Alaska Air Flight 261 Crash Aftermath
[Sorry, the video for this story has expired, but you can still read the transcript below. ]
JIM LEHRER: First on the discovery that a critical part on that Alaska Airlines plane, the plane that was on Flight 261, there was a part on there that was found faulty but it was not replaced. This was in 1997. That was the jackscrew. Explain what that process was all about.
LEE DICKINSON: The process itself, Jim, is the jackscrew itself is a basically a rod that’s about two feet long and it’s about one-and-a-half inches in diameter. It has threads on it. It screws down into this gimbel nut that was supposed to have been replaced or was inspected in September of 1997 and apparently was not replaced. The jackscrew itself is attached to the front of the horizontal stabilizer. When it moves down or screws down into this gimbel nut, it pulls the front of the stabilizer down as it unscrews and moves up, it pushes the horizontal stabilizer up which controls the pitch of the aircraft.
JIM LEHRER: Makes the plane go up or down.
LEE DICKINSON: It does.
JIM LEHRER: Yeah, right. Now, Mr. Goldfarb, the word on this was that they discovered this thing had a problem but then they reinspected it and decided not to replace it and that was considered perfectly within the rules, is that correct?
MICHAEL GOLDFARB: Upon the reinspection they found it was within the normal limits. What both the board and the FAA have to look at is the procedures for doing maintenance at Alaska Air. You know, 8 out of 24 of the planes at Alaska Air have these problems. It’s too early to make any conclusions either on the crash or what this jackscrew problem may be.
JIM LEHRER: But let’s go through that. Alaska air found 8… how many of these planes did they have?
MICHAEL GOLDFARB: I think a fleet of 34. A fairly high percentage of planes that had some kind of problem with the jackscrew, not necessarily the shavings of the gimbel nut off them, maybe just grease – but, in other words, some problems, enough to warrant the FAA concern.
JIM LEHRER: What about an overview here. There were almost 1200, about 1100 of these planes that were MD-80, 83s and planes that were related in some way to this plane that went down, Alaska Airlines Flight 261, and they found 22 altogether that had stabilizer problems. Did that surprise you? Is that a lot of them to have a problem?
LEE DICKINSON: As Mike indicated, Jim, I don’t think 22 out of 1100 or 1200, unless you know specifically what that problem is — because we don’t know if it was all the same problem is related to that area. That’s something that the Board will be investigating. So 22 out of 1100 or 1200 is a small number. However, to put that more in perspective, if 8 of those 22 are from a fleet of 34, the board will have to specifically look at what were the problems on those 8 of Alaska Airlines’ 34.
JIM LEHRER: Explain why these planes are all related, why the DC-9s and others.
MICHAEL GOLDFARB: It’s a family of planes, a series of planes. The airlines put different names on those aircraft as they give the next modern upgrade. The DC-9 became the MD-80; the 83 a stretch version. The airlines ordered different kinds but they’re all basically the same aircraft configuration. The component parts may be different but it’s very important that the order that the FAA announced extends to all the planes that have the stabilizer and the horizontal trim configured in the same manner. Right now, we have nothing to indicate yet what caused this crash. The worst thing in aviation is not to know why because you don’t know what corrective action to take. This is precautionary. There’s been no indication yet that even the stabilizer itself brought down the plane off the California coast.
JIM LEHRER: But they have found the screw jack off of 261 and it was damaged.
MICHAEL GOLDFARB: Absolutely.
JIM LEHRER: Now the question is how do you determine what damaged it, right?
LEE DICKINSON: That’s exactly right. Again, it’s like I indicated — we have to make sure. The Boards especially have to make sure that they don’t focus in on something that may be the triggering event. It may end up being but it’s too early to tell. So they are focusing right now on looking at the material. They have determined that some of the material, these shavings that are on this jackscrew are indeed from the interior part of the gimbel nut. That is softer material than the jackscrew itself. They need to compare the information they’re getting from that analysis to the other airplane parts they’re examining.
JIM LEHRER: We have a little diagram that shows what you all have been talking about. Anybody who in all of this have had occasion to occasionally to screw a screw into a nut and it can get loose and the shavings you’re talking about are just normal wear and tear.
LEE DICKINSON: Could be.
JIM LEHRER: Now, just for additional perspective here, the nut itself is how big?
LEE DICKINSON: The nut itself is about, if you can see, probably several inches, maybe 6 or 8 inches if I’m correct in that. The diameter of the inside of the nut is just a little bit larger than the diameter of the jackscrew itself.
JIM LEHRER: Which is one point, an inch-and-a-half, right?
LEE DICKINSON: 1.6 inches, about an inch-and-a-half, that’s correct. What happens is that jackscrew screws down into this gimbel nut. And there are a couple motors that are sitting on top of this whole… the jackscrew itself. They move up and down as the jackscrew screws down or screws up, that part is connected to the horizontal stabilizer which indeed is moved up or moved down to control the pitch of the aircraft.
JIM LEHRER: Now, Mr. Goldfarb, both of you say, hey, wait a minute, 22 out of 1,000 or more airplanes is not a problem but why wouldn’t these 22 and the 8 in Alaska Airlines and this one on Flight 261 if, in fact, that’s the cause here or the problem here, why wouldn’t they have been found in routine investigations and inspections?
