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Tags airplane incidents , government shutdown

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Old 14th March 2019, 04:10 PM   #81
smartcooky
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Originally Posted by theprestige View Post
That's fine for my purposes.

My concern right now is not so much staying off of 737-MAX flights (though that's also a concern for me). My concern right now is staying the **** away from airlines that continued to operate the 737-MAX between the time they knew it had problems and the time the planes got grounded because of the problems they already knew it had.

To me, that speaks to an institutional laziness that almost certainly extends beyond their fleet of MAXs. If I can't trust Southwest to do the right thing with a 737-MAX, how can I trust them to be doing the right thing with a 737-800?

On the other hand, if you were to find an airline that had MAXs in service, and voluntarily grounded them when they understood the problem, I'd be happy to give them my business.

Meanwhile, there's airlines like Alaska, that don't have any MAXs in their fleet anyway, and haven't yet gotten a track record of bad behavior with their other planes. So they can keep my business for the time being. The 737-700/800/900 family is reportedly a more reliable and proven plane, so I'm not yet ready to give up on Boeing entirely. Plus it would be almost impossible to fly anywhere in the western hemisphere if I did that.

Which might not be a bad idea.

Hopefully, they have improved their maintenance standards since AA261

https://www.ntsb.gov/news/press-rele...light_261.aspx
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Old 14th March 2019, 04:13 PM   #82
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Originally Posted by smartcooky View Post
Hopefully, they have improved their maintenance standards since AA261



https://www.ntsb.gov/news/press-rele...light_261.aspx
A ten year moratorium seems entirely reasonable.
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Old 14th March 2019, 07:29 PM   #83
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Originally Posted by smartcooky View Post
I think its both.

I might be pre-empting things here, but assuming it is MCAS that caused the difficulty the pilots had with controlling the aircraft I'm going to go right ahead and call early what I think the conclusion of the investigation will be.

CAUSE
- Pilot error

CONTRIBUTING FACTORS
- Insufficient training by the airline and by Boeing.
- Poor documentation by Boeing
- Delays in certification by the FAA due to the US Government shutdown in 2019
If MCAS caused it, how could it be pilot error?

Also, how would the pilot know that MCAS was causing the issue and that the thing to do would be to turn it off?
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Old 16th March 2019, 09:25 AM   #84
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Originally Posted by Puppycow View Post
If MCAS caused it, how could it be pilot error?

Also, how would the pilot know that MCAS was causing the issue and that the thing to do would be to turn it off?

Brazil demanded new training protocols for the new plane. But not the U.S.
Quote:
n October 2017, Brazilian regulators flew to Miami to test out the brand-new Boeing 737 Max 8. The team scrutinized the sleek new jetliner’s flight systems and soon published a list of over 60 operational changes, from landing systems to cockpit displays, that Brazilian pilots would need to learn.

Among the new features regulators said pilots would have to familiarize themselves with was the Maneuvering Characteristics Augmentation System, a safety system that could nose the plane downward if it sensed a potential stall. The regulators mandated an interactive course for pilots to go over the changes and recommended “two legs of SLF,” or supervised flight, according to a copy of their report obtained by The Washington Post.

In those same months, the Federal Aviation Administration was making its final revision to a 53-page report that would make up the backbone of Max 8 training guidelines for pilots across the United States and in almost every other country around the world.
https://www.washingtonpost.com/inves...=.06963c8e2476
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Old 16th March 2019, 01:24 PM   #85
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Originally Posted by Puppycow View Post
If MCAS caused it, how could it be pilot error?

Also, how would the pilot know that MCAS was causing the issue and that the thing to do would be to turn it off?
Understand that Pilot error is not always directly blaming the pilot for the crash.

If an aircraft system fails, but that failure is resolvable, and the pilot fails to resolve it and the aircraft crashed, that is pilot error.

If the pilot was unable to resolve the failure because of poor or inadequate training, that is a mitigating factor.

