US administration blames foreign pilots for 737 Max crashes [Archive]

Lonewolf_50

16th May 2019, 14:24

To now blame foreign customer's pilots is the worst strategy to get over this crisis. The market for the MAX is global. Offending foreign countries will not help to get it flying again soon and then to sell more. I guess we have a few posters here from the "the hatch just blew" school of accident investigation. I agree with you, though, that this whole thing is highly politicized, which helps nothing.

I've been reading the observations from experienced flight deck pros on PPRuNe for a bit over 10 years (so I am a relative newby).
What is rather apparent from soaking that all up is that there is NOT an international standard for airline pilots that any of us can comfortably assume when we sit down in the tube and strap that seat belt on while the CC brief us on the O2 mask and where the exits are. Culture informs cockpit culture; lessons learned sometimes aren't; corporate cultures - not just national culture - have influences that may or may not have been addressed in the testimony in re what you can assume that a given crew on a flight deck does or can do. After decades of folding in the hard lessons learned in the interest of safety, I am not impressed by those who will stick their heads in the sand and pretend that those lessons have been spread evenly across all passenger carrying organizations.

The 777 @ SFO reopened that can of worms. But even that crash points to something else also - being comfortable with one system, and then transitioning to another system where some functions are "similar but different" ... can lead to technical surprise and crew confusion. The remedy to that is training and system mastery: where's that as a priority? (Was the Captain in the ET Max crash well served by that, training? Color me skeptical).

There seems to be a problem, that a few posts in this thread demonstrate, with confronting the fact that not all flight deck crews are equal in ability nor in experience. (FWIW, the US regulators made a decision to demand 1500 hours experience before carrying passengers, as compared to 200 hours in a variety of other countries, to include maybe a few in Europe. How much that helps safety I don't know, but I don't think it hurt).
But that's one data point of many that hardly addresses the issues of assaults on training/recency/currency due to financial pressure.

None of the above relieves Boeing of: (1) some (IMO) bizarre choices in implementing the systems in the Max (single point of failure being one such choice in re AoA signal and triggering ... ) and (2) how crews were taken by surprise by a new feature due at least in part to the roll out/implementation scheme.
Those are causal factors related to the machine, and to training philosophy, but I digress.

I will ask posters to stop with the hair pulling in re someone speaking a truth - not all systems that produce Captains and FOs are equal. Well, no, they aren't. (I won't begin to offer which is the best, but anyone running an airline and/or a national regulatory agency sure as hell ought to be looking into that ...)

FACT for you: some airlines are so egregiously bad that certain nations or aviation authorities ban them from their airspace.
It isn't their machines that are the problem, it's the wet ware.

If one is to believe PPRuNe's collective memorey/experience* base of flight deck professionals over the course of 20 years of putting stuff down into internet posts, there is a willful failure demonstrated (in the posts here) to confront the variabilty of FD crews across the globe where some causal factors are Not The Machine.
And of course, some factors are related to The Machine.

Unbunch your knickers.
What irks me about this political process (as reported in the news article, so who knows how much of it is even right?) is that someone seems to be looking for a single smoking gun barrel.
Sorry, that's wrong headed.
A gatling gun is what's smoking.

Less Hair

16th May 2019, 14:37

The job is to get the MAX safely flying with the existing real world pilot population and customer base. If something needs improvement, like training, improve it. To just blame them is not enough.

Lonewolf_50

16th May 2019, 14:41

The job is to get the MAX safely flying with the existing real world pilot population and customer base. If something needs improvement, like training, improve it. To just blame them is not enough. I don't think 'just blame them' is what is being done, and the training issue falls well within national and corporate responsibility. (And I'm sorry if my response to you was a bit snarky, I was folding up my impression of a bunch of posts into one. I think we likely agree on more than we disagree).

Less Hair

16th May 2019, 14:59

Check post #1.

WHBM

16th May 2019, 15:27

I wonder why the Foreign Pilots are not crashing the A320s or the A320 Neos ......

Chronus

16th May 2019, 18:31

Lonewolf_50

16th May 2019, 19:50

I wonder why the Foreign Pilots are not crashing the A320s or the A320 Neos ......
How soon we forget. Go back over the past 10 years. Have any 320's gone down? Where?
(At least 1 737 has gone down in that time also ... we had an extended discussion here on PPRuNe on one that went down in Russia)
Check post #1. Suggest you also check gums' post (https://www.pprune.org/showthread.php?p=10472639). ;) (IMO, the politicization of this is zero value added ... )

beardy

16th May 2019, 20:56

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.
I take it you understand what happened? The aircraft did exactly what it was designed to do as outlined in the FCOMs. It seems that the pilot was surprised by that.

funfly

16th May 2019, 20:57

The ultimate target is not more and more pilot training but aircraft that poorly pilots will be able to fly/ manage with safety.
You should not have to train pilots up to a new aircraft but make a new aircraft safer for the less trained pilot.
Nothing against pilot training but the facts are that, for various reasons, not all pilots are trained to the highest level.

SquintyMagoo

16th May 2019, 22:35

Only after the Lion Air accident global operators learned about MCAS and only recently they learned about AoA-disagree-warnings not working in MAX standard configuration as advertised.

Isn't a stick shaker only on one side an indication of AoA disagree?

EXDAC

16th May 2019, 23:02

Isn't a stick shaker only on one side an indication of AoA disagree?

This keeps coming up and it came up in the hearing. (Yes, I watched it all). Will someone who has actually experienced stick shaker activation on one side only in a 737 please comment. Is the shaker also felt in the other mechanically linked column? I'm quite sure it would be on a DC10, MD-10 or MD-11. If it is felt then is it possible to determine if only one stick shaker motor is running?

Loose rivets

16th May 2019, 23:24

Yes, I wondered that. I assumed there'd be a significant loss of the vibrational 'sharpness' in transmitting it across the connecting mechanics.

Smythe

16th May 2019, 23:27

FACT for you: some airlines are so egregiously bad that certain nations or aviation authorities ban them from their airspace.

yet Airbus and Boeing continue to sell them aircraft...knowing this?

If a gun shop sells a felon a weapon....

a bar sells a drunk another drink.

tdracer

17th May 2019, 00:16

yet Airbus and Boeing continue to sell them aircraft...knowing this?

If a gun shop sells a felon a weapon....

a bar sells a drunk another drink.

What a ridiculous post...
Every new generation of commercial aircraft has gotten safer than the previous generation (the MAX not withstanding). So you're going to take the countries and operators that need the most help with their aircraft safety and prevent them from purchasing new, safer aircraft. Effectively condemning them to operating older, less safe aircraft.
Brilliant :ugh:

LowObservable

17th May 2019, 00:39

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.

Err, two wrongs don't make a right, as my Granny would say. And I'd hope that transparency in air safety is something we'd hope to see improving over three decades.

So why blame Trump for trying to avert an even bigger disaster of Boeing going belly up.

If that's indeed what is happening, I think Trump would be blameworthy,

Old Dogs

17th May 2019, 00:41

What an insult to the rest of the world.

Well done, ..... I guess. 🤔🇨🇦

BFSGrad

17th May 2019, 00:58

Never thought I'd see a Dana Milbank political screed used as the basis for a PPRuNe topic but here we are...

gums

17th May 2019, 01:55

Salute!
Never thought I'd see a Dana Milbank political screed used as the basis for a PPRuNe topic but here we are...

Thank you BFS,

I could not read the article as it is pay walled and it is also shown as "opinions" when I Googled it. So it has zero, if not negative credibility when considering the politically neutral WaPo, huh?

I'll wait for something with name, rank and serial number versus "sources". But I saw the hearing and I did not see a single official from NTSB or FAA agree with one or more of the clueless cmte members as to poorly trained or incompetent foreign crews. And of course, our Yeager clones here would have saved the day on both accidents.

Gums sends...

Old Dogs

17th May 2019, 02:09

Salute!

Thank you BFS,

I could not read the article as it is pay walled and it is also shown as "opinions" when I Googled it. So it has zero, if not negative credibility when considering the politically neutral WaPo, huh?

I'll wait for something with name, rank and serial number versus "sources". But I saw the hearing and I did not see a single official from NTSB or FAA agree with one or more of the clueless cmte members as to poorly trained or incompetent foreign crews. And of course, our Yeager clones here would have saved the day on both accidents.

Gums sends...

You may wish to read the article. 😏

Old Dogs

17th May 2019, 02:23

ironbutt57

17th May 2019, 04:54

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?

Bend alot

17th May 2019, 05:03

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?
The USA pilots that did a SIM reconstruction used up all 8,000 ft of altitude to recover by using the yo-yo procedure not in MAX checklist.

So that would a NO, or if the Yo-Yo was in the checklist a maybe but dependant on calibration tolerances.

And they were prepared for the reconstruction.

Bend alot

17th May 2019, 05:07

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

ironbutt57

17th May 2019, 05:38

The USA pilots that did a SIM reconstruction used up all 8,000 ft of altitude to recover by using the yo-yo procedure not in MAX checklist.

So that would a NO, or if the Yo-Yo was in the checklist a maybe but dependant on calibration tolerances.

And they were prepared for the reconstruction.

think the issue may be does anybody learn to actually FLY anymore, or is it all procedures and checklists, any reerence to the USA sim re-constructions? what about trimming out the pitch when it happens and then stab trim de-activate...people are complaining they didnt know about MCAS, fair enough, regardless, take necessary actions to keep the airplane upright...

Bend alot

17th May 2019, 06:12

flash8

17th May 2019, 06:17

Those with long memories may remember the baggage handler vilification back at Ermenonville, airplane apparently was fine... certification was fine... FAA (dumb and) happy... nothing changes.

DaveReidUK

17th May 2019, 06:23

pilotmike

17th May 2019, 06:40

Yobo

17th May 2019, 06:50

I wonder why the Foreign Pilots are not crashing the A320s or the A320 Neos ......

"Thank God we're in an A330, eh?"

So said one Pierre-Cedric Bonin.

Now for the second bird with that one stone, perhaps Airbus might not want to sell aircraft to Air France, since only God knows how many Bonins are flying their aircraft.

And for the idiotic let's all blame Trump and the Repubs crowd:

“This is an example of a win-win situation where the people of the region are going to be able to benefit from an outstanding airline,” President Barack Obama said in 2011 when Lion Air Group signed a $22 billion order for Boeing planes, the largest single order in the manufacturer’s history.

So where we're you when it came to blaming ole Obama for that sale in light of Lion Air's rather pathetic history? Don't bother answering. I mean, he's lauding the sale in light of: Over the years, Lion planes have collided with a cow, a pig and, most embarrassingly, each other. Two days in a row in 2011, Lion planes skidded off the same airport runway. Can't post a URL but there is a 2018 NYT piece on Lion Air following the 737 Max crash that indeed details the rather pathetic history.

Now for why you sell the planes and never mind the safety history:Barr, the USC safety instructor, said even equipped with the best planes from Boeing or Airbus, airlines still must provide routine maintenance and highly trained crews to operate safely."It doesn't matter how good the plane is if you give it to a bunch of mechanics who don't know what to do or to a bunch of pilots who fall asleep in the cockpit," said Barr. Kinda like this:

One of the latest problems was aboard a Jet Airways flight in August from Mumbai to Brussels that plunged 5,000 feet over Turkey with one pilot asleep and the other busy with an iPad. Nobody was injured.

By the way, since I mentioned the late Pierre-Cedric Bonin, to give him some small measure of relief, that accident does not happen if the flight was during the day. A look out the window would have told him that he was not flying but instead falling. And, yeah, generally safe, and then there's the money, but one wonders what some think of those WWII stories where trained pilots crashed at night, inverted, into the sea. Maybe that its better to fly during the day? And so interesting that such wasn't a causal factor in the report, when it very clearly was. Oh, and did I mention as well, generally safe, so 1 in 1 million flights in the developing world we have a fatality whereas 1 in 23.9 million in the developed world, or so wrote the one MIT statistician who examined the data. And some of the developing are worse than others, so sub-Saharan Africa the worst and so on. Hello Ethiopian Airlines. And another bad spot, consider Lion Air in the NYT piece. Not just them but that part of the world. I'd also avoid India and China like the plague. Well, all of India except for the one biggie, and in Lion Air's part of the world there's always PAL. The difference between the two isn't the corruption and/or love of money, by the way, as the difference is instead that PAL flies to LA, SF, HNL, Vegas, Newark, NYC and London Gatwick and Heathrow while Lion Air doesn't. So PAL has to play by our rules.

This administration is an extension of Boeing and the acting defense secretary about to be nominated officially should have told you all that. draining the swamp!

"For the last several days, I've been talking about how we have to make sure that we've got a presence in this region, that it can result directly in jobs at home," Obama said in a statement. "And what we see here -- a multibillion-dollar deal between Lion Air -- one of the fastest-growing airlines not just in the region, but in the world -- and Boeing is going to result in over 100,000 jobs back in the United States of America, over a long period of time."

The largest sale of aircraft ever. What were saying then?

Bend alot

17th May 2019, 06:59

I'm not sure what your point is. Graves' statement is perfectly correct.
Can you supply the flights over the last decade including cargo operations in the United States.

He did not say one passenger fatality - just one fatality.
The most recent Atlas Air flight 3591 has a non paying passenger certainly he was not crew>

Given Graves full comments on "one" fatality being attributed to United States superior flight training compared to the rest of the world - every one of the dead crew were trained in the United States and some of them caused fatalities on American soil.

Can you also comment on Graves accuracy on his "look out the window and the AH's, they are your primary AoA's" at the 57:50 mark of the hearing.

Bend alot

17th May 2019, 07:42

think the issue may be does anybody learn to actually FLY anymore, or is it all procedures and checklists, any reerence to the USA sim re-constructions? what about trimming out the pitch when it happens and then stab trim de-activate...people are complaining they didnt know about MCAS, fair enough, regardless, take necessary actions to keep the airplane upright...

It is also reported in the Seattle Times but has a pay wall.

Keep in mind number one event was stick shaker and trim wheel movement is normal due STS, and a fair call for Sully reaction time just to turn or not was 35 seconds. Sully did not get a second startle event like a MCAS, that most likely he would have had if that was a B737 MAX (Flaps up and damaged AoA).

https://news.ycombinator.com/item?id=19902068
"WASHINGTON—A simulator session flown by a U.S.-based Boeing 737 MAX crew that mimicked a key portion of the Ethiopian Airlines Flight 302 (ET302) accident sequence suggests that the Ethiopian crew faced a near-impossible task of getting their 737 MAX 8 back under control, and underscores the importance of pilots understanding severe runaway trim recovery procedures.Details of the session, shared with Aviation Week, were flown voluntarily as part of routine, recurrent training. Its purpose: practice recovering from a scenario in which the aircraft was out of trim and wanting to descend while flying at a high rate of speed. This is what the ET302 crew faced when it toggled cutout switches to de-power the MAX’s automatic stabilizer trim motor, disabling the maneuvering characteristics augmentation system (MCAS) that was erroneously trimming the horizontal stabilizer nose-down.

In such a scenario, once the trim motor is de-powered, the pilots must use the hand-operated manual trim wheels to adjust the stabilizers. But they also must keep the aircraft from descending by pulling back on the control columns to deflect the elevator portions of the stabilizer upward. Aerodynamic forces from the nose-up elevator deflection make the entire stabilizer more difficult to move, and higher airspeed exacerbates the issue.

The U.S. crew tested this by setting up a 737-Next Generation simulator at 10,000 ft., 250 kt. and 2 deg. nose up stabilizer trim. This is slightly higher altitude but otherwise similar to what the ET302 crew faced as it de-powered the trim motors 3 min. into the 6 min. flight, and about 1 min. after the first uncommanded MCAS input. Leading up to the scenario, the Ethiopian crew used column-mounted manual electric trim to counter some of the MCAS inputs, but did not get the aircraft back to level trim, as the 737 manual instructs before de-powering the stabilizer trim motor. The crew also did not reduce their unusually high speed.

