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US administration blames foreign pilots for 737 Max crashes

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US administration blames foreign pilots for 737 Max crashes

Old 17th May 2019, 16:23
  #61 (permalink)  
 
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Originally Posted by oggers
The advice to control pitch using electric trim has been in the NNC for 19 years now. It is number 2 memory item. Furthermore, the amplifying remarks promulgated with the AD were a de facto amendment to the FCOM that the operators were required to action within 3 days.
Oggers,
re-read parallely the abnormal procedure AND the interim accident report.
You'll conclude that the pilots have followed the procedure until flipping the cutout switches.
1 Control column. . . . . . . . . . . . . . . . . Hold firmly
2 Autopilot (if engaged) . . . . . . . . . . . . .Disengage
Do not re-engage the autopilot.
Control airplane pitch attitude manually with control column and main electric trim as needed.
3 If the runaway stops:
- - - - - -
4 If the runaway continues: STAB TRIM CUTOUT
switches (both) . . . . . . . . . . . . . . . . CUTOUT
If the runaway continues:
Stabilizer trim wheel . . . . . . . . . . Grasp and hold
- - - - - - - - - - - - - - - - - - - - - - -
5 Stabilizer . . . . . . . . . . . . . . . . . . . Trim manually
6 Anticipate trim requirements.
7 Checklist Complete Except Deferred Items
And, in the accident interim report, you can read:
05:39:56: auto-pilot disconnects
05:40:00: MCAS kicks in and trims down for a duration of 9 seconds
05:40:13: the pilot trims up for 3 seconds
05:40:21: MCAS trims down for a reduced duration of 7 seconds (interrupted by the pilot trimming up)
05:40:28: the pilot trims up for 10 seconds
05:40:38: end of pilot trim up action. Somewhere between 05:40:38 and 05:40:43 the cutout switches are actioned.
05:40:43: the next MCAS activation doesn't move the STAB.

So:
- As per item number 2 in the check list, the pilots did control the airplane with control column and main electric trim after noticing the uncommanded trim behaviour.
Then, as the runaway continued, they actioned the cutout switches (item number 4)
- The whole sequence took place in 43 seconds.

If one has plenty of time to consider the situation and choose the best course of action, he could read the point 4 in the check list as
4 If the runaway continues: STAB TRIM CUTOUT
main electric trim. . . . . . . . . . . . . . . trim until needed control column force is light
switches (both) . . . . . . . . . . . . . . . . CUTOUT
If the runaway continues:
Stabilizer trim wheel . . . . . . . . . . Grasp and hold
Unfortunately, if one is shaken and startled, it is the written list that will be executed.

Last edited by Luc Lion; 17th May 2019 at 16:44.
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Old 17th May 2019, 16:48
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Originally Posted by Chronus
When that new A320-111 crashed at the Mulhouse- Habsheim air show back in 1988 the French govt did manage to stick the blame on the pilot. So why blame Trump for trying to avert an even bigger disaster of Boeing going belly up.
Because two wrongs don't make a right.
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Old 17th May 2019, 17:56
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Originally Posted by Bend alot
A very armchair response and can you explain Mr Groves (a airman's) explanation of AoA being as simple as look out the window? He is a highly trained pilot that could sit in any seat in any American Airliner - just without me in the aircraft if I can know.

So simple tasks or simple people?
Bend alot
Not armchair response at all. If you are unsure what your aircraft is doing,f one pilot fly the the plane, usually includes setting an appropriate power setting, normally doesn’t include leaving T/O power set continuously.
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Old 17th May 2019, 18:00
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Originally Posted by Luc Lion
Oggers,
re-read parallely the abnormal procedure AND the interim accident report.
You'll conclude that the pilots have followed the procedure until flipping the cutout switches.

And, in the accident interim report, you can read:
05:39:56: auto-pilot disconnects
05:40:00: MCAS kicks in and trims down for a duration of 9 seconds
05:40:13: the pilot trims up for 3 seconds
05:40:21: MCAS trims down for a reduced duration of 7 seconds (interrupted by the pilot trimming up)
05:40:28: the pilot trims up for 10 seconds
05:40:38: end of pilot trim up action. Somewhere between 05:40:38 and 05:40:43 the cutout switches are actioned.
05:40:43: the next MCAS activation doesn't move the STAB.

So:
- As per item number 2 in the check list, the pilots did control the airplane with control column and main electric trim after noticing the uncommanded trim behaviour.
Then, as the runaway continued, they actioned the cutout switches (item number 4)
- The whole sequence took place in 43 seconds.