A good example is Air France 447.
• temporary inconsistency between the measured speeds, likely as a result of the obstruction of the pitot tubes by ice crystals, causing autopilot disconnection and reconfiguration to alternate law;
• the crew made inappropriate control inputs that destabilized the flight path;
• the crew failed to follow appropriate procedure for loss of displayed airspeed information;
• the crew were late in identifying and correcting the deviation from the flight path;
• the crew lacked understanding of the approach to stall;
• the crew failed to recognize the aircraft had stalled and consequently did not make inputs that would have made it possible to recover from the stall
The initial failure was airspeed indication due to iced pitot tube. This was a mechanical system failure, but the pilots were unable to resolve it...

The cause was ultimately ruled to be pilot error.
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Old 16th March 2019, 03:02 PM   #86
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Originally Posted by ponderingturtle View Post
This is just a claim to try to justify the existence of the FAA and its excessive regulations and intrusions on business. They are clearly all useless and worthless and properly should be fired like all government regulators. That is the conservative answer to this.
Yes, absolutely right. The market decided in this case, as it always should. Keep planes flying until enough people die and no one wants to fly on the planes any more. Simple, yet effective.
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Old 16th March 2019, 03:35 PM   #87
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Originally Posted by smartcooky View Post
Understand that Pilot error is not always directly blaming the pilot for the crash.

If an aircraft system fails, but that failure is resolvable, and the pilot fails to resolve it and the aircraft crashed, that is pilot error.

If the pilot was unable to resolve the failure because of poor or inadequate training, that is a mitigating factor.

A good example is Air France 447.
• temporary inconsistency between the measured speeds, likely as a result of the obstruction of the pitot tubes by ice crystals, causing autopilot disconnection and reconfiguration to alternate law;
• the crew made inappropriate control inputs that destabilized the flight path;
• the crew failed to follow appropriate procedure for loss of displayed airspeed information;
• the crew were late in identifying and correcting the deviation from the flight path;
• the crew lacked understanding of the approach to stall;
• the crew failed to recognize the aircraft had stalled and consequently did not make inputs that would have made it possible to recover from the stall
The initial failure was airspeed indication due to iced pitot tube. This was a mechanical system failure, but the pilots were unable to resolve it...

The cause was ultimately ruled to be pilot error.
OK, I won't argue over it, but since it's (apparently) happened twice already since these planes have been introduced, something might be seriously wrong with the software or some other component of the system. Also, it may not be apparent to the pilots which system has failed. Especially if there is no mention in the manual they use or established procedure to follow. They had in each case thousands of hours of experience, but perhaps something like this had never happened to them before. Suddenly the plane is out of control and not responding to stick inputs.
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Old 16th March 2019, 05:24 PM   #88
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Originally Posted by Puppycow View Post
OK, I won't argue over it, but since it's (apparently) happened twice already since these planes have been introduced, something might be seriously wrong with the software or some other component of the system. Also, it may not be apparent to the pilots which system has failed. Especially if there is no mention in the manual they use or established procedure to follow. They had in each case thousands of hours of experience, but perhaps something like this had never happened to them before. Suddenly the plane is out of control and not responding to stick inputs.
Oh, I agree.

The point I'm making is that, if it was a faulty MCAS (which is starting to look more and more likely*) then the problem could have been overcome by disabling it (there is no way to actually turn the MCAS off).

There are two possible ways to do that (well three actually, but I won't go into the third as it gets complicated)

1. Lower the flaps to Flaps 1. MCAS is supposed to only be enabled with the flaps in the fully retracted position.

2. Turn the Stab Trim switches to OFF. This disables the horizontal stabilizer's automatic trim completely, and reverts to manual trim so that even if the MCAS is still erroneously detecting a stall, it cannot send trim inputs to the FCS.



*Update

https://www.washingtonpost.com/world...=.56baceff2f62
Investigators found a device known as a jackscrew in the wreckage. The jackscrew, used to set the trim that raises and lowers the plane’s nose, indicates the jet was configured to dive, according to John Cox, a former pilot and an airline-safety consultant with the Washington-based aviation-safety consulting firm Safety Operating Systems.
Also, CNN are reporting that the pilot reported control system problems almost immediately after takeoff... about the time when the flaps are retracted. Also, that ATC tracked the aircraft pitching up and down wildly, and accelerating and decelerating.

