Air Crash Thread: Boeing MAX and Other Problems

clear that MCAS can alter the trim much, much faster than a (single) human can do manually, and disabling MCAS does not return the trim to its original position. I think the pilots ran out of time and that even following procedures was not enough.

As I linked somewhere earlier it takes a lot of turns on the trim wheel to return it to the correct position, and there's no marked correct position as it changes on every single loaded flight. FCOM gives the correct take-off trim and neutral flight trims but you can't set those with auto-trim off, nor can you use the PFD to set it as you already know the readings are faulty and/or absent.
 
As I linked somewhere earlier it takes a lot of turns on the trim wheel to return it to the correct position, and there's no marked correct position as it changes on every single loaded flight. FCOM gives the correct take-off trim and neutral flight trims but you can't set those with auto-trim off, nor can you use the PFD to set it as you already know the readings are faulty and/or absent.

It seemed, based on the article I linked, that they didn't simply run out of time to turn the wheels and recover. They re-engaged the MCAS. Something else was happening.

https://www.cnbc.com/2019/04/03/pilots-followed-boeings-emergency-steps-before-737-max-crash-report.html
It’s not clear why Ethiopian Flight 302 pilots turned the automated system back on rather than continuing to follow Boeing’s standard emergency steps. Government officials and investigators said it’s likely that manual controls to raise the nose of the plane didn’t work, and pilots tried to reengage the system to combat the nose-down angle of the jet and failed, the Journal reported.
 
It seemed, based on the article I linked, that they didn't simply run out of time to turn the wheels and recover. They re-engaged the MCAS. Something else was happening.

I wonder if the black box recorded whether or not the pilots attempted to re-trim the airplane while MCAS was disengaged. That would seemingly be part of the emergency procedure, but maybe they didn't get to it, and had a panic as the ground approached and turned on MCAS again as a last resort? I hope the investigation gives good answers.
 
It seemed, based on the article I linked, that they didn't simply run out of time to turn the wheels and recover. They re-engaged the MCAS. Something else was happening.

Your links (sort of) disagree, one says they turned it back on, the other says it may have turned itself back on. What seems likely is that the FDR shows it came back on. That would need matching with the CVR to see if the flight crew did that or if it was automatic.

It seems (if true) that even the Boeing test pilots (specifically testing this issue and aware of the event in advance) only had a few seconds to get the plane into a recoverable position. Remember that 500 feet at 300-ish mph is over very quickly. If it's 500 feet and the plane is pushing down at 2,000 feet per minute you have 15 seconds to make that into 0 feet per minute... and in the case of the Ethiopian Crash they need a positive rate of climb due to ascending terrain.
 
Your links (sort of) disagree, one says they turned it back on, the other says it may have turned itself back on. What seems likely is that the FDR shows it came back on. That would need matching with the CVR to see if the flight crew did that or if it was automatic.

It seems (if true) that even the Boeing test pilots (specifically testing this issue and aware of the event in advance) only had a few seconds to get the plane into a recoverable position. Remember that 500 feet at 300-ish mph is over very quickly. If it's 500 feet and the plane is pushing down at 2,000 feet per minute you have 15 seconds to make that into 0 feet per minute... and in the case of the Ethiopian Crash they need a positive rate of climb due to ascending terrain.

Again, not an aviation expert....but is that even possible? That is a ton of inertia to overcome.
 
Your links (sort of) disagree, one says they turned it back on, the other says it may have turned itself back on. What seems likely is that the FDR shows it came back on. That would need matching with the CVR to see if the flight crew did that or if it was automatic.

It seems (if true) that even the Boeing test pilots (specifically testing this issue and aware of the event in advance) only had a few seconds to get the plane into a recoverable position. Remember that 500 feet at 300-ish mph is over very quickly. If it's 500 feet and the plane is pushing down at 2,000 feet per minute you have 15 seconds to make that into 0 feet per minute... and in the case of the Ethiopian Crash they need a positive rate of climb due to ascending terrain.

Here's some data, doesn't seem that helpful.




Here's some more information. It seems that they achieved at least some altitude, though not enough to recover obviously.

https://globalnews.ca/news/5044215/ethiopian-airlines-crash-timeline/
The plane climbed to 8,600 feet before data stopped being sent from the plane three minutes later.

