Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

[TailwheelPilot]

The MAX must have some pretty nasty habits if they thought that there was such a high chance of stalling it to put the mcas in.

I have not seen a definitive answer from Boeing or the FAA. It sounds like MCAS is only required on the MAX because of a regulatory requirement - as the plane approaches the stall the force to pitch up must not decrease. The larger and more forward engine nacelles at high angles of attack cause the force required to pitch up at high angles of attack to decrease.

Nothing to do with poor handling (which is reportedly no different from the NGs in normal operations) or a high chance of stalling.

[J31]

One of the things that drives me nuts is how the airframer sales people sell these airplanes to their airline customers - usually bean counters and MBA's.
"Really easy to fly, no problem bringing low time cadets on board."
" Reduced training costs. All your XXX pilots need is an internet based differences course."
" There is nothing to it, you can covert your XXX pilots with a short course."
But let one of their nearly self driving airplanes create a new underground aluminum deposit and the same airframers say "Not our fault, your guys didn't fly it like our test pilots would have."

Boeing (and many posters) say "Hey, it's just a trim runaway. Do the drill and all is good." But this is not the simple trim runaway that the QRH contemplates. It starts with a stall warning stick shaker shortly after lift off. Close to the ground this will, and should consume both pilots undivided attention. After a number of seconds they realise that the airplane hasn't stalled and they start figuring out that they may have an airspeed and/or AOA problem. This is a second problem to deal with on top of the first. And they can't shut the &%$#@ stick shaker off once they realise that it may be spurious. The PM will be frantically scanning the panel to try and find some clue what is going on. And this whole time, among the din of the stick shaker, crews concern for the airplanes flight path, and the confusing instrument indications, MCAS has been intermittently dialing in nose down trim. Not steadily, in a calm cockpit at altitude like the QRH contemplates. But intermittently in the background of chaos, noise, and confusion. At some point, well past when it would have been timely, the task saturated PF realizes that the trim is working against him/her and the stab cutout switches get turned off. (hopefully)

But the shitshow isn't over. Because of everything else going on, this took too long and the airplane is way out of trim. The Lion Air crew reportedly had 60 KG of back pressure on the yoke. Close to the ground, and relying on the lifting component of the underslung engines to help keep the nose up, the crew do not dare reduce power. Now the crew needs to manually trim the airplane, but the airplane is way, way off its trim speed. The B737 QRH makes reference to the large forces that may be required to break free a servo clutch:
"3 If needed:Use force to cause the disconnect clutch to disengage. Approximately 1/2 turn of the stabilizer trim wheel may be needed.
Note:A maximum two-pilot effort on the trim wheels will not cause a cable or system failure."

Worse, the "Manual Stabilizer Trim" section of the Boeing FCTM talks about the air loads on a grossly out of trim stab requiring a speed change to reduce the force required to manually trim:
"Excessive air loads on the stabilizer may require effort by both pilots to correct mis-trim. In extreme cases it may be necessary to aerodynamically relieve the air loads to allow manual trimming. Accelerate or decelerate towards the in-trim speed while attempting to trim manually."

Sweet Jesus how did this thing get certified? A guy (or petite gal) has a 60 KG+ force on the yoke trying to stop the airplane from impaling itself into the hard ground just a few thousand feet below, and now he/she has to brute force trim the airplane as well, requiring involved coordination with the PM. Still with all the stick shakers, aural warnings, goofy instrument readings, and whatever else is happening to distract the crew and making communication almost impossible. It is not hard to see how quickly it becomes overwhelming.

In addition to a fix for the airplane, if they keep the MCAS system (instead of designing a whole new wing or tail for the airplane), they will have to train the pilots who fly it to deal with its failure. Right now, there is not a single Max pilot in the world who has been trained for this failure because - there isn't a single simulator in the world that can replicate it. But when they do, all those pilots that claimed "it's just a trim runaway" are going to have a very eye opening simulator session.

Very good description of what can happen! Add along with the stick shaker the possible aural alerts yelling at you "Airspeed Low" "Too low Terrain", "Don't Sink", "Obstacle"!

