jollo wrote:morrisond wrote:mjoelnir wrote:
We were talking about what Boeing and the FAA did after the LionAir crash and what the FAA and Boeing did after the Etiopian Air crash, before they were forced to ground the MAX.
Perhaps you point out where in the emergency AD, MCAS is mentioned, explained how it works, mentioned that MCAS cuts out the column switch off, that the AoA disagree warning is not working and mentioned that the manual trim wheel will not work. Neither it is mentioned the time MCAS trims, the rate of those trim action and that the will start after 5 seconds again. You will find non of the above.
Also the ops manual buletin does not mention or even explain the working of MCAS. Neither does it mention that the manual trim wheel will not work and that you can only use the cut out switches after having electrical trimmed the nose up.
It is actually not mentioned, that a MAX will behave differently from a NG.
I'll assume you didn't see my last post before responding to my previous one.
Actually if you read all three sources it about covers everything you mentioned as well. The OPS bulletin covers the 5 second issue.
You said Boeing and the FAA did nothing after Lionair and kept it secret.
You would be wrong on that point.
Do they really need to point out that one of the controls might not work if they are outside the normal operating envelope?
Most of the controls won't work so well below stall speed either.
Please notice that I was responding to the question "Did the recommended actions include trimming electrically to neutral trim before cutting the switches?". You may argue that puzzling together bits and pieces of various communications would have enabled inquiring minds to string together a set of "recommended actions" which would have saved the accident flights. Maybe in a courtroom this would be accepted as evidence, but this would be strictly with the benefit of hindsight and the luxury of lots of idle time.
The middle of an upset is no time to assemble sources. The only things pilots should turn to in a crisis are: training, NNCs and ADs. MAX-specific training was actively prevented, the relevant NNC went through MAX certification and the aftermath of a fatal accident unchanged, and FAA's AD (verbatim copy of Boeing's OMB) mentioned only as a footnote that electric trim can - not "must" - be used (before stab trim cut out, obviously) to help overcome excessive aero loads. So IMO the answer to the original question is: no, not where it would have mattered.
It's right in the middle of the Ops bulletin that you can use Electric Trim to neutralize the control forces - in the section Operating instructions - What are you talking about?
You need to read the OPS bulletin as well and not just the AD. The crews would have gone off the OPS Bulletin. Here it is again on this page if you missed it about half way down - number MLI-15 http://www.b737.org.uk/mcas.htm
It's a note as it's left up to the pilots discretion whether or not they wanted to use it. The plane might not have been that out of trim and might not have needed to use the Electric trim. Maybe Boeing thought that after the Lionair crash that crews might take MCAS seriously and might actually take the time to understand the Ops bulletin.
And again does Boeing need to warn it's crews in every bulletin that they need to maintain sufficient thrust to remain above stall speed? No - just like they should not have to warn them about the dangers of excess thrusts and remaining above Vmo.
This is basic pilot stuff they are required to know. Or should there whole training manual be part of every OPS bulletin?