The vertical speed — basically, how fast the plane was rising (or falling) — was erratic, according to flight data. The plane rose for 10 seconds before levelling off and then rose again. At 8:39 a.m., the plane dipped and rose a couple times, losing a few hundred feet in altitude on both occasions.

Data was only available until 8:41 a.m.

The pilot issued a distress call and was told to return to the airport.

Edit:

Looks like maybe ~1200 ft above the airport.
 
Interesting that, based on that data, the airplane appeared to be climbing for the last 15 seconds or so. V-speed = ft/min, correct ? So it was travelling at +2600ft/min vertically when it crashed? Or could the data be bad based on the AoA sensor? Maybe the airplane 'thought' it was climbing when it was actually falling out of the sky?
 
Interesting that, based on that data, the airplane appeared to be climbing for the last 15 seconds or so. V-speed = ft/min, correct ? So it was travelling at +2600ft/min vertically when it crashed? Or could the data be bad based on the AoA sensor? Maybe the airplane 'thought' it was climbing when it was actually falling out of the sky?

The publicly available data ends before the crash. When the publicly available data ends, they were climbing at about 3000 ft/min (according to a different article). Obviously that didn't continue. It did seem like the crew struggled with the issue for minutes, having varying degrees of success. Several times during the first few minutes the plane loses altitude, and then climbs again.
 
Interesting that, based on that data, the airplane appeared to be climbing for the last 15 seconds or so. V-speed = ft/min, correct ? So it was travelling at +2600ft/min vertically when it crashed? Or could the data be bad based on the AoA sensor? Maybe the airplane 'thought' it was climbing when it was actually falling out of the sky?

The AoA sensor doesn't give altitude, and the altitude shown on that data is the plane's barometric reading of altitude above sea level, not radar altitude above ground. The altitude of the flight starts at 7,200 feet AMSL, the point where the instruments start measuring. Normally you'd see a flight start to climb at about 3,000 feet per minute, give-or-take, this flight never achieved that and went quite quickly from climb to descent on several occasions. The terrain at the crash point is 8,130 feet AMSL. The plane barely made it 500 feet above ground during the pictured time, and presumably after that too.

The publicly available data ends before the crash. When the publicly available data ends, they were climbing at about 3000 ft/min (according to a different article). Obviously that didn't continue. It did seem like the crew struggled with the issue for minutes, having varying degrees of success. Several times during the first few minutes the plane loses altitude, and then climbs again.

Yup, that ADS-B data is hobbyist-collected usually, it could be that it's out of range of a pickup (possibly the airbase at Bishoftu).
 
IMO, the inherent and unfixable(?) problem with 737 MAX is the unbalanced design with the center of gravity way too far forward. I don't think the commercial aviation industry really needs this airplane right now.
 
IMO, the inherent and unfixable(?) problem with 737 MAX is the unbalanced design with the center of gravity way too far forward. I don't think the commercial aviation industry really needs this airplane right now.

The centre of gravity (really the centre of moment in flight) isn't that much more unbalanced, no aircraft flies with exactly the same cargo and passengers twice after all. I think the real issue is the amelioration of high-thrust scenarios changing the centres of lift and moment through a system which can make, literally, a fatal error. Ultimately this crash comes down to airspeed/AoA disagreements between the sensors, the current system evidently handles that very badly. Other aircraft get exactly the same kind of errors but the statistics show that they crash far less often (I believe there's even a 737-800 loss from auto stab trim).

Once well-scrutinised system/training/manual updates are in place I believe we'll see the MAX enjoying the kind of safety record that's expected from Boeing, although it will cost them dearly in reputation and payouts.
 
The family of an American woman who died in last month's Ethiopian Airlines crash has filed a wrongful death lawsuit against Boeing, Ethiopian Airlines and a Delaware company alleged to have manufactured a defective part of the plane.

https://www.cnn.com/2019/04/04/us/ethiopian-airlines-wrongful-death-lawsuit/index.html

I think we knew this was coming.



