Ethiopian ET302 Crash.

[ZeeOSix]

Originally Posted by oil_film_movies
From the looks of this, I think they will eventually get some green young engineer and/or experienced one to testify, matching internal emails, that they noted runaway trim due to MCAS stab trim movement could pester a pilot enough to confuse them in flight, as it did with the lightly-trained Lion Air and Ethiopian pilots. I know the thought was pilots would "simply" hit the trim cutout switches if they didn't like pitch behavior, so don't worry about this MCAS mode. Their defense.


"Lightly trained" is a huge factor in these crashes. And as pointed out earlier, after the Lion Air crash, Boeing informed everyone flying the 787 Max of the possible MCAS safety concerns while they were actively working on changes to the system to enhance its safey.

For some reason the pilots of the Ethiopian crash didn't react correctly even though they supposedly got the safety concern information. Where did that fall through the cracks. All they had to do is just shut off the MCAS system. Why didn't they know to do that after being told about it - where's the disconnect?

 

[MolaKule]

Originally Posted by Win


..It could be that the report is completely false or a half truth; grand jury proceedings are supposed to be secret, so, really, all one can do is speculate right now, and wait for more leaks. Which may or may not be true.


Hopefully there are not a lot of shredders running at subpoena speed right now.

 

[oil_film_movies]

Originally Posted by ZeeOSix
"Lightly trained" is a huge factor in these crashes. And as pointed out earlier, after the Lion Air crash, Boeing informed everyone flying the 787 Max of the possible MCAS safety concerns while they were actively working on changes to the system to enhance its safey.
For some reason the pilots of the Ethiopian crash didn't react correctly even though they supposedly got the safety concern information. Where did that fall through the cracks. All they had to do is just shut off the MCAS system. Why didn't they know to do that after being told about it - where's the disconnect?

Bewildering, yes you are correct.
Pilots are humans with flaws. Example: One Air France 447 pilot held the stick back inexplicably, killing all. The Lion Air and Ethiopian 737 crews had to... (1) Recognize the unwanted trimming; and ....(2) flip switches to turn it off.
Sounds easy, right? Well that's why some engineers at Boeing & the FAA thought this auto-trim MCAS thing wasn't so bad when they pushed it through. There were at least a couple of engineers who didn't like the amount of stab movement & persistence of MCAS, but were always told the Cutout Switches are right there, so don't worry.

 

[ZeeOSix]

When pilots fight an airplane over and over to keep the nose horizontal, the first thing they should know is to disable any automatic systems associated with keeping the nose horizontal and start flying manually. They should be trained to be aware and recognize that they are fighting an automatic system that could be malfunctioning.

Yes, people are human and make mistakes, but proper pilot training is supposed to engrain the required knowlege to make pilots "one with the airplane" and know why it's doing what it's doing. These automatic systems are designed to make flying easier, but it seems pilots are becoming more and more disconnected with the airplane as they become more "self flying". Maybe the level of training isn't keeping up, especially for emergency situations.

 

[E365]

In a little defense of pilots and human nature, in general...

Even in a 4-hr simulator session, when you know a runaway trim is coming up, it's not that uncommon for it to get so bad that controlling pitch becomes quite the fight.

Now imagine the same thing happening a few YEARS after doing it maybe ONCE in a sim during initial training on that aircraft type. Not really that hard to see it getting really bad.

Smartly designed planes like the MD80/90 series honk a horn at you occasionally if you move the trim enough. And, will even announce "STABILIZER MOTION" when the Stab trim has been running by the autopilot longer than normal.

 

[Tdog02]

So when the planes are grounded do they still allow the airlines to shuttle them around? Or do test flights? I was on my way in to work and saw a Southwest 737 max land at Austin Bergstrom International Airport. This would have been about 7:30pm central on Monday night.

 

[Wolf359]

Originally Posted by Tdog02
So when the planes are grounded do they still allow the airlines to shuttle them around? Or do test flights? I was on my way in to work and saw a Southwest 737 max land at Austin Bergstrom International Airport. This would have been about 7:30pm central on Monday night.


I believe I recall reading that they were allowed to move them to different airports without passengers. I think they just need FAA approval or something like that which they got.

I wonder how they're going to calculate what Boeing owes the airlines for having the planes grounded.

 

[Shannow]

Yes, they were allowed to leave Australia unloaded.

Just leaving the Colorado at the airport carpark for two nights last week cost $190....I can't imagine what parking a 737 on the tarmac would cost.

 

[JustN89]

Originally Posted by Tdog02
So when the planes are grounded do they still allow the airlines to shuttle them around? Or do test flights? I was on my way in to work and saw a Southwest 737 max land at Austin Bergstrom International Airport. This would have been about 7:30pm central on Monday night.

