Boeing 777 Flight Control Problems

[ClearedHot]

Air France Boeing 777 suffers control problems on approach to Paris

[Pooter]

It'll be interesting if this is tied back to Boeing. That 737max documentary was pretty damning in regards to their trends in corporate culture, quality control, and transparency. 

[StoleIt]

Audio from said event:

 

Any 777 drivers here to ID the alarms in the background audio?

[herkbum]

The article I read attributed it to 5G, but too early to tell.

I heard the autopilot disconnect for sure and I think Master Warning/Caution. May have heard a GCAS alert as well.


Sent from my iPhone using Baseops Network mobile app

[TreeA10]

Can't say I've got excellent recall on them but it sounds like autopilot disconnect and configuration (e.g. gear not down and landing flaps selected, speed brakes extended, etc.) warnings. 

[ClearedHot]

That didn't sound like fun...at all.

[TreeA10]

Could have been a botched go-around. If you select gear-up prior to bringing the flap lever up from landing flaps (25 or 30), you will get the configuration warning.  But if I've got a low altitude flight control issue and don't hit the ground while cleaning up the jet, whatever works is fine with me. 

[TheNewGazmo]

5G could be the culprit. Nothing a quick FDR download can't see. The 777 has been a tried and true airframe for decades without a whole lot of problems. I can't imagine this is a widespread sysyems issue.

[AirGuardianC141747]

Well, I was considering a jump to our 777s - not now… kidding of course, but 5G is what we’re definitely watching out for as our -8s fall into some restrictions.  Our older 74s do fine as I examine our tails # on a list every time I fly them. I don’t even have a 5G phone so I guess I’m alright correct? 😂

Edited April 13, 2022 by AirGuardianC141747

[VMFA187]

On 4/6/2022 at 2:32 PM, Pooter said:

It'll be interesting if this is tied back to Boeing. That 737max documentary was pretty damning in regards to their trends in corporate culture, quality control, and transparency. 

That documentary didn't mention the incredible lack of experience or requirements for foreign pilots, did it? I watched it and remember them doing nothing but blame Boeing. 

[TreeA10]

Yeah, I don't how someone would fall to do something, anything to stop the aircraft from accelerating uncontrolled.  Never say never but I don't think the Max accidents would have happened within US or European airlines. 

[HossHarris]

3 hours ago, TreeA10 said:

Yeah, I don't how someone would fall to do something, anything to stop the aircraft from accelerating uncontrolled.  Never say never but I don't think the Max accidents would have happened within US or European airlines. 

Documentary also said that if you didn’t counteract runaway mcas, an issue nobody was aware of at the time, within 10 seconds it was unrecoverable. 

[HuggyU2]

6 hours ago, TreeA10 said:

I don't think the Max accidents would have happened within US or European airlines. 

My rule of thumb: if I cannot drink the tap water in a country, I won't fly on their national airline. 

[TreeA10]

6 hours ago, HossHarris said:

Documentary also said that if you didn’t counteract runaway mcas, an issue nobody was aware of at the time, within 10 seconds it was unrecoverable. 

I flew the 737, not the Max version, and my understanding was A) the STAB TRIM CUTOUT switches still work and would have stopped MCAS, B) the jet is controllable with full nose down trim but only at slower speeds (w/flaps?), and C)  higher airspeeds put too much pressure on the stab and that pressure prevents manual trimming of the stab. 

Any 737 guys with better info?

[Lord Ratner]

22 hours ago, VMFA187 said:

That documentary didn't mention the incredible lack of experience or requirements for foreign pilots, did it? I watched it and remember them doing nothing but blame Boeing. 

Because it was at least 99% Boeing's fault. That said, at least at American Airlines it is highly unlikely that emergency would have led to a crash. Our pilots are much more proficient at hand flying and do so for somewhere between 5000 to 25,000 ft each leg, mostly on climb out.

 

But the system was designed in a phenomenally poor manner, with what appears to be no thought for what happens if something in that system were to break. That's what happens when you prioritize marketing over engineering, a problem within the American executive class that is not limited to Boeing.