In this report Boeing is agreeing a bad part is involved


From Discover on Google https://www.businessinsider.com/boe...triggered-faulty-software-before-crash-2019-4
 
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The centre of gravity (really the centre of moment in flight) isn't that much more unbalanced, no aircraft flies with exactly the same cargo and passengers twice after all. I think the real issue is the amelioration of high-thrust scenarios changing the centres of lift and moment through a system which can make, literally, a fatal error. Ultimately this crash comes down to airspeed/AoA disagreements between the sensors, the current system evidently handles that very badly. Other aircraft get exactly the same kind of errors but the statistics show that they crash far less often (I believe there's even a 737-800 loss from auto stab trim).

Once well-scrutinised system/training/manual updates are in place I believe we'll see the MAX enjoying the kind of safety record that's expected from Boeing, although it will cost them dearly in reputation and payouts.
I'm NOT an expert, but...

The horizontal stabilizer of the 737 MaX is designed (like a racing car wing) to generate downforce needed to counteract the "weight" ahead of the center of lift, exerting force to balance the plane. A small force downward tilts the nose down, a larger force downward tilts the nose up. Air flow on the elevator forces the nose up. Opposing forces on the jackscrew from the elevator resists manual efforts to swivel the stabilizer down. With the automatic systems cut off, aero forces on the tail were too strong for the crew to move it enough.

In my very, very humble opinion, this design is not pilot-friendly like Boeing designs traditionally have been.
 
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You mean like... mechanically? via direct linkage?

Based on the cockpit video posted earlier (though that was a simulator) it does appear to be a mechanical linkage. The 737NG appears to have a fully manual connection. Obviously not the same plane, but I have a feeling the architecture must be similar.

Introduction The primary flight control system uses conventional control wheel, column and pedals linked mechanically to hydraulic power control units which command the primary flight control surfaces; ailerons, elevators and rudder. The flight controls are powered by redundant hydraulic sources; system A and system B. Either hydraulic system can operate all primary flight controls. The ailerons and elevators may be operated manually if required (Manual Reversion)...

...Cables connect the pilots’ control columns to elevator power control units (PCUs) located in the tail compartment and powered by hydraulic system A and B. The elevators are interconnected by a torque tube. With loss of hydraulic system A and B the elevators can be mechanically positioned by forward or aft movement of the pilots’ control columns. Control forces are higher due to friction and aerodynamic loads.

I think Dotini's post raises a very valid point.
 
Based on the cockpit video posted earlier (though that was a simulator) it does appear to be a mechanical linkage. The 737NG appears to have a fully manual connection. Obviously not the same plane, but I have a feeling the architecture must be similar.

It's not apparent to me that there was a hydraulic failure though. There's a difference between an automated control system and hydraulically-assisted manual control. It's not clear to me at all that disabling the automatic control system entails a loss of hydraulic assistance.
 
I'm NOT an expert, but...

The horizontal stabilizer of the 737 MaX is designed (like a racing car wing) to generate downforce needed to counteract the "weight" ahead of the center of lift, exerting force to balance the plane. A small force downward tilts the nose down, a larger force downward tilts the nose up. Air flow on the elevator forces the nose up.

Yes, but that's true of every 737 (and many more passenger jets). Take off trim, as an example, is set for every flight according to the CG of the load (pax, cargo, fuel), air temperatures, rollout speeds and so on. It's never exactly the same twice, aircraft are always being trimmed at take off, at cruise and during landing. The MAX doesn't need trimming any more excessively than other planes until it gets into that specific failure envelope. The design causes that envelope to exist but it isn't unsafely unbalanced in itself.

Opposing forces on the jackscrew from the elevator resists manual efforts to swivel the stabilizer down. With the automatic systems cut off, aero forces on the tail were too strong for the crew to move it enough.

That would require a failure of the triply-redundant hydraulic systems though. You'd need to lose the hydraulic generators on both engines AND the APU ram AND the air ram for that to happen. That's a rare, rare case that I can only recall on DC-1x frames (doubly redundant but both running through a weak point in the airframe).

In my very, very humble opinion, this design is not pilot-friendly like Boeing designs traditionally have been.

You've been closer to these jets for a longer time than anyone at these forums but in this case I think you're describing an totally different emergency.
 
I just now took out an online subscription to the Seattle Times so I could post this story, as my free views had run out.


737 MAX stabilizer trim wheel

Press reports citing people briefed on the crash investigation’s preliminary findings said the pilots hit the system-cutoff switches as Boeing had instructed after October’s Lion Air MAX crash, but couldn’t get the plane’s nose back up. They then turned the system back on before the plane nose-dived into the ground.

