Ethiopian ET302 Crash.

[oil_film_movies]

Originally Posted by Shannow
Problem with the big red button...and automation...

As I've explained in the autonomous vehicle threads, and with respect to automation in control systems in (lets say complex things like power stations) is that removing the driver from...driving...means that when the whoop hits the fan and after a number of alarms, and unexpected control system reaction to a few stabs at the controls, the driver has to all of a sudden review the entire system and see what world they are currently driving in in terms of positioning and control response...to work out a rational corrective action, or what could be in fact a serious mechanical failure that thye have to diagnose.

It's not as easy as Elon Musk saying .... driver, it's your turn now.


In this case, a big red automation-off button would switch to a reversion manual control mode. For example, the JAS 39 Gripen has one, where pilot stick operates the stabilators proportionately (and canards feather). In the case of a 737 or A330, one button to turn off auto-trim and auto-pilot and activate proportional ('Direct' Law), which is functionally simple enough to look like a B-17 direct cable set-up. One button instead of having to remember which circuit breakers and other switches to flip while the may-day is happening and you're plunging from the sky trying to flip through emergency checklists..... (i.e., Trump: "I don't want Albert Einstein to be my pilot.")

If you watch the docu-drama https://www.smithsonianchannel.com/shows/air-disasters/free-fall/802/3467449 for example, a big red button to kill all automation aids would have been nice to have during the ruckus. In the reenactment, the pilot turns the autopilot off, yet Airbus flight automation is still there, not in 'Direct Law' there. (AoA from a bad ADIRU is still corrupting the system.)

....Sort it out on the ground.....

You'd be without stall protection and a little wobbly without pitch rate damping (not bad), nothing any pilot can't handle in rare emergencies. They are easily hand flown and landed.
Essentially turns the pilot flying into Charles Lindbergh trying to get to Paris. His computers failed too.

Jimmy Stewart could do it...

 

[ZeeOSix]

Automated flight being played with even way back when.

https://youtu.be/Wwovm1FJ_Bo?t=510

 

[BusyLittleShop]

I gather Boeing designed the MCAS to help like your Flight Instructor
would... if your AOA is growing at alarming rate the FI pushes the
nose down to reduce the risk of stall... continue routine flight...

 

[ZeeOSix]

Originally Posted by BusyLittleShop
I gather Boeing designed the MCAS to help like your Flight Instructor
would... if your AOA is growing at alarming rate the FI pushes the
nose down to reduce the risk of stall... continue routine flight...


True .. but a faulty MCAS is like a crazy FI trying to push the nose down all the time when there is no need to. MCAS works fine if all senors and systems are operating normally.

Problem is when something goes wrong like a faulty AoA sensor there isn't a fail safe designed into the system to recognize that and do something about it (ie, warn the pilots, kick off MCAS, etc).

 

[BusyLittleShop]

If I lost control of my bird on a clear day due to a AOA fault... I'd give myself a good talking too!!!

 

[BusyLittleShop]

Our stick and rudder man was spring loaded to the successful flight
position...

Quote Charles Lindbergh:
"Why shouldn't I fly from New York to Paris? I'm almost 25. I have more
than 4 years of aviation behind me, and close to 2,000 hours in the
air. I've barmstromed over half of the 48 States. I've flown my mail
through the worst of nights. I know the wind currents of the Rocky
Mountains and the storms of the Mississippi Valley as few pilots know
them. During my year at Brooks and Kelly [US Air Corps] as a flying
cadet, I learned the basic elements of navigation. I'm a Captain in the
110th Observation Squadron of Missouri's National Guard. Why am I not
qualified for such a flight?"

 

[oil_film_movies]

Would you fly on the 737 Max8 or 9 today?
I would. At the first sign of weird nose-down behavior, all pilots would reach for the autotrim cutout switches faster than you can say "Looks like I picked the wrong week to quit sniffing glue."

 

[BusyLittleShop]

Originally Posted by oil_film_movies
Would you fly on the 737 Max8 or 9 today?
I would.


Heck yes I would too... a bird under this much scrutiny is safer than another birds unknowns...

 

[AdmdeVilleneuve]

More discussion on the MAX/MCAS topic from The Seattle Times just posted this evening.
https://www.seattletimes.com/boeing...affled-even-those-who-worked-on-the-jet/

 

[DriveHard]

probably no related to the issues being discussed...but not good news for the 737 max nonetheless.

https://www.cnn.com/2019/03/26/us/boeing-737-max-emergency-landing/index.html

 

[JustN89]

Originally Posted by DriveHard
probably no related to the issues being discussed...but not good news for the 737 max nonetheless.

https://www.cnn.com/2019/03/26/us/boeing-737-max-emergency-landing/index.html

Local news is reporting that the engine ingested FOD and suffered performance issues which, if true, would be a non-story.