[Lord Ratner]

16 hours ago, HossHarris said:

Documentary also said that if you didn’t counteract runaway mcas, an issue nobody was aware of at the time, within 10 seconds it was unrecoverable. 

Not true. The nose trim switch is fully functional during an mcas failure, however every time you release it it will fight you in the opposite direction (nose down). I believe anybody who regularly hand flies the 737 would instinctually use the trim switches while fighting the forward tendency of the mcas, until the other pilot realized that the trim was running away and disabled it.

 

The big risk would be disabling the trim system after it already put in a ton of forward trim. But that is less likely for someone who instinctually trims away pressure on the yoke. The manual trim wheel does not work very well when there is a high amount of force on the yolk.

[Lord Ratner]

9 hours ago, TreeA10 said:

I flew the 737, not the Max version, and my understanding was A) the STAB TRIM CUTOUT switches still work and would have stopped MCAS, B) the jet is controllable with full nose down trim but only at slower speeds (w/flaps?), and C)  higher airspeeds put too much pressure on the stab and that pressure prevents manual trimming of the stab. 

Any 737 guys with better info?

The nose trim switch is override the MCAS, so the MCAS would begin trimming the nose down very quickly, but using the reverse direction would reverse the trim. Once you let go of the switch, it will resume trimming those down. After the fix, this system is now limited in how many times it will try to trim forward.

 

The stab trim cutouts which is always work. However the control column trim cut out, which disables nose up trim when you push the yoke forward and disables nose down trim when you pull the yolk back, did not override the MCAS system. This is because the system was basically designed to prevent you from stalling the aircraft, so it would by necessity need to override the pilot pulling back. The system still does this after the fixes. 

Correct on the stab pressure locking out the trim wheel. Ironically, I didn't realize that 737 crews aren't trained on how to resolve this because the trim system is similar in the KC135, where I was taught how to deal with it. For runaway nose down trim, if you cut it out while massively out of trim, the solution is to have the pilot flying put their feet up on the console and pull back as hard as they can, with the assistance of the other pilot, and get the plane somewhere around 20° nose up. Then the pilot not flying releases the yoke, while the pilot flying allows the plane to enter a vomit comet Arc, somewhere between -1 and 1G. While the nose tracks down from 20° back to the horizon the other pilot furiously trims the plane nose up, and at the horizon both pilots get back on the yoke and pull it nose high again. Rinse and repeat until the pressure is neutralized and the wheel is once again usable.

[VMFA187]

30 minutes ago, Lord Ratner said:

Because it was at least 99% Boeing's fault. That said, at least at American Airlines it is highly unlikely that emergency would have led to a crash. Our pilots are much more proficient at hand flying and do so for somewhere between 5000 to 25,000 ft each leg, mostly on climb out.

 

But the system was designed in a phenomenally poor manner, with what appears to be no thought for what happens if something in that system were to break. That's what happens when you prioritize marketing over engineering, a problem within the American executive class that is not limited to Boeing.

Was the 1% attributed to the co-pilot who was praying to Allah during the mishap instead of trying to address the issue?

[StoleIt]

33 minutes ago, Lord Ratner said:

Correct on the stab pressure locking out the trim wheel. Ironically, I didn't realize that 737 crews aren't trained on how to resolve this because the trim system is similar in the KC135, where I was taught how to deal with it. For runaway nose down trim, if you cut it out while massively out of trim, the solution is to have the pilot flying put their feet up on the console and pull back as hard as they can, with the assistance of the other pilot, and get the plane somewhere around 20° nose up. Then the pilot not flying releases the yoke, while the pilot flying allows the plane to enter a vomit comet Arc, somewhere between -1 and 1G. While the nose tracks down from 20° back to the horizon the other pilot furiously trims the plane nose up, and at the horizon both pilots get back on the yoke and pull it nose high again. Rinse and repeat until the pressure is neutralized and the wheel is once again usable.