While the new software fix Boeing has proposed will likely prevent this situation recurring, if the preliminary investigation confirms that the Ethiopian pilots did cut off the automatic flight-control system, this is still a nightmarish outcome for Boeing and the FAA.

It would suggest the emergency procedure laid out by Boeing and passed along by the FAA after the Lion Air crash is wholly inadequate and failed the Ethiopian flight crew.

MAX-737-Horizontal-tail-W-780x473.jpg


A local expert, former Boeing flight-control engineer Peter Lemme, recently explained how the emergency procedure could fail disastrously. His scenario is backed up by extracts from a 1982 Boeing 737-200 Pilot Training Manual posted to an online pilot forum a month ago by an Australian pilot.

That old 737 pilot manual lays out a scenario where a much more elaborate pilot response is required than the one that Boeing outlined in November and has reiterated ever since. The explanation in that manual from nearly 40 years ago is no longer detailed in the current flight manual.

-------------------------------

......Lemme said the Ethiopian pilots most likely were unable to carry out that last instruction in the Boeing emergency procedure — because they simply couldn’t physically move that wheel against the heavy forces acting on the tail.

“The forces on the tail could have been too great,” Lemme said. “They couldn’t turn the manual trim wheel.”

The stabilizer in the Ethiopian jet could have been in an extreme position with two separate forces acting on it:

  • MCAS had swiveled the stabilizer upward by turning a large mechanical screw inside the tail called the jackscrew. This is pushing the jet’s nose down.
  • But the pilot had pulled his control column far back in an attempt to counter, which would flip up a separate movable surface called the elevator on the trailing edge of the tail.
The elevator and stabilizer normally work together to minimize the loads on the jackscrew. But in certain conditions, the elevator and stabilizer loads combine to present high forces on the jackscrew and make it very difficult to turn manually.

As the jet’s airspeed increases — and with nose down it will accelerate — these forces grow even stronger.

In this scenario, the air flow pushing downward against the elevator would have created an equal and opposite load on the jackscrew, a force tending to hold the stabilizer in its upward displacement. This heavy force would resist the pilot’s manual effort to swivel the stabilizer back down.

This analysis suggests the stabilizer trim wheel at the Ethiopian captain’s right hand could have been difficult to budge. As a result, the pilots would have struggled to get the nose up and the plane to climb.

If after much physical exertion failed, the pilots gave up their manual strategy and switched the electric trim system back on — as indicated in the preliminary reports on the Ethiopian flight — MCAS would have begun pushing the nose down again.

----------------------

a separate analysis done by Bjorn Fehrm, a former jet-fighter pilot and an aeronautical engineer who is now an analyst with Leeham.net, replicates Lemme’s conclusion that excessive forces on the stabilizer trim wheel led the pilots to lose control.

Fehrm collaborated with a Swedish pilot for a major European airline to do a simulator test that recreated the possible conditions in the Ethiopian cockpit.

A chilling video of how that simulator test played out was posted to YouTube and showed exactly the scenario envisaged in the analysis, elevating it from plausible theory to demonstrated possibility.

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.

The Swedish pilot says at the start of the video that he’s posting it both as a cautionary safety alert but also to undercut the narrative among some pilots, especially Americans, that the Indonesian and Ethiopian flight crews must have been incompetent and couldn’t “just fly the airplane.

Early Wednesday, the Swedish pilot removed the video after a colleague advised that he do so, given that all the facts are not yet in from the ongoing investigation of the crash of Flight 302.

More detailed instructions that conceivably could have saved the Ethiopian plane are provided in the 1982 pilot manual for the old 737. As described in the extract posted by the Australian pilot, they require the pilot to do something counterintuitive: to let go of the control column for a brief moment.

As Lemme explains, this “will make the nose drop a bit,” but it will relax the force on the elevator and on the jackscrew, allowing the pilot to crank the stabilizer trim wheel. The instructions in the old manual say that the pilot should repeatedly do this: Release the control column and crank the stabilizer wheel, release and crank, release and crank, until the stabilizer is swiveled back to where it should be.

