2002-05-11 / Community

Retired Airline Pilot Sees Problems With NTSB Investigation

By Captain Ray Lahr, Retired

Retired Airline Pilot Sees Problems
With NTSB Investigation
By Captain Ray Lahr, Retired

Lahr is a Graduate Engineer from USC, former Navy pilot (WWII) vintage, former Air Line Pilots Association Safety Representative, and a former United Air Lines Pilot and Captain.

A press conference was called by the NTSB to assure the public that it is actively working on the AA587 investigation. Since the NTSB seems to be steering the investigation away from politically sensitive areas, the press conference needed to be tightly controlled. It was held at the NASA facilities on the Langley Air Force Base near Hampton, Virginia. This assured that only invited guests could gain access to the press conference. NASA was chosen to conduct the research on the vertical tail assembly of AA587, and all of those parts of the aircraft have been transported to this NASA facility for testing. The joint participation of NASA in the conference assured that the conference would be kept focused on NASA's portion of the investigation.

The conference commenced at 10:30 a.m. and Marion Blakey, chairman of the NTSB, did a good job of summarizing the work of the NTSB and NASA regarding the investigation of the composite materials used in the construction of the vertical stabilizer and rudder. She was backed up by a panel of experts. Nothing revolutionary was revealed. Frankly, I predict that nothing revolutionary will be revealed because that could ground the whole Airbus fleet. That would be very awkward politically. There should be no compromise with truth in an accident investigation. The British had the courage to openly test the Comet and reveal the results, even though it cost them dearly. The whole world benefited from their honesty.

The conference was then opened to questions from the floor. Most reporters seemed generally content to ask questions about composite materials. Victor Trombettas was able to ask one question about the crew's comments calling for "max power" and that they had "lost control" and where those comments came in relation to the five rudder movements. Marion Blakey stated that the NTSB had yet to synchronize the CVR with the FDR and that they would place that info in the "docket" when "they have it". This is a troubling answer for a couple of reasons. Victor will elaborate in a separate article. I had signaled for the microphone because I wanted to ask (tongue in cheek) if the eyewitnesses had helped them determine the breakup sequence of the rudder and vertical stabilizer. (Some of eyewitnesses saw an explosion before the vertical tail separated from the aircraft.) The mike never reached me, and I never got to ask the question.

That was the weakness of the conference. No tough questions were asked from the floor. Our guardians of the press seem content to be spoon-fed. I was able to speak to a member of the NTSB staff while we were waiting for the upcoming tour of the hanger where the tail assembly was kept. I asked if a witness group had been formed. "Oh yes," was the answer. I asked how many witnesses had been interviewed. "Well, the NTSB has collected over three hundred witness statements which are still being arranged into categories." I then asked how many eyewitnesses had actually been interviewed. He didn't know, so one can probably infer that there were only a few, if any. Golly gee, in the accident investigations in which I have participated, the witness group was one of the first to be formed, and we attempted to start interviewing the eyewitnesses in the first day or two while memories were still fresh. Sure, some individual eyewitnesses are mistaken on some points, but the composite viewpoint is amazingly accurate. It is very valuable in an investigation. Normally, an NTSB investigator in charge briefs the press on the progress of the whole investigation (Robert Benzon, the Investigator In Charge for 587, was not present at this press conference). When it becomes time for the public hearing, the important witnesses are called to testify. My, oh my, how times have changed.

Two of the important keys to this investigation are the black boxes. Here it is, six months into the investigation, and the NTSB still hasn't revealed what is on the Flight Data Recorder. Some of the flight control parameters were averaged before they were sent to the flight instruments and the FDR. The filtered results are good enough for the pilots to fly the airplane and are good enough for the FDR but not good enough to be released in an accident investigation. Hmmm. But averaged or not, the timing sequence of the separate recorded events remains unchanged, and it is this timing sequence that Victor has been trying to get. So far, no luck. Victor has been able to put together a very reasonable timing sequence from the other sources available, and he would like the FDR timing for verification.

Two call-outs on the Cockpit Voice Recorder are crying out for an explanation. The calls for maximum power and "try escape" indicate a desperate situation before the rudder movements. It is hard to imagine that this could be the result of wake turbulence from the JAL 747, which was at a normally safe distance from AA587. Plans are under way to test various turbulence or improper control scenarios in the simulators at NASA Ames, but there are no plans to test for sabotage as the cause of the tail separation.

The quick and dirty solution so far has been to blame the pilots. Directives have been issued warning the pilots that rapid rudder reversals can tear off the tail of the aircraft. As a pilot, this riles me. Pilots are fully aware of what violent rudder inputs can do. First of all, it can kill and injure people in the back of the aircraft who don't have their seatbelts fastened. When pilots get into wake turbulence, they just kind of wallow through without making violent control inputs. Just keep the aircraft upright and within the proper speed range. Let the altitude change if it has to. Don't make any violent control inputs. Don't hurt the passengers. If there is any reason at all to expect turbulence, have everyone (including the flight attendants) 'fasten your seatbelts'.

Rather than impugning the pilots, who aren't here to defend themselves, the NTSB should be recommending a directive to provide backup power and crash information to the black boxes. This accident is yet another example where power and crash information to the black boxes failed at a critical moment. There should be a rechargeable battery built into each black box. It is not a big deal. For a hundred dollars, I have a backup power supply on my home computer. Actually, there is already a separate battery within each black box, which can operate the pinger for up to 30 hours. It is true that power could still fail to some (or all) of the sensors that send information to the black boxes, but a mike installed in the CVR and an accelerometer installed in the FDR could still provide some final crash data and provide timing for the whole final sequence of events. For something as important as this is to accident investigation, these modifications to the black boxes should be mandatory.


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