Granted I did my 737/C-40 training and type with FTI at Boeing in Miami, but we did a stab trim runaway during our initial in 2017 (so before the Max accidents). My sim partner and I both flew the tanker before so it was basically a non-event and we treated it exactly like the 135. I do forget if it was in the syllabus or if the sim instructor just thought he could catch us sleeping.

[SurelySerious]

Granted I did my 737/C-40 training and type with FTI at Boeing in Miami, but we did a stab trim runaway during our initial in 2017 (so before the Max accidents). My sim partner and I both flew the tanker before so it was basically a non-event and we treated it exactly like the 135. I do forget if it was in the syllabus or if the sim instructor just thought he could catch us sleeping.

When I did my 73 training last year and the runaway stab quick reaction item was new to them, I was astounded. As referenced, the plain stab trim part of the system is nearly the same as both old Boeing products the AF flies and has had BF items for years to address.

[BFM this]

5 hours ago, Lord Ratner said:

Because it was at least 99% Boeing's fault. That said, at least at American Airlines it is highly unlikely that emergency would have led to a crash. Our pilots are much more proficient at hand flying and do so for somewhere between 5000 to 25,000 ft each leg, mostly on climb out.

Don't get me wrong, Boeing owns the Max fiasco fair and square.  But which is it, 99% Boeing's fault, or it wouldn't have happened here because of our training and proficiency?  Ignoring the airmanship (or conspicuous lack thereof) in either Lion Air or Ethiopian is about as valid as completely ignoring it in AF447.

Of course, what I really want to know is what the Nav thinks, with two votes on the topic.  [popcorn gif]

[Lord Ratner]

1 hour ago, BFM this said:

Don't get me wrong, Boeing owns the Max fiasco fair and square.  But which is it, 99% Boeing's fault, or it wouldn't have happened here because of our training and proficiency?  Ignoring the airmanship (or conspicuous lack thereof) in either Lion Air or Ethiopian is about as valid as completely ignoring it in AF447.

Of course, what I really want to know is what the Nav thinks, with two votes on the topic.  [popcorn gif]

It's 99% Boeing's fault. They sell the plane to foreign countries the same way Airbus does. Gear up auto pilot on.

 

It's not the training and proficiency, it's the idiosyncracy of specific pilot groups who hand fly well beyond what is necessary that just happened to apply a software-based malfunction for a system that wasn't even taught to the pilots in a meaningful way.

 

This wasn't just runaway trim, and there was no way prior to the crash to train for an malfunction we weren't taught about.

 

My thoughts only.

[StoleIt]

1 hour ago, Lord Ratner said:

It's 99% Boeing's fault. They sell the plane to foreign countries the same way Airbus does. Gear up auto pilot on.

 

It's not the training and proficiency, it's the idiosyncracy of specific pilot groups who hand fly well beyond what is necessary that just happened to apply a software-based malfunction for a system that wasn't even taught to the pilots in a meaningful way.

 

This wasn't just runaway trim, and there was no way prior to the crash to train for an malfunction we weren't taught about.

 

My thoughts only.

Agreed, but you can't train for every malfunction or contingency. Just like the KC-135 crew that flew depressurized for several hours with pax in the back passed out. At a certain point, you have to have the skill, knowledge, situational awareness, and leadership to safely operate the aircraft as a professional aviator.

Should the aircrew have been able to handle a runaway stab trim/MCAS malfunction situation? Yes.

Should Boeing have included that system in the pubs? Yes.

Foul on both parties.

Is Boeing responsible for aircrew not setting the altitude window correctly on takeoff and taking a B777 low level through a city? No...but it is really popular to villainize the company now (for good reason).

[HeyEng]

As I have been both a civilian and AF FE, the Air Force did much more extensive training on runaway trim than the civilian world. 

[arg]

6 hours ago, joe1234 said:

If a jet hadn't crashed in the 90s because of a runaway trim, it wouldn't be nearly as stressed in training. Just like how unscheduled rudder and dutch roll recovery was glossed over until 2013 even though there's warnings and boldface addressing it in the manual.

 

There were several incidents, and I think two crashes, with the rudder actuator going full travel or something like that.