261. Even though it would appear as if the chances are remote, that survivors will be found. This is in large part because of the plunge the aircraft made from an altitude of 17,000 ft, as well as the temperature, 53 degrees Fahrenheit of the ocean water.

Question from Sunny1: I've heard this crash is in 750 feet of water. How difficult is the recovery operation going to be?

Charles Feldman: Any time you have a recovery operation involving that depth of water, it is an extremely difficult task. For one reason, the pressures involved at a depth of more than 700 feet require very special equipment, as well as highly trained and skilled divers. The ocean currents can be quite severe at that depth, especially if there are stormy seas. Which is, fortunately, not the case today.

Question from Aurora: Mr. Feldman, approximately how far was the plane from LAX when the crash occurred?

Charles Feldman: The estimates of how far the plane was from LAX varies between 30 to 45 miles depending on the exact area where the aircraft went down. Close enough that had the pilot been able to maintain at least minimal control, experts say, he might have been able to successfully land at LAX. The fact that he could not might be one indication of how severe the loss of control was.

Question from Sunny1: Is there any speculation on what caused the plunge from that altitude?

Charles Feldman: Well, we don't need to speculate so much as to go to whatever slim facts we have. The only real fact we have is the pilot radioed to air traffic control that he was experiencing a problem with the MD-83's stabilizer trim. Why there was such a precipitous drop from 17,000 feet to the ocean is one of the mysteries to be answered.

Question from BostonGal: What do the experts say about this particular aircraft? Good reputation? Safe?

Charles Feldman: Most, if not all, of commercial certified jetliners flown by US airlines have fairly good safety records. In fact the MD-83 is in many ways a workforce for airlines on short to medium routes. The MD-83 is part of a family of jets, the MD-80 series which are more recent ancestors of the old McDonnell Douglas DC9 twin engine jet. The MD-83 has more seating capacity, more powerful engines and a larger range than the earlier versions. And there are no indications as of now that the aircraft involved in the crash had any particularly unusual problems with maintenance history.

Question from sm: What exactly is stabilizer trim?

Charles Feldman: On the back of the tail of the MD83, the tail is actually composed of two large structures in the shape of a "T." The vertical stem of the T is known as the vertical stabilizer. Attached to the vertical stabilizer as part of that structure is the rudder, which controls the movement of the nose of the aircraft in a right to left or left to right direction. Along what is called the "vertical axis."

The motion that it is controlled is called a "yaw." The top of the T, the horizontal part is what is known as the horizontal stabilizer. A part of the elevator functions in what is know as the elevator and moves up or down, depending upon the position the pilot places the wheel or "yoke" of the aircraft in. The elevator controls the pitch of the aircraft, that is whether the nose is up for a climb or down for a descent.

Because of the great speeds that airplanes travel, the flow of wind over these control surfaces can make it very difficult for a pilot to keep the yoke in the position desired. That is to say, he may need to exert enormous forward or aft pressure in order to keep the aircraft along the flight path desired. The trim mechanism is attached to that elevator-horizontal stabilizer structure. And it is a way of reducing the pressures that would otherwise be exerted by the wind on those surfaces. The trim can be set either electronically or by the use of a wheel that is manually spun up or down by the cockpit crew.

So if for example, the pilot wishes to climb, he would first pull back on the yoke, which would cause the horizontal stabilizer/elevator to deflect upward, which forces the tail down and the nose up. Once the aircraft is in the position and at the speed the pilot wishes, the trim is set electronically or manually in order to keep the aircraft flying in that position, hands off if needed, because the pressure has been all but eliminated.

Question from Go-seki: Charles what potential is there for the maintenance check to have contributed to the crash? Say an inspection hatch not replaced or some similar error.

Charles Feldman: Well, you know all these issues, maintenance, the aircraft's service record... these are things that will be looked at by the investigators by the NTSB. They will interview the mechanics that worked on the aircraft, review the flight records and maintenance records and try to talk to other crewmembers that may have flown that plane in the recent past. So at this time it is not possible to determine what role if any maintenance or lack thereof may have played in the crash of the Flight 261

Question from Sunny1: Have the searchers picked up the pings from the black boxes yet?

Charles Feldman: Yes, they have located the pings from what are believed to be the flight data recorder and the cockpit voice recorder. But because of the depth of the debris, and the necessity of getting specialized equipment and personnel to the scene, those so-called black boxes, which by the way aren't black, have not been recovered.

Chat Moderator: What are some of the other obstacles to the recovery mission?

Charles Feldman: Sure. The obstacles are many in terms of recovering any information from an ocean crash site. You are faced with environmental problems such as ocean currents, the depths and pressures of the sea, fish and other predators on the ocean floor that might cause a problem in terms of dealing with evidence that needs to be looked at.

The mere fact that the aircraft is immersed in saltwater has a detrimental effect to the integrity of some of the evidence that needs to be analyzed to help determine the cause of the crash. And because it is out to sea it limits to a large degree the search and rescue mission to daylight hours. Because it is considerably more difficult lighting up portions of the Pacific Ocean than it would be to illuminate a land area in which a plane crash occurred.

Question from jetmom: How long will they be looking for survivors?

Charles Feldman: Well they will look for survivors until the local officials on the scene charged with the responsibility for deciding when to call it off make that decision. Typically they will wait at least a few days just in case someone has managed to somehow survive. But at some point -- probably within the next few days -- the decision will likely be made, if no survivors have been found, to change the operation from a search and rescue mission to a salvage operation, designed to retrieve as much of the aircraft and as many bodies within or around the aircraft as possible.

Question from Sunny1: Where is the base for the recovery operation located?

Charles Feldman: Good question. I believe it is at a place called "Port Hueneme." But I'm not 100% sure. I have not been at the scene.

Chat Moderator: Any final observations you wish to share with us?

Charles Feldman: Only that whenever there is a major airline accident, which is not often, understandably many people's concerns grow over the safety of commercial aviation. The fact is that airline accidents involving US carriers are very few and very far between. And flying remains perhaps one of the safest means of transportation.

Chat Moderator: Thank you for chatting with us today.

Charles Feldman: I thank everybody who participated in this chat. I'm sorry we don't have more time to answer more questions. Perhaps another time.