An Improbable ‘Probable Cause’
By Victor Trombettas
On December 6, 2004––more than three years after the crash of American Airlines Flight 587 (AA 587)––the NTSB released the full version of their Final Report on the crash.
The NTSB released this probable cause statement on October 26, 2004, at the Final Report Meeting in Washington, D.C.:
“The National Transportation Safety Board determines that the probable cause of this accident was the in-flight separation of the vertical stabilizer as a result of the loads beyond ultimate design that were created by the first officer’s unnecessary and excessive rudder pedal inputs. Contributing to these rudder pedal inputs were characteristics of the A300-600 rudder system design and elements of the American Airlines Advanced Aircraft Maneuvering Program.”
For those who were present at the Meeting, what the NTSB was really saying came through loud and clear. AA 587 encountered mild wake turbulence. Investigators who participated in simulations of the flight felt the second alleged wake encounter was “barely perceptible”. The Pilot “inappropriately handled” the aircraft and set off a chain of events that led to the separation of the tail. There was no reason for the Pilot to react the way he did. His overreaction was worsened by an overly sensitive rudder control system and by some negative wake turbulence training he had received from American Airlines. But had he not overreacted and applied unnecessary control inputs . . . AA 587 would not have crashed.
The NTSB used the words “excessive”, “unnecessary”, and “inappropriate” close to a dozen times in describing the actions of First Officer Sten Molin. Stan Molin, the father of the Pilot, himself a retired airline Captain, was sitting near the front of the NTSB’s conference center in Washington, D.C. He had expected that his son was going to take a large part of the blame––this had been leaked to the media by the NTSB or Airbus almost a month before the meeting. Molin, who taught Sten to fly, had a sense, just days after the crash, that the NSTB would lay the blame on his son. Even though they knew this was coming it was still very unpleasant for the Molins to hear the NTSB says the words –– “excessive”, “unnecessary”, “inappropriate” –– again and again and again –– in reference to their son’s piloting.
The Molin’s did find some consolation in hearing some of the NTSB investigators (later in the day) state that their son had gotten caught up in a piloting phenomenon called adverse Aircraft Pilot Coupling (APC), although this wording is not found in the probable cause statement. To explain this in lay terms –– it basically means that due to a very sensitive rudder pedal system (never mentioned in the AA training program because Airbus never disclosed its unique nature to the airline), the Pilot quickly got caught up in a situation where, the NTSB believes, he didn’t know that the side-to-side (lateral) forces he was sensing were mostly caused by his own rudder movements. As he repeatedly tried to compensate with the rudder, he made matters worse–– to the point where, in just seven and a half seconds, the tail broke off. Adverse APC implies that there is a design/systems flaw that confused the Pilot and the two “systems” are equally responsible in the subsequent failure. But the way in which the NTSB presented their findings, and the way in which they critiqued the Pilot’s actions over and over again, left no doubt in the minds of the major media: “Pilot Error” was the cause, and that is how most reported it.
Airbus walked out of the final report meeting with a big “whew” written across their heads. It could have been much worse for them. As one Airbus lawyer was leaving the conference center he stated to a Pilot’s Union representative, “better luck next time”. The Airbus lawyer was referring to intense lobbying by both American Airlines and the Union (even up to the night before the meeting) to get the NTSB to highlight Airbus’ 1997 failure to communicate known defects with the A300-600 rudder system and the role that rudder reversals played in the American Airlines Flight 903 (AA 903) accident. In that 1997 accident, the aircraft’s tail experienced higher loads than the loads placed on AA 587’s tail. American Airlines and the Union firmly believed there was a link between AA 903 and AA 587–– they were pushing and hoping to get the NTSB to see it that way. The fact the NTSB did not is the most obvious proof that the NTSB’s investigation was compromised –– probably by the powerful lobbying by Airbus. This lobbying (by both sides) was even acknowledged by the NTSB Chairman at a breakfast meeting with reporters on January 5th 2005, and described by her as “inappropriate”, “intense”, and having led to a delay of the final report’s release. The Chairman conceded that in the presence of such lobbying the “potential for contaminating the investigation exists”. Is it possible that one party (Airbus) “contaminated” the NTSB?
The family of the Pilot, American Airlines, and the Union, were not the only interested parties considerably displeased by the NTSB’s conclusions. Many of the victims’ families were dismayed at the findings. They couldn’t believe that they had waited almost three years for a probable cause statement which placed the majority of the blame literally at the feet of a dead man. In the minds of these disappointed people –– the NTSB had failed.
On March 26th, 2004, U.S.Read released an exclusive article titled, “ Coverups, Foulups, and Credibility Lost ”. This article was not about an NTSB cover-up. It was about a five year old Airbus cover-up of very relevant safety information dating back to 1997. And it was a cover-up –– U.S.Read’s analysis of the AA 587 docket material uncovered Airbus’ cover-up of the rudder travel limiting system failures on AA903 in 1997. We also discussed the failures of the NTSB –– from 1997 through the present –– to identify and disclose very troubling behavior on the part of Airbus. Most importantly, we showed that even if the NTSB was correct that AA 587’s tail separation was the cause of the crash, the NTSB had lost credibility in determining why or how the tail had separated.
The NTSB could not be trusted to go after Airbus if that was where the evidence pointed. In fact, if one believes that tail separation was the cause of the AA 587 crash, the evidence certainly pointed against Airbus. If the NTSB was unreliable in highlighting the fairly obvious in relation to the tail separation and rudder limiter issues and the Airbus’ coverups dating back to 1997 –– then the NTSB’s ability to determine the actual initiating event on AA 587 was even less likely.
At the Final Report meeting the NTSB proved beyond any doubt that the their credibility in the investigation had been lost. The NTSB basically let Airbus slip away on the most critical issue and even created a grossly erroneous and incomplete presentation that was favorable to Airbus.
American Airlines Flight 903
(AA 903) in 1997
To anyone even remotely familiar with the AA 587 crash, there was no doubt that the AA 903 accident in 1997 near West Palm Beach was very relevant and very connected to AA587. Most experts who believe tail separation was the cause of AA 587’s crash agree that had the NTSB and FAA been informed by Airbus about the role that rudder reversals and the faulty RTLU (Rudder Travel Limiting Unit) had on the extreme loads placed on AA 903’s tail, the crash of AA 587 could have been prevented. There were such obvious similarities between the two flights, and such an obvious failure or cover-up on the part of Airbus to communicate very important safety information to federal investigators, that Bernard Loeb, who headed the National Transportation Safety Board’s aviation division until January 2001, said the following to USA Today (May 27, 2003):
“When I heard (about what Airbus knew), [about AA 903] it made me sick ... People are kicking themselves .”
It would seem that Mr. Loeb got worked up about nothing –– because the NTSB went out of their way at the AA 587 final report meeting to say there was “no connection” between the two flights –– no “eureka” piece of information from AA 903 that could have prevented AA 587. Even with the benefit of hindsight available to them the NTSB’s statement was very far from the truth. This is why the Airbus attorney walked out of the meeting at the end of the day and told the pilot’s union representative, “better luck next time”. Airbus’ lobbying efforts had paid off well –– the NTSB had been rendered mostly impotent –– and the bulk of the blame had been placed on a Pilot who allegedly used the controls “excessively” and “inappropriately”.
Instead of blaming the aircraft, Clarke’s presentation had “Pilot training” as the number one issue, and as the only similarity between the two flights. There is no doubt that Pilot training was an issue in both cases –– both Pilots had never received training about the dangers of rudder reversals. But there is also no doubt that Airbus (a) never told the NTSB and FAA that AA 903’s tail experienced loads beyond the ultimate load, that (b) the rudder reversals contributed to the very high loads, and that (c) the RTLU failed several times during the AA 903 event, which led to a direct increase in the loads experienced by AA 903’s tail.
Had Airbus told the NTSB in 1997 about all of these facts, when Airbus knew them, then the NTSB would have issued its warnings to the aviation community about rudder reversals, about the peculiar characteristics and sensitivities of the A300-600’s rudder system, and about the failure modes of the RTLU. Had the NTSB done so in 1997, AA 587’s Pilot, Sten Molin, would have known not to reverse the rudder long before November 12,2001.
The NTSB was able to look at these same facts, these obvious connections between the two flights, and state that nothing from AA 903 could have prevented AA 587. This NTSB distortion and whitewash of the AA 903 affair solidifies the conclusion that the NTSB had lost credibility in the AA 587 investigation. If they were incapable of connecting the obvious dots, they couldn’t be expected to identify the actual, elusive, initiating event on board AA 587.
Perhaps one clue as to why the NTSB reached this illogical conclusion about the AA 903 connection is found in Mr. Loeb’s statement to USA Today: “People [in the NTSB] are kicking themselves.” Perhaps the NTSB was encouraged to downplay the significance of AA 903 in an effort to veil the significance of their own failures in the AA 903 investigation. Why else would Mr. Loeb say “kicking themselves”?
The NTSB whitewash was not only evident in Mr. Clarke’s slide (Figure 1 above), but in the very words of the NTSB Board Members: Board Member Rosenker said he was “comfortable” that there was no relation between AA 587 and AA 903. Board Member Carmody: “we need to lay this thing (the AA 903 connection) to rest”. She also described her feelings about the Airbus’ 1997 cover-up as “[I] am less than satisfied in a less than perfect situation”. Director John Clarke focused solely on AA903’s “vertical” loads (which were higher than AA 587’s) and failed to highlight the extremely high lateral loads AA 903 experienced (as high as 0.7g) ––loads that were as much as two times more severe than those AA 587 experienced. Mr. Clarke referred to Airbus’ deliberate withholding of the tail loads data during the AA 903 investigation as ...”oblique”. What made Mr. Bernard Loeb “sick” was only an “oblique” offense for Mr. Clarke. NTSB Chairman Connors provided the closest statement approaching a rebuke when she said Airbus “did not meet moral obligations”. But that was the height of the criticism against Airbus––it quickly descended into a love fest again with Board Member Hersman, perhaps exposing the NTSB’s bias in favor of Airbus, revealing “we don’t want to single out a single party”. Unfortunately, the NTSB’s final report did just that ––it mostly singled out the Pilot.