What the U.S. crew found was eye-opening. Keeping the aircraft level required significant aft-column pressure by the captain, and aerodynamic forces prevented the first officer from moving the trim wheel a full turn. They resorted to a little-known procedure to regain control.

The crew repeatedly executed a three-step process known as the roller coaster. First, let the aircraft’s nose drop, removing elevator nose-down force. Second, crank the trim wheel, inputting nose-up stabilizer, as the aircraft descends. Third, pull back on the yokes to raise the nose and slow the descent. The excessive descent rates during the first two steps meant the crew got as low as 2,000 ft. during the recovery.

The Ethiopian Ministry of Transport preliminary report on the Mar. 10 ET302 accident suggests the crew attempted to use manual trim after de-powering the stabilizer motors, but determined it “was not working,” the report said. A constant trust setting at 94% N1 meant ET302’s airspeed increased to the 737 MAX’s maximum (Vmo), 340 kt., soon after the stabilizer trim motors were cut off, and did not drop below that level for the remainder of the flight. The pilots, struggling to keep the aircraft from descending, also maintained steady to strong aft control-column inputs from the time MCAS first fired through the end of the flight.

The U.S. crew’s session and a video posted recently by YouTube’s Mentour Pilot that shows a similar scenario inside a simulator suggest that the resulting forces on ET302’s stabilizer would have made it nearly impossible to move by hand.

Neither the current 737 flight manual nor any MCAS-related guidance issued by Boeing in the wake of the October 2018 crash of Lion Air Flight 610 (JT610), when MCAS first came to light for most pilots, discuss the roller-coaster procedure for recovering from severe out-of-trim conditions. The 737 manual explains that “effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions,” but does not provide details.

The pilot who shared the scenario said he learned the roller coaster procedure from excerpts of a 737-200 manual posted in an online pilot forum in the wake of the MAX accidents. It is not taught at his airline.

Boeing’s assumption was that erroneous stabilizer nose-down inputs by MCAS, such as those experienced by both the JT610 and ET302 crews, would be diagnosed as runaway stabilizer. The checklist to counter runaway stabilizer includes using the cutout switches to de-power the stabilizer trim motor. The ET302 crew followed this, but not until the aircraft was severely out of trim following the MCAS inputs triggered by faulty angle-of-attack (AOA) data that told the system the aircraft’s nose was too high.

Unable to move the stabilizer manually, the ET302 crew moved the cutout switches to power the stabilizer trim motors—something the runaway stabilizer checklist states should not be done. While this enabled their column-mounted electric trim input switches, it also re-activated MCAS, which again received the faulty AOA data and trimmed the stabilizer nose down, leading to a fatal dive.

The simulator session underscored the importance of reacting quickly to uncommanded stabilizer movements and avoiding a severe out-of-trim condition, one of the pilots involved said. “I don’t think the situation would be survivable at 350 kt. and below 5,000 ft,” this pilot noted.

The ET302 crew climbed through 5,000 ft. shortly after de-powering the trim motors, and got to about 8,000 ft.—the same amount of altitude the U.S. crew used up during the roller-coaster maneuvers—before the final dive. A second pilot not involved in the session but who reviewed the scenario’s details said it highlighted several training opportunities.

“This is the sort of simulator experience airline crews need to gain an understanding of how runaway trim can make the aircraft very difficult to control, and how important it is to rehearse use of manual trim inputs,” this pilot said.

While Boeing’s runaway stabilizer checklist does not specify it, the second pilot recommended a maximum thrust of 75% N1 and a 4 deg. nose-up pitch to keep airspeed under control.

Boeing is developing modifications to MCAS, as well as additional training. Simulator sessions are expected to be integrated into recurrent training, and may be required by some regulators, and opted for by some airlines, before pilots are cleared to fly MAXs again. The MAX fleet has been grounded since mid-March, a direct result of the two accidents."

DaveReidUK

17th May 2019, 08:06

He did not say one passenger fatality - just one fatality.

OK.

I was assuming that you had quoted him accurately (I haven't listened to the recording yet):

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."

RickNRoll

17th May 2019, 08:40

What the U.S. crew found was eye-opening. Keeping the aircraft level required significant aft-column pressure by the captain, and aerodynamic forces prevented the first officer from moving the trim wheel a full turn. They resorted to a little-known procedure to regain control.

That is consistent with the Mentour video on you tube.

Bend alot

17th May 2019, 09:01

OK.

I was assuming that you had quoted him accurately (I haven't listened to the recording yet):
His comment/s clearly based on reporting since the recent 10 year anniversary of the Colgan Air Flight 3407 media reports.

But the flights numbers clearly seem to include large cargo operations regular flights including international operations not just domestic.

At 1:23:00 the NTSB guy Sumwalt then use this statistic as if fact.

It is worth the 3 hrs 10 minutes to watch, not listen and certainly do not use the transcript (that is very inaccurate on what was said).

ironbutt57

17th May 2019, 10:02

i suppose never reducing the power from takeoff thrust didn't help the situation either did it

Tay Cough

17th May 2019, 10:29

i suppose never reducing the power from takeoff thrust didn't help the situation either did it

The pitch-power couple with a thrust reduction would also cause the aircraft to pitch down in that situation and require a nose-up pitch input to counter. Intuitive maybe but not necessarily helpful.

Bend alot

17th May 2019, 10:44

i suppose never reducing the power from takeoff thrust didn't help the situation either did it
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 .

Luc Lion

17th May 2019, 11:34

https://news.ycombinator.com/item?id=19902068
"WASHINGTON—A simulator session flown by a U.S.-based Boeing 737 MAX crew
...
but did not get the aircraft back to level trim, as the 737 manual instructs before de-powering the stabilizer trim motor.
...
"
That statement is wrong.
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 QRH just says
If the runaway continues:
STAB TRIM CUTOUT switches (both) . . . . . . . . . . . . . . . . CUTOUT.

The only information akin to that is in the airworthiness directive AD 2018-23-51 and it only says:
Note: Initially, higher control forces may be needed to overcome any stabilizer nose down trim already applied. Electric stabilizer trim can be used to neutralize control column pitch forces before moving the STAB TRIM CUTOUT switches to CUTOUT.
(my emphasis)

"can be used", in a note, is hardly an instruction.

ManaAdaSystem

17th May 2019, 11:41

With the trim near full nose down, you need all your strenght to keep the aircraft somewhat level. If you let go for just a few seconds, you will lose 4-5000 ft before to get it level again. This happens really fast.
Manual trim is impossible when you maintain «level» flight. It’s not a matter of difficult, it’s impossible.

Bend alot

17th May 2019, 13:03

That statement is wrong.
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 QRH just says

The only information akin to that is in the airworthiness directive AD 2018-23-51 and it only says:

(my emphasis)

"can be used", in a note, is hardly an instruction.
No disagree - I just posted the link.

The note is misleading in such an event in my opinion. I expect it was that way for Loin Air reasons (blame the pilot!)

Thing is a MCAS event before MCAS was known, was reported as a STS operating the wrong direction as the fault - after fighting it for a very long time.

While that certainly is a good reason to shut down the trim - it is not a trim runaway. Then what exactly is going to work opposite to what it should? Manual trim wheel??

oggers

17th May 2019, 14:23

That statement is wrong.
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 and it only says:

(my emphasis)

"can be used", in a note, is hardly an instruction.

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.

cessnapete

17th May 2019, 14:42

i suppose never reducing the power from takeoff thrust didn't help the situation either did it

As above. Leaving the thrust Levers at TOGA from T/O until it impacted, must be a major reason for the crews inability to control the MCAS problem. If the crew had disengaged the automatics (anathema as an SOP in some airlines) and manually flown a quick circuit to land ,(they would not be continuing the flight with an erroneous stick shaker) No need to retract the flaps, and MCAS would not have activated.
Presumably they retracted the flaps because of the high speed after take off, not recognising the T/O power was still set.
Obviously MCAS is a problem in the Max, but if flown by properly experienced and trained crews ( and the naughty word Airmanship) the tragedies might not have happened.

Bend alot

17th May 2019, 14:50

As above. Leaving the thrust Levers at TOGA from T/O until it impacted, must be a major reason for the crews inability to control the MCAS problem. If the crew had disengaged the automatics (anathema as an SOP in some airlines) and manually flown a quick circuit to land ,(they would not be continuing the flight with an erroneous stick shaker) No need to retract the flaps, and MCAS would not have activated.
Presumably they retracted the flaps because of the high speed after take off, not recognising the T/O power was still set.
Obviously MCAS is a problem in the Max, but if flown by properly experienced and trained crews ( and the naughty word Airmanship) the tragedies might not have happened.
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?

edmundronald

17th May 2019, 14:57

yanrair

17th May 2019, 14:58

I guess we have a few posters here from the "the hatch just blew" school of accident investigation. I agree with you, though, that this whole thing is highly politicized, which helps nothing.

I've been reading the observations from experienced flight deck pros on PPRuNe for a bit over 10 years (so I am a relative newby).
What is rather apparent from soaking that all up is that there is NOT an international standard for airline pilots that any of us can comfortably assume when we sit down in the tube and strap that seat belt on while the CC brief us on the O2 mask and where the exits are. Culture informs cockpit culture; lessons learned sometimes aren't; corporate cultures - not just national culture - have influences that may or may not have been addressed in the testimony in re what you can assume that a given crew on a flight deck does or can do. After decades of folding in the hard lessons learned in the interest of safety, I am not impressed by those who will stick their heads in the sand and pretend that those lessons have been spread evenly across all passenger carrying organizations.

The 777 @ SFO reopened that can of worms. But even that crash points to something else also - being comfortable with one system, and then transitioning to another system where some functions are "similar but different" ... can lead to technical surprise and crew confusion. The remedy to that is training and system mastery: where's that as a priority? (Was the Captain in the ET Max crash well served by that, training? Color me skeptical).

There seems to be a problem, that a few posts in this thread demonstrate, with confronting the fact that not all flight deck crews are equal in ability nor in experience. (FWIW, the US regulators made a decision to demand 1500 hours experience before carrying passengers, as compared to 200 hours in a variety of other countries, to include maybe a few in Europe. How much that helps safety I don't know, but I don't think it hurt).
But that's one data point of many that hardly addresses the issues of assaults on training/recency/currency due to financial pressure.

None of the above relieves Boeing of: (1) some (IMO) bizarre choices in implementing the systems in the Max (single point of failure being one such choice in re AoA signal and triggering ... ) and (2) how crews were taken by surprise by a new feature due at least in part to the roll out/implementation scheme.
Those are causal factors related to the machine, and to training philosophy, but I digress.

I will ask posters to stop with the hair pulling in re someone speaking a truth - not all systems that produce Captains and FOs are equal. Well, no, they aren't. (I won't begin to offer which is the best, but anyone running an airline and/or a national regulatory agency sure as hell ought to be looking into that ...)

FACT for you: some airlines are so egregiously bad that certain nations or aviation authorities ban them from their airspace.
It isn't their machines that are the problem, it's the wet ware.

If one is to believe PPRuNe's collective memorey/experience* base of flight deck professionals over the course of 20 years of putting stuff down into internet posts, there is a willful failure demonstrated (in the posts here) to confront the variabilty of FD crews across the globe where some causal factors are Not The Machine.
And of course, some factors are related to The Machine.

Unbunch your knickers.
What irks me about this political process (as reported in the news article, so who knows how much of it is even right?) is that someone seems to be looking for a single smoking gun barrel.
Sorry, that's wrong headed.
A gatling gun is what's smoking.
I asked of a few friends here which hospital in our country they would go to with a life threatening illness. One came out top, a couple good and the rest forget it. So it is with airlines and pilots and I am at a loss to understand why Joe Public things they are all the same. Nothing else is. All medical matters are regulated internationally and national to WHO guidelines yet nobody really believes they are all the same.

To Lonewolf
In an airline that I worked for I reckoned on a scale of 1-10 that most pilots were 1-5. Some 5-8 and a few scraping along at 10 where 10= can just pass annual checks. Where 1= nothing and I mean nothing would get past them.
And that Airline was No 1
Then the airlines are the same where No1 is like the No. 1 hospital - a centre of excellence. The worst at 10 is, along with hundreds of others, banned from flying in the EU.
So it. isn't a mystery.
The best pilots in the best airlines are probably 100 times better than the worst in the worst. Now, I realise I am no being dead accurate in these stats but they are not far wrong.
And like my pals who know which hospital go to and even which consultant to see there, I know who to fly with.
Happy flying

Y

Luc Lion

17th May 2019, 16:23

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.

L337

17th May 2019, 16:48

cessnapete

17th May 2019, 17:56

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.

oggers

17th May 2019, 18:00

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......

Luc Lion

17th May 2019, 18:48

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" !!

Australopithecus

17th May 2019, 20:12

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)

L39 Guy

18th May 2019, 02:15

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.

Old Dogs

18th May 2019, 02:31

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 ........

Old Dogs

18th May 2019, 02:35

Old Dogs

18th May 2019, 02:38

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.

ironbutt57

18th May 2019, 03:02

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

Old Dogs

18th May 2019, 03:25

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.

L39 Guy

18th May 2019, 03:29

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.

Old Dogs

18th May 2019, 03:34

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. 🤔

L39 Guy

18th May 2019, 03:39

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.

ironbutt57

18th May 2019, 03:39

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..

L39 Guy

18th May 2019, 03:42

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.

Old Dogs

18th May 2019, 03:45

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.

Old Dogs

18th May 2019, 03:54

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. 👏

Bend alot

18th May 2019, 03:57

One would hope Aussie pilots are currently using the B787 simulator for double engine failures, or they might very soon blemish that Western record.

ironbutt57

18th May 2019, 04:11

You might want to check that out some time on final...flaps give a nose down trim.
dont fly the 737, dont know, "some airplanes"...thats why I said SOME airplanes...probably not all

ironbutt57

18th May 2019, 04:13

Flaps give a nose down trim. (Unless you are in an ME-109, apparently.)

select flaps 18 from clean in an Avro/RJ and tell me all about the pitch down...and what could an ME-109 possibly have to do with any of this?

Takwis

18th May 2019, 04:13

Apparently, there is a sub-type of the ME-109 that gets a pitch up from flap extension. Strange enough to be remarkable. Generally speaking, a high wing airplane will give a nose up pitch, and low wings a nose down. But since we are talking about what a 737 pilot should do in a certain situation, he or she should know that extending the flaps will give a pitch down moment.

ironbutt57

18th May 2019, 04:21

Apparently, there is a sub-type of the ME-109 that gets a pitch up from flap extension.

absolutely no idea about any ME 109, initial flap extension on most airplanes I have flown induces a pitch up, but not all, the point is to use any possible tool to one's advantage, more manual flying can increase a pilot's awareness of his airplanes reactions to flaps, speedbrakes, etc that one day could save his life...

L39 Guy

18th May 2019, 05:10

You are absolutely right, American, German, Brit, Japanese, Aussie, and Kiwi pilots are far superior to Canadian pilots.

Did I say that? Please reread my post. Carefully.

It’s a fools game to say who are better or worse...the Operating environment in Canada is a difficult and unforgiving environment and the accidents reflect that. Resolute - non-radar environment, mountainous terrain, no TAWS, flying around in true, 400 miles to the alternate, etc. Dryden - F28 with a broken APU, icing conditions on the ground, both engines need to be shut down to de-ice which would ground the aircraft.

Old Dogs

18th May 2019, 05:13

Did I say that? Please reread my post. Carefully.

It’s a fools game to say who are better or worse...the Operating environment in Canada is a difficult and unforgiving environment and the accidents reflect that. Resolute - non-radar environment, mountainous terrain, no TAWS, flying around in true, 400 miles to the alternate, etc. Dryden - F28 with a broken APU, icing conditions on the ground, both engines need to be shut down to de-ice which would ground the aircraft.

This is EXACTLY what you said:

Originally Posted by L39 Guy https://www.pprune.org/images/buttons/viewpost.gif (https://www.pprune.org/showthread.php?p=10473961#post10473961)
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.

L39 Guy

18th May 2019, 05:14

You are absolutely right.

You must be one of those superior non-Canadian "western" pilots. 👏

I don’t think personal insults are warranted.

