My goal in telling this story has always been to tell it in a compelling and unbiased manner. That’s why the book relies so heavily on the comments and writings of some of the very people who were there at the time. If what I write comes across as biased, it’s only because I find the evidence so overwhelmingly against the NTSB findings. So when Dave Haase, one of the members of the TWA accident investigative team working on TWA 841, wanted to share his thoughts about the investigation, I was more than happy to give him this forum. You can also hear and see a portion of the interview I did with Dave in the post overlooked clues. One last thing before I hand it over to Dave, I had an opportunity to work with a very talented 3D animator, Mike James of mikejamesmedia.com who provided a number of images I plan to use in the book. The image in this post is one of the great images he provided.
Dave Haase Former TWA accident investigator
I was privileged to be a member of the TWA ALPA accident investigation team in the case of TWA 841 and worked with Jim McIntyre, the then chairman of the TWA ALPA accident investigation committee, as well as with Dale Bebee a TWA pilot representing TWA flight operations management. We were assisted by ALPA’s then Director of Accident Investigation, Harold Marthinsen. Subsequent work by Leigh Johnson, among others, shed additional light on a number of important technical aspects.
My work was primarily on the technical side of flight data recorder analysis. The recorder on the aircraft involved, a Boeing 727-100 series, used an earlier recorder, a foil tape unit that did not have the capability to record the aircraft’s pitch or roll attitudes. However, using equations of motion for a vertical gyro and available recorder data (namely time, altitude, heading, vertical acceleration and airspeed), it was possible to derive pitch and roll attitudes.
Preliminary data analysis submitted to the NTSB by the manufacturer showed roll attitudes that did not match the flight crew’s recollection. But, based on some of the work we did, our analysis generated different results. We presented our findings to a staff engineer at the NTSB for his review. After examining the information, he concluded the preliminary analysis was incorrect and what we had submitted was valid. The interesting point is that this new analysis showed roll attitudes that corresponded with flight crew’s and particularly Capt. Gibson’s recollection of events. Throughout the investigation I never came across any information that contradicted Hoot’s testimony.
Of all the investigations that the Board had conducted, the formal 841 NTSB investigation was one of the most significant in the Board’s history and one of the longest, lasting more than two years. Over that time I met with Hoot and others numerous times and he was the same person in business meetings as he was in informal settings such as when we went out to dinner.
After the investigation was completed by the NTSB it was then time for the five member board to make a judgment based on the report put together by NTSB staff and to vote on “the probable cause.” Of some interest, only three of the five members were present at the Board meeting. Of those three Board members, I found the statements of member Francis McAdams of particular interest because he dissented, in part, on the probable cause statement. I have copied that statement from the formal NTSB report and it is shown below.
FRANCIS H. McADAMS, Member, filed the following concurring and dissenting
Although I voted to approve the Board’s report which concluded that the extension of the leading edge slat was due to flight crew action, I do so reluctantly. The report as written, based on the available evidence, i.e., the analysis of the flight data recorder, the simulator tests, .the flight tests, and the tilt table tests, appears to support the Board’s conclusion. However, I am troubled by the fact that the Board has categorically rejected the crew’s sworn testimony without the crew having had the opportunity to be confronted with all of the evidence upon which the Board was basing its findings. At the time of the first deposition, the following evidence was not available to the crew or to the Board: the flight data recorder analysis, the results of the simulator and flight tests, and the tilt table tests. Although the crew was deposed a second time, their testimony was limited to one issue, i.e., the physical location of the flight engineer at the time of the incident. I had recommended that since the Board was ordering a second deposition it be conducted denovo so that the crew would have been aware of all the evidence. The Board did not agree.
Furthermore, I do not agree that a probable cause of this accident, as stated by the Board, was “the captain’s untimely flight control inputs to counter the roll resulting from the slat asymmetry.” In my opinion, the captain acted expeditiously and reasonably in attempting to correct for the severe right roll condition induced by the extended slat.
At the least, I was disappointed by the Board’s handling of the accident. But, I was thankful that McAdams spoke up, argued on behalf of the crew and provided his dissenting opinion. And, I firmly believe that Hoot saved the day in difficult circumstances.
It should be noted that, after appropriate review, TWA fully reinstated Capt. Gibson to normal flight status and he subsequently qualified on the L-1011.
About three months ago, Hoot and I talked on the phone for at least half and hour. We had a great discussion of times past, and as was typical for him, he was most generous and gracious with his thanks. He will not be forgotten.