This is definitely looking like a flight control system problem.
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Old 16th March 2019, 07:10 PM   #89
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Originally Posted by smartcooky View Post
Oh, I agree.

The point I'm making is that, if it was a faulty MCAS (which is starting to look more and more likely*) then the problem could have been overcome by disabling it (there is no way to actually turn the MCAS off).

There are two possible ways to do that (well three actually, but I won't go into the third as it gets complicated)

1. Lower the flaps to Flaps 1. MCAS is supposed to only be enabled with the flaps in the fully retracted position.

2. Turn the Stab Trim switches to OFF. This disables the horizontal stabilizer's automatic trim completely, and reverts to manual trim so that even if the MCAS is still erroneously detecting a stall, it cannot send trim inputs to the FCS.

https://www.dropbox.com/s/yntgr47fa9...able.jpg?raw=1

*Update

https://www.washingtonpost.com/world...=.56baceff2f62
Investigators found a device known as a jackscrew in the wreckage. The jackscrew, used to set the trim that raises and lowers the plane’s nose, indicates the jet was configured to dive, according to John Cox, a former pilot and an airline-safety consultant with the Washington-based aviation-safety consulting firm Safety Operating Systems.
Also, CNN are reporting that the pilot reported control system problems almost immediately after takeoff... about the time when the flaps are retracted. Also, that ATC tracked the aircraft pitching up and down wildly, and accelerating and decelerating.

This is definitely looking like a flight control system problem.
Sounds like a phugoid motion, the flight crew was certainly having a bad day.
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Old 17th March 2019, 12:54 AM   #90
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Originally Posted by Delphic Oracle View Post
Sounds like a phugoid motion, the flight crew was certainly having a bad day.
Indeed! The VS plots of the Ethiopian Airlines and Lion Air flights bear a disturbing similarity



The 15-20 second interval of climb and dive points directly to MCAS being a chief suspect.

A typical climb out rate after takeoff is 1800 fpm... note that the EA flight almost hit 3000 fpm; an airliner like the 737 would not be able to maintain that for long without putting the nose down or a stall would result.

Those last few minutes would have been utterly terrifying for the passengers.
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Old 17th March 2019, 06:34 AM   #91
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Originally Posted by Puppycow View Post
OK, I won't argue over it, but since it's (apparently) happened twice already since these planes have been introduced, something might be seriously wrong with the software or some other component of the system.
.....

From this, it sounds like the 50+ year-old design has been modified and revised beyond its capacity.
Quote:
First introduced in West Germany as a short-hop commuter jet in the early Cold War, the Boeing 737-100 had folding metal stairs attached to the fuselage that passengers climbed to board before airports had jetways. Ground crews hand-lifted heavy luggage into the cargo holds in those days, long before motorized belt loaders were widely available.

That low-to-the-ground design was a plus in 1968, but it has proved to be a constraint that engineers modernizing the 737 have had to work around ever since. The compromises required to push forward a more fuel-efficient version of the plane — with larger engines and altered aerodynamics — led to the complex flight control software system that is now under investigation in two fatal crashes over the last five months.
https://www.latimes.com/local/califo...315-story.html
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Old Yesterday, 05:55 AM   #92
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Originally Posted by smartcooky View Post
Hopefully, they have improved their maintenance standards since AA261

https://www.ntsb.gov/news/press-rele...light_261.aspx
But fortunately all that kind of garbage regulation went out the window with the regulators during the shutdown.
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Old Yesterday, 12:57 PM   #93
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For reference these are some other major airframe groundings, the cause, and how long they lasted.

Boeing 787 Dreamliners, grounded worldwide for 3 months in 2013 after two separate cases of battery fires (one caused an emergency diversion and landing, the other happened on an unoccupied plane on the runway. No crashes or fatalities.)

