Aircraft Accidents and Misdirection, Part Two

In 1826, James Fenimore Cooper’s protagonist in his Leatherstocking series, Nathaniel ‘Natty’ Bumppo returned in The Last of the Mohicans.  Natty was a modest character, a fearless warrior, fearless friend and marksman; a quiet and unassuming man.  In 1992, Director Michael Mann and actor Daniel Day Lewis managed to ruin the character because they wanted to give the audience their interpretation of what Cooper was saying 166 years before.  The character was changed without any good reason why, ruining the story.

Three weeks ago, the National Transportation Safety Board (NTSB) Chairman’s ‘Message From the Chairman’ embarked on shining light on a minor problem without any clear reason why:

https://www.linkedin.com/feed/update/urn:li:activity:6440565827719741440

As written two weeks ago concerning a fatal ballooning accident in Lockhart, Texas, the Chairman is changing the conversation, redirecting attention from the true issues, resulting in confusion and misdirection.  This Chairman’s venue is being misused, making incorrect recommendations outside of the NTSB accident report.

The Chairman’s Blog and the accident report are not the means to second guess the decisions of those involved, nor is this article.  Indeed, American 383’s crew should be praised, not criticized, for handling an absolutely unique experience with professionalism.

The travelling public needs to understand this.  The public has no choice but to trust the Department of Transportation and all its divisions, e.g. the Federal Aviation Administration and NTSB, to provide factual information.  Instead, the public hears the NTSB Chairman – a Presidential Appointee – writing in his Blog: Message From Chairman, “If you design something with enough complexity, don’t be surprised if someone can’t use it when they really need it.”  Then, when the Chairman ‘gets the fix wrong’, it results in recommendations that are ambiguous, at best.

The Blog posting was about American 383, a Boeing B767 with a number two engine fire during takeoff roll on October 28, 2016.  Chairman Sumwalt’s concern: during the emergency, a flight attendant (FA) could not contact the flight crew (FC) through the newly designed interphone system receiver as the cabin filled with smoke.  This accident was so unique, it is extremely confusing why the Chairman overstates the importance of an interphone system modification, while ignoring the more critical issues that he should have focused on in his Blog instead.  This accident was unique, but not surprising.

American 383 was on its takeoff roll, when the number two engine’s second stage high-pressure turbine (HPT) disc failed, breaking into several pieces.  With the engine at takeoff power, a large section of the HPT disc, weighing 57 pounds, was launched through the engine casing, subsequently penetrated the lower and upper wing sections before being propelled a half mile away, where it broke through the roof of a warehouse.

As American 383’s emergency progressed, the pilots – who were made aware of the emergency with the cockpit’s flashing lights and aural warnings – had to abort the takeoff while running through the emergency shutdown checklist, a high stress process with the airplane on fire.  Meanwhile, the passenger cabin filled with smoke.  Passengers left their seats; one passenger deployed the over wing escape slide directly behind the number one engine.  He was seriously hurt by the engine’s jet blast.

The Chairman’s concern is for a redesigned interphone handset’s confusing complexity; that the FAs were not properly trained on the new handset; that the mix-up directly resulted in the passenger’s injury.

What?!

To fully understand the situation, it is necessary to explain the scenario from the flight deck.  While smoke is entering the cabin, the FC is focused on making the airliner safe – NOW.  The fire MUST BE extinguished to allow for a safe evacuation from at least two of the eight exits, possibly one – all while preventing an explosion.  After the number two engine failed, the aircraft was braking to a stop.  Why not shut down the number one engine?  The number one engine generator was the only guaranteed source of power for emergency evacuation lighting, fire protection and radios.  The Auxiliary Power Unit was shut down, no jet stream to power the Ram Air Turbine.  The number one engine was the only means of power until the number two engine fire was put out.  The number one engine was kept running for a full minute after the aircraft came to a stop.

The moment the engine fire alarm went off in the cockpit, the Captain controlled the aircraft’s momentum; the First Officer probably armed the first Halon bottle and fired it while the number two engine was still spooling down.  When the fire extinguisher system was armed, the number two engine generator was disconnected, hydraulics and fuel to the number two engine were cut off.  As the Captain stopped the jet, the First Officer called ground control to alert them and get the aircraft rescue and firefighting trucks rolling.  This flurry of activity probably occurred before the plane came to a stop.

When the aircraft stopped, the pilots immediately ran through their approved emergency shutdown checklist: a series of verbal challenges that assured the pilots shut off systems that could make the emergency worse, disabled unnecessary components and enabled a safe path to evacuation.  It is crucial, in the pursuit of safety, that the FC be able to accomplish these tasks … without interruption.

NOTE: an accident of this type has never occurred before, one where the high-pressure turbine disc penetrated the twin-engine airliner’s wing fuel tanks, dousing the hot engine and main gear brakes with thousands of pounds of gravity-fed fuel migrating to the lowest point in the tank, causing an unquenchable fire.  In contrast, Delta 1288, the disc breached the MD-80’s tail section and United 232 the disc tore through the tail, but no fuel sources.  American 383’s fire, on and around the number two engine, was the main contributor to the flood of smoke entering the cabin.

Why is Member Sumwalt concerned about the interphone system?  Is it a complexity problem or a training issue?  It would most likely be a training issue since the Flight Attendants often talk with the Flight Crew during regular flights, e.g. informing the crew that the cabin is prepped for takeoff, when the FC needs the aisles blocked for a bathroom break, requests to raise or lower the cabin temperature.  The interphone is not an ‘Emergency Only’ device.  The FAs talk on the interphone to the cockpit all the time.

Was the FA’s inability to use the interphone the root cause of the passenger chaos?  Does Member Sumwalt suggest that the interphone was so complex as to be unusable in an emergency but not in normal use?  Does the report state why the flight attendants needed to contact the cockpit?  An interphone problem is a training issue that can be solved with a class, a video or a simple revision to the flight attendant manual.  Should the flight attendant have used the interphone to speak to the passengers instead of the flight crew?  What specific action would have stopped the passenger from deploying the slide or getting injured?

As the flight crew ran through their priority checklist, they would not likely have answered the phone; it would have been a distraction to the pilots’ priority of keeping the emergency from progressing.  So, the question stands: Why did the FA use the interphone to call the crew?  Did the FA need, e.g. the Captain to drop the O2 masks?  Did the FA need advice on which emergency slides to deploy?  The flight attendants had better eyes on the situation, e.g. how the fire was progressing or which slides were safe to deploy.  The flight crew had a limited view of the wings, even when not previously occupied.

However, if the Chairman is going to suggest a safety risk, then he or she should spell out what the risk is and employ root cause analysis to suggest a solution.  Recommendations are teaching moments, not preaching moments.  Besides, there is one more solution they missed; one more possible scenario to look at:

What if the interphone became damaged and did not work at all?

2 thoughts on “Aircraft Accidents and Misdirection, Part Two”

  1. Interesting and well thought out and written. One very minor (and unimportant to your point) correction, the NTSB is not part of the DOT, it is a stand alone agency that reports directly to the Whitehouse.

    1. Gary, Thank you for the submission and I agree with you that as of 1974, the NTSB became a separate entity from the DoT. However, it reports to the US Congress, not the White House; the President appoints the Board Members, but, as per the NTSB website, Congress oversees them.

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