 

[oil_film_movies]

Boeing's 737Max8/9 MCAS software "fix" is being presented today in front of around 200 people.

 

[oil_film_movies]

http://www.airforcemag.com/Features...shes-KC-46-Uses-Similar-MCAS-System.aspx ..."The 737 MAX 8 uses an MCAS to deal with weight and balance issues driven by the narrow ground clearance of its engines. It will automatically direct a nose-down attitude to prevent the aircraft from stalling if the angle of attack is too high. The KC-46 uses a similar system because the weight and balance of the tanker shifts as it redistributes and offloads fuel. The KC-46 has a two-sensor MCAS system, which "compares the two readings," the Air Force said.

Moreover, while the MAX 8 MCAS will reset and come back on automatically, the KC-46's system is "disengaged if the pilot makes a stick input," according to the Air Force. "The KC-46 has protections that ensure pilot manual inputs have override priority.""

 

[ZeeOSix]

Originally Posted by DriveHard
probably no related to the issues being discussed...but not good news for the 737 max nonetheless.

https://www.cnn.com/2019/03/26/us/boeing-737-max-emergency-landing/index.html


Typical news media spin ... any aircraft can have an engine failure. It's totally unrelated, yet media hypes it up because of the 737 MAX issues with MCAS going on.

 

[oil_film_movies]

They had the big meeting, and Mike Sinnett, a former student of mine from 1984, has laid out a summary of the changes:

They are going to kill MCAS if the 2 AoA vanes disagree by 5.5 degrees. What he's not saying is whether or not there is a time component, as in, usually dual-sensor fault detection where there is turbulence noise uses an algorithm to declare a disagree if the values are different enough for x number of seconds.

Also, they are going to kill MCAS if it activates once, until some time or condition at which point it could re-engage. It can go 10 seconds at a time.

Then you might have heard there will be a cockpit AoA Disagree warning shown. Not optional, standard warning now.

Mike is having a rough career in some ways. He took a lot of flak when Li-ion batteries grounded the 787 a few years ago (he was Chief Engineer), and now he is VP for Product Strategy and Future Airplane Development, where he gets to sit in the hot seat and face the press on this 737 issue.

 

[Garak]

Happy birthday, by the way!

 

[fdcg27]

Originally Posted by BusyLittleShop
Originally Posted by oil_film_movies
Would you fly on the 737 Max8 or 9 today?
I would.


Heck yes I would too... a bird under this much scrutiny is safer than another birds unknowns...


Yes, especially since I think we all have a pretty good idea of the accident sequence in both losses.
No pilot will be trapped clueless in this scenario again even with no changes at all to the software or hardware.
I think we flew on a MAX8 MCO to SJU last month, but it could have been an -800.
It was obviously a very recent delivery since interiors don't remain as fresh as this one was for very long.
Wish I had paid more attention at the time. I do recall seeing the funky nacelles, but those might have been on the aircraft at the next gate.
I guess our 4:30 am awakening dulled my spotter instincts.

 

[oil_film_movies]

Wonder how many pilots might just turn the Stab Trim off proactively at takeoff, and just set trim to start out in the green zone. Manual trim for the whole flight.
At least on these Max8/9 ferry flights. Its against procedure to do that when the "fix" is in...



Originally Posted by john_pifer
Guys, coming from an A&P, this stuff is very interesting. Thanks for posting...enjoying keeping up with this thread.

Another solution to this stall pitch-up forward nacelle problem is to have an A&P attach strakes to the underside on the rear, similar to what Piaggio did years ago. Smaller and farther up, aft on the 737 shouldn't bother fuel burn (??). No MCAS needed then.

 

[E365]

Would be nice to see an all-new, composite 737 replacement using all the technology they're developing for the 797. Just blow the A320 series away on efficiency. ðŸ‘ðŸ»

 

[oil_film_movies]

Originally Posted by E365
Would be nice to see an all-new, composite 737 replacement using all the technology they're developing for the 797. Just blow the A320 series away on efficiency. ðŸ‘ðŸ»
That's next. They will offer a 737 with a composite fuselage as the next step. Easier to re-certify the aircraft if it retains the Max8's wings, and uses similar parts for the fuselage as the 787. Lightens the thing up quite a bit.