Yes, airlines are allowed to ferry flight the aircraft wherever they need to in order to prep them for long-term parking. A special exception must be filed for and accepted by the FAA in order to ferry the aircraft.

American has shuttled most of our MAXs to Tulsa, where they will be parked at our maintenance facility and have the fuel and oil drained and the systems flushed. This was going on all of last week and I believe we still have a few more that will be done this week.



Edit: Nevermind, looks like we wrapped up all ferry flights over the weekend.

 

[CT8]

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

 

[JustN89]

Originally Posted by CT8
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

You're not kidding.

With no idea as to when the MAX will be up in the air, we are preparing to go through our summer schedule without those 24 aircraft (which are some of our most efficient aircraft as well). Unfortunately, over 60% of our revenue comes from those 4 months of summer service (May, June, July and August). So we will be going through our most profitable time of the year shorthanded and operating less efficient aircraft in hopes to make up for that lack of service. I'm expecting my profit sharing next year to be about

.

 

[Exhaustgases]

Originally Posted by Astro14
Originally Posted by Wolf359
So what's the way forward now? Wait til the software fix is out which they claim will be next month or just disable that system and start flying again?


The system was installed because the airplane had an identified handling flaw*.

MCAS has to remain in place, or the airplane will lose its certification.

But, clearly, MCAS failure needs to be trained better, AOA sensors need to be made more reliable, and perhaps, a software fix will allow "implausible" sensor readings to be ignored so that the system is not triggered by faulty data.



*Ironically, the system was installed to make the airplane safer.

In taking the 1968 design (737) And upgrading it yet again with larger engines, Boeing discovered some handling problems.

Well, no kidding. If I had taken in 1968 Chevrolet Vega, added a modern engine, Bluetooth, and stretched it into an SUV, there might be some handling problems.

The fix for the handling problems was the system MCAS.

It had to be given sufficient authority to keep the airplane from stalling.

Enough authority, that it would override pilots.

And it's actions are predicated on inputs from angle of attack sensors on the airplane.

It's my strong suspicion that every single one of these problems starts with an AOA sensor failure.

The airplane thinks something is happening, when it is not.

Authority to over ride the pilots ! Just what I've been saying the computers do the flying and won't allow pilot intervention. With the weight involved I know there are no control cables to the yoke on a fly by wire plane. And once the jack screw power is shut off how would they remove the nose down trim? Since some here say to just flip off the switches. Even if there was a manual override to the jack screw the gear ratio would be such that it would take a half hour to hand wheel it from the cockpit.

 

[Astro14]

Again, the 737 is NOT fly by wire. It has control cables. Don't conflate this with other airplanes.

It's very easy to stop/disable MCAS. Use manual trim, or use the cutout switches. Done.

The airplane CAN be flown with full nose down trim. But it takes some serious muscle.

The trim wheel itself is connected by cables and it WORKS when the electric power to the jackscrew is removed. So, disable MCAS through the cutout, and you CAN trim the 737. (You can't trim a 747, 757, or 767 with the electric trim disabled, by the way).

Please read all of my posts on this.

The problem isn't just the airplane. This accident, and Lion Air, were likely caused by a sensor failure, that triggered this system, and a lack of understanding and proper response from the pilots.

It's not a simple matter. The same thing (MCAS engagement based on faulty sensor input) has happened to several US airlines. Their 737 MAX crews had the exact same failure.

They were successful in handling it. They recognized the problem. They acted correctly. They were experienced and they were trained.

So, no crash.

See? It CAN be flown with this failure. The crashes have multiple contributory factors. It's not just the jet.

Please don't oversimplify this accident. First, we are still not sure of the cause, and next, it is not a single cause. It's complex.

 

[Cujet]

Originally Posted by Astro14
The same thing (MCAS engagement based on faulty sensor input) has happened to several US airlines. Their 737 MAX crews had the exact same failure.

They were successful in handling it.


To those of us deep in the aviation world, it goes without saying that proper training is essential. The world at large seems to believe that some of the most complex machines mankind has ever produced need to be "idiot proof".

Aviation is a very harsh operating environment. Aeronautical engineers have done a remarkable job producing components/engines/avionics/airframes that are as reliable and safe as they are. Even so, component failures will happen and crews need to be properly trained to deal with such failures. It's no surprise foreign carriers sometimes fall short.