I don’t know about you but I use flight controls like the elevator and stab trim to control pitch not engine thrust moments. Maybe I am doing something wrong. Please let me know if I am.

L39 Guy

18th May 2019, 05:19

This is EXACTLY what you said:

Originally Posted by L39 Guy https://www.pprune.org/images/buttons/viewpost.gif (https://www.pprune.org/showthread.php?p=10473961#post10473961)
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.

Better safety records does not necessarily mean better pilots. As I demonstrated, the operating environment in Canada, one of the factors in safety records among others such as pilot training, maintenance and hundreds of others, is way more difficult.

Don’t be so sensitive. Crikey.

MemberBerry

18th May 2019, 05:45

Sorry for the off-topic post, but I'm extremely saddened when otherwise rational and intelligent people seem to suddenly throw rationality out the window whenever their favorite political team becomes part of a discussion. And this applies to all sides of the political spectrum.

As an example I'm an EU citizen, and I was discussing a health care related issue with a friend, and we reached the same conclusion, without any disagreement whatsoever. Then I mentioned the political party he voted for had a completely different opinion regarding that issue. He went "Actually...", and suddenly started finding excuses for that political party's position regarding the issue.

I'm probably guilty of this as well, probably sometimes even without realizing it. The first instinct when I hear something bad about my favorite political party is to defend it. Which can result in something similar to confirmation bias. I know it's not always easy, but we should try to let facts and logic and not emotion guide the conversation.

CurtainTwitcher

18th May 2019, 06:26

Sorry for the off-topic post,
---
The first instinct when I hear something bad about my favorite political party is to defend it...
Instinct 0, to even have a favourite political party is a mistaken assumption, in my view. Political parties don't appear to work for people at our level, just the top 0.1%. Exhibit A, the 737MAX fiasco.

I knew an (almost) honest politician, once.

See also Celine's Third Law (https://en.wikipedia.org/wiki/Celine%27s_laws)
An honest politician is a national calamity
Celine recognizes that the third law seems preposterous from the beginning. While a dishonest politician is interested only in bettering his own lot through abusing the public trust, an honest politician is far more dangerous since he is honestly interested in bettering society through political action, and that means writing and implementing more and more laws.

Celine argues that creating more laws simply creates more criminals. Laws inherently restrict individual freedom (https://en.wikipedia.org/wiki/Freedom_(political)), and the explosive rate at which laws are being created means that every citizen in the course of his daily life does not have the research capacity to not violate at least one of the plethora of laws. It is only through honest politicians trying to change the world through laws that true tyranny (https://en.wikipedia.org/wiki/Tyrant) can come into being through excessive legislation.

Corrupt politicians simply line their own pockets. Honest idealist politicians cripple the people's freedom through enormous numbers of laws. So corrupt politicians are preferable according to Celine, despite the possibility of an honest politician who honestly opposes the formation of new laws (or wants to do away with some).

Bend alot

18th May 2019, 07:03

Aussie's got pretty lucky with QF 32 even QF 72 could have ended much different if it had one more event (still no know reason for it).

Interesting is the fact until the 737 MAX crash Ethiopian Airlines had a similar safety record to the United States over the last 12 years.

Or put another way over the decade from 11 Feb 2009 - 2019 Ethiopian airlines had a perfect safety record compared to the United States of 51 fatalities (+ cargo ops crew and jump seater's) for the same period.

alf5071h

18th May 2019, 07:38

Member Berry, et al, # 90
Not so much off topic, but the reality of managing difficult situations.
Such problems are described as ‘wicked’ - https://en.m.wikipedia.org/wiki/Wicked_problem
“Wicked problems cannot be tackled by the traditional approach in which problems are defined, analysed and solved in sequential steps. The main reason for this is that there is no clear problem definition of wicked problems.”

This thread topic highlights the problem of understanding, unfortunately complicated by politics, legal ramifications, and human behaviour - before, during and after the event.

The current situation could be a defining point for human factors in flight safety; will the FAA standup and ‘be counted’ - practicing what they preach.
There are similar defining points for the processes of certification, design, operations; here external agencies might tip the balance, but I wound not bet on either a quick or meaningful change.

‘If you continuously compete with others you become bitter,
but if you continuously compete with yourself, you become better.’

A one page CRM / HF primer on thinking http://ta-tutor.com/sites/ta-tutor.com/files/handouts/ (http://ta-tutor.com/sites/ta-tutor.com/files/handouts/thinkng.pdf)
And more expansive view of thinking required for ‘wicked problems’. https://www.demos.co.uk/files/systemfailure2.pdf

Gove N.T.

18th May 2019, 09:09

"It just bothers me that we continue to tear down our system based on what has happened in another country.”

If what we read in the pprune forum and from what we hear from Boeing and the regulatory bodies in the USA, it is worrying that the FAA "outsource" a portion of its certification to the aircraft manufacturer. It is worrying that it appears there are significant gaps in the training, that a safety feature is left out but you can buy it at a modest few thousand (belittles that hackneyed phrase "safety is our number 1 concern")
Some drongo politician disparages all (non US) countries and carriers and in effect crew "I'm trying to not to be disrespectful because they are deceased" (and then promptly do so by association)"...do we not have concerns not only with the training of pilots in other nations....."

If a system is questionable then perhaps "we" should "continue to tear down our system" and make it better regardless of which country is involved since the manufacturer sells aircraft worldwide.

Boeing says that aircraft when (properly) re-certified to fly will be the safest aircraft to fly. Well I should hope that all aircraft that aircraft manufacturers deliver should be so.

And yes, there are differing standards in the capability of cockpit crew regardless from which country the come

fdr

18th May 2019, 10:08

The latest reported comments ascribed to Boeing and the FAA are offensive to the majority of customers for the US product that these two entities have responsibility over.

At some point, perhaps the CEO of Boeing should take time out and read the FCTM that his company provided to the crew.

For the record, Boeings own document states that in the case of a severe out of trim condition, that the aircraft should be flown to regain the speed commensurate to the out of trim case, and then the trim forces will be relieved sufficiently to permit the trim system to be reset as desired. It is remarkable that Boeing and the FAA apparently cite keeping power on as a sign of incompetence, when the trim moment form thrust on is nose up, and the out of trim condition requires gaining high speed as soon as possible, which suggests keeping power on as not being such a stupid idea that it would be used to make offensive comment from the people who gave MCAS unannounced, killed 350+ people... frankly, I am embarrassed on their behalf. For the pilot brethren who suggest in the forum herein that keeping power on was stupid, go back and do some simple maths guys before making assertions of incompetence on the dead crews.

Boeing designs a system that has the authority to put in more than 3 times the certified out of trim demonstration requirement FAR 25.255(a), without condescending to tell the apparently deficient foreign devils that fly their magnificent product. It was Boeing and the FAA ODA system that oversaw the MCAS design, and it was Boeing who decided not to bother telling the crews of the system until it was necessary following the first blood spill. Following that, it was Boeing who still did not reinforce the extent that out of trim would give catastrophic problems to a crew in handling, it was up to a newspaper report to show that a competent crew would find the handling nearly impossible when doing a briefed simulation of the event.

Boeing and the FAA are stating, not even insinuating that the crews involved here, and for good measure adding collective guilt to all 'foreign" pilots are of lesser competency than good ol' boys. M'kay, For the record, having spent 40 years flying with US and foreign pilots, in military and airline operations, having flown all Boeings from the 727 to the 787 as well as the 320, 330, and 340, I have to say, there is more commonality than anything else, sorry Mr Trump's band of brothers, the crews from S%$t'ole are not that much different. Is US air travel safer than overseas? Generally, yes, but that says as much about the infrastructure and rules as it does on crew training. Is crew training of a lesser standard overseas? Well, before the CEO of Boeign goes on record on that matter, was he aware that Boeing is or has been the training provider for Ethiopian???? Seems kind of odd to bitch about standards, when the legally responsible party to the standards is.... Boeing. Comments have been made about the AZ214 at San Francisco, where the training organisation was again Boeing, who held contracts for training for KE and AZ for the last 20 odd years in various forms and names of entities, Alteon, Boeing etc.

A B767 just got parked awkwardly in Texas, there was no sudden cry from the S%$t'ole countries concerned with FAA standards... nope, not a word, and nor should there have been.

Over the years I have flown with F15, F16 F22 and A10 pilots, some are great, most are good, some I would not let near a Cessna 150 without supervision. I have flown with Ethiopian pilots, and in fact the absolute best instructor I have ever seen work a simulator was an Ethiopian. Back in the day, the red necks from the usual countries, both sides of the equator would be disparaging with the national pilots and most other foreign pilots, however would fawn over the Ethiopian instructor, he was that good. Two of the best instructors I have had on helicopters were not US, they were Japanese, and I cherish the training they gave me. The next one of note on choppers was a poor little french farm boy from Guadaloupe, and he was and is exceptional. On the Boeing aircraft, without any doubt the best instructors I have ever had didn't come from Seattle, they were oddly almost uniformly Zoroastrians, The most knowledgeable airbus pilot I have ever worked with was a refugee from Iran, and he had a better knowledge base on the aircraft than the TP's that I was also working with at the same time. I don't mind flying with US pilots, I do not however see a great divide between them and the rest of the world, nor in fact do I see much difference between airline operation in audit of European airlines, Asian airlines, North and South American airlines, when conducting partner airline audits. In accident investigation, I have seen people of all skin colour and backgrounds do odd things occasionally with bad results. The US pilot contingent in that group had their share of odd ball events, more or less in keeping with the great unwashed from the S%$t'ole countries that are suggested to be incompetent.

Overall, I am hardly surprised that the OEM and the NAA of the disgrace that is the saga of MCAS are striking out, but they are off base with their assertions. The OEM is in danger of angering their customer base by such comments, and it is not going to add to their bottom line, rather it may well detract. Personally, as a stinking foreigner, albeit with pink skin, I would not buy a Boeing product by choice given the Trump like comments made on the competency of foreign pilots. The foreign airlines have a choice of products to acquire, and having flown more or less all of the offerings, the competition is competent, and comes without the racist bigoted comments of recent reports.

Take out the rhetoric and racism, and fix your plane guys. Suggest that you test your products with the intent of 25.255(a) not just the inadequate words that have so grossly failed us, the pilots and the passengers who pay for the purchase of your product. The aviation world was sharply awoken to the difference between certification standards and the perceived safety that flows from that by the AA587 loss. (it is interesting to note that no bigoted, disparaging comments were made on the pilot of that flight, nor on the pilots of AA965, AA1572, DL191 etc... just sayin'....)

Hofstede discusses the differences between cultures that do have some effect in the operation of a crew, however, this problem was a fundamental flying capability problem, and Boing and the FAA are hardly winning hearts and minds by their comments, coming hot on the heel of the Colgan debacle, Comairs efforts in Kentucky, and the B767 parked in the bayou. The MD11 at RJAA was dispalying a shiny USA flag on the tail...

:mad:

P.S., the FAA has good people in it, most fighting the system above them, in TAD, FSDOs at and various other acronyms, such as ACO and MIDO's. As a standard, having had professional licenses in 10 different countries, the FAA is not of any particular standout quality in their requirements or process. The FAA happens to be big and that is about the sum of it.

P.P.S. When is a full, honest investigation into the airworthiness of all of the B737NGs built with non compliant structure going to occur? It is hardly the behaviour of a first world nation to sack the QA auditors that brought that to light, that smacks of a 3rd world S%$t'ole type country response in itself.

P.P.P.S. the B767 Captain off the Comorros was a heroic person (ET961). He was being hit over the head with a damn fire axe as he ditched an aircraft without engines against that level of distraction. Sully and Jeff at least were not being accosted when they demonstrated their professionalism on the Hudson.

Bigotry is demeaning to all.

https://www.aerotime.aero/clement.charpentreau/22646-boeing-737-max-faa-defends-its-processes-blames-pilots

https://www.washingtonpost.com/opinions/after-two-faulty-boeing-jets-crash-the-trump-administration-blames-foreign-pilots/2019/05/15/e940a692-774e-11e9-b3f5-5673edf2d127_story.html?noredirect=on&utm_term=.9b2b63241a64 (https://www.washingtonpost.com/opinions/after-two-faulty-boeing-jets-crash-the-trump-administration-blames-foreign-pilots/2019/05/15/e940a692-774e-11e9-b3f5-5673edf2d127_story.html?noredirect=on&utm_term=.9b2b63241a64 )

https://www.seattletimes.com/business/boeing-aerospace/how-much-was-pilot-error-a-factor-in-the-boeing-737-max-crashes/

BluSdUp

18th May 2019, 10:32

I was just about to post a basic fact, and then You beat me to it.
It is like this:
At one point sooner or later speed hast to be controlled and if the stab is so out of trim that pitch up and climb is not possible to control speed, power to idle is next.
On the 737-800 the nose drop is pronounced , but manageable.
The MAX has less as the thrust line is higher.

Regardless of initial nose down pitch you need to get speed back to the 270- 220 range.
So:
Idle
Full speedbrake
Pull like the Dickens and the speed WILL slow down, and the aircraft becomes easier to control and trim.
( I would even consider the gear, but lets keep it simple)
Keeping 94% N1 flat out , level will most likely give close to supersonic speed with M-buffet ,Tuck under and what have you.

The multiple false statements that reducing power is not an option is just ridicules.

With regards to blaming different " Pilot cultures" for this mess, I think that is a rather weak defense for a inherently flawed design.

We all have choices to make now that FAA is about to approve the patch.
I hope the major N-CAAs and EASA can see that this aircraft can not fly without aerodynamic modifications.
If they feel lucky and certify it, at least a two hr sim session MUST apply in a full MAX sim.

I for one am looking forward to fly it, but there is no way I will be a pax or deadhead in it.
I always knew the 737-800 had its killing corners which we trained , but letting this one loose is a pure gamble.
In my educated opinion.

Regards
Cpt B
737-800

edmundronald

18th May 2019, 11:33

ManaAdaSystem

18th May 2019, 12:07

Takwis

18th May 2019, 12:31

Beautifully, and accurately said, fdr. Copied and saved as an example of a logical factual, and unbiased reply to the garbage exemplified by the subject, and some commenters on, this thread.

Takwis

18th May 2019, 12:36

I

I for one am looking forward to fly it, but there is no way I will be a pax or deadhead in it.

But you would put passengers in it? Interesting.

edmundronald

18th May 2019, 12:42

infrequentflyer789

18th May 2019, 12:55

Is crew training of a lesser standard overseas? Well, before the CEO of Boeign goes on record on that matter, was he aware that Boeing is or has been the training provider for Ethiopian???? Seems kind of odd to bitch about standards, when the legally responsible party to the standards is.... Boeing.

This is perhaps my biggest issue, Boeing simply cannot have it both ways and now say that the pilots were not adequately trained for the MAX when they themselves said (quite loudly, and apparently betting $$$ on it) that the existing training that the pilots had was adequate for flying it (with addition of one iPad session - and no one has yet stated that ET or Lion crews had not done this additional training).

With the existing training the NG has a fatal crash rate of 0.06 (per million flights), while the MAX is at 3 (50 times the NG rate), which would be top of the table if not for Concorde. Neither of the MAX crashes had any adverse assistance from weather or poor visibility or external factors (PR-GTD), as several of the NG crashes have.

Take out the rhetoric and racism, and fix your plane guys. Suggest that you test your products with the intent of 25.255(a) not just the inadequate words that have so grossly failed us,

Looks like this might have been happening, from e.g. https://www.satcom.guru/2019/05/the-beat-goes-on.html quoting the hearings:

What is new is that MCAS stab authority will be limited based on available elevator pitch up authority - that the elevator will be able to apply 1.5g pitch up after one MCAS stabilizer trim command.

I don't think it is coincidence that the ability to apply 1.5g pitch up is one of the requirements of 25.255. Could be wrong though, the number may have come from somewhere else, and I don't suspect we'll ever see an admission that it wasn't in compliance before.

