Lion Air Crash: Pilots Struggled To The End

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As lawsuits swirl around last month’s crash of a Lion Air 737 MAX8 into the Java Sea, Indonesian investigators say the crew struggled to control the aircraft right up to the moment of impact. And a member of Indonesia’s National Transportation Safety Committee confirmed to The Guardian that the aircraft had experienced similar problems on its previous flight.

As the aircraft pitched down, Nurcahyo Utomo of the NTSC told the Indonesian parliament Thursday, it became “increasingly difficult to control the airplane” because the load on the controls apparently became too heavy for the pilots to counter manually. The airplane crashed into the Java Sea on Oct. 29, shortly after taking off on a flight to the nearby island of Pangkal Pinang. It crashed about 11 minutes after takeoff, killing all 189 people aboard. Utomo told parliament that the aircraft’s speed at impact was more than 400 MPH.

Although it hasn’t been implicated in the crash, the post-accident investigation revealed that Boeing fitted the MAX series with an automated trim and stall-protection system called MCAS. The system activates when the airplane is being hand flown with flaps up at high angle of attack and high load factors. It automatically rolls in nose-down stabilizer trim and can be disabled only by using the airplane’s stabilizer cutout switches or lowering the flaps. It’s also inactive when the autopilot is engaged.

Boeing has been criticized by pilot unions for not clearly documenting MCAS—Maneuvering Characteristics Augmentation System—so it could be addressed in MAX differences training. Pilots at Southwest and American Airlines, both of which fly the MAX, said they were unaware of its existence.

Meanwhile, a law firm representing the families of the victims has filed a lawsuit against Boeing in a U.S. District Court claiming that the MAX series control design “in unusual conditions, can push (the plane’s nose) down unexpectedly and so strongly that flight crews can’t pull it back up.” The suit further alleges that the flight control computer was incapable of filtering inaccurate information from faulty sensors and that the approved flight manual didn’t warn pilots of these potential faults. The suit is at least the second. A Florida firm filed a suit against Boeing last week on behalf of the parents of Dr. Rio Nanda Putrama, who was killed in the crash.

Indonesia‘s NTSC said it will publish a preliminary accident report by the end of November.

Comments (6)

Another component of this crash is that with MCAS stab-trim movement isn't halted with elevator movement. As I understand it, one of the protections against stab-trim runaway is that the system automatically halts stab-trim movement with a sharp elevator input. The assumption is the only time a pilot would make such a control input is to counteract runaway stab-trim. If the stab-trim were indeed running uncommanded, it would halt with a sharp elevator movement, giving the pilot time to then disengage with the stab-trim cutout switched. That automatic halt of stab trim movement with elevator input is bypassed when MCAS is engaged.

According to another article I read, Boeing installed MCAS because the larger engines installed farther forward on the 737 MAX generate a pitch-up moment at high angles of attack; enough of a pitch-up moment, in fact, to push the aircraft into a stall. Allegedly, MCAS is supposed to prevent that with an automated nose-down trim. If the system malfunctions then standard stab-trim runaway procedures should suffice to keep the aircraft flying. I'm guessing this is why Boeing didn't feel the need to put anything in the training material about it. If MCAS is the reason this plane crashed then the question is why didn't the pilots notice uncommanded trim movement and hit the stab-trim cutout switches? If there is something about MCAS engagement that hides the fact it is moving the stab trim then Boeing should've made pilots aware of it.

Posted by: Mark Sletten | November 23, 2018 12:19 PM    Report this comment

Bad instrument readings because of faulty maintenance, and a flight crew that was behind the curve.
I'm "struggling" to understand why they are blaming Boeing.

Posted by: Mark Fraser | November 24, 2018 7:46 AM    Report this comment

Follow the money trail. Boeing has deep pockets. People know that. And Boeing is local and easier to sue than a foreign airline.

Posted by: Rob McDowell | November 26, 2018 3:17 PM    Report this comment

>>can be disabled only by using the airplane's stabilizer cutout switches

According to the material Boeing put out, it can also be defeated (at least temporarily) by the use of the manual-electric trim (in other words the pilot trim switches on the yoke) or by manual-manual trim (nut-up and grab the spinning trim wheel on the console).

Any touch of the trim switches on the yoke will defeat MCAS for either five or ten seconds (I read conflicting reports) but in any case, long enough to catch your breath and decide if the trim cutout switches are for you. Also gives you the option of using the manual-electric trim to get back to neutral before you hit the cutoff and resort to manual-manual flight.

Posted by: David Bunin | November 26, 2018 5:51 PM    Report this comment

Rob nailed it.

Posted by: Mark Fraser | November 26, 2018 6:57 PM    Report this comment

"Another component of this crash is that with MCAS stab-trim movement isn't halted with elevator movement. As I understand it, one of the protections against stab-trim runaway is that the system automatically halts stab-trim movement with a sharp elevator input. The assumption is the only time a pilot would make such a control input is to counteract runaway stab-trim. If the stab-trim were indeed running uncommanded, it would halt with a sharp elevator movement, giving the pilot time to then disengage with the stab-trim cutout switched. That automatic halt of stab trim movement with elevator input is bypassed when MCAS is engaged."

Thank you Mark for this information.

The over-riding issue in all this is the crew was unaware of MCAS. If you think you have a runaway trim situation, and you follow the procedures for that specific issue, any pilot would not be expecting something repeatedly shoving the nose down, over and over again...every 5 to 10 seconds possibly...evidently putting the airplane in such extreme attitudes there was not enough pilot strength and diminishing elevator authority/control responses due to the ever increasing pitch attitudes ending with a 400mph impact almost vertically. That relatively slow airspeed shows that this crew was indeed actively flying the airplane. Plus, a 737 is no Extra 540 or even C150 in control response.

If they were simply clueless to the events unfolding around them, after a couple of MCAS induced nose-down excursions, this airplane would have hit the water well over the speed of sound.

It makes me sick to see so many still accusing them as woefully untrained, incapable of "manfully" taking control of the situation as real pilots like themselves or Yeager or Hoover would certainly have done due to superior US training,

I am convinced Boeing's lawyers are and will continually feed this automatic knee-jerk feeding frenzy, that Lion Air being Indonesian is therefore substandard in it's maintenance practices, provides sub-standard pilot training, and whose only pursuit is the almighty buck no matter what the human cost is. Those same lawyers will then follow up with that disgusting rhetoric with the statement " after all Boeing has done" by installing MCAS as an invisible back up to keep ignorant, poorly trained, foreign airlines with their ham-fisted pilots and ignorant mechanics from killing passengers. Even if there is a negligent history, this particular flight was in an almost new airplane with a crew fighting for their lives right up to the moment of impact.

Boeing will make sure that the public will get what the public wants to believe rather than what really happened. Pure narcissism at the least and sinister at it's worst.

Posted by: Jim Holdeman | November 27, 2018 11:11 AM    Report this comment

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