During all this racket the MCAS can be trimming for 10 seconds covering 2 units of trim. That is 26 turns on the manual trim to get back in trim!

Normal Speed trim and normal pilot actioned trim is 1-2 turns.

Lots of talk about the MCAS system but virtually nothing from Boeing. There is nothing on the MCAS system in the Boeing MAX FCOM.

And yes I fly the MAX. The MAX is grounded because of inaction by Boeing.

[Eric Janson]

One of the reasons I like Boeing over airbus is the fact the pilot is able to override the computer - such as it will in this case.

airbus is no different - you can put the aircraft into Direct Law where it becomes a conventional aircraft. Stick deflection will give a proportional flight control deflection and you have to trim manually.

Thanks to a Red Bulletin that came out a few years ago every airbus Pilot knows the steps to disable most of the protections and regain control in the event of uncommanded nose down pitch inputs.

I was surprised to see that the latest versions of the 737 are still equipped with dual everything as opposed to triple redundancy on just about every other aircraft.

The 737 was designed for short flights - not for the flights that are currently being done with it.

@ant_321 - thanks for the insight into transitioning from the NG to the MAX

[goingnowherefast]

I was surprised to see that the latest versions of the 737 are still equipped with dual everything as opposed to triple redundancy on just about every other aircraft.

Boeing has no redundancy on some parts. MCAS for example, works with ONLY the left side AOA probe. No comparison, so agreement required, just one prope. Single point of failure.

Still waiting to see if this is what happened to Ethiopian.

[Jet Jockey]

I was surprised to see that the latest versions of the 737 are still equipped with dual everything as opposed to triple redundancy on just about every other aircraft.

Boeing has no redundancy on some parts. MCAS for example, works with ONLY the left side AOA probe. No comparison, so agreement required, just one prope. Single point of failure.

Still waiting to see if this is what happened to Ethiopian.

If this is true about the MCAS, then Boeing deserves a kick in the a$$ big time and the MAX deserves to be grounded.

The fact Boeing makes no or very little reference to the system in any manuals and that no particular training on a possible failure of this system was mandated/required is very surprising.

I'm siding with those that say it is not as clear cut as it seems... There seems to be a possibility of multiple warnings (lost of airspeed indication, stick shaker activation, AOA disagree indications, trim pitching nose down etc...) which could overwhelm the pilots at a crucial phase of flight.

Anything happening at low altitudes that can affect the controllability of an aircraft, in this case MCAS should be thought in class to the pilots.

I would like to know why American and Southwest apparently got extra information/training for their pilots on MCAS. The Brazilian authorities also mandated additional info or training on MCAS be required for their pilots.

Finally I'd like to know why it seems American (and maybe others) felt it necessary and decided to get an additional system installed in their aircrafts (I think it's an additional AOA) because of this MCAS system and whether this is an option available to others and whether it was available from the start of production of the MAX.

[Jet Jockey]

I don't know how accurate this is but I just found this article dated March 17th (today) from the Seattle Times, very interesting read...

https://www.seattletimes.com/business/b ... air-crash/

Some of the highlights from the article from Boeing insiders and I quote...

Current and former engineers directly involved with the evaluations or familiar with the document shared details of Boeing’s “System Safety Analysis” of MCAS, which The Seattle Times confirmed.

The safety analysis:

•Understated the power of the new flight control system, which was designed to swivel the horizontal tail to push the nose of the plane down to avert a stall.

When the planes later entered service, MCAS was capable of moving the tail more than four times farther than was stated in the initial safety analysis document.

•Failed to account for how the system could reset itself each time a pilot responded, thereby missing the potential impact of the system repeatedly pushing the airplane’s nose downward.

•Assessed a failure of the system as one level below “catastrophic.” But even that “hazardous” danger level should have precluded activation of the system based on input from a single sensor — and yet that’s how it was designed.

The people who spoke to The Seattle Times and shared details of the safety analysis all spoke on condition of anonymity to protect their jobs at the FAA and other aviation organizations.