LEVC

18th May 2019, 12:59

How soon we forget. Go back over the past 10 years. Have any 320's gone down? Where?
(At least 1 737 has gone down in that time also ... we had an extended discussion here on PPRuNe on one that went down in Russia)
Suggest you also check gums' post (https://www.pprune.org/showthread.php?p=10472639). ;) (IMO, the politicization of this is zero value added ... )

One A320 that went down in the past 10 years https://en.wikipedia.org/wiki/Indonesia_AirAsia_Flight_8501

Bend alot

18th May 2019, 13:04

Just to be clear -
Interesting is the fact until the 737 MAX crash Ethiopian Airlines had a similar safety record to the United States over the last 12 years.

Or put another way over the decade from 11 Feb 2009 - 2019 Ethiopian airlines had a perfect safety record compared to the United States of 51 fatalities (+ cargo ops crew and jump seater's) for the same period.
https://www.pprune.org/images/statusicon/user_offline.gif

FrequentSLF

18th May 2019, 13:28

My 2 cents...
MAX was designed to be a replacement of older 737, thus all the grandfathering, no need of training (other than an IPAD session)... which means that the plane was designed to be flow by pilots that are flying older 737... there was no commercial requirement to get grab market from AB, and retrain the pilots from AB to MAX, the whole business plan was to keep existing 737 customer buying an "upgraded product"!
Now FAA, Boeing, pilots in the "western countries" are saying... that those pilots in 3rd countries that have been flying the older 737 are not skilled enough to fly a plane that has been certified with grandfathering from the very same planes that they have been flying for the past 40 years...
I do not get it, can someone from "first world country" can explain me?

futurama

18th May 2019, 13:59

Or put another way over the decade from 11 Feb 2009 - 2019 Ethiopian airlines had a perfect safety record compared to the United States of 51 fatalities (+ cargo ops crew and jump seater's) for the same period.
What? First of all, you're comparing apples vs. oranges. But even then:

January 2010, ET409 crashed in Lebanon due to "flight crews mismanagement of [speed, altitude, and headings]". All 90 passengers and crew perished.
February 2014, ET702's co-pilot decided to hijack (!) his own plane, over Sudan, with nearly 200 passengers on board. He flew to Switzerland where the plane ran out fuel on approach and managed to land with one engine operating.
January 2015, ET 737-400F cargo destroyed in Ghana when pilots lost control of the aircraft during landing at Accra.
March 2019, ET302 happened.

L39 Guy

18th May 2019, 14:43

The original Boeing 737 entered airline service in February 1968 with Lufthansa. In 1968 they didn't do digital processing and Kalman filtering of flight instrument data. In other words the MCAS system is based on recent tech, the MAX is to some extent a hybrid of old and new, and thus the type certificate which was based on validating an entirely mechanical design should not have been extended without a very painstaking review.

After the pitch-down incident of QF72, the fault was pinned on bad processing of AoA data. The final report (http://www.atsb.gov.au/media/3532398/ao2008070.pdf) dwells in detail on the *novel* difficulties posed by the validation of digital systems and the problems posed by complex systems. Incorporating a new system for attitude correction (MCAS) and digital processing in the 737 raised both of these issues, and allowed new problems to creep unnoticed into an old design.

Let me try and be clearer - a pilot knows that if your airspeed falls too low, the plane stalls. An engineer knows that if you add a computer to an existing design of a mechanical machine you get an unpredictable new design that will be unpredictable unless it is tested to death. This is engineering 101, and the guys at Boeing who added MCAS to the Max knew it, the FAA guys knew it, and in the end the pilots who tested it to death proved it yet again.

Edmund

Your analysis is largely correct except that Boeing assumed that pilots would be able to manage this situation as an MCAS failure exhibits identical characteristics to a pilot as a well known emergency, Stab Trim Runaway that has been in the 737 (and virtually every other aircraft with electric trim) emergency checklist and training regime since day one.

And they were proven correct with the Lion Air incident the day before where the crew managed the situation and flew the remainder of the 1 1/2 flight. Boeing and every other aircraft manufacturer knows that engines are going to fail periodically and they count on the pilots, trained to manage engine failure events at the most critical time (just prior to or just after V1, the go no-go decision speed) to manage the situation.

L39 Guy

18th May 2019, 15:25

What? First of all, you're comparing apples vs. oranges. But even then:

January 2010, ET409 crashed in Lebanon due to "flight crews mismanagement of [speed, altitude, and headings]". All 90 passengers and crew perished.
February 2014, ET702's co-pilot decided to hijack (!) his own plane, over Sudan, with nearly 200 passengers on board. He flew to Switzerland where the plane ran out fuel on approach and managed to land with one engine operating.
January 2015, ET 737-400F cargo destroyed in Ghana when pilots lost control of the aircraft during landing at Accra.
March 2019, ET302 happened.

You are correct in noting these accidents, two of which are fatal. That, in 9 years from a fleet of 82 aircraft today.

Bend alot likes to cherry pick data including an earlier post with a start date shortly after the Lebanon accident to demonstrate that US air carriers are equally unsafe. But consider in the US, Southwest alone has 750 B737's, United 768 jet aircraft, American 960 jet aircraft, 886 jet aircraft. And I am not including JetBlue and the others. Thousand of jet airliners flying every day and only a single passenger fatality in the past 10 years. That's impressive. Consider that BA has 274 aircraft, KLM 120, Lufthansa 310 and they have not had a fatality that I can think of for decades.

Lots of airplanes, lots of flying hours, millions of passengers of decades with such amazing accident records. That is no fluke. 2 fatal accidents in 9 years from 89 aircraft, Lion Air 1 fatal but many more close calls including landing short of the runway and into the sea with no fatalities (luckily) in less than five years with a fleet of 117 aircraft. That's not good.

As I stated earlier, "western" air carriers should not be ashamed or embarrassed to point out their safety record. These are facts. Just take a look at where all of the accidents are happening these days and that tells the story.

Smythe

18th May 2019, 15:33

Today it was reported that the MAX sims do not replicate MCAS recovery procedure properly and a software fix was required.

Has anyone been in a MAX sim? Did they use the stab trim switch config from the NG or the MAX?

Stab Trim Runaway that has been in the 737 (and virtually every other aircraft with electric trim) emergency checklist and training regime since day one.

Sorry, but the STS runaway for the NG is not the same for the MAX due to the differences in the functionality of the stab trim switches...

also note that in sim testing, even at 250 kts, the manual trim wheel would not budge and they had to roller drive the ac to move the stab...IF that is the case with the MAX, that is a problem and outside of STS procedures, no?

L39 Guy

18th May 2019, 15:44

False. The classic stab trim runaway is a stuck, or fused switch, which causes the trim to run "continuously", to the limits of the jackscrew in one motion. The characteristics of an MCAS input are actually closer to those of the STS, i.e. intermittent running of the trim, starting and stopping. Pilots that fly the 737 are very used to the STS trimming in the background on departure, and generally ignore it. MCAS is "identical" to neither situation, but closer to "STS running backward", as the surviving crew noted in the logbook.

There is a very good thread in the tech section, I suggest you educate yourself by going to read through it: https://www.pprune.org/tech-log/614997-b-737-speed-trim-system.html?highlight=b737+max

Really? Show me where in the Boeing manuals that a Stab Trim Runaway is a case where the trim runs continuously to the limits of the jackscrew?

And how, as a pilot if you are a pilot, are you to determine if the trim reaches the jack screw or not? I would also suggest that any competent pilot will react to a trim runaway long before it reaches the jack screws.

Or would you just watch it run continuously, pitch the nose down 40 degrees then wait until it stops (at the jackscrew limit if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws".

Or would you just watch it run continuously, pitch the nose up 40 degrees then wait until it stops (at the jackscrew limit if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws"

Or would you cut the stab trim out after maybe 5 degrees of nose down (or up) attitude and recover

I know what I would do.

According the the NNC, a Runaway Stabilizer is defined as: Uncommanded stabilizer trim movement occurs continuously. STS is commanded trim, for those that are shown it in training and is a perfectly normal trim response. How do you define continous? 1 second, 5 seconds, 10 seconds, a 60 seconds?

As far as educating myself on the trim system, I have 16 years of B737 experience. How about you?

gearlever

18th May 2019, 15:48

Really? Show me where in the Boeing manuals that a Stab Trim Runaway is a case where the trim runs continuously to the limits of the jackscrew?

And how, as a pilot if you are a pilot, are you to determine if the trim reaches the jack screw or not? I would also suggest that any competent pilot will react to a trim runaway long before it reaches the jack screws.

Or would you just watch it run continuously, pitch the nose down 40 degrees then wait until it stops (at the jack screws if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws".

Or would you just watch it run continuously, pitch the nose up 40 degrees then wait until it stops (at the jack screws if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws"

Or would you cut the stab trim out after maybe 5 degrees of nose down (or up) attitude and recover

I know what I would do.

According the the NNC, a Runaway Stabilizer is defined as: Uncommanded stabilizer trim movement occurs continuously. STS is commanded trim, for those that are shown it in training and is a perfectly normal trim response. How do you define continous? 1 second, 5 seconds, 10 seconds, a 60 seconds?

As far as educating myself on the trim system, I have 16 years of B737 experience. How about you?
The trim is always via the jack screw, isn't it?

L39 Guy

18th May 2019, 15:51

Sorry, but the STS runaway for the NG is not the same for the MAX due to the differences in the functionality of the stab trim switches...

also note that in sim testing, even at 250 kts, the manual trim wheel would not budge and they had to roller drive the ac to move the stab...IF that is the case with the MAX, that is a problem and outside of STS procedures, no?

True about the differences in the functionality of the trim switches however the emergency procedure is identical, i.e. turn off both switches, is it not?

I can't speak for the simulator, its manual trim system and its fidellity but how do you explain the Lion Air incident crew (the day before the accident) being able to manually trim with the trim wheel after switching off both stab trim switches and flying for 1 1/2 hours to the planned destination and landing? Or do you think they strong armed it for that hour and a half? I suspect that they were able to crank the trim wheel.

L39 Guy

18th May 2019, 15:52

Yes, it runs via the jackscrew but one does not let it get to the limit of the jackscrew before taking action on a stab trim runaway.

Takwis

18th May 2019, 16:42

STS is commanded trim, for those that are shown it in training and is a perfectly normal trim response.

OMG, this is hilarious! So if STS is "commanded trim", and if the MCAS is merely software driving the trim through the STS system, then that means (drum-roll, please)... MCAS is "commanded trim"! Therefore the checklist does not apply!

A320ECAM

18th May 2019, 16:59

Well it was pilot error on both accidents.

Lion Air: the previous flight was saved by an off duty pilot jumpseating.

Ethiopian: aircraft was flying too fast because they never managed the throttles during the entire accident. Let me guess, straight after takeoff the PF's hand never returned to the throttles like any skilled pilot's hand should!

So my question is, would any AA/Delta/United/Air Canada/BA/Emirates pilots have the same trouble?

Junkflyer

18th May 2019, 17:00

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

.... I guess. 🤔
In all fairness, the SWA flt fatality occurred due to an uncontained engine failure breaking a window-the fatality was sucked into the window frame and was killed.
The National Airlines was unrecoverable due to massive weight shift.
UPS flight in the desert was a cargo fire due to lithium ion batteries, not pilot error.
Really can't fault the crew in these three.

L39 Guy

18th May 2019, 17:12

OMG, this is hilarious! So if STS is "commanded trim", and if the MCAS is merely software driving the trim through the STS system, then that means (drum-roll, please)... MCAS is "commanded trim"! Therefore the checklist does not apply!

STS is an expected trim action that one learns about and experiences with the procedures trainer, simulator and his or her first line trip. Moreover, STS works to bring the aircraft into trim, not out of trim. There are no surprises here.

Having the trim system pitch the nose down with 10 seconds of trim with MCAS or any other reason where trimming action is not expected is “uncommanded trim” and is a surprise. A big surprise.

Have you been able to find the reference stating that a stab trim runaway has to go to the stops yet? I am anxious to see this.

L39 Guy

18th May 2019, 17:17

I suspect that they weren't as far out of trim.
They experienced the full meal deal MCAS so I would suggest that they were way out of trim too.

The big difference between them and the accident flights is that they executed the UAS drill after takeoff, flew the aircraft and controlled the speed making manually trim wheel possible after the stab trim shutoff switches were activated.

Dualbleed

18th May 2019, 17:26

Time for a warning that tells that stab is trimming when not supposed to.

L39 Guy

18th May 2019, 17:30

It doesn't need to mention the jackscrew in the manuals...that's where it goes. When it hits the end, it has to stop. Classic "runaway trim" is, as I said, a stuck switch, or fused, or a short somewhere, and the motor is going to run it to the end, barring any pilot intervention. Boeing is trying to say this is just like that, for legal reasons, and there are plenty of pilots to join in on the chorus, but the fact is, an MCAS activation is NOT identical.

You could still stand to do a bit of reading, about other pilots experiences in the plane that may not have happened to you. Somebody in one of the threads said they had seen the STS go for 10 seconds. Hmmm, what's that look like? I flew with a guy last month that had a runaway trim in an E-6 (707). Kept going after they cut off the switches, even. Wrong grease on the screw. Ever grab a spinning trim wheel and make it stop? You'll hurt yourself, maybe break a thumb if you do it wrong.

The source of the activation is academic, the result is what matters and the result is the aircraft not doing what the pilot, manually flying it, is commanding it to do.

As far as Boeing CYA, how would you word a Stab Trim Runaway that would cover all possibilities? How many Stab Trim Runaway checklists would you like to have and have to memorize? Do you really want to be diagnosing the problem while your hair is on fire fighting with the airplane ?

A fundamental difference between STS and MCAS is that STS is trimming the aircraft toward the trim for the speed, C of G, etc, and not working against the pilots and not pulling the controls out of their hands. Whether that takes 1 second of trim or 10 seconds of trim or anything in between, the system is working as it should and with the pilot not against it.

Stopping the trim wheel with your hand will definitely take a couple layers of skin off; using the bottom of one’s shoe works pretty good.

L39 Guy

18th May 2019, 17:39

You have evidence they experienced the MCAS trimming to zero units, full nose down?

No, I am relying upon the preliminary report from the accident flight and it does not have any detail of where the stab trim went to before they did the stab trim NNC. Perhaps they thought that waiting to hit the jacks crew stops (0 units) was not a wise idea. I would agree.

But what I do know is that they did the UAS drill, according to the report, managed to control the airspeed making manual trimming significantly easier compared to the accident flights roaring around at Vne and flew to their destination with manual trim and in stick shaker.

In other words, they did exactly what was expected of them as professional aviators.

L39 Guy

18th May 2019, 20:45

If I want a 737 to climb, from an intermediate altitude, I push up the power. No elevator required. Same for a descent...pull power, down we go. Then elevator can be used to fine tune airspeed. Man, I wish Al Haynes was still around. He'd probably say "don't they teach anyone to FLY any more?"

This comment was directed to the individual that thought that pulling the power off on an aircraft like the B737 (with under wing engines) was the worst thing one could do to counteract a nose down trim situation at high speed.

You know, you really should read the comments that form a discussion before interjecting.

L39 Guy

18th May 2019, 20:52

The classic stab trim runaway is a stuck, or fused switch, which causes the trim to run "continuously", to the limits of the jackscrew in one motion.
I can't have a conversation with someone who keeps repeating the same nonsense. Yes, they didn't let it get that far. That made manually trimming significantly easier for them.

So when do you think it crosses the line and becomes a Stab Trim Runaway and pilot intervention is required? After 5 secords, a minute or how about in terms of pitch change? 5 degrees, 10 degrees? Or do you let it go to the stops?

I would also say that it need not be a fused switch; it could be an intermittent short circuit somewhere in the wiring that would cause the trim motor to run for a period of time before hitting the stops of the jack screw. Intermittent short circuits are not a new concept.

Uk.Engineer

18th May 2019, 21:22

The point of MCAS was to make the plane easier and more familiar to fly for pilots who were already used to the previous generation of 737. This was a requirement of the certification otherwise additional training was required. If MCAS is going to switch off when there is AOA disagree does this mean the plane will again feel unfamiliar to a pilot and additional training without MCAS will be requirement to deal with this situation. If not, why would there be a requirement for MCAS in the first place?

Is everyone sure that that pushing the nose down is to the only thing that MCAS does or is this the only failure mode found? When the MAX was being developed, experienced pilots found the controls of the aircraft felt unfamiliar: unusually light, and rather different to what they had experienced before. I am not a pilot but it doesn’t fit comfortably with me that all of this is corrected by simply occasionally pushing the nose down ?

Sakon

18th May 2019, 22:12

This issue has nothing to do with any nation pilot superiority in piloting an aircraft. This issue is directly related to the manufacturer who in this instance neglects to inform airlines and pilots of a system that is new and contrary to any Boeing aircraft behavior we longtime pilots have ever endured. I a Boeing pilot for over 30 years have always been confident knowing that once I had disconnected the autopilot and auto throttle, the aircraft was mine, and mine alone.

Please see this matter as it is, do not blame people who have perished in this unfortunate result of the production of this aircraft that has grown way outside of its 1968 envelope.

My take on this, remove the MCAS system altogether and make that public, for every pilot, stewardess and passenger, so they may embark once again on the 737 be that a MAX or not, in confidence and trust in the Boeing Company.

Loose rivets

18th May 2019, 23:02

Stopping the trim wheel with your hand will definitely take a couple layers of skin off; using the bottom of one’s shoe works pretty good.

It's a 50 year old memory, but the BAC 1-11 had large trim wheels for the T-Tail which had a 3 degree slack in the movement to temporarily cut out the Mach Trim. This slightly annoying hysteresis had light springing to actuate the cut-out switches, akin to strut micro-switches.

What I would like to see from Boeing, is a pair of wheels that have a similar, albeit a bit heavier, sprung region - which cuts out all power to the H-Stabilizer motor/clutches as soon as you grab the wheel.

fdr

19th May 2019, 02:12

Re FLAPS and THRUST:

1. Flaps extended give an AND pitch moment. Retracting the flaps gives an ANU TRIM moment which counters to an extent an unwanted AND input from the MCAS.

2. Thrust gives an ANU trim moment, which counters the unwanted, erroneous and unknown cause MCAS input. Keeping thrust on assists in regaining trim.

3. Increasing speed reduces the AND trim error, and unloads the stabiliser which is necessary once the aircraft is out of trim. Increasing airspeed comes from either permitting the aircraft to pitch nose down due to the erroneous MCAS input ultimately relieving the trim load either by achieving near the actual trim speed, or by impacting the terrain, where your trim problems are suddenly over.

4. Comment made on the momentary pilot trim on the wrong sense does no justice to the crew. If you have no approapriate and expected result from an input, it is not unreasonable to ascertain if the whole system has failed, or if the system is acting in reverse (like that has never happened... even with Airbus FBW LH aileron reversal) To object to a momentary opposite input is unjust and unreasonable.

The crew are the result of the global industry's race to the bottom, not the cause, they are victims of the collective actions of regulators, OEM's and the airlines, who have given us the state we have today. It is offensive for the OEM and the Regulator to make disparaging comments on the pilots while they have been directly responsible for the loss of two jets from their actions. I doubt that it was a deliberate set of actions within the OEM, I certainly hope not...

wonkazoo

19th May 2019, 04:26

The latest reported comments ascribed to Boeing and the FAA are offensive to the majority of customers for the US product that these two entities have responsibility over.

At some point, perhaps the CEO of Boeing should take time out and read the FCTM that his company provided to the crew.

For the record, Boeings own document states that in the case of a severe out of trim condition, that the aircraft should be flown to regain the speed commensurate to the out of trim case, and then the trim forces will be relieved sufficiently to permit the trim system to be reset as desired. It is remarkable that Boeing and the FAA apparently cite keeping power on as a sign of incompetence, when the trim moment form thrust on is nose up, and the out of trim condition requires gaining high speed as soon as possible, which suggests keeping power on as not being such a stupid idea that it would be used to make offensive comment from the people who gave MCAS unannounced, killed 350+ people... frankly, I am embarrassed on their behalf. For the pilot brethren who suggest in the forum herein that keeping power on was stupid, go back and do some simple maths guys before making assertions of incompetence on the dead crews.

Boeing designs a system that has the authority to put in more than 3 times the certified out of trim demonstration requirement FAR 25.255(a), without condescending to tell the apparently deficient foreign devils that fly their magnificent product. It was Boeing and the FAA ODA system that oversaw the MCAS design, and it was Boeing who decided not to bother telling the crews of the system until it was necessary following the first blood spill. Following that, it was Boeing who still did not reinforce the extent that out of trim would give catastrophic problems to a crew in handling, it was up to a newspaper report to show that a competent crew would find the handling nearly impossible when doing a briefed simulation of the event.

Boeing and the FAA are stating, not even insinuating that the crews involved here, and for good measure adding collective guilt to all 'foreign" pilots are of lesser competency than good ol' boys. M'kay, For the record, having spent 40 years flying with US and foreign pilots, in military and airline operations, having flown all Boeings from the 727 to the 787 as well as the 320, 330, and 340, I have to say, there is more commonality than anything else, sorry Mr Trump's band of brothers, the crews from S%$t'ole are not that much different. Is US air travel safer than overseas? Generally, yes, but that says as much about the infrastructure and rules as it does on crew training. Is crew training of a lesser standard overseas? Well, before the CEO of Boeign goes on record on that matter, was he aware that Boeing is or has been the training provider for Ethiopian???? Seems kind of odd to bitch about standards, when the legally responsible party to the standards is.... Boeing. Comments have been made about the AZ214 at San Francisco, where the training organisation was again Boeing, who held contracts for training for KE and AZ for the last 20 odd years in various forms and names of entities, Alteon, Boeing etc.

A B767 just got parked awkwardly in Texas, there was no sudden cry from the S%$t'ole countries concerned with FAA standards... nope, not a word, and nor should there have been.

Over the years I have flown with F15, F16 F22 and A10 pilots, some are great, most are good, some I would not let near a Cessna 150 without supervision. I have flown with Ethiopian pilots, and in fact the absolute best instructor I have ever seen work a simulator was an Ethiopian. Back in the day, the red necks from the usual countries, both sides of the equator would be disparaging with the national pilots and most other foreign pilots, however would fawn over the Ethiopian instructor, he was that good. Two of the best instructors I have had on helicopters were not US, they were Japanese, and I cherish the training they gave me. The next one of note on choppers was a poor little french farm boy from Guadaloupe, and he was and is exceptional. On the Boeing aircraft, without any doubt the best instructors I have ever had didn't come from Seattle, they were oddly almost uniformly Zoroastrians, The most knowledgeable airbus pilot I have ever worked with was a refugee from Iran, and he had a better knowledge base on the aircraft than the TP's that I was also working with at the same time. I don't mind flying with US pilots, I do not however see a great divide between them and the rest of the world, nor in fact do I see much difference between airline operation in audit of European airlines, Asian airlines, North and South American airlines, when conducting partner airline audits. In accident investigation, I have seen people of all skin colour and backgrounds do odd things occasionally with bad results. The US pilot contingent in that group had their share of odd ball events, more or less in keeping with the great unwashed from the S%$t'ole countries that are suggested to be incompetent.

Overall, I am hardly surprised that the OEM and the NAA of the disgrace that is the saga of MCAS are striking out, but they are off base with their assertions. The OEM is in danger of angering their customer base by such comments, and it is not going to add to their bottom line, rather it may well detract. Personally, as a stinking foreigner, albeit with pink skin, I would not buy a Boeing product by choice given the Trump like comments made on the competency of foreign pilots. The foreign airlines have a choice of products to acquire, and having flown more or less all of the offerings, the competition is competent, and comes without the racist bigoted comments of recent reports.

Take out the rhetoric and racism, and fix your plane guys. Suggest that you test your products with the intent of 25.255(a) not just the inadequate words that have so grossly failed us, the pilots and the passengers who pay for the purchase of your product. The aviation world was sharply awoken to the difference between certification standards and the perceived safety that flows from that by the AA587 loss. (it is interesting to note that no bigoted, disparaging comments were made on the pilot of that flight, nor on the pilots of AA965, AA1572, DL191 etc... just sayin'....)

Hofstede discusses the differences between cultures that do have some effect in the operation of a crew, however, this problem was a fundamental flying capability problem, and Boing and the FAA are hardly winning hearts and minds by their comments, coming hot on the heel of the Colgan debacle, Comairs efforts in Kentucky, and the B767 parked in the bayou. The MD11 at RJAA was dispalying a shiny USA flag on the tail...

:mad:

P.S., the FAA has good people in it, most fighting the system above them, in TAD, FSDOs at and various other acronyms, such as ACO and MIDO's. As a standard, having had professional licenses in 10 different countries, the FAA is not of any particular standout quality in their requirements or process. The FAA happens to be big and that is about the sum of it.

P.P.S. When is a full, honest investigation into the airworthiness of all of the B737NGs built with non compliant structure going to occur? It is hardly the behaviour of a first world nation to sack the QA auditors that brought that to light, that smacks of a 3rd world S%$t'ole type country response in itself.

P.P.P.S. the B767 Captain off the Comorros was a heroic person (ET961). He was being hit over the head with a damn fire axe as he ditched an aircraft without engines against that level of distraction. Sully and Jeff at least were not being accosted when they demonstrated their professionalism on the Hudson.

Bigotry is demeaning to all.

https://www.aerotime.aero/clement.charpentreau/22646-boeing-737-max-faa-defends-its-processes-blames-pilots

https://www.washingtonpost.com/opinions/after-two-faulty-boeing-jets-crash-the-trump-administration-blames-foreign-pilots/2019/05/15/e940a692-774e-11e9-b3f5-5673edf2d127_story.html?noredirect=on&utm_term=.9b2b63241a64

https://www.seattletimes.com/business/boeing-aerospace/how-much-was-pilot-error-a-factor-in-the-boeing-737-max-crashes/

fdr (as usual) nails it.

Forget about who you want to blame- that argument has been hashed over 5,000 posts in the original ETA thread.

Instead read 14CFR section 25.255 "Out of trim characteristics."

If you do you will read about the limits that either the electronic or autopilot trim systems can autonomously input to the point where control is taken/given to/or regained by the pilot. The reason for this certification requirement is simple: If your autopilot fails and trims nose down (or up) until the point where it can no longer maintain control over pitch will you be handed an airplane that you can recover when the AP disconnects, or will you be unable to control the AC?? Basically 25.255 insures that the two (traditional) electronic mechanisms that control the horizontal stab are tested to insure that neither one is likely to fail into a box that leaves the AC unrecoverable. It does this by arbitrarily setting a three second cap on manual inputs and the maximum input that the AP can make before it cannot control the aircraft.

Sounds good yes?? 25.255 insures that any system that can exert control over the horizontal stab is identified, specified, tested and certified to insure that it does not put the airplane outside the envelope at any time. Take the system to the maximum input it can make and see if the pilots can recover it. Great!!

Except, well wait a minute. There is this new system, called MCAS, that has the authority to run the trim all the way to the nose down stops. In nine-second bursts, wait five, rinse and repeat. 30 to 40 seconds is all it will take it to run your horizontal stab not only beyond your ability to recover, but to the max ANU position.

Ahhh, don't worry, you don't need to know about that system!! And rumors to the effect that it is reliant on a single data source are, oops, true!! Who knew??

This is the moral failure that Boeing made, and the bog which they are now in.

1. Boeing engineers KNEW what MCAS did.
2. They KNEW that under current certification regulations MCAS would not be permitted to be designed or implemented as they did as it could not comply.
3. They KNEW that MCAS could not pass numerous certification requirements, so they buried its existence from view to pretty much everyone. (The Three Monkeys approach...)
4. They KNEW that they submitted certification documents seeking .6 (IIRC) of trim per activation, but put into service a system with more than FOUR TIMES the control authority than that Certificated.
4. They KNEW that they created a system which had full and autonomous control authority over pitch and relied on a SINGLE data point. (C'mon, why are we even discussing this. that fact alone- that alone should put Boeing in custodial care or receivership...)

And the FAA stood by and cheered them on as profits went through the roof.

The cynic in me thinks two years from now Boeing will once again be flying the friendly skies uninhibited by such scrutiny, but the optimist in me thinks they might have actually done it this time. Allowed a deregulated environment to run so far off the rails that the Government actually steps back in and reasserts control.

We'll see I guess-

dce

Bend alot

19th May 2019, 05:04

I would add to fdr's post that the best aircraft maintenance staff I have worked with, were African's from Zimbabwe.

MemberBerry

19th May 2019, 07:27

In that instance, L39 and I were talking about the penultimate Lion Air flight... they managed to land safely, and most likely never let the trim get that far forward. We have no data on it.

Actually, we do have some data on it, the FDR traces from the preliminary report, but they are so poorly done that they ofuscate the actual values for the trim position, they even seem to use different scales:

https://reports.aviation-safety.net/2018/20181029-0_B38M_PK-LQP_PRELIMINARY.pdf

Assuming the accident Lion Air flight reached almost 0 degrees of trim before impacting water, we can deduce that the trim scales start at 0.0 degrees, it seems that on the trace for the accident flight each major division is one unit, and for the previous flight each minor division represents one unit.

This would mean on both flights the takeoff trim was between 6.5 - 7.0 units, and on the accident flight the trim reached close to 0.0 units before impact. Assuming that is correct, it means the previous Lion Air flight experienced MCAS bringing trim down to about 2.0 units after about 2 minutes of fighting it, then they fought it for about 3 more minutes, then they used the cutout switches for the first time.

Also, we can deduce that the aircraft was in trim at about 5.0 units on the previous flight. This means MCAS took them out of trim by a maximum about 3.0 units at the worst point, to 2.0 units, and that the stabilizer was not more than 1.5 units out of trim when they used the cutout switches. The trim position seems to oscillate between 3.5 and 6.5 units for most of their fight with MCAS, if we exclude the spike where it seems MCAS was able to temporarily bring the trim down to around 2.0 units.

With the same assumptions, when they re-enabled the electric trim later, MCAS was able to bring the trim down to about 3.0 units. Then, after they brought the trim electrically to about 3.5 units, they used the cutout switches again to turn electric trim off for the rest of the flight. After that it seems they used the trim wheels to bring the aircraft back in trim from about 3.5 units to about 5.0 units.

In any case, assumptions aside, it's clear that the previous flight didn't reach 0.0 units of trim at any point, this is how the trace from the previous flight looked:

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1257x378/euugxgp_9e0d566237e5d40d394d170ed1a1ec8e5a750319.png

One thing to consider is that MCAS can be much worse than a classical stabilizer runaway caused by stuck or fused thumb switches. With the flaps up, there are limits to how much the main electric trim can bring the nose down. Depending on the 737 model, the limit is around 4.0 units from full nose down trim.

Also Satcom Guru recently tried to find 737 runaway stabilizer incidents in NTSB's database, and he wasn't able to find any:

https://www.satcom.guru/2019/05/737-pitch-trim-incidents.html

So the 737 runaway stabilizer procedure was rarely if ever tested in real incidents. And in any case, an MCAS runaway can be much worse than a classical runaway. With that in mind, Boeing insistence that the existing stabilizer runway procedure is enough to deal with MCAS misbehaving is questionable.

beardy

19th May 2019, 08:43

Time for a warning that tells that stab is trimming when not supposed to.
If any system, be it monitoring or actioning, knows that it is doing something it should not ie is trimming when it shouldn't, then it's not beyond the wit of man, or even an engineer, to have a feedback mechanism to stop it doing what it shouldn't. Oh and give a warning that it encountered a problem.

fenland787

19th May 2019, 10:39

If any system, be it monitoring or actioning, knows that it is doing something it should not ie is trimming when it shouldn't, then it's not beyond the wit of man, or even an engineer, to have a feedback mechanism to stop it doing what it shouldn't.

...and even an engineer might spot a logical inconsistency in that statement!

LowObservable

19th May 2019, 12:11

Funny how people use "western" in a way that includes Australians and New Zealanders, who are as far apart in longitude from other "westerners" as possible.

It's almost as if "western" is being used as a substitute for another word.

And fdr has it exactly right, as opposed to the FTFA-fundies who haven't encountered an MCAS failure, even in a sim, but are utterly certain that they and their "western" buddies would have handled it just fine, without even putting down their coffee cups.

Luc Lion

19th May 2019, 13:17

And in any case, an MCAS runaway can be much worse than a classical runaway. With that in mind, Boeing insistence that the existing stabilizer runway procedure is enough to deal with MCAS misbehaving is questionable.
MCAS runaway is worse than a classical runaway, not only because it is an intermittent runaway, but even more so because it is caused by a faulty AOA reading that also drives the Elevator Feel System to MULTIPLY BY 4 the force opposing the pilot pitch up force on the control column.

The combination of high speed trim runaway AND elevator force multiplied by 4 is a killer.

MemberBerry

19th May 2019, 13:51

Indeed, the high speed made it worse, MCAS ran 50% faster main electric trim.

In addition to that, MCAS didn't stop at around 4.0 units of trim with the flaps up, like the main electric trim does, and also MCAS couldn't be stopped by pulling on the yoke.

The intermittent nature and the 4x feel force are factors that probably confused the pilots, not to mention the additional physical effort required to fight that.

Counting, there are 5 reasons why a MCAS induced stabilizer runaway is worse than a classical runaway. Or 6 reasons, if we include the fact that the Lion Air pilots didn't even know MCAS existed.

Caygill

19th May 2019, 14:26

The Washington Post is reporting that top US administration officials are blaming the pilots for the two 737 Max crashes. The paper quotes them as saying that "...the problem isn’t that Boeing put a faulty aircraft into the skies, nor that the Federal Aviation Administration’s lax oversight kept it flying. The trouble, they argued, comes from lousy foreign pilots..." https://www.washingtonpost.com/opinions/after-two-faulty-boeing-jets-crash-the-trump-administration-blames-foreign-pilots/2019/05/15/e940a692-774e-11e9-b3f5-5673edf2d127_story.html?utm_term=.14f59e6a0943

The full hearing, with ranking member very literally stating time after time that the issue was mismanagement of the situation due to poor training: https://transportation.house.gov/committee-activity/hearings/aviation-subcommittee-hearing-status-of-the-boeing-737-max

gums

19th May 2019, 14:47

Salute!

TNX. For reminding us of that feel increase mentioned back in November, hmmmm

I also wonder is they tested inadvertent MCAS activation while descending to the approach at fairly high “q” and reduced power. Or maybe cruising along near the critical mach . Spoilers up/down. After all STS, feel force and shaker and ...... depend on AoA to work as intended. The interaction of several sftwe mods to the basic design keeps haunting this old systems engineer.

Something rotten in ...... errr, Seattle

Gums sends....

gums

19th May 2019, 14:57

Salute!

Hey!, Cay....... did you miss the many assertions by the chairman et al concerning possible lapses in the certification process or one member that was concerned about introducing a new system without telling the users?

WaPo will cherry pick testimony to fit their agenda, as do many so called news media reporters these days and actual technical knowledge does not count.

Gums sends...

BluSdUp

19th May 2019, 15:53

Having watched a few Congress Comity hearings lately , I find it counterproductive to Aircraft Safety.
It is good they care , but the ignorance and aggressiveness reminds me a bit of High School Debates.

Bread and circus to the people?

bill fly

19th May 2019, 16:23

[QUOTE=LowObservable;10474893]Funny how people use "western" in a way that includes Australians and New Zealanders, who are as far apart in longitude from other "westerners" as possible.

It's almost as if "western" is being used as a substitute for another word.

Yers.. I guess Oz and NZ are so far East that the only direction is West...

formulaben

19th May 2019, 17:18

Anyone care to address this? Or is everyone too dug in on the perspective that any critique of pilot performance stops with the pilots and has nothing to do with the institutions that trained them?

Yes, that post is by far one of the best posts in this thread or others...conversely, at the other end of the spectrum are incontinent posts with mentions of Trump, racism, and bigotry.

bill fly

19th May 2019, 18:02

Yes, that post is by far one of the best posts in this thread or others...conversely, at the other end of the spectrum are incontinent posts with mentions of Trump, racism, and bigotry.

So Trump has nothing to do with the Administration? Good.

LowObservable

19th May 2019, 19:26

Nothing per se wrong with critiques of pilot performance. Blanket critiques of non-wh... errrm, non-"western" pilots, on the other hand...

MathFox

19th May 2019, 19:58

As armchair engineer I do have a question: Why isn't there an MCAS cut-off switch that keeps the electric trim buttons operational?

Nothing per se wrong with critiques of pilot performance. Blanket critiques of non-wh... errrm, non-"western" pilots, on the other hand...

I think that there is agreement that an MCAS runaway gives pilots very hard problems to solve. Where a good pilot may save the plane (and his skin) on a good day. I don't think we want to keep this system unmodified on the 737MAX. It seems some blame already is passed, but I'm waiting for the investigation reports for my final opinion. (It's a Boeing system engineering issue that this MCAS was fitted on the plane, I wonder what the root causes are.)

yanrair

19th May 2019, 21:57

[QUOTE=Bend alot;10473165]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[/QUOTE
And all of these not large mainstream carriers that you and I would fly on.
Every year there are crashes but most , and in 2017 , all, were military, cargo or others non standard passenger revenue flights. Rarely in first world developed countries does an airliner crash with major fatalities. Exceptions exist. AF447 being a classic example.
Y

yanrair

19th May 2019, 22:07

Actually, we do have some data on it, the FDR traces from the preliminary report, but they are so poorly done that they ofuscate the actual values for the trim position, they even seem to use different scales:

https://reports.aviation-safety.net/2018/20181029-0_B38M_PK-LQP_PRELIMINARY.pdf

Assuming the accident Lion Air flight reached almost 0 degrees of trim before impacting water, we can deduce that the trim scales start at 0.0 degrees, it seems that on the trace for the accident flight each major division is one unit, and for the previous flight each minor division represents one unit.

This would mean on both flights the takeoff trim was between 6.5 - 7.0 units, and on the accident flight the trim reached close to 0.0 units before impact. Assuming that is correct, it means the previous Lion Air flight experienced MCAS bringing trim down to about 2.0 units after about 2 minutes of fighting it, then they fought it for about 3 more minutes, then they used the cutout switches for the first time.

Also, we can deduce that the aircraft was in trim at about 5.0 units on the previous flight. This means MCAS took them out of trim by a maximum about 3.0 units at the worst point, to 2.0 units, and that the stabilizer was not more than 1.5 units out of trim when they used the cutout switches. The trim position seems to oscillate between 3.5 and 6.5 units for most of their fight with MCAS, if we exclude the spike where it seems MCAS was able to temporarily bring the trim down to around 2.0 units.

With the same assumptions, when they re-enabled the electric trim later, MCAS was able to bring the trim down to about 3.0 units. Then, after they brought the trim electrically to about 3.5 units, they used the cutout switches again to turn electric trim off for the rest of the flight. After that it seems they used the trim wheels to bring the aircraft back in trim from about 3.5 units to about 5.0 units.

In any case, assumptions aside, it's clear that the previous flight didn't reach 0.0 units of trim at any point, this is how the trace from the previous flight looked:

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1257x378/euugxgp_9e0d566237e5d40d394d170ed1a1ec8e5a750319.png

One thing to consider is that MCAS can be much worse than a classical stabilizer runaway caused by stuck or fused thumb switches. With the flaps up, there are limits to how much the main electric trim can bring the nose down. Depending on the 737 model, the limit is around 4.0 units from full nose down trim.

Also Satcom Guru recently tried to find 737 runaway stabilizer incidents in NTSB's database, and he wasn't able to find any:

https://www.satcom.guru/2019/05/737-pitch-trim-incidents.html

So the 737 runaway stabilizer procedure was rarely if ever tested in real incidents. And in any case, an MCAS runaway can be much worse than a classical runaway. With that in mind, Boeing insistence that the existing stabilizer runway procedure is enough to deal with MCAS misbehaving is questionable.

The runaway STAB drill is designed to stop the runaway way before the trim gets into bandit territory . In the movie earlier in this thread , the runaway is arrested as per the NNP in about 8 seconds. Moreover if you are running away AND continuously or stop/go , but inexorably nose-down, you can still trim back to say 4=units electrically , overriding any of the three auto inputs, and then STAB SWITCHES OFF
Job done
. MCAS can get worse if it’s was not arrested - true but why would it not be arrested?
y

yanrair

20th May 2019, 13:55

Look at it from the point of view of the FAA

First the FAA is going to deny all wrongs so as to preserve their pensions. Which is why they will explain that their certification is only appropriate for US-trained pilots.
Then they will cooperate with Boeing to get the plane flying fairly safely. Because the pressure is huge.
Lastly they will take some measures to fix their process. Probably they will erase the possibility of easy certification of a follow-on type, and respecify startle factor as a risk in itself. At this point they might even move to ask for additional verification of the MAX systems.

Edmund
PS. Apparently in the US lawyer-based culture *any* admission of there being an issue is evidence. So the FAA guys cannot admit any problem existing, notrcan Boeing, and any hearings become empty posturing.
Hi there Edmund
Nor can Ethiopian authorities. Or Indonesian, Or Russia. Because they are all total home goals in that they are national carriers (or close cousins) , crashing in the capital city and being investigated by that same national authority. Don't expect anything too damning in the official reports of any of those three. Saying that the FAA will lie, and Boeing will lie which seems to be a popular trend on this forum is crass in the extreme. Boeing is a fine planeemaker with a wonderful record. The FAA may have flaws which need correcting but rest assured, that will happen. And in any event, many on this forum believe as I do the Max is perfectly flyable even in the circumstances that happened on these two crashes. And remember that the day before a crash WAS avoided by using the correct technique. Yes, yes, it was a funny guy in the jump seat who somehow knew what to do but doesn't that prove the point? How come he know what to do?
I am not so sure that the same can be said of a lot of other Certification Authorities where the national interest is at the forefront. And it is not confined to developing countries as we know.
Cheers for now.
y

yanrair

20th May 2019, 14:07

This issue has nothing to do with any nation pilot superiority in piloting an aircraft. This issue is directly related to the manufacturer who in this instance neglects to inform airlines and pilots of a system that is new and contrary to any Boeing aircraft behavior we longtime pilots have ever endured. I a Boeing pilot for over 30 years have always been confident knowing that once I had disconnected the autopilot and auto throttle, the aircraft was mine, and mine alone.

Dear Sakon. I have flown Boeings since 1967 and have always known that the biggest killer on a 737 is the stab trim getting away from you. Nothing you can do will stop that killing you except regaining trim and SWITCHES OFF. Since the 707 right through to the MAX this is still true.
I am sorry to tell you that disconnecting the AP and AT only solve part of the problem. The plane is not yours until you get the stab. back in control.
y

GlobalNav

20th May 2019, 16:47

Interesting that at no point during the congressional hearings did anyone ask how come the AoA indication failed on both crashed planes.

I am just an engineer with a PhD, not a pilot, and so for me the origin of a malfunction is significant. Safety doesn't start when someone puts his ass on the seat in the pointy end. And as a computer geek I do suspect that the AoA indicator issue is entirely spurious, a software artefact. In a similar occurrence, QF72, the AoA issues were entirely a software problem.

I suspect this sudden silence on an important topic is because a failed sensor is not a liability issue, while a bug is squarely in Boeing's wheelhouse.

Edmund
I agree with you and would add that regardless of how the AoA input became invalid, leading to the MCAS behavior, a key problem is that the probability of one, even two, invalid AoA sources is too high considering the catastrophic consequences. One facet of the safety problem, which occurred in the design phase, was to accept a single AoA input, regardless of its validity/integrity. A mere software tweak does not go deep enough or far enough to remediate the unsatisfactory design.

GlobalNav

20th May 2019, 16:56

fdr (as usual) nails it.

Forget about who you want to blame- that argument has been hashed over 5,000 posts in the original ETA thread.

Instead read 14CFR section 25.255 "Out of trim characteristics."

If you do you will read about the limits that either the electronic or autopilot trim systems can autonomously input to the point where control is taken/given to/or regained by the pilot. The reason for this certification requirement is simple: If your autopilot fails and trims nose down (or up) until the point where it can no longer maintain control over pitch will you be handed an airplane that you can recover when the AP disconnects, or will you be unable to control the AC?? Basically 25.255 insures that the two (traditional) electronic mechanisms that control the horizontal stab are tested to insure that neither one is likely to fail into a box that leaves the AC unrecoverable. It does this by arbitrarily setting a three second cap on manual inputs and the maximum input that the AP can make before it cannot control the aircraft.

Sounds good yes?? 25.255 insures that any system that can exert control over the horizontal stab is identified, specified, tested and certified to insure that it does not put the airplane outside the envelope at any time. Take the system to the maximum input it can make and see if the pilots can recover it. Great!!

Except, well wait a minute. There is this new system, called MCAS, that has the authority to run the trim all the way to the nose down stops. In nine-second bursts, wait five, rinse and repeat. 30 to 40 seconds is all it will take it to run your horizontal stab not only beyond your ability to recover, but to the max ANU position.

Ahhh, don't worry, you don't need to know about that system!! And rumors to the effect that it is reliant on a single data source are, oops, true!! Who knew??

This is the moral failure that Boeing made, and the bog which they are now in.

1. Boeing engineers KNEW what MCAS did.
2. They KNEW that under current certification regulations MCAS would not be permitted to be designed or implemented as they did as it could not comply.
3. They KNEW that MCAS could not pass numerous certification requirements, so they buried its existence from view to pretty much everyone. (The Three Monkeys approach...)
4. They KNEW that they submitted certification documents seeking .6 (IIRC) of trim per activation, but put into service a system with more than FOUR TIMES the control authority than that Certificated.
4. They KNEW that they created a system which had full and autonomous control authority over pitch and relied on a SINGLE data point. (C'mon, why are we even discussing this. that fact alone- that alone should put Boeing in custodial care or receivership...)

And the FAA stood by and cheered them on as profits went through the roof.

The cynic in me thinks two years from now Boeing will once again be flying the friendly skies uninhibited by such scrutiny, but the optimist in me thinks they might have actually done it this time. Allowed a deregulated environment to run so far off the rails that the Government actually steps back in and reasserts control.

We'll see I guess-

dce
Sorry, while I am critical of Boeing’s design decisions and the regulatory system, I do not accept that we KNOW the Boeing engineers were fully aware of all the non-normal characteristics of the MCAS, nor that regulators deliberately overlooked them. I hope the various investigations do uncover how all this went wrong, and correctly identify the systematic flaws in the delegation system that minimizes substantial technical oversight by the FAA.

I won’t deny, though, that minimizing the visibility of the MCAS to the regulators and certainly the pilots may have deliberately occurred to minimize differences training for the MAX and meet contractural obligations.

Ian W

20th May 2019, 17:59

If only there was some sort of switch, acted upon by the control column, whereby if a pilot pulled back on the yoke, the switch automatically cut off forward trimming (and vice versa). Pilots wouldn't even have to think about it...it would be instinctive.

Oh, wait! I just checked my MAX FRM. It says there IS such a system! Section 9.2.5.2.1

It goes on to describe the STAB TRIM OVRD switch, to take that column switch out of the loop, in case that it fails. It does NOT mention the fact that the MCAS is wired into that OVRD switch, and defeats the purpose of the column cutout switches. Actually, it doesn't mention MCAS at all...but we already knew that.

So following your sequence, the stab trim is running away and not being overridden - so the stab trim runaway NNC is followed trim back to level then stab trim cut out.

As I have said before the runaway could be due to a now dead rodent that chewed an electric cable. The pilot does not have to know _why_ the stab trim is stepping nose down - only that the pilot wants/needs to stop it and to do that follow the Stab Trim runaway NNC as was done by the first Lion Air flight and was published by Boeing along with the AD after the crashed Lion Air flight. Neither crashed aircraft followed the Stab Trim Runaway NNC correctly.