MICHAEL GOLDFARB: First of all, I don’t believe either Lee or I said they weren’t a problem — the fact that one additional problem on a plane can be very significant to aviation investigators. So the number isn’t as important as what they’re coming up with. These tail stabilizers are really torn apart during heavier maintenance, called c-check, it’s simply when they tail the tail apart. It’s not done everyday on a routine inspection. And there’s been no prior history. There have been five or six MD-80s that had stabilizer problems but none tied to this jackscrew. So there’s no prior way that either the FAA or the airlines would have known that this problem that we’re finding here is probably a first of its kind in terms of a safety concern.
JIM LEHRER: Now why would that be? Because what could be the possible explanations for that? Why this was never uncovered or never a problem before?
MICHAEL GOLDFARB: Flying so safe and it doesn’t feel that way with such high profile crashes lately, quite frankly there’s millions of parts on an aircraft. Every aircraft has a service bulletin on it, or directive about something, just like your engine light comes on, change your oil soon, on a car. So there’s millions of parts that need repair or replacement, and the ability to regulate and oversee an industry that precisely is pretty much like to the manufacturer and to the airlines and they have a pretty good maintenance programs in general. That’s why crashes are so rare. But here’s a case where we just don’t know; we don’t know what’s going on here. It may not have been the stabilizer. It may have been exacerbated by the crew. We have to look at the piloting of the aircraft; we have to look at many other things before we can be definitive. And I think they are moving fairly rapidly here to come to some answers but the FAA didn’t want to take chances. And they said let’s not have the benefit of the doubt. Let’s take the benefit of the doubt. Let’s ground, you know, inspect this fleet immediately so there isn’t an unforeseen problem.
JIM LEHRER: What would you add to that just in terms of the process? I mean the layman would look at this and say, that’s fine, guys, after a plane goes down, then everybody inspects 1,000 airplanes and finds 22 that are damaged in some way — why the normal process of inspection doesn’t find something like this?
LEE DICKINSON: Well, again, you have to keep in mind that, as Mike indicated, this is a high-profile accident. The aviation safety record is superb.
JIM LEHRER: On this particular airplane, yeah.
LEE DICKINSON: The MD-80 itself. The aviation safety in general is superb in the United States and worldwide. The MD-80 specifically is a very safe airplane. If you look at the accident rates on MD-80s, it’s very good in terms of numbers. One thing you have to keep in mind though is there has not been a history of a problem such as this. One of the things you need to do is look to see if data suggests a problem does or does not exist. The fact that the safety board has uncovered through these inspections with the Federal Aviation Administration 22 airplanes that may have problems, again, I caution– may have problems-
JIM LEHRER: May have problems, right.
LEE DICKINSON: — we have to know what the problems are, are all 22 the same problems? Does one have more grease or less grease than another? I mean, that may be something that’s more or less important in these others. But there’s no question that with the focus right now on the investigation, that the jackscrew, the gimbel nut, the horizontal stabilizer, the board needs to find out what went wrong and did this happen — was this 20% into the accident where something happened or did this trigger the event? They’ll look at maintenance, inspections, the operating procedures of the crew. They’ll look at a whole number of things, the physical evidence in terms of the parts themselves that they’re retrieving from the ocean. They’ll look at what the airplane was doing from the flight data recorder – they’ll couple that with what the crew was saying when they were putting inputs into the plane itself. That is all the foundation for the investigation that will then lead to the cause of the accident.
JIM LEHRER: Mr. Dickinson has said on this program before, Mr. Goldfarb, that usually it’s more than one thing that goes wrong that causes calamity such as Alaska Airlines 261 — that it’s not usually one thing. It’s this and that, has that been your experience as well?
MICHAEL GOLDFARB: Absolutely. I think it’s a unique series of events that come together simultaneously. Even that horrible TWA crash off Long Island Sound about three years ago, a first of a kind center fuel tank, plane sitting on a tarmac, hot temperatures, not having their tanks loaded. It’s always a series of things coming together which is why, you know, people say, well, you have a problem here, why don’t you just go after it across all those aircraft. Sometimes the cure is worse than the problem you’re trying to solve. It takes time in aviation to remedy and find the right fix to these things. They tend to be not what’s always apparent which is why early speculation on crashes invariably go back on the shelf prior… Early speculation turns out often to be not what the cause of the crash was.
JIM LEHRER: But based on what you know, this thus far about Alaska– I’ve asked this question before — does this smell like one we’ll get a definitive answer to eventually?
MICHAEL GOLDFARB: I believe we will. It was absolute luck and wonderful that the Navy was able to come up with the flight data recorder and the cockpit voice recorder in that deep of water. That was amazing. The fact that they’re bringing up the rest of the wreckage is terrific from an investigative standpoint. We’re not faced with months of dredging the ocean floor with these pieces. With the information they have and with this known problem hopefully fairly rapidly we put this together and come up with at least a probable cause if not a definitive one. Based on probable cause repair and remedy can be done so that people can stop being so white knuckled when they fly and stop saying that this plane is going to be a problem.
JIM LEHRER: Okay. Thank you both very much.
LEE DICKINSON: You’re welcome.