Ed 737 Max Crashes (was Shutdown caused Boeing crash.)

[smartcooky]

To be fair, all pilots are trained in recognizing and ways to avoid stalls almost from the very beginning of their training. Wings are designed so that the stall begins at the wing root and progresses outwards, allowing the ailerons to remain effective for roll control even when the inboard portion of the wing is stalled. Most, but not all, small aircraft have some sort of stall warning systems to aid the pilot in that regard.

But large jets with swept wings are much less forgiving. Hence the need for more sophisticated warning systems. It can be a horn or light, followed by a stick shaker and then a stick pusher in some planes. If one wing stalls first, the plane can enter a spin - recoverable in most small planes but possibly not in a large jet.

Anyway, it’s hardly fair to automatically blame the pilots for not “managing” the perceived stall warnings properly.

I'm aware of all that.

My issue with with an "autonomous" stall system - something that actively takes control away from the pilot, and keeps it away from him.

If MCAS can predict the onset of a potential stall, and take action, why not instead, just have a warning bell/horn and/or a Bitchin' Betty - "Warning: Stall Imminent!"

I learned to fly in a Cherokee 140. It had a red stall warning light and a "whiny" horn that would sometimes go off intermittently about 50 to 300 feet AGL on climbout, particularly in blustery conditions. The response was usually to just ease the yoke forwards a little to slightly lower the RoC.

If it had a system that pitched the nose down autonomously at 50 feet, I don't think I would be here to post this!

 

[Fast Eddie B]

For anyone interested, the FAA has two excellent trading guides for free online:

The Pilot’s Handbook of Aeronautical Knowledge

Airplane Flying Handbook

Both easy to find online.

 

[a_unique_person]

https://www.seattletimes.com/busine...-737-max-may-have-failed-on-ethiopian-flight/


According to this, the remedy for the MCAS failure was to manually trim. They must have never tested this because a test was done by a qualified training pilot in a 737 simulator and he found he could not save the plane using the Boeing supplied procedure.



The MAX should have been grounded after the first crash.

The Swedish pilot is a 737 flight instructor and training captain who hosts a popular YouTube channel called Mentour Pilot, where he communicates the intricate details of flying an airliner. To protect his employment, his name and the name of his airline are not revealed, but he is very clearly an expert 737 pilot.
In the test, the two European pilots in the 737 simulator set up a situation reflecting what happens when the pre-software fix MCAS is activated: They moved the stabilizer to push the nose down. They set the indicators to show disagreement over the air speed and followed normal procedures to address that, which increases airspeed.
They then followed the instructions Boeing recommended and, as airspeed increases, the forces on the control column and on the stabilizer wheel become increasingly strong.
After just a few minutes, with the plane still nose down, the Swedish 737 training pilot is exerting all his might to hold the control column, locking his upper arms around it. Meanwhile, on his right, the first officer tries vainly to turn the stabilizer wheel, barely able to budge it by the end.
If this had been a real flight, these two very competent 737 pilots would have been all but lost.

 

[a_unique_person]

I'm aware of all that.

My issue with with an "autonomous" stall system - something that actively takes control away from the pilot, and keeps it away from him.

If MCAS can predict the onset of a potential stall, and take action, why not instead, just have a warning bell/horn and/or a Bitchin' Betty - "Warning: Stall Imminent!"

I learned to fly in a Cherokee 140. It had a red stall warning light and a "whiny" horn that would sometimes go off intermittently about 50 to 300 feet AGL on climbout, particularly in blustery conditions. The response was usually to just ease the yoke forwards a little to slightly lower the RoC.

If it had a system that pitched the nose down autonomously at 50 feet, I don't think I would be here to post this!

It's not an anti-stall system. It is there to make the MAX behave the same as the NG in conditions where the nose goes up and the back force on the column reduces.


https://www.pprune.org/tech-log/619918-mcas-certification-single-sensor-no-warning.html

§25.671 General.

(a) Each control and control system must operate with the ease, smoothness, and positiveness appropriate to its function.

To meet this requirement the tendency of the MAX to pitch up under high power was greater than that in the NG because the engine cowling generates more lift. MCAS was designed to reduce that pitch up and give the pilot a more even response that was similar to the NG in such a situation.


