Ethiopian ET302 Crash.

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Originally Posted by DoubleWasp
Ok, so this manual trim wheel is literally a mechanical connection of some sort dependent on sheer mechanical force to operate?
yes

Originally Posted by DoubleWasp
With the KC-46, does that mean that a pilot who had to "fight" the MCAS would automatically and permanently lock out the system just by grabbing the yoke and giving input?
yes. This is called the "yoke jerk" method of turning electric trim off. "Much like tapping the brake pedal in a car to disengage cruise control, a sharp tug on the controls of older models of Boeing Co's 737 used to shut off an automatic trim system that keeps the plane flying level, giving the pilot control. But Boeing disabled the "yoke jerk" function when it brought out the 737 MAX, the latest version of its top-selling jet — and many pilots were unaware of the change, aviation experts told Reuters." -- https://graphics.reuters.com/ETHIOPIA-AIRLINE-CONTROLS/0100916V1NZ/index.html

Originally Posted by DoubleWasp
Possible the ET302 crew put the switches back on to try to recover with electric trim realizing they weren't going to win against resistance using the mechanical trim? Situation looked even worse, so try turning the system back on to recover before MCAS cuts in, and then shut it back off soon as it tries?
Likely, from the looