It is difficult for the average aviation safety professional to learn from an airline accident investigation. Even though trained to be objective, it is difficult to discard any preconceptions, personal knowledge and/or business preferences (our company operates the same aircraft and hope that there are no airworthiness issues). Your observations may be driven by such collateral considerations. The below series of articles provide a useful case study to learn about the NTSB process without any distortions.
The rationale for this restriction is that throughout the process is susceptible to external pressures, such as theories with high public interest, but little probability to support following that theory. The quintessential example was the guided missile theory which the press incited in the TWA 800 crash in 1996.
So here, very early in the NTSB review, the Mayor of Philadelphia made the following pronouncement:
“’Clearly it was reckless in terms of the driving by the engineer. There’s no way in the world he should have been going that fast into the curve,’ Mayor Michael Nutter told CNN.
‘I don’t know what was going on with him (the engineer). I don’t know what was going on in the cab, but there’s really no excuse that can be offered, literally, unless he had a heart attack.’”
That precipitous conclusion caused the NTSB Member-in-Charge to take time out of his crowded schedule to say:
“’You’re not going to hear the NTSB making comments like that,’ he said. ‘We want to get the facts before we start making judgments.”
Sumwalt said they would interview Bostian after he’d had a chance to settle down a bit from his crash trauma.
‘You have a lot of questions; we have a lot of questions,’ Sumwalt said Wednesday evening. ‘We intend to answer many of those questions in the next 24 to 48 hours.’”
The point is that rushes to judgement are all too frequently false; so it’s best to maintain radio silence and let the NTSB make the statements.
LESSON #2 : the NTSB process is necessarily iterative. This is closely associated with Lesson #1 if not its corollary.
The third article below demonstrates how the search for the probable cause involves multiple stages. After the blame of the engineer theory lost currency, a new theory was raised by a quote from an assistant conductor. She was quoted as telling a NTSB investigator that she overheard a communication between an SEPTA operator and his dispatcher about his window had been shattered by an unknown projectile while traveling in the same area on the parallel track.
Not very long after the first projectile theory was surfaced, the FBI determined that the windshield was not hit by a bullet, but that the NTSB “has not ruled out the possibility that another object may have struck the windshield.”
So within days, the theories of this case have included at least two hypotheses. None has been proved or disproved. The wise observations that can be drawn from this tragic Amtrak case are
- there are good reasons to not speculate, and
- the NTSB process is necessarily iterative in nature.
So remember when the NTSB’s Go Team heads out to aviation crash, that people, who do not incorporate these lessons in their practices, are not likely to look smart.