The 1982 manual refers to this as “the ‘roller coaster’ technique” to trim the airplane, which means to get it back on the required flight path with no force pushing it away from that path.

“If nose-up trim is required, raise the nose well above the horizon with elevator control. Then slowly relax the control column pressure and manually trim nose-up. Allow the nose to drop below the horizon while trimming (manually). Repeat this sequence until the airplane is trim,” the manual states.

The Australian pilot also posted an extract from Boeing’s “Airliner” magazine published in May 1961, describing a similar technique as applied to Boeing’s first jet, the 707.

Clearly this unusual circumstance of having to move the stabilizer manually while maintaining a high stick force on the control column demands significant piloting skill.

“We learned all about these maneuvers in the 1950-60s,” the pilot wrote on the online forum. “Yet, for some inexplicable reason, Boeing manuals have since deleted what was then — and still is — vital handling information for flight crews.”

Aviation safety consultant John Cox, chief executive of Safety Operating Systems and formerly the top safety official for the Air Line Pilots Association, said that’s because in the later 737 models that followed the -200, what was called a “runaway stabilizer” ceased to be a problem.

Cox said he was trained on the “roller coaster’ technique” back in the 1980s to deal with that possibility, but that “since the 737-300, the product got so reliable you didn’t have that failure,” said Cox.

However, he added, the introduction of MCAS in the 737 MAX creates a condition similar to a runaway stabilizer, so the potential for the manual stabilizer wheel to seize up at high airspeed has returned.

Cox said the failure of both Boeing and the FAA to warn pilots of this possibility will be “a big issue” as the Ethiopian crash is evaluated.

“I don’t think Boeing realized the complexity of the failure,” he said.

Etcetera. Read it all below:
https://www.seattletimes.com/busine...-737-max-may-have-failed-on-ethiopian-flight/
 
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I just now took out an online subscription to the Seattle Times so I could post this story, as my free views had run out.


737 MAX stabilizer trim wheel

So you're telling me there's no hydraulic assistance for the trim? Because that seems like a bit of an oversight if forces can cause the trim to be too hard to move manually. One would think that pilots would be given sufficient control authority to be able to adjust the trim under all anticipated loads.

This is just a poor excuse. It's not a problem with the concept of the airplane, or with technology, or an insurmountable problem posed by the configuration of the aircraft. This is just dumb.
 
I just now took out an online subscription to the Seattle Times so I could post this story, as my free views had run out.

I see what you mean now - I'd thought you were talking about loss of hydraulics from yoke->elevator, my bad.

I thought the design of Boeing trim wheels (a "legacy" item still present in all their models except the 787) was designed so that the pilot still had enough leverage. If the assertions of your article are correct (and they seem well qualified) then that brings a new dimension to this accident that casts a light across 90% of in-service Boeings. As @Danoff says... this is just dumb.
 
I see what you mean now - I'd thought you were talking about loss of hydraulics from yoke->elevator, my bad.

I thought the design of Boeing trim wheels (a "legacy" item still present in all their models except the 787) was designed so that the pilot still had enough leverage. If the assertions of your article are correct (and they seem well qualified) then that brings a new dimension to this accident that casts a light across 90% of in-service Boeings. As @Danoff says... this is just dumb.

Yes... I'm still processing this information. The idea that the accepted procedure was the roller coaster so that you could physically move the wheel... ugh... that's so phenomenally dumb.

72Xr.gif


I don't want to get in any more planes.
 
Yes... I'm still processing this information. The idea that the accepted procedure was the roller coaster so that you could physically move the wheel... ugh... that's so phenomenally dumb.

72Xr.gif


I don't want to get in any more planes.

Yeah, this isn't great. Do I remember something where observers of the EA crash saw debris coming from the tail of the airplane before it crashed? If it was indeed moving at 600mph, with the elevator at it's max position, I wonder if the aerodynamic drag could have caused it to break apart.
 
Yes... I'm still processing this information. The idea that the accepted procedure was the roller coaster so that you could physically move the wheel... ugh... that's so phenomenally dumb.

72Xr.gif


I don't want to get in any more planes.