If one has plenty of time to consider the situation and choose the best course of action, he could read the point 4 in the check list as


Unfortunately, if one is shaken and startled, it is the written list that will be executed.
Mate, I think you have lost the plot. What you wrote was:
There is nothing in the FCOM nor in the QRH that instructs to use electric trim buttons to put the aircraft in trim prior to flip the cutout switches,
even though I reckon that, calmly sitting in a chair in front of a computer, it looks like a good idea....The only information akin to that is in the airworthiness directive AD 2018-23-51
...so let me repeat: the advice to control pitch using electric trim has been in the NNC for 19 years now. It is number 2 memory item. Furthermore, the amplifying remarks promulgated with the AD were a de facto amendment to the FCOM that the operators were required to action within 3 days.

Your latest post is tilting at some windmill. But go ahead and explain why you think it means that the advice to use electric trim is not really in the NNC and the information in the AD was not an amendment to the FCOM after all......

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Old 17th May 2019, 18:48
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I just meant that the NNC does NOT say "put the airplane in trim before using the cutout switch".

I think that, without having been explained the importance and impact of each step, there is a (bad) chance that the crew executes the procedure mecanically.
I read between the lines of the ET302 report that the crew was totally ignorant that the aerodynamic forces would prevent them from using the manual trim.

Nowhere in the official documents provided to the pilots, is it stated that :
"switching the cutout switch to off is a NO NO while the airplane is strongly out of trim because you will be unable to use the manual trim" !!
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Old 17th May 2019, 20:12
  #66 (permalink)  
 
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Another thing about stab trim may have been forgotten...

Boeing reduced the diameter of the manual trim wheel on the NG and Max by 10%. That's ten percent less leverage on a stabiliser also farther aft than it was on the classic. The change was needed because the old wheel (200 and classics) didn’t fit with the change to the avionics.

A colleague told me yesterday that in the NG sim* with a gross mistrim even the electric trim wouldn’t run and they had to aerodynamically unload to get the trim to move at all.

Regarding the stick shaker...a single shaker does shake both sides, but its more vigorous and louder on the affected side. (Really loud, in fact)
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Old 18th May 2019, 02:15
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Originally Posted by Bend alot
That is 100% correct.

Reasons they did not are human factor issues not procedure issues or memory items and do not forget never ever has an American crew been faced with a MCAS issue in 57,000 flights. So it is only an assumption they may have been equal in performance to one other crew that faced it. Never has an American crew correctly dealt with a MCAS event but only a foreign crew with less than a 1500 hr limit for a commercial licence .
Human factors issues why they did not do a simple, memory checklist? If that is the case, the travelling public is doomed if professional pilots couldn’t even do a simple drill of turning off the automatics, setting an attitude and power setting and flying the aircraft. If professional pilots can’t do that then they (and their passengers) totally screwed with a substantive emergency such as an engine failure, a rapid decompression, smoke in the cockpit, etc. which require a lot more moxy to address.

While you claim that “human factors” prevented the crews of the accident aircraft from doing the UAS checklist, can you explain how the crew of the Lion Air incident aircraft the previous day managed to do the UAS checklist, control the aircraft, deal with the MCAS trim issue, then fly for an hour and a half to the planned destination with unreliable airspeed while manually trimming the aircraft. We’re they super human? Or did just do what was expected of type rated B737 pilots? I would submit it was the latter.
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Old 18th May 2019, 02:31
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Originally Posted by ironbutt57
weren't both airplanes that crashed in fact totally controllable if the stab trim checklist were complied with?, regardless of where the pilots were from?
No ........
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Old 18th May 2019, 02:35
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Originally Posted by Bend alot
Quote - Sam Graves 15 May 2019.

"In the last decade, in the United States there have been nearly 7 Billion passengers flown on 90 Million flights with ONE fatality."

Atlas Air FLT 3591 - 23 Feb 2019 - 3 Fatal
SWA FLT 1380 - 17 Apr 2018 - 1 Fatal
UPS FLT 1354 - 14 Aug 2013 - 2 Fatal
National Air FLT 102 - 29 Apr 2013 - 7 Fatal
UPS FLT 6 - 3 Sep 2010 - 2 Fatal

American pilots are far superior to all other pilots around the world, .....

.... I guess. 🤔
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Old 18th May 2019, 02:38
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Originally Posted by ironbutt57
i suppose never reducing the power from takeoff thrust didn't help the situation either did it

Actually, it did in one respect.

Pull the power back and the nose drops like a stone.
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Old 18th May 2019, 03:02
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Originally Posted by Old Dogs
Actually, it did in one respect.

