Pilots Say Boeing Didn't Tell Them About a Safety Feature Tied to a Deadly Crash

Started by OldGuy, November 14, 2018, 02:57:31 AM

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OldGuy

"Boeing rushed out a bulletin last week to inform pilots all over the world about the new flight control system and exactly what to do to shut it down if it goes haywire. But the Lion Air crew didn't have that information and may have been confused by a key handling difference that the system could have caused during the flight."

Yikes. And you can quote me on that.


TheSkyHornet

Quote from: Live2Learn on November 19, 2018, 05:56:03 PM
Paul writes that "Todd Insler, chairman of the United Airlines ALPA unit, questioned why ALPA publicly pushed Boeing to provide more information on the auto trim system, insisting that pilots are already well trained to handle any uncommanded trim events. ... In an interview with the Seattle Times, Insler compared automated background systems on airliners to watching television. "I don't need to know how it works," he said."

Leave it to ALPA...

I just got into an argument yesterday over whether or not conditions needs to be listed in the AOM or GOM as to when a maintenance write-up is required for exceeding airspeed limitations (specifically Vmo) during flight.

The argument was "This is common sense. You can't put everything into a manual for every situation."
"So when a pilot doesn't write it up, it's literally because they're not required to. You can't hold them to it."
"Then they shouldn't be operating an airplane if they don't have that common sense."
"Why have manuals at all?"

Not everything needs to be in a manual, but any time there is going to be a cause-and-effect, it should be in there, especially if it involves aircraft performance, automated systems, or maintenance issues.

To say "pilots don't need to know how their aircraft works" is asinine.

Live2Learn

Quote from: TheSkyHornet on November 20, 2018, 05:33:26 PM

To say "pilots don't need to know how their aircraft works" is asinine.


+1

Especially if a mod will affect performance under excursions from a pre-set "normal" envelope, or could respond in a counter intuitive manner to a sensor or other system failure. 

Live2Learn

https://www.aviationtoday.com/2018/11/20/lion-air-boeing-737-investigation-places-flight-controls-focus/?marketo_id=30777932&mkt_tok=eyJpIjoiWkdVelkyWTJaV1kzWlRBMCIsInQiOiJnUkI4SjVRZkpMcVpLQnRhSFZxWXp6cjZ4aTFuNGdsdGF4QlRFT094cjdEUWRMM202eHlnXC9TWUI2bExTY21lN1RJaFVhM3FsR3E2OGh5STdhbjc0UzhBUWkybnppS0s0NE5FZ0Niam9PYUJNWTNoVVJyek05c1hEMFZlaGpaVXAifQ%3D%3D

Avionics International reports "an update on the crash investigation from Capt. Nurcahyo Utomo of Indonesia's National Transportation Safety Committee (KNKT) ...[said]..the FDR review also concluded that the aircraft airspeed indicator was malfunctioning on four consecutive flights prior to the crash. Utomo also indicated the pilots should have recognized the malfunction when it occurred on flight JT610."

Wouldn't intermittant failure of the ASI be a known, pre-existing airwortiness fail?

PHall

The crew on the previous flight had written it up and maintenance had "fixed" it and signed it off.
Intermittent write ups are a real pain to duplicate so I'm not really surprised they "thought" they had fixed it.
But the new crew should have been watching for this problem like a hawk and that's why you have the back up indicator.
It is totally independent from the "normal" airspeed indicators. About the only thing they share is the pitot-static system.

TheSkyHornet

I can't speak for Lion's entire organizational structure and what programs they're approved to conduct...

I would guess that the repeat write-ups really don't play into the legal maintenance airworthiness of the aircraft. This is more of a chronic tracking/trending issue under a CASS program to try to identify the systemic issue and correct it.

What they likely did was MEL it as much as possible, but when the write-up continued, they would do an Ops Check (which ran satisfactory because they couldn't duplicate it), and marked that off in the logbook. Thus, airworthy.

Pinecone

Let's see, runaway trim was considered such an issue that Boeing put the trim disconnect switches to the left and slightly after of the throttles, on a pedestal to raise them above the other switches in the console.

The MAX?  No, the 737-100.  The FIRST model.

There are many reasons the trim may run away.  The MAX added an additional system that could cause that.

The Lion Air flight dealt with over 20 (TWENTY) uncommanded nose down trim incidents.  And no one opened the checklist to see what to do.  The previous flight, a pilot in the jump seat told the flying crew to TURN OFF THE TRIM.

The Ethiopian flight, they turned off the trim, then turned it back on.  BTW, the FO had 270 hours.  TOTAL TIME.  Data indicates that they may have turned on the trim after the FO manually trimmed the nose down instead of up.

In both cases, the aircraft were WAY overspeed.  Which makes it harder to manually trim.  The Ethiopian plane was over a 100 knots above limiting Mach, IIRC.

TheSkyHornet

Quote from: Pinecone on October 07, 2021, 07:31:35 PMThe Lion Air flight dealt with over 20 (TWENTY) uncommanded nose down trim incidents.  And no one opened the checklist to see what to do. 

You don't open the checklist during a flight control failure or runaway; it's a flow procedure (memory action item). You crack the checklist afterward to run the Emergency/Abnormal Check for that item to verify all steps were followed and subsequent steps adhered to prevent further issue.

A runaway flight control does not warrant pausing to run the QRH.

Blanding

Quote from: TheSkyHornet on October 08, 2021, 01:55:47 PMYou don't open the checklist during a flight control failure or runaway; it's a flow procedure (memory action item).

Yep. Everything above the long horizontal dashed line is a memory item:


PHall

Otherwise known as BOLDFACE and CAPS (Critical Action Procedures) in the military.
You're expected to have them memorized cold. And you get tested on them too.
Basically it's the stuff that will kill you in the next 30 seconds...

Pinecone

Then even a larger failure, in that 6 pilots, "qualified" in the aircraft, did not know that.

But if you DON'T remember, and you have two pilots, and something keeps happening, maybe the pilot not flying might want to see if they can find the answer.

I say 6, because the Capt and FO of the Lion Air flight before the mishap flight did not know it.  The guy in the jump seat knew what to do.