That's not the only way of moving the trim, there are electric buttons on the yoke and moving the yoke itself controls pitch through the elevators*. If the trim wheel system was fatally flawed it would have been involved in many accidents, and it hasn't been. If you look at the case experiment in @Dotini's post you'll see that it was the yoke force acting against the trim wheel - the counter-intuitive method of letting go of the yoke removes the opposing pressure on the trim wheel and allows it to be moved as easily as normal.

Again, this is a real edge case where the flight was already effectively doomed and, if Boeing and the FAA do their work correctly, shouldn't be able to occur again.

* EDIT: This is in the 99.9999% of normal flights - obviously in this case the trim setting is runaway due to the MCAS intervention
 
If you look at the case experiment in @Dotini's post you'll see that it was the yoke force acting against the trim wheel - the counter-intuitive method of letting go of the yoke removes the opposing pressure on the trim wheel and allows it to be moved as easily as normal.

Yea... and... that's horrible. Sometimes you don't have enough altitude to just let go of the yoke while you crank away on the trim. It's bad enough that a runaway trim situation can occur. It's worse that when it does happen, it can easily put you in a situation where you're not physically strong enough to crank the trim back into place after you disable the malfunctioning system. I get that if you have enough altitude and remember the technique from the 1960s you could let go of the yoke while you crank... but there is just no reason why that should be needed. Even if for some reason you can't put a hydraulic system in place to allow the trim to be set easily, can we not get enough mechanical leverage to make sure that the trim tabs can be adjusted in a scenario where there's a large amount of force on them? That's just... why? why would you do that? I've been thinking about this all evening. The fact that this rollercoaster business was even a thing... ever... is so ridiculous.
 
Yea... and... that's horrible. Sometimes you don't have enough altitude to just let go of the yoke while you crank away on the trim. It's bad enough that a runaway trim situation can occur. It's worse that when it does happen, it can easily put you in a situation where you're not physically strong enough to crank the trim back into place after you disable the malfunctioning system. I get that if you have enough altitude and remember the technique from the 1960s you could let go of the yoke while you crank... but there is just no reason why that should be needed. Even if for some reason you can't put a hydraulic system in place to allow the trim to be set easily, can we not get enough mechanical leverage to make sure that the trim tabs can be adjusted in a scenario where there's a large amount of force on them? That's just... why? why would you do that? I've been thinking about this all evening. The fact that this rollercoaster business was even a thing... ever... is so ridiculous.

But that isn't the problem, and there are only two crashes where it is theorised it might have been. The jet has to be travelling at a great overspeed, with uncontrolled runaway trim and in a situation where the pilots feel compelled to be putting their full body force into the yoke. At that stage some kind of disaster is highly likely. If this was something that could happen on any other jet we'd see lots of crashes or inflight break-ups from jets whose trim couldn't be controlled. We don't.

That's why I've been saying for several pages/posts now that I think Boeing have a lot of questions to answer. They introduced a system that could allow a jet to autonomously keep trimming down. They did it with barely any announcement, they didn't stipulate simulator conversion, didn't put recovery information into the checklists or manuals, and they seemingly misled the FAA about the power of the system as they self-certified it. You're right to think that it's ridiculous but I would happily step onto any other Boeing variant right now for a flight - just not a MAX until the software updates and training are verified.
 
But that isn't the problem, and there are only two crashes where it is theorised it might have been.

I understand. From an engineering perspective, I hate it. I hate that the rollercoaster concept enabled them to not address it. I don't like identifying any region of the flight envelope (I'm misusing that word, but it's the best illustration for what I'm getting at) where either disaster or shenanigans are needed. The fact that this might have ultimately resulted in the EA crash, and could have easily been dealt with earlier really bugs me.

If this is what caused the EA crash, I'll blame it on this more than the runaway stabilizer situation. You might think "well they'd never have gotten there without the runaway stabilizer situation" and that's true, but they followed the procedure for that fault, and that procedure should have gotten them out of it. The fact that pulling back on the yoke (when the plane was near the ground) caused the trim to be too stiff to move after the failure procedures were followed is just inexcusable. It's something that was known ahead of time, and the known fix (rollercoastering) is absolutely unacceptable immediately following takeoff. If this is what cause the EA crash, it's this known and not-addressed phenomenon that prevented what should have been a recovery from a system fault. And it's a dumb reason.

I don't like that anything like this is allowed to just stay in aircraft. And that's why I said it makes me want to stay off of them.
 
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