The Airbus uses FBW so you can't stall it. Pull all the way back on the stick and it will nose up to a limit and just sit there, crawling along through the air.

 

[a_unique_person]

Video of A330 doing the alpha protect thing.

 

[smartcooky]

It's not an anti-stall system. It is there to make the MAX behave the same as the NG in conditions where the nose goes up and the back force on the column reduces.

https://www.pprune.org/tech-log/619918-mcas-certification-single-sensor-no-warning.html

To meet this requirement the tendency of the MAX to pitch up under high power was greater than that in the NG because the engine cowling generates more lift. MCAS was designed to reduce that pitch up and give the pilot a more even response that was similar to the NG in such a situation.

The Airbus uses FBW so you can't stall it. Pull all the way back on the stick and it will nose up to a limit and just sit there, crawling along through the air.

OK, so "technically" MCAS is not an anti-stall system; its a system that alters the aircraft's handing characteristics so that the pilots don't inadvertently put it into a stall.

Frankly, I don't see any thing here that could not be accomplished by the regular method of the pilot (or in more complex A/C, the FMS) calculating the necessary take off trim setting. In most flight management systems I have ever encountered, the pilot can input the zero fuel weight, the fuel on board, the take-off flap settings, V1, Vr, V2 and well as the C of G from the load sheet, and the FMS will calculate the trim setting required. The pilots preset that manually. IMO, there is no reason why the aircraft's tendency to nose up at TOGA could not also be a factor that the FMS takes into account to reach the correct trim setting.

I have a real issue with A/C systems that take autonomous control from the pilot in low speed/low altitude flight modes and then actively making control inputs. Pointing the nose down at 450 AGL and V2+15 is a really, really, really BAD idea!

https://www.seattletimes.com/busine...-737-max-may-have-failed-on-ethiopian-flight/

According to this, the remedy for the MCAS failure was to manually trim. They must have never tested this because a test was done by a qualified training pilot in a 737 simulator and he found he could not save the plane using the Boeing supplied procedure.

That is seriously shocking!

The MAX should have been grounded after the first crash.

100%

Video of A330 doing the alpha protect thing.

Awesome, and I would imagine, very uncomfortable for the aircrew.

 

[zooterkin]

Interesting analysis looking at the bigger picture, placing the blame on deregulation and defunding of the FAA.

 

[smartcooky]

Interesting analysis looking at the bigger picture, placing the blame on deregulation and defunding of the FAA.

Well, that winds us back to maybe the thread title at least being partly right.

In any case, the Max 8 is clearly a flawed design.

 

[Puppycow]

https://www.seattletimes.com/busine...-737-max-may-have-failed-on-ethiopian-flight/


According to this, the remedy for the MCAS failure was to manually trim. They must have never tested this because a test was done by a qualified training pilot in a 737 simulator and he found he could not save the plane using the Boeing supplied procedure.



The MAX should have been grounded after the first crash.

That's horrifying.

Here is that youtube channel but I'm not sure which video it is:

https://www.youtube.com/channel/UCwpHKudUkP5tNgmMdexB3ow/videos

 

[Andy_Ross]

Trump Tweets

What do I know about branding, maybe nothing (but I did become President!), but if I were Boeing, I would FIX the Boeing 737 MAX, add some additional great features, & REBRAND the plane with a new name.
No product has suffered like this one. But again, what the hell do I know?

 

[TurkeysGhost]

Trump Tweets

What do I know about branding, maybe nothing (but I did become President!), but if I were Boeing, I would FIX the Boeing 737 MAX, add some additional great features, & REBRAND the plane with a new name.
No product has suffered like this one. But again, what the hell do I know?

They should just slap a thick pad of rubber along the bottom of the plane, that way it will bounce when it does its patented nosedive.

You can call it the "Boing 737".

 

[Fast Eddie B]

Trump Tweets

What do I know about branding, maybe nothing (but I did become President!),
but if I were Boeing, I would FIX the Boeing 737 MAX, add some additional great features, & REBRAND the plane with a new name.
No product has suffered like this one. But again, what the hell do I know?