McDonnell Dougles DC-10, grounded for 37 days in 1979 after 273 people were killed in a crash in Chicago caused by an engine separating from the wing in flight.

Lockheed L-049 Constellation, grounded for 6 weeks in 1946 after one crash that killed 4 and several reports of engine fires.
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Old Yesterday, 02:31 PM   #94
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Originally Posted by JoeMorgue View Post
McDonnell Dougles DC-10, grounded for 37 days in 1979 after 273 people were killed in a crash in Chicago caused by an engine separating from the wing in flight on takeoff.
Turned out be a maintenance issue leading to component failure.

Originally Posted by JoeMorgue View Post
Lockheed L-049 Constellation, grounded for 6 weeks in 1946 after one crash that killed 4 and several reports of engine fires.
Electrical fire in the wings

Of course there is also the famous grounding of the DH Comet 1, grounded twice; once in January 1954, and again in April 1954, less than a month after flights resumed

Cause was a design flaw combined with metal fatigue.
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Old Yesterday, 02:57 PM   #95
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Originally Posted by smartcooky View Post
Of course there is also the famous grounding of the DH Comet 1, grounded twice; once in January 1954, and again in April 1954, less than a month after flights resumed

Cause was a design flaw combined with metal fatigue.
Was that the square window problem?
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Old Yesterday, 03:03 PM   #96
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Originally Posted by JoeMorgue View Post
Was that the square window problem?
Square windows fit in square holes in the skin of the plane. The corners of the square holes concentrated skin stress at those points, causing the skin to fail. As you can imagine, this is suboptimal for airplanes. Especially at times of high and prolonged stress, such as flying through the air.

Most planes have windows with rounded corners, distributing the stress more evenly across the skin around the window, and avoiding having your plane come unskinned at 30,000 feet with a hundred lives on board.
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Old Yesterday, 03:07 PM   #97
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Originally Posted by smartcooky View Post
If they were trained, retrained or briefed about it, but it seems they may not have been. Plenty of Max 8 pilots are claiming they have heard little or nothing from Boeing.

https://www.washingtonpost.com/busin...a61_story.html

Nothing on the MCAS

After the Ethiopian Airlines crash Sunday, Boeing said it would update flight-control software, provide more training, introduce “enhancements” to external sensors that measure the direction of an aircraft and make changes to how MCAS is activated.

But two pilots who attended the meeting with Boeing in November after the Lion Air crash said pilots had suggested that the company take these actions at that time.

“Whatever level of training they decided on [before the Lion Air crash], it resulted in an iPad course that I took for less than an hour,” Tajer, the American Airlines pilot, said. “A lot of pilots here at American did that course.”

But he said the course did not cover the new MCAS system. “There was nothing on the MCAS because even American didn’t know about that. It was just about the display scenes and how the engines are a little different,” he said.

That's what I've heard in the coverage on the radio here; Boeing chose to present the 737 Max as a minor upgrade, not a new plane, to avoid the costs involved in certification and training that new plane would entail. I've not heard that there was any actual bug in what the plane was doing, just that it was unexpected from the pilot's point of view, so they didn't know how to react.
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Old Yesterday, 03:19 PM   #98
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Originally Posted by theprestige View Post
Square windows fit in square holes in the skin of the plane. The corners of the square holes concentrated skin stress at those points, causing the skin to fail. As you can imagine, this is suboptimal for airplanes. Especially at times of high and prolonged stress, such as flying through the air.

Most planes have windows with rounded corners, distributing the stress more evenly across the skin around the window, and avoiding having your plane come unskinned at 30,000 feet with a hundred lives on board.
WW2 'Liberty ships' had the same problem with hold hatch corners causing cracking of the main deck.
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Old Yesterday, 05:21 PM   #99
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Originally Posted by zooterkin View Post
That's what I've heard in the coverage on the radio here; Boeing chose to present the 737 Max as a minor upgrade, not a new plane, to avoid the costs involved in certification and training that new plane would entail. I've not heard that there was any actual bug in what the plane was doing, just that it was unexpected from the pilot's point of view, so they didn't know how to react.
And here is the really important point about this. If you start having problems such as your aircraft pitching nose down at cruise speed and altitude, you have margin; you have time to sort it out, because you have some altitude and airspeed to work with.