Aihkio

20th May 2019, 18:28

I would place a large bet that some engineer at Boeing new exactly what SCAM errr... MCAS does and when. In a project like this somebody knows what any one part or fuctionality does. It is just what happens in a design process.

LowObservable

20th May 2019, 19:26

Yanrair -

And remember that the day before a crash WAS avoided by using the correct technique. Yes, yes, it was a funny guy in the jump seat who somehow knew what to do but doesn't that prove the point? How come he know what to do?

I have to say I'm getting a little tired of this kind of superficial blather from people who, according to their claims of experience, ought to know better. It's a bit ridiculously obvious that the third pilot didn't have to busy himself with the other things going on in the cockpit, and could place the trimwheels in the center of his vision and focus on them for long enough to see what they were doing. The other two pilots could not do so, just like the accident crews.

To pretend to ignore those facts is to reveal a preference for point-scoring over honest debate, just like the continued posturing about how hypothetical "western" pilots would have coped with the problem easily.

RickNRoll

20th May 2019, 21:22

Sorry, while I am critical of Boeing’s design decisions and the regulatory system, I do not accept that we KNOW the Boeing engineers were fully aware of all the non-normal characteristics of the MCAS, nor that regulators deliberately overlooked them. I hope the various investigations do uncover how all this went wrong, and correctly identify the systematic flaws in the delegation system that minimizes substantial technical oversight by the FAA.

I won’t deny, though, that minimizing the visibility of the MCAS to the regulators and certainly the pilots may have deliberately occurred to minimize differences training for the MAX and meet contractural obligations.

From the attitude we have seen from Boeing management to date, we have to consider possibility the engineers who worked on MCAS were given design constraints to work under that mandated a substandard system.

yoko1

20th May 2019, 22:14

From the attitude we have seen from Boeing management to date, we have to consider possibility the engineers who worked on MCAS were given design constraints to work under that mandated a substandard system.

The evidence seems to suggest it.

krismiler

21st May 2019, 06:47

https://youtu.be/ZtHBz2-YpWE

Fly Aiprt

21st May 2019, 10:35

That video is typical of the amateurish analysis that pervades the debate around these two accidents. If you really want to know if a different crew could have saved the aircraft you would start from the initial state existing when the malfunction occured, as opposed to this scenario where they began from the point the cutout was selected. The simulation shows that once the ET302 disabled the MCAS, the upset was virtually unrecoverable.
You cannot replicate the startle effect with a warned crew.
What would be of interest is, get a measure of the time window a crew actually has before throwing the cutout switches and still be able to recover.
I'd say if it is less than one minute, this is a very short time indeed, even for a first class crew on a good day.

KRUSTY 34

21st May 2019, 11:57

[QUOTE=GlobalNav;10475730]
Sorry, while I am critical of Boeing’s design decisions and the regulatory system, I do not accept that we KNOW the Boeing engineers were fully aware of all the non-normal characteristics of the MCAS,

Well, they bloody well should have been!

Luc Lion

21st May 2019, 15:16

What would be of interest is, get a measure of the time window a crew actually has before throwing the cutout switches and still be able to recover.
It must be less than 43 seconds, because this is the elapsed time between MCAS activation and activation of the cutout switches in the ET302 case.
Possibly even less than 38 seconds as there is a 5 seconds uncertainty on the cutout switch activation time.
It is quite short.

And if the crew is not aware that there is a missing line in the trim runaway NNC
- "Put back the airplane in trim using the electric trim buttons before flipping the cutout switches",
and if the crew had only trained this NNC in a simulator where the manual trim forces are lighter than what they are in reality,
and if the crew is quite exhausted fighting an Elevator Feel System that creates ANU opposing forces 4 times the normal forces,
why wouldn't they have flipped the switches as soon as possible ?

In my armchair and after receiving much more information than the crew had at hand, I can see that there existed better options than what the crew chose to do.
But why is there here so many pilots convinced that they would have done better ?

IMHO, the point where the crew could have taken the time to discuss and think twice at their options is after flipping the cutout switches.
The time when they had a stable and controllable airplane, albeit with difficulties.

edmundronald

21st May 2019, 15:26

Hi there Edmund
Nor can Ethiopian authorities. Or Indonesian, Or Russia. Because they are all total home goals in that they are national carriers (or close cousins) , crashing in the capital city and being investigated by that same national authority. Don't expect anything too damning in the official reports of any of those three. Saying that the FAA will lie, and Boeing will lie which seems to be a popular trend on this forum is crass in the extreme. Boeing is a fine planeemaker with a wonderful record. The FAA may have flaws which need correcting but rest assured, that will happen. And in any event, many on this forum believe as I do the Max is perfectly flyable even in the circumstances that happened on these two crashes. And remember that the day before a crash WAS avoided by using the correct technique. Yes, yes, it was a funny guy in the jump seat who somehow knew what to do but doesn't that prove the point? How come he know what to do?
I am not so sure that the same can be said of a lot of other Certification Authorities where the national interest is at the forefront. And it is not confined to developing countries as we know.
Cheers for now.
y

[
Actually in the case of AF 447, AFAIK, the french investigatory authorities made a bunch of recommendations, which included meteorologic research, AoA display, mods to training and CRM, data transmission and flight recorders. One question which the report clearly posed is whether the actions of the crew were confined to that crew or would have been expected of any crew.

You can read the AF 447 final report at this link, the interesting stuff in my view starts around page 190.
[url]https://www.bea.aero/docspa/2009/f-cp090601.en/pdf/f-cp090601.en.pdf

Note that here too there is a specific recommendation involving the fact that AoA display should be mandatory. (page 205).

4.2.2 Recommendation relating to Certification

Angle of Attack Measurement

The crew never formally identified the stall situation. Information on angle of attack is not directly accessible to pilots. The angle of attack in cruise is close to the stall warning trigger angle of attack in a law other than normal law. Under these conditions, manual handling can bring the aeroplane to high angles of attack such as those encountered during the event. It is essential in order to ensure flight safety to reduce the angle of attack when a stall is imminent. Only a direct readout of the angle of attack could enable crews to rapidly identify the aerodynamic situation of the aeroplane and take the actions that may be required.

Consequently, the BEA recommends:

€ that EASA and the FAA evaluate the relevance of requiring the presence of an angle of attack indicator directly accessible to pilots on board aeroplanes.

My view after reading both the AF447 report and viewing the congressional hearings in the US is that the rot ie. regulatory capture is more serious in the US, although the french are by no means perfect, they did make an effort. Of course, there is the fact that calling all AF pilots *exceptionally *stupid won't work in France. When you have an accident, you want to tell your customers that you are going to do anything you can to avoid it, including changing the certification requirements and training curriculum. Telling your customers that they are idiots doesn't usually make them happy, Calling them foreign idiots as the congressional inquiry is doing is much worse..

Edmund

FrequentSLF

21st May 2019, 15:29

It must be less than 43 seconds, because this is the elapsed time between MCAS activation and activation of the cutout switches in the ET302 case.
Possibly even less than 38 seconds as there is a 5 seconds uncertainty on the cutout switch activation time.
SLF here, system engineer background...
I am still wondering why there are two cutout switches, renaming them from previous versions, removing the possibility of cutoff of automatics...
From a system design, i would question any engineer that feels the need to have two cutout (a primary and a back up) when the whole systems is based on a single input and a single actuator. The CB is already a back up of a failing cutout switch. The understanding of the reasons why such idiotic cut out system was designed is the basis to fully understand how the whole system was though... or NOT

Luc Lion

21st May 2019, 16:01

Just guessing here :
I believe that the changes to the wiring diagrams that resulted in having the column cutout switches (the ones hidden in the control columns) work effectively for autopilot and STS but be ineffective for the MCAS signals pushed towards having a single electric channel feeding the STAB motor with a single cutout switch.
And removing one of the two switches was not desirable for keeping the FCTMs of the Max and the NG as close as possible.
Solution : 2 switches wired in serie. One is labeled "main" and the other "backup".

Zeffy

21st May 2019, 20:19

https://www.wsj.com/articles/boeing-official-played-down-scenario-that-may-have-doomed-ethiopian-jet-11558439651

Boeing Official Played Down Scenario That May Have Doomed Ethiopian Jet
Talking to pilots, executive suggested sensor troubles could be nuisance rather than serious hazard

By Alison Sider and Andy Pasztor
Updated May 21, 2019 11:59 a.m. ET

Four weeks after faulty sensor data led a 737 MAX jet to crash in Indonesia last year, a high-ranking Boeing Co. BA 1.69% executive raised and dismissed the possibility of a bird collision triggering a similar sequence of events that could cause a second accident.

U.S. aviation authorities increasingly believe that a version of that scenario, described by Boeing executive Mike Sinnett at a November meeting with American Airlines pilots, may have led to the Ethiopian Airlines crash nearly four months later, according to officials familiar with the details. The crash happened after a sensor sent faulty data—possibly due to a bird strike—causing an automated flight-control system known as MCAS to misfire and repeatedly push the nose of the plane down.

At the meeting, Mr. Sinnett, vice president of product strategy, expressed confidence that well-trained pilots following established procedures could safely respond to a potential repeat of such equipment trouble, according to a recording of the meeting, which was reviewed by The Wall Street Journal. He also said he felt “absolutely” confident that heightened pilot awareness of potential dangers further reduced the chances of another accident.

Now, Ethiopian Airlines is pushing back against criticism of its pilots by complaining the plane maker didn’t do enough to warn them. The carrier suggests that Boeing’s failure to provide functioning cockpit alerts about problems with sensors made it more difficult for the Ethiopian crew to recognize the hazards they confronted before the second MAX accident in March.

The plane’s computers received erroneous data from a sensor known as an “angle of attack” or AOA vane about the pitch of the aircraft’s nose, activating a system that strongly pushed down the nose and ended in a fatal, high-speed dive.

“Although the pilots followed the procedures” spelled out by Boeing and U.S. safety regulators to counteract the automated commands, “none of the expected warnings appeared in the cockpit, which deprived the pilots of necessary and timely information,” Ethiopian Airlines said Friday.

Cockpit alerts such as a speed indicator and a stall warning called the “stick shaker”—which vibrates the pilot’s controls—did activate during the flight, according to a preliminary report issued by the Ethiopian government. But an indicator warning that the AOA sensors were out of sync didn’t go off, and excerpts from the cockpit voice recorder released as part of the preliminary report also indicate that despite those clues, it took the crew about five minutes to realize the AOA sensor problem.

U.S. aviation authorities regard a collision with one or more birds as the most likely reason for trouble with the sensor, according to industry and government officials familiar with the details of the crash investigation.

In his discussion with the American pilots months earlier, Mr. Sinnett raised the possibility of a bird hitting or damaging a sensor on a MAX jet shortly after takeoff. But he then appeared to play down the resulting risks, suggesting that pilots could quickly resolve such a situation and that the result of relying on what are called AOA alerts could be nothing more than the nuisance of flying back to the departure airport.

“The vast majority of AOA problems come from bird strikes after the airplane departs,“ Mr. Sinnett said. “You don’t want to have to return to base after a bird strike on an AOA vane.”

Ethiopian crash investigators said in a preliminary report that they “found no evidence of foreign-object damage” on the sensor. The point was reiterated last week in the airline’s statement, which specifically said no evidence of a bird strike has been found.

When birds hit such sensors, it is often difficult to find evidence conclusively proving that is what occurred.

U.S. government and industry safety experts, however, have said information downloaded from “black box” flight-data recorders points strongly to a sensor that was sheared off or otherwise rendered inoperable shortly after takeoff.

A Boeing spokesman declined to comment.

The October crash of the Lion Air jet in Indonesia and the Ethiopian crash in March took a total of 346 lives. The global fleet of 737 MAX aircraft has been grounded since shortly after the second crash.

Whatever caused the faulty data on the Ethiopian jet, Boeing has been on the defensive about its onboard alerting system. Alerts to inform pilots whether such sensors are transmitting incorrect data haven't been working on much of the global MAX fleet due to a software error stretching back to production, though they did function on American’s planes.

Despite the criticism of Boeing by Ethiopian Airlines, acting FAA chief Daniel Elwell last week said that the pilots of the Ethiopian jet didn’t fully adhere to required procedures. He also told a House aviation panel that the agency concluded working alerts “wouldn’t have changed either accident.”

Some pilots and safety experts disagree with his conclusion.

Write to Alison Sider at [email protected] and Andy Pasztor at [email protected]

safetypee

21st May 2019, 21:19

An alternative reason for an erroneous AoA signal; overview including assessment of vane failures - see discussion and comments.
https://www.satcom.guru/2019/03/regulations-around-augmentation-systems.html

The incident report as referenced above, indicating a complex and difficult fault to identify as an internal vane failure.
Note the multiple AoA interactions resulting in several system alerts; similar to the 737. The experienced crew (same as first event) elected to abort the takeoff - see sensible AAIB assessment of the decision, because of the uncertainty of multiple alerts.
http://www.smartcockpit.com/docs/Boeing_B747-Stick_Shakers_Activation_On_Takeoff.pdf

krismiler

21st May 2019, 22:31

You cannot replicate the startle effect with a warned crew.

Exactly, the results in the simulator when Airbus pilots replicated the landing in the Hudson river where very different when time was allowed for the startle effect and recognition on the second attempt. On the first go they got it onto a runway, however they knew what was going to happen, when it was going to happen and exactly where the closest airport was. On the next go they crashed short after having to allow a short time for recognition and decision making.

yoko1

22nd May 2019, 00:25

Originally Posted by LowObservable;
10475835 (tel:10475835)]

I have to say I'm getting a little tired of this kind of superficial blather from people who, according to their claims of experience, ought to know better. It's a bit ridiculously obvious that the third pilot didn't have to busy himself with the other things going on in the cockpit, and could place the trimwheels in the center of his vision and focus on them for long enough to see what they were doing. The other two pilots could not do so, just like the accident crews.

It really isn't possible to say whether or not the first Lion Air crew would have eventually found their way to the trim cutoff switches without the jumpseater's help. What we can say is that until that point, the crew was maintaining aircraft control by opposing the MCAS input. It should be noted that the Captain was initially flying this aircraft, but at some point handed it over to the First Officer. Both pilots demonstrated the ability to maintain aircraft control in spite of MCAS.

In the case of the second Lion Air flight & subsequent accident, initially the crew also maintained aircraft control by opposing the MCAS inputs. There is no official CVR transcript of the Lion Air accident flight, but there have been "leaks" that suggest that the Captain was initially flying and then turned over primary flying duties to the FO and then went "heads down" in the QRH to find an appropriate procedure. There is also a definite inflection point on the FDR data that shows a transition from the flying pilot successfully opposing MCAS to a situation where the opposing inputs are not large enough thus resulting in a greater and greater out of trim state. It is reasonable to speculate that this inflection point occurred when the Captain handed off control to the First Officer, and then didn't notice the FO losing the battle with the trim until it was too late.

In Ethiopian accident is that the Captain never really caught up with the trim even though he could have. Why that was the case is a bit of a mystery.

In summary, three out of five pilots who acted as the flying pilot demonstrated the capacity to maintain aircraft control with an erroneous MCAS input - the Captain and FO on the first Lion Air flight, and the Captain on the second Lion Air flight. Two pilots - the second Lion Air First Officer and the Ethiopian Captain did not.

The evidence strongly suggests that a majority of these non-Western trained pilots actually did have the required aviation skills to successfully oppose MCAS for a number of minutes of active flight and keep the plane aloft. Since they were able to do this for several minutes, there doesn’t seem to be a practical limit to how long they could have continued to do so. As a direct consequence, there is no compelling evidence that there was any “reaction time” required to solve the MCAS problem. Given significantly more time to work the problem, I think it is worth asking whether even a minimally proficient crew would have eventually worked out a solution to the errant MCAS inputs. Given enough time, it seems they would even have enough time to be phone patched right to Boeing.

Time was never a problem.