[goingnowherefast]

The same article mentions the single point failure for the AOA - MCAS system

...black box data retrieved after the Lion Air crash indicates that a single faulty sensor — a vane on the outside of the fuselage that measures the plane’s “angle of attack,” the angle between the airflow and the wing — triggered MCAS multiple times...

[Jet Jockey]

The same article mentions the single point failure for the AOA - MCAS system

...black box data retrieved after the Lion Air crash indicates that a single faulty sensor — a vane on the outside of the fuselage that measures the plane’s “angle of attack,” the angle between the airflow and the wing — triggered MCAS multiple times...

Yes I saw that and it is totally ridiculous that a single vane failure can bring an aircraft down.

Really poor design from Boeing and they will pay big time for their cost cutting on the MAX.

[Victory]

Reminds me of that bridge that started oscillating and broke apart in terms of absolute engineering failures. Step back from the drafting table or computer and think about the real world for once. You cost people their lives and hope you answer for that.

[J31]

https://www.cbc.ca/news/world/ethiopia- ... -1.5059971

Preliminary data retrieved from the flight data recorder of the Ethiopian Airlines plane that crashed shows "a clear similarity" with an earlier disaster in Indonesia, Ethiopia's transport minister said Sunday.

Dagmawit Moges told reporters that the Ethiopian government intends to release detailed findings within one month.

"The black box has been found in a good condition that enabled us to extract almost all the data inside," she told reporters Sunday evening.

[Eric Janson]

Serious issues with the MAX that weren't caught in the certification process which also appears to be a complete joke with the FAA allowing Boeing to do a lot of it themselves.

A lot of people at Boeing and the FAA need to be fired and possibly prosecuted for Criminal Negligence.

I think we're well past a simple 'Software Fix' at this point - the entire certification is in jeopardy.

I'm sure some of you are wondering 'What went wrong at Boeing?'

The answer is right on the Boeing website - they're so self unaware that they can't see the problem....

http://www.boeing.com/principles/divers ... ve-for-all

Be sure to watch both videos.

Replacing qualified people with 'Diversity', 'Equality' (of outcome) and Virtue Signalling. What could possibly go wrong?

There is no place for this PC garbage in Aviation imho.

[LittleNelly]

The same article mentions the single point failure for the AOA - MCAS system

...black box data retrieved after the Lion Air crash indicates that a single faulty sensor — a vane on the outside of the fuselage that measures the plane’s “angle of attack,” the angle between the airflow and the wing — triggered MCAS multiple times...

Yes I saw that and it is totally ridiculous that a single vane failure can bring an aircraft down.

Really poor design from Boeing and they will pay big time for their cost cutting on the MAX.

A single vane failure did not bring down an aircraft.

The sensor was faulty, the plane thought it was approaching stall(as any plane would, not just the 737), then it’s up to the crew to do their job and determine if in fact they are about to stall(as with any crew on any aircraft type), the previous Lion air crews did this correctly, took manual control and noticed that whenever they stopped manual trip input that it would trim back down, so runaway trim drill, they disconnected the trim, returned to land without incident. Wrote it up.

The cause was improper maintenance in regards to the sensor(Lion air was sanctioned for poor maintence practices, and the tech director was fired), and pilot error in not identifying the AOA disagree.

The MCAS was not a cause, merely a symptom of the problem. The plane thought it was stalling so the MCAS did what it was designed to do, as was approved by every aviation authority In the world, and begin trimming down. It’s up to the pilots to determine if they do stall recovery if it’s in fact a stall or override if it’s not a stall as was the case. This is the same procedure for any airliner in production.

The fact is the MCAS cannot override the pilot. Electronic, manual, or disconnect overrides it. As was shown with the successful return of the previous lion air flight before the crash. The Boeing response to Lion air(as was accepted) by once again every authority around the world) was to tell operators to make sure they include AOA disagree in procedures(that’s on the airlines and the regulators to ensure proper training and procedures) and more importantly stress the importance of Stabilizer Runaway non-normal checklist. basically Boeing had to tell airlines make sure your crews do their job!