However, an aircraft just after take-off is still climbing and accelerating. Typically, a 737-800 take off speed is about 130 -160 kts (fuel and load dependant) and in climb-out, it is accelerating to its cruise speed of around 500 kts. Three minutes into flight its probably still only around 5,500 ft at 300 kts. Anything goes wrong, there is not a lot of margin for the pilot to work with.
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Old Yesterday, 06:24 PM   #100
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Originally Posted by smartcooky View Post
And here is the really important point about this. If you start having problems such as your aircraft pitching nose down at cruise speed and altitude, you have margin; you have time to sort it out, because you have some altitude and airspeed to work with.

However, an aircraft just after take-off is still climbing and accelerating. Typically, a 737-800 take off speed is about 130 -160 kts (fuel and load dependant) and in climb-out, it is accelerating to its cruise speed of around 500 kts. Three minutes into flight its probably still only around 5,500 ft at 300 kts. Anything goes wrong, there is not a lot of margin for the pilot to work with.
National Airlines 102, for instance. Poor guy just never had time to sort it out. Amazingly, after nearly rolling over and with questionable flight controls he was just about wings level and slightly pitched down when he ran out of time.

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National Airlines Flight 102

Quote:
On 2 June 2013, investigators from the Ministry of Transport and Civil Aviation of Afghanistan confirmed the load shift hypothesis as the starting point: three armoured vehicles and two mine-sweeping vehicles, totalling 80 tons of weight, had not been properly secured. At least one armoured vehicle had come loose and rolled backwards against the airplane's rear bulkhead, damaging the bulkhead. This also crippled key hydraulic systems and damaged the horizontal stabilizer components - most notably the jackscrew, which rendered the airplane uncontrollable.[3] Control of the aircraft was therefore lost, with the abnormal pitch-up rotation, stall, and crash to the ground ensuing.[1] The damage made it impossible for the crew to regain control of the aircraft.

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Old Yesterday, 07:58 PM   #101
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Originally Posted by JoeMorgue View Post
Of American based airlines:

Alaska Air has 32 on order, but is not currently flying any.
American Airlines has 100 on order, has 22 in its fleet.
Ryan Air has 135 on order, but is not currently flying any.
Southwest has 280 on order, has 31 in its fleet.
United has 136 on order, has 14 in its fleet.
2 have been delivered to individuals/companies for use as personal or corporate jets. I assume they would be affected by the grounding.

I cannot find any carrier world wide that is flying only the 737 Max (some small budget carriers only fly one make/model of plane to keep costs down.)
Ryan Air is an Irish airline.
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Old Today, 05:39 AM   #102
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I came across this speculation by a friend and fellow pilot, that I found well-informed and I thought I’d share.

***Warning contains my own uninformed speculation... I am posting it ONLY to see if people agree or disagree... ***

It seems clear to me that a chain of well known information could give us a possible explanation and the reasons for the recent 737 max 8 crashes.

Overall its the problem of adding envelope protection and automation to an older Boeing aircraft design that, unlike Airbus, was never designed for fly by wire automation, and an addition that is against the normal design philosophy of the manufacturer - - - Boeing.

Airbus has had fly by wire and computer based flight controls designed in from the begining, Boeing however have never before really embraced this idea.

While the lunar module and many agile fighter jets would be unstable without fly by wire, Boeing have normally designed aircraft that fly 'naturally'..

This can be seen clearly in the design of the pilot interface to the aircraft, a big old fashioned yoke in the Boeing and a small side stick like a games controller in the Airbus and the Apollo era lunar module.... .

But here's the problem, when Boeing added bigger engines and other changes like fuselage length to the 737-max series they upset the natural flight characteristics, engines needed to be more forward in a different position, and had more thrust. I heard Boeing found this affected control, badly, at some edges of the flight envelope including the full power stall characteristics of the aircraft.

