Ethiopian 737 MAX 8 crash

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With rest of world taking opposite position, FAA has no choice but to capitulate (if not for technical/safety reason, but for other reasons), regardless of what satellite data and their enhancements say.

However, within 48 hours post 2nd crash, I thought Boeing/FAA was trying quite hard to convince public that it is safe to fly with 737 Max.

We told German that their car have emission problems, we told Chinese their telecom equipment can spy you on mobile networks. For our own planes, we told the world that you need to wait for us as we are data driven. To me this sounds like a convenient excuse.
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When I read the NASA reports from other pilots, I wonder if this is all about MCAS. The reports seem to indicate that the MAX issues came into play with the autopilot engaged during climb out, but they were able to stop the decent when they switched the auto pilot off and flew manually. This is not indicative of an MCAS problem as I understand MCAS. My current understanding is that MCAS only functions during manual flight control and therefor would not be engaged during use of autopilot. If this understanding is correct, then it leads me to wonder if there is an issue with the autopilot as well as the MCAS - because I cannot imagine why any pilot would not disconnect autopilot in the Lion Air situation. Yet, NASA reports are saying the issue corrected once the autopilot was disconnected and they flew manually. These two are counter to each other and seems to leave open more than MCAS as cause.

I have never flown the 737, I moved from the 320 to the 777. But I cannot imagine why the FAA feels there is minimal training and they can call the MAX the same or nearly the same as the NG. I have JS on both and other than the archaic overhead panel, they seem vastly different to me - then toss in the MCAS and no training, or even awareness of the system from initial deployment of the aircraft into service.... wow, just wow. The FAA and Boeing should be ashamed of themselves for doing such a thing.

As I stated earlier in the thread, I have JS prior on the MAX, but generally if I can, I will try to go on the Bus just for comfort. That said, post these two events, I would avoid the MAX for an abundance of caution, as I do not want to be a first hand witness to the fight with MCAS (or whatever is going on with the control system). Glad that the US finally came to ground them until this can be sorted out.

It is a shame really, the 737 is such a durable workhorse and Boeing seems to have damaged its reputation immensely; will take years to recover from the bad press if this keeps going for too long.
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Quote: Yet, NASA reports are saying the issue corrected once the autopilot was disconnected and they flew manually. These two are counter to each other and seems to leave open more than MCAS as cause.
NASA report is also similar to prior flight experience (which landed safely) of the 1st crashed 737 Max last year per preliminary report:

The aircraft departed at 1420 UTC (2220 LT) at night time, the DFDR showed the stick
shaker activated during the rotation and remained active throughout the flight. About 400 feet,
the PIC noticed on the PFD the IAS DISAGREE warning appeared. The PIC handed over
control to the SIC and cross checked the PFDs with the standby instrument and determined
that the left PFD had the problem. The PIC noticed the aircraft was automatically trimming
AND. The PIC moved the STAB TRIM switches to CUT OUT and the SIC continued the
flight with manual trim without auto-pilot until the end of the flight
.

The remainder of the flight was uneventful and the aircraft landed Jakarta about 1556 UTC.
After parking, the PIC informed the engineer about the aircraft problem and entered IAS and
ALT Disagree and FEEL DIFF PRESS problem on the AFML.
The engineer performed flushing the left Pitot Air Data Modul
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Quote: NASA report is also similar to prior flight experience (which landed safely) of the 1st crashed 737 Max last year per preliminary report:

The PIC moved the STAB TRIM switches to CUT OUT and the SIC continued the
flight with manual trim without auto-pilot until the end of the flight
.

The remainder of the flight was uneventful and the aircraft landed Jakarta about 1556 UTC.
This is exactly what has been puzzling me. The two pilots on the previous flight were familiar with the CUT OUT switches and the two on the accident flight were not? The earlier two even proved the problem by activating the switches again which initiated the AND condition again before shutting them off for the rest of the flight. If you look at the DFDR graph on the initial report, the accident crew looked to be fighting the automation to the end.
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Quote: This is exactly what has been puzzling me. The two pilots on the previous flight were familiar with the CUT OUT switches and the two on the accident flight were not? The earlier two even proved the problem by activating the switches again which initiated the AND condition again before shutting them off for the rest of the flight. If you look at the DFDR graph on the initial report, the accident crew looked to be fighting the automation to the end.
I think this is related to the phase of flight they were in. As I recall the first crew had the issue occur in cruise, so they had altitude, energy and time to figure things out. The second crew had everything go to hell on them right after rotation.... stick shaker, trim wheels spinning, stall warnings, etc. They didn't have a lot of energy or altitude to play with.
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Quote: I think this is related to the phase of flight they were in. As I recall the first crew had the issue occur in cruise, so they had altitude, energy and time to figure things out. The second crew had everything go to hell on them right after rotation.... stick shaker, trim wheels spinning, stall warnings, etc. They didn't have a lot of energy or altitude to play with.
Doesn't really sound like that's the case. Read two posts above.


The aircraft departed at 1420 UTC (2220 LT) at night time, the DFDR showed the stick shaker activated during the rotation and remained active throughout the flight. Etc, etc.
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Quote: Doesn't really sound like that's the case. Read two posts above.


The aircraft departed at 1420 UTC (2220 LT) at night time, the DFDR showed the stick shaker activated during the rotation and remained active throughout the flight. Etc, etc.
Thanks, I missed that.
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Quote: This is exactly what has been puzzling me. The two pilots on the previous flight were familiar with the CUT OUT switches and the two on the accident flight were not? The earlier two even proved the problem by activating the switches again which initiated the AND condition again before shutting them off for the rest of the flight. If you look at the DFDR graph on the initial report, the accident crew looked to be fighting the automation to the end.
An MCAS malfunction won’t exactly present itself as a runaway trim situation, which makes it even more dangerous (especially considering the pilots aren’t even briefed on the system).

Unlike a typical stab trim runaway, MCAS trims for 10 seconds at a time and then takes a 5 second break. So the trim isn’t running away nonstop and it can also be stopped by activating electric trim. You can’t really fault the late pilots for not running the memory items for a stab trim runaway because not all the signs of a stab trim runaway were present; indeed, they were faced with the malfunction of a system they didn’t even know existed.
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Quote: ...indeed, they were faced with the malfunction of a system they didn’t even know existed.
Part of my puzzlement remains, why did the crew on the previous flight know how to do a cut off on the MCAS and this crew didn't.
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Quote: Part of my puzzlement remains, why did the crew on the previous flight know how to do a cut off on the MCAS and this crew didn't.
They didn’t cut off the MCAS, they prevented the MCAS from operating the trim. It sounds like the first captain just happened to notice the trim driving nose down and turned it off. Perhaps there weren’t as many bells and whistles going off. If they knew what the MCAS was and how to cut it off they were amongst a very small minority.
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