If nothing else going back to basic airmanship and disconnecting the stab trim during a trim runaway situation would have saved the flight.

Fly the plane, don’t let the plane fly you.


So in fact if the Ethiopian flight is “similar” to the Lion air then it is good news for Boeing since no fault has thus far been found with the 737 design. This is based on the actual reports which have been drowned out by sensationalist media like the national post which uses random internet bloggers and anonymous posters on web forums to write articles to scare the public off murderous computers on planes taking control.

[sstaurus]

A single vane failure did not bring down an aircraft.

Yes but obviously it was a big hole in the swiss cheese that shouldn't have been there.

[LittleNelly]

Serious issues with the MAX that weren't caught in the certification process which also appears to be a complete joke with the FAA allowing Boeing to do a lot of it themselves.

A lot of people at Boeing and the FAA need to be fired and possibly prosecuted for Criminal Negligence.

I think we're well past a simple 'Software Fix' at this point - the entire certification is in jeopardy.

I'm sure some of you are wondering 'What went wrong at Boeing?'

The answer is right on the Boeing website - they're so self unaware that they can't see the problem....

http://www.boeing.com/principles/divers ... ve-for-all

Be sure to watch both videos.

Replacing qualified people with 'Diversity', 'Equality' (of outcome) and Virtue Signalling. What could possibly go wrong?

There is no place for this PC garbage in Aviation imho.

What negligence?

No fault has thus far been found in the 737 design in the Lion air crash. The stall protection system including MCAS did EXACTLY what it was designed to do when it detected a stall from the faulty AOA. It’s up to the crew to determine if it’s an actual stall, if not then take action to remedy the situation(which the previous Lion air crews did).

[LittleNelly]

A single vane failure did not bring down an aircraft.

Yes but obviously it was a big hole in the swiss cheese that shouldn't have been there.

As was the frozen sensor on AF 447...... I think we can agree that crash was on the crew.

Pilots get paid to deal with emergencies not babysit an FMS.

But even then the AOA vane was on Lion air maintence as per the investigation. Not Boeing.

['97 Tercel]

poor Boeing

[Ki-ll]

Serious issues with the MAX that weren't caught in the certification process which also appears to be a complete joke with the FAA allowing Boeing to do a lot of it themselves.

This has been the norm for decades, at least since the 70s. FAA, or any other regulator, has neither manpower nor the expertise to wholly certify an airliner.

[Gino Under]

As I’m understanding it, a STAB TRIM RUNAWAY is not the same as an MCAS activation.
Anyone else reading the same info from the numerous reports coming up with the same conclusion?
Boeing is going to take a $$bath$$ for rushing this aircraft to market.

https://www.adn.com/nation-world/2019/0 ... ol-system/

Gino Under

[Flying Low]

The only difference between a Stab Trim Runaway and the MCAS situation is that the pilot can intervene with the electric trim and stop it momentarily.

Would you keep trying to fly with an autopilot that wasn't doing what you wanted or use an auto throttle system that wasn't giving you the results you were looking for? I sincerely hope the answer is a NO!

The Lion Air crew flew around with a malfunctioning trim for the better part of ten minutes before completely losing control of the aircraft and never thought to turn the electric trim off?

My biggest question about this isn't about Boeing's design of the MCAS but the training of a crew that would continue to use a malfunctioning system for 10 minutes.

[tsgas]

The only difference between a Stab Trim Runaway and the MCAS situation is that the pilot can intervene with the electric trim and stop it momentarily.

Would you keep trying to fly with an autopilot that wasn't doing what you wanted or use an auto throttle system that wasn't giving you the results you were looking for? I sincerely hope the answer is a NO!

The Lion Air crew flew around with a malfunctioning trim for the better part of ten minutes before completely losing control of the aircraft and never thought to turn the electric trim off?

My biggest question about this isn't about Boeing's design of the MCAS but the training of a crew that would continue to use a malfunctioning system for 10 minutes.

Sort of like the Sunwing crew in Belfast that let the plane fly itself , without manually adding any extra throttle.