Pilots who practice full power stalls know they are scary at the best of times. This aircraft was apparantly even more scary, so much so that it could probably not have been certified.

So automation shy Boeing were forced to depend on Airbus style software protection to prevent these edges of the flight envelope ever being reached.

Hense the MCAS system was born, an override that would automatically forward trim the aircraft at high angles of attack approaching the stall in this configuration, flaps up full power, ( you know like the climb phase close to the ground just after take off) to eliminate the possibility of the stall...

Trouble is, the airframe was designed years ago. The trim on the 737 trims the angle of the WHOLE tail stabiliser.... not just the elevators. Yes that 'wing at the back' actually changes its position relative to the fusalage... its whole angle.... this is actually a very powerful, coarse control input in the wrong hands.... .. the pilot controlled elevator for pitch control at the back is only part of this whole flying surface... so I imagine that trim can, at full defection, be a stronger force than elevator input.

So a faulty angle of attack sensor could trigger this forward stabiliser trim if it detects a phantom stall... . Boeing say this is what happened in the first lion Air crash... a faulty sensor.. but they blamed pilot training... really?

So what actually happens? Well every 10 seconds or so, unless the whole trim system is disabled, the MCAS forces the nose down using this very powerful stabiliser trim, to avoid the phantom stall.

You can imagine a pilot fighting this in two ways, pulling back on that big yoke, and trimming backwards to reverse the false input, but every time he does the system kicks in again and undoes his fixes... there are two additional problems the poor pilot faces... .

Firstly because the aircraft thinks its stalling it starts shaking this yoke. imagine pulling to save your life on a yoke that is shaking, it's like the aircraft is disobeying wanting to nose down and still want you to fight it. But hang on... secondarily the Yoke has an artifical feedback system designed to give flying the plane a more natural 'feel' for pilots. This system can make the controls feel stiffer at high speed for example and looser at low speed, even though, like the steering wheel of a car the controls are power assisted.... in a stall guess what? this artificial feedback system kicks in to make it very hard to pull back on the yoke... its stiffens as if to say 'don't do that'...

So we have runaway trim, moving the whole rear stabiliser into a dangerous nose down flight position... possibly faster that the pilot can fix it, a shaking stick, and a yoke that actively resists pilot input to pull back! Even if the pilots disconnected the trim system (as per Boeing 'fix'...) its likely to be left in a nose heavy trim position... which takes time to fix...

Then the poor pilot has to try and pull up, using a small (relatively speaking) elevator, against a stiff, artificially resistant pressure on the yoke, possibly with a shaking stick.... all close to the ground?

I can imagine easily how a runaway nose down trim, resistant and shaking controls and nose down path of the aircraft could quick result in loss of control, and ground impact, whatever the pilot did. Too little time to fight the disobedient aircraft..

To avoid it I guess they would need to very quickly identify what is happening (how can they when the problem has never been practiced?) disconnect the auto trim, manually fix the trim position quick enough to regain elevator authority, all while the stick is shaking and refusing or resisting to be pulled back?

I think this must qualify as a design flaw, that results on trying to add automation and envelope protection onto an aircraft concept and pilot interface where so many other design decisions have assumed automation is not present.

Thank goodness they have grounded the aircraft. Finally. But what can Boeing do to fix it? I suggest replacing MCAS with a good old fashioned Stall Warning horn, and let the pilots fly.. put a placard on the console saying 'Full power stalls prohibited'.. what else can they do?

Discuss?


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Old Today, 04:00 PM   #103
Puppycow
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https://www.nytimes.com/2019/03/19/p...pia-crash.html

Short version is that this plane was made to compete with a similar sized Airbus plane, which is more fuel-efficient than earlier models of the 737. The selling point was that pilots who already know how to fly the 737 won't need any retraining or flight simulator time. They even decided that pilots didn't need to know about the new MCAS system, so when they ran into problems, the pilots didn't even know that the system existed or that it was what was causing the problem.
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