Smythe

22nd May 2019, 14:52

It appears EASA has put their foot down pretty hard

Europe’s aviation safety agency has set out strict conditions before it will allow Boeing’s 737 Max aircraft back into the skies, in a sign of the depth of the rift emerging among global regulators after two deadly crashes.

EASA (https://www.irishtimes.com/topics/topics-7.1213540?article=true&tag_organisation=EASA) said it had three “pre-requisite conditions”, including demands that design changes by Boeing (https://www.irishtimes.com/topics/topics-7.1213540?article=true&tag_company=Boeing) are approved by the European agency, before it would lift the grounding of the Max following the crashes in Ethiopia (https://www.irishtimes.com/topics/topics-7.1213540?article=true&tag_location=Ethiopia) and Indonesia (https://www.irishtimes.com/topics/topics-7.1213540?article=true&tag_location=Indonesia).

News of the conditions will heap further pressure on the US safety regulator, the Federal Aviation Administration (https://www.irishtimes.com/topics/topics-7.1213540?article=true&tag_organisation=Federal+Aviation+Administration) (FAA), ahead of a meeting of global regulators in Texas on Thursday to review Boeing’s application to get the Max back in the air.

The conditions are: that any design changes by Boeing are EASA approved and mandated; that an additional independent design review being conducted by the agency is completed; and that Max flight crews “have been adequately trained”.

“We are working on having the 737 Max 8 (https://www.irishtimes.com/topics/topics-7.1213540?article=true&tag_event=737+Max+8) return to service as soon as possible, but only once there is complete reassurance that it is safe,” a spokesman told the Financial Times.

Patrick Ky (https://www.irishtimes.com/topics/topics-7.1213540?article=true&tag_person=Patrick+Ky), EASA’s executive director, said in March the agency would make its own study of the Max’s safety and would not allow the plane to resume service until it was satisfied, irrespective of what the FAA decided.

https://www.irishtimes.com/business/manufacturing/european-agency-s-demands-on-boeing-signal-rift-among-regulators-1.3900462

EASA will also continue to analyse any new information that emerges about the two crashes in which 346 people died in Ethiopia in March and Indonesia in October.

The agency has communicated its conditions to both Boeing and the FAA, the spokesman added.

It is not unprecedented for EASA to conduct its own safety review, but it is unusual and underlines the splintering among regulators following the Max crashes.

bill fly

22nd May 2019, 19:24

SLF here, system engineer background...
I am still wondering why there are two cutout switches, renaming them from previous versions, removing the possibility of cutoff of automatics...
From a system design, i would question any engineer that feels the need to have two cutout (a primary and a back up) when the whole systems is based on a single input and a single actuator. The CB is already a back up of a failing cutout switch. The understanding of the reasons why such idiotic cut out system was designed is the basis to fully understand how the whole system was though... or NOT

I guess
1. because they tried to make the cockpit appear as similar to the previous versions as possible and
2. two switches in series are a big factor less likely to fail closed than one

Two birds with one stone...

BluSdUp

22nd May 2019, 19:34

Ooops, there goes a few more months!
Looking forward to what comes out of tomorrows meeting.
Particularly from EASA, Canada MOT, Russia , Australia and China.
Oh and not to forget Indonesia and Ethiopian CAA.

Not able to post the next few days , so any links appreciated.
Regards
CptB

jimjim1

22nd May 2019, 22:42

Does not appear to have been posted on pprune.

Estate of one of the passengers on the Ethiopian aircraft and others v Boeing.

http://cdn.cnn.com/cnn/2019/images/05/21/thugge-v-boeing.pdf
84 pages. The full complaint. Civil Action No. 2:19-cv-01443-DCN

Highly critical of Boeing, as you would expect in a legal claim of this nature within an adversarial legal system. Relates the management of the rudder hardover events of decades ago and the management of the current MCAS issues for example. Makes for attention-getting reading.

I have not extracted any of it to post here since it seems that the document cannot be copied/pasted.

gums

22nd May 2019, 22:58

Salute!

Yep, they are going after Boeing and could have a little jab at FAA, but mainly Boeing. We may finally get to hear from the "third pilot" when testimony is heard. Get the popcorn ready.

Always respected Mary, but I will be surprised if she is seen a lot on TV as the lawsuit is in progress. However, with present news and legal stuff going on in the U.S., we might still see her. Just seems she is jumping on too soon.

Gums sends...

capngrog

22nd May 2019, 23:31

jimjim1;

Thanks for posting the link to the Thugge v. Boeing lawsuit. As you said, it "makes for attention-getting reading. I'm all too familiar with the history of the B-737 rudder problems, and think that some of the points of the lawsuit are misleading at best; however, as you said, the U.S. legal system is, if nothing else, extremely adversarial in nature. I've looked at some information on the Montreal Convention which limits air carrier liability (in most cases), but doesn't specifically cover aircraft manufacturers. Is there an international treaty limiting the liability of aircraft manufacturers?

Cheers,
Grog

Loose rivets

23rd May 2019, 00:09

Back to the switches for a moment. The RH switch wiring shows a little more complexity than simply a series backup toggle. Bear in mind, a million posts back, someone said each switch was 'dual gang' - but even so, the toggle lever could just fail* Anyway two it is. If only . . . if ONLY, Boeing had said, Now, this is what MCAS is, and this is what it does, If you don't like it, the right hand switch will turn it off. Leave the left one on if the wheels have stopped spinning and you want to be able to use thumb trim. IF only.

As it is, the left one still cuts all power to the horizontal stabilizer motor/clutches - even if we'd dearly love our thumb trim switches to still work.

Remember, the column pull back (hidden) rear switch still allows MCAS. It's been rewired to the point one pundit described it as no longer being there on the MAX.

A CB in a crisis? Okay if it's pre-flagged in red and in reach. Don't want to be twisting our spines when all kinds of g forces are being applied to our bodies. And certainly don't need to be looking in books of instructions on how to fly a plane. FFS, resorting to check-lists before quick memory actions would be unconscionable. It is the most powerful flying surface and even I know how it works learning with one foot in the grave.

I have every understanding that the bizarre circumstances diminished the crew's abilities, sad, but many top guns on here have eventually admitted that they may well have not known what's going of for those first few minuets.

It's vital 'we' know how anything connected to that 47' 1" tail works . . . and what every relay does, and as I've said before, know the importance of system interactions - the hardest part of any course for me - and I'd come off an electronics workbench to fly.

*

FrequentSLF

23rd May 2019, 01:48

Back to the switches for a moment. The RH switch wiring shows a little more complexity than simply a series backup toggle. Bear in mind, a million posts back, someone said each switch was 'dual gang' - but even so, the toggle lever could just fail* Anyway two it is. If only . . . if ONLY, Boeing had said, Now, this is what MCAS is, and this is what it does, If you don't like it, the right hand switch will turn it off. Leave the left one on if the wheels have stopped spinning and you want to be able to use thumb trim. IF only.

As it is, the left one still cuts all power to the horizontal stabilizer motor/clutches - even if we'd dearly love our thumb trim switches to still work.

*
Based on the electrical drawings posted on this forum, the LH switch has 3 contacts while the LH has two contacts. Both contacts on the RH are in series with the RH contacts supplying 28 VDC to the whole circuit, the 3rd contact on the RH switch enables the brushless drive. So any of the switches will cut 28 VDC to the circuit. I cannot see how MCAS or STS can be disconnected without cutting power to the whole circuit. There is now way to keep ONLY thumb controls.
I do not accept the justification that two in series provide a better fail mode in case one contact is stuck, fused, etc. If that would be a design concept all switches should have a back up, and thousands of earlier 737 are unsafe. IMHO either CB are the fail safe in case contacts are fused. One CB cuts 115 VAC and the other cuts 28 VDC.
It can also be noted that one contact from the LF switch provides a cut out signal to FCC, which seems that was not used by the SW, since the FDR traces show MCAS activation with switches in CUT OFF position.
Would be interesting to know the number of occurrences of fused contacts on those switches....

Smythe

23rd May 2019, 02:02

It can also be noted that one contact from the LF switch provides a cut out signal to FCC, which seems that was not used by the SW, since the FDR traces show MCAS activation with switches in CUT OFF position.
Would be interesting to know the number of occurrences of fused contacts on those switches....

aircraft a few weeks old with fused contacts???

bill fly

23rd May 2019, 02:27

aircraft a few weeks old with fused contacts???
Nobody said it was fused on the accident aircraft. We are just trying to work out the switch logic.

Old Dogs

23rd May 2019, 02:49

krismiler

23rd May 2019, 11:25

DP Davies insisted on modifications to the B707 before it went onto the British register due to its marginal handling on 3 engines under certain conditions. I wonder if EASA will do something similar with the MCAS ? Expect the Chinese to be the most difficult of all given the ongoing trade dispute with the US.

Bergerie1

23rd May 2019, 12:03

DPD also required the fitting of a stick nudger on UK registered 747s. This was because, (I quote page 262) with the flaps up and a trim speed of 1.3Vs, after a small elevator force to start the speed reduction, the stick force falls to zero while the aeroplane quietly progresses all the way to the stall on its own. The fix was the nudger. This is a gentle stick force augmentor of about 16lbs in the nose down sense which operates when the stick shaker starts to operate and remains effective until the stick shake cancels. In a fairly rough and ready manner it restores the pre-stall longitudinal stability and satisfies the requirements at little cost and with no snags.

Since the very start of this whole debate on the 737MAX, I have always wondered why Boeing didn't try something similar rather than using the MCAS to drive the whole horizontal stabilser.

Fly Aiprt

23rd May 2019, 12:17

The fix was the nudger. This is a gentle stick force augmentor of about 16lbs in the nose down sense which operates when the stick shaker starts to operate and remains effective until the stick shake cancels. In a fairly rough and ready manner it restores the pre-stall longitudinal stability and satisfies the requirements at little cost and with no snags.

Since the very start of this whole debate on the 737MAX, I have always wondered why Boeing didn't try something similar rather than using the MCAS to drive the whole horizontal stabilser.

The reason might be that a stick pusher means some hardware has to be added to the aircraft, which would be hard to conceal and so would have mandated some certification and flight manual mods and additional simulator time.
Exactly what Boeing was wishing to avoid.

Less Hair

23rd May 2019, 14:21

Fly Aiprt

23rd May 2019, 14:54

Is MCAS really about stick feel only? It's power got boosted over the planned force as if the nose must be brought down at any cost before stalling it.
What is the raw, non MCAS, stall behavior of the MAX 8? Anything nasty?

Nothing has been released to the public as to the exact MAX 8 stall behavior. It may happen that even Boeing didn't really know much before the catastrophes.
Concerning stick forces, I'd say yes, since MCAS is only there to change "the feel", and is not needed when on autopilot - who doesn't care about stick forces.

Zeffy

23rd May 2019, 14:58

https://www.seattletimes.com/business/boeing-aerospace/faa-administrator-elwell-says-737-max-will-return-to-flight-but-timetable-is-uncertain/

FAA head says Boeing 737 MAX will return to flight, but timetable is uncertain
May 22, 2019 at 5:00 pm Updated May 22, 2019 at 8:09 pm
Dominic Gates By Dominic Gates
Seattle Times aerospace reporter

FORT WORTH, TEXAS — The head of the Federal Aviation Administration (FAA) on Wednesday insisted there’s no fixed schedule for lifting the order that has grounded Boeing’s 737 MAX since March 13.

“It takes as long as it takes,” said Acting FAA Administrator Dan Elwell. “The 737 MAX will fly again when we have gone through all of the necessary analysis to determine that it is safe to do so.

“If it takes a year to find everything we need to give us confidence to lift the order, then so be it,” he added. “I’m not tied to a timeline.”

Though the plane could still potentially return to service in the U.S. as early as August, that fast-track schedule privately suggested last month by both Boeing and the FAA may have been delayed by technical hitches and by public unease.

Ahead of Thursday’s meeting of top officials from civil aviation authorities around the globe to discuss what’s needed before the MAX can fly again, Elwell said Boeing has still not submitted its final proposed software fix for the flight-control system that erroneously activated on Lion Air and Ethiopian Airlines 737 MAXs and led to two deadly crashes — despite Boeing’s announcement last week that the software fix was “completed.”

An FAA spokesman on the sidelines of the meeting said the safety agency has a clear idea of the main elements of Boeing’s fix and knows the steps that need to be done to certify and validate Boeing’s work. How long those steps will take remains fuzzy.

Daniel Elwell, the acting administrator of the Federal Aviation Administration. Daniel Elwell, the acting administrator of the Federal Aviation Administration.

Elwell said Boeing had earlier committed to deliver its software fix on March 26, but at the last minute decided it needed to make adjustments after an independent internal Boeing review found problems that needed to be addressed.

Fifty-seven delegates representing civil aviation authorities in 33 countries have gathered for the meeting Thursday at the FAA’s southwest regional office in Fort Worth — including officials from Indonesia and Ethiopia, the two countries leading the investigations into the two fatal MAX accidents that killed 346 people.

“We will be sharing with them the safety analysis that will form the basis for our return-to-service decision,” Elwell said.

At his side during the press briefing was Ali Bahrami, the FAA’s head of aviation safety, who called this “a very extensive review” of Boeing’s software fix.

Elwell was asked how this safety analysis will be done differently than the FAA’s safety analysis of the original flight-control system, an analysis that, as the Seattle Times reported in March, was largely written by Boeing engineers and missed several crucial flaws that are now being fixed in the software update.

He responded only by saying that during the MAX’s initial certification the FAA followed the same proven procedures that have been used for 50 years.

The FAA has confirmed that among other issues, the original safety assessment, as detailed in the March Seattle Times story, did not take into account an increase in the authority of the problematic flight control system, called MCAS (Maneuvering Characteristics Augmentation System).

Boeing found during flight tests that for certain flight conditions, it needed to allow MCAS 2.5 units of movement instead of 0.6, quadrupling its power to move the jet’s tail and push the its nose down. Many FAA technical staff who worked on the MAX were never made aware of this change, and the system safety assessment done during original certification was never updated to include it.

An FAA spokesman said that the higher authority was designed only for “high angle of attack, low-speed turns,” and that “the change to MCAS didn’t trigger an additional safety assessment because it did not affect the most critical phase of flight, considered to be higher cruise speeds.”

However, at a crucial moment during the doomed Ethiopian flight, MCAS moved the tail 2.5 units and pushed the nose drastically down, even though the aircraft was moving at higher than normal speed.

The politics of getting international consensus as well as restoring the confidence of the traveling public may prove lengthy.

Elwell conceded that there may be a crisis of public confidence in Boeing’s jet “right now,” but said that the longstanding and proven processes of his agency that have produced the unrivaled U.S. aviation safety record over the past two decades will restore that lost confidence over time.

“I’m not worried about the future of public confidence, because I’m not worried about the future of aviation safety.” Elwell said.

He described the purpose of the international meeting as information sharing, so that a consensus may emerge.

“The idea is that we are working globally from the same sheet of music,” Elwell said. “So that when we are ready to lift the prohibition (on the MAX flying), there’s absolutely no question in any country’s mind why we are doing it and how we got there.”

He said the FAA will “explain our understanding of the risks that need addressed, the steps we propose to address those risks and how we’ll propose to bring the 737 MAX back into service.”

Though the U.S. safety agency typically takes the lead in the aviation world, consensus could be elusive after regulators in other countries decided to move first in grounding the plane and then learned of flaws in the FAA’s certification processes.

Countries such as China have indicated that they want to study the safety of the new system for a longer period and do their own assessment of it rather than just following the FAA.

It’s unclear if the FAA would move forward without key players on its side, including the European Union Aviation Safety Agency (EASA) and the Canadian civil aviation authority. But Elwell seemed to suggest that the US will take the lead and move first.

Because the U.S. is where the MAX was designed and issued its initial certification, which was then separately validated by regulators around the world, the ungrounding of the aircraft must follow a similar pattern, Elwell said. When its analysis is complete, the U.S. will certify the fix and lift the grounding, then other countries must validate the FAA’s work and make their own decisions, he said.

Dominic Gates: 206-464-2963 or [email protected]; on Twitter: @dominicgates.