News media is generally unhelpful, as few reports contain the level of accuracy or detail necessary to make proper aviation decisions.


https://www.aopa.org/news-and-media/all-news/2019/march/14/faa-grounds-boeing-737-max-fleet

 

[oil_film_movies]

Originally Posted by Astro14
The same thing (MCAS engagement based on faulty sensor input) has happened to several US airlines. Their 737 MAX crews had the exact same failure.They were successful in handling it.
Reference source for your claim this has happened on the Max?

USAToday:
'Daniel Elwell, acting administrator of the FAA, told NBC's Today show Thursday the MCAS software change is described in flight manuals. He said the FAA studied data from 40,000 U.S. flights of this type of plane and found no incidents of the software being activated.

"There was not a single incident in our examination of this MCAS system being activated or pilots having to work with it or deal with it," Elwell said. "It has not been an issue.""

 

[JustN89]

Originally Posted by oil_film_movies
Originally Posted by Astro14
The same thing (MCAS engagement based on faulty sensor input) has happened to several US airlines. Their 737 MAX crews had the exact same failure.They were successful in handling it.
Reference source for your claim this has happened on the Max?

USAToday:
'Daniel Elwell, acting administrator of the FAA, told NBC's Today show Thursday the MCAS software change is described in flight manuals. He said the FAA studied data from 40,000 U.S. flights of this type of plane and found no incidents of the software being activated.

"There was not a single incident in our examination of this MCAS system being activated or pilots having to work with it or deal with it," Elwell said. "It has not been an issue.""

Then someone's lying..

Quote
Airline pilots on at least two U.S. flights have reported that an automated system seemed to cause their Boeing 737 Max planes to tilt down suddenly.
The pilots said that soon after engaging the autopilot on Boeing 737 Max 8 planes, the nose tilted down sharply. In both cases, they recovered quickly after disconnecting the autopilot.

 

[Astro14]

Originally Posted by JustN89
Originally Posted by oil_film_movies
Originally Posted by Astro14
The same thing (MCAS engagement based on faulty sensor input) has happened to several US airlines. Their 737 MAX crews had the exact same failure.They were successful in handling it.
Reference source for your claim this has happened on the Max?

USAToday:
'Daniel Elwell, acting administrator of the FAA, told NBC's Today show Thursday the MCAS software change is described in flight manuals. He said the FAA studied data from 40,000 U.S. flights of this type of plane and found no incidents of the software being activated.

"There was not a single incident in our examination of this MCAS system being activated or pilots having to work with it or deal with it," Elwell said. "It has not been an issue.""

Then someone's lying..

Quote
Airline pilots on at least two U.S. flights have reported that an automated system seemed to cause their Boeing 737 Max planes to tilt down suddenly.
The pilots said that soon after engaging the autopilot on Boeing 737 Max 8 planes, the nose tilted down sharply. In both cases, they recovered quickly after disconnecting the autopilot.



And Acting Administrator Elwell was replaced today by a permentently appointed head of the FAA.

The data, resides in ASRS, the NASA safety reporting system.

Six incidents. Airlines de-identified.

But their crews handled it and wrote their reports into the ASRS system.

Clearly, they survived.

What isn't known: how many other crews had this, handled it, and DIDN'T write an ASRS.

ASRS is a voluntary, not compulsory, report.

 

[oil_film_movies]

Originally Posted by JustN89
Then someone's lying.. ..
Quote
Airline pilots on at least two U.S. flights have reported that an automated system seemed to cause their Boeing 737 Max planes to tilt down suddenly. The pilots said that soon after engaging the autopilot on Boeing 737 Max 8 planes, the nose tilted down sharply. In both cases, they recovered quickly after disconnecting the autopilot.

No, MCAS is off when the autopilot is on. (MCAS is also off when flaps are extended. The problems you saw were not MCAS. Autopilot reset issues.

Originally Posted by Astro14
The data, resides in ASRS, the NASA safety reporting system. Six incidents. Airlines de-identified.
I thought you'd cite ASRS. No, not true. Those were not MCAS events. Please read them again.

 

[oil_film_movies]

The lesson learned here should be that news media reports of loose interpretations of ASRS complaints is not reliable.
Take the FAA's Elwell's direct word for it. For him to be lying is not likely, a lot of integrity there.

Sometimes with all this publicity the flight control law block diagrams (transfer functions, tables, logic, etc.) will be leaked or even presented. Nice if the source code was leaked as well!
Then I could analyze it to find out what they are doing on a detailed level.
One guy years ago came to our avionics company with a bunch of block diagrams from a company I won't name..... not right to do unless the times calls for it.
In cases of public safety and with all the political confusion like this one, Boeing should make public the details or someone should leak it.

 

[BusyLittleShop]

Auto didn't get confused and fly into ground... Pilots did... that's what I gather after 11 pages...