Pull the power back and the nose drops like a stone.
yes, and caused terrific speed to build up rendering the manual trim wheel useless
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Old 18th May 2019, 03:25
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Originally Posted by ironbutt57
yes, and caused terrific speed to build up rendering the manual trim wheel useless
Very true.

So which would you prefer, rapid pitch down with power reduction in an already massively pitch down situation, ... or inop trim at high speed ... a phenomenon nobody told you about?

Quick now, you have only a few seconds to decide.

I might add I am not real keen to fly an aircraft designed such that the manual pitch trim becomes inop at high speed.
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Old 18th May 2019, 03:29
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Originally Posted by Old Dogs
Actually, it did in one respect.

Pull the power back and the nose drops like a stone.
Pull the power back and the speed decreases and so do the control forces, roughly 1/velocity^2. Half the speed, one quarter of the force required.
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Old 18th May 2019, 03:34
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Originally Posted by L39 Guy

Pull the power back and the speed decreases and so do the control forces, roughly 1/velocity^2. Half the speed, one quarter of the force required.
And by doing so you take an aircraft in a uncontrollable pitch down situation low to the ground - and make it pitch down some more.

Might work. 🤔
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Old 18th May 2019, 03:39
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Originally Posted by Old Dogs
American pilots are far superior to all other pilots around the world, .....

.... I guess. 🤔
The safety record of “western” airlines is pretty damn good and no one has to be ashamed or apologize for that. How many fatal jet crashes in Canada? 2011, a B737 at Resolute Bay. Prior to that, 1989 in Dryden, Ontario.

The Germans, Brits, Japanese, Aussie’s, Kiwi’s, etc. have even better safety records. And when one considers how many aircraft operate in all of these countries, the relative safety record of “western” airlines is even more impressive.

Is this a fluke? Or maybe, just maybe, “western” pilots know how to fly, particularly when the automation either fails or is not useable and, heaven forbid, one actually has to fly an airplane.
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Old 18th May 2019, 03:39
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well in hindsight, when one's aircraft is trying to head to the ground and pull forces are exceeding the crew's ability, one might try to think of other ways to raise the nose, on some airplanes speedbrakes tend to pitch the aircraft up, flaps as well...the pilots were in a ****-fight to save the airplane, without having a clue what was happening to them, unfortunately ab initio programs do not seem to prepare "pilots" for any eventuality that doesn't come with a checklist.. and this where the unforgiveable failure of Boeing to present the info to the crews comes into play, for not designing a proper procedure to deal with a potentially very disorienting failure, not insisting on proper training and recognition of such, and for designing a single-point of failure system for stability augmentation in the first place....yes it is a stability augmentation system, nothing to do with stall avoidance...goodness, the short-bodied MerlinIII I flew 35 years ago had the same system, as well as did the Piper Cheyenne II, but their systems were imposing the downforce on the elevator circuit as opposed to trimming the stab, even on the little airplane we had a checklist, and were trained to deal with the system going haywire..
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Old 18th May 2019, 03:42
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Originally Posted by Old Dogs
And by doing so you take an aircraft in a uncontrollable pitch down situation low to the ground - and make it pitch down some more.

Might work. 🤔
It’s true that underwing mounted engines creating a pitching moment. I would submit that on balance the decrease in speed and hence control forces would be significantly more beneficial than the pitching moment created by the thrust of the engines.
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Old 18th May 2019, 03:45
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Originally Posted by L39 Guy

The safety record of “western” airlines is pretty damn good and no one has to be ashamed or apologize for that. How many fatal jet crashes in Canada? 2011, a B737 at Resolute Bay. Prior to that, 1989 in Dryden, Ontario.

The Germans, Brits, Japanese, Aussie’s, Kiwi’s, etc. have even better safety records. And when one considers how many aircraft operate in all of these countries, the relative safety record of “western” airlines is even more impressive.

Is this a fluke? Or maybe, just maybe, “western” pilots know how to fly, particularly when the automation either fails or is not useable and, heaven forbid, one actually has to fly an airplane.
You are absolutely right, American, German, Brit, Japanese, Aussie, and Kiwi pilots are far superior to Canadian pilots.
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Old 18th May 2019, 03:54
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Originally Posted by L39 Guy

It’s true that underwing mounted engines creating a pitching moment. I would submit that on balance the decrease in speed and hence control forces would be significantly more beneficial than the pitching moment created by the thrust of the engines.
You are absolutely right.

You must be one of those superior non-Canadian "western" pilots. 👏
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Old 18th May 2019, 03:57
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One would hope Aussie pilots are currently using the B787 simulator for double engine failures, or they might very soon blemish that Western record.
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