Actually, not a ridiculous idea.

There was a horrible crash in the Everglades of a ValuJet flight*. ValuJet always seemed to be followed by the word “crash”. It still is if you Google “ValuJet”. The way out was to rename the airline AirTran Airways. So compelled rebranding is not an insane idea - though it certainly should not be first and foremost with Boeing at this point.


*I was flight instructing in S FL at the time. It was eerie how the swamp swallowed up virtually the entire plane, barely leaving a trace on the surface.

 

[Skeptic Ginger]

The real reason Boeing's new plane crashed twice:

It's the backstory of what led to the introduction of the MCAS in the Boeing 737 MAX and how it caused the two crashes. It's a Vox video but it's short (5 minutes) and uses every minute explaining what I didn't see in any news reports. It wasn't the shutdown but rather an attempt to compete with Airbus by copying some very specific elements.

 

[quadraginta]

The real reason Boeing's new plane crashed twice:

It's the backstory of what led to the introduction of the MCAS in the Boeing 737 MAX and how it caused the two crashes. It's a Vox video but it's short (5 minutes) and uses every minute explaining what I didn't see in any news reports. It wasn't the shutdown but rather an attempt to compete with Airbus by copying some very specific elements.

No real surprises.

I didn't see anything in it that wasn't already available for anyone who had tried to read more deeply on the subject than headlines and short news blurbs, but it did summarize the most salient points succinctly.

 

[Skeptic Ginger]

No real surprises.

I didn't see anything in it that wasn't already available for anyone who had tried to read more deeply on the subject than headlines and short news blurbs, but it did summarize the most salient points succinctly.

When you say 'read more deeply', where was it reported the engine was moved making the plane out of balance when taking off? And that it was because copying Airbus' increased engine size led to the position change?

I'm guessing the competition with Airbus having a new plane that didn't require more training was mentioned somewhere. I didn't notice it.

 

[Trebuchet]

When you say 'read more deeply', where was it reported the engine was moved making the plane out of balance when taking off? And that it was because copying Airbus' increased engine size led to the position change?

I'm guessing the competition with Airbus having a new plane that didn't require more training was mentioned somewhere. I didn't notice it.

Dudalb pretty much said that on the first page of this thread.

 

[quadraginta]

When you say 'read more deeply', where was it reported the engine was moved making the plane out of balance when taking off? And that it was because copying Airbus' increased engine size led to the position change?

I'm guessing the competition with Airbus having a new plane that didn't require more training was mentioned somewhere. I didn't notice it.

Here's an article in Digital Trends from roughly two weeks after the second accident.

It covers all of that and more.

Digital Trends wasn't exactly front-line on this.

The information was there, and there wasn't all that much digging required.

 

[smartcooky]

When you say 'read more deeply', where was it reported the engine was moved making the plane out of balance when taking off? And that it was because copying Airbus' increased engine size led to the position change?

I'm guessing the competition with Airbus having a new plane that didn't require more training was mentioned somewhere. I didn't notice it.

If you are really interested in how engine placement affects flight characteristics (or if anyone else here is) and you are prepared to spend 15 minutes of your day learning something new, then this guy is worth watching and listening to....

 

[Skeptic Ginger]

Dudalb pretty much said that on the first page of this thread.

This is what he said:

The engines just look too big for the wing span.
That seems to be the problem:Boeing tried to marry large engines to an airframe that cannot handle them.

That's not the news media.

I'm not surprised some very intelligent folks in the thread knew all that. That was not my point.

I said

...explaining what I didn't see in any news reports.

Same goes for tech websites like Digital Trends.

 

[quadraginta]

This is what he said:

That's not the news media.

I'm not surprised some very intelligent folks in the thread knew all that. That was not my point.

I said

Same goes for tech websites like Digital Trends.

And I didn't disagree with any of that. I said it was a concise summary for people who hadn't dug any deeper than the short news reports.

We seem to be in agreement on that point.

But it wasn't needful for someone to be "very intelligent" to learn more, just take the time to look for a little bit more information.

It isn't like it was carefully hidden. A few clicks, maybe scanning beyond the first couple of google hits.

This would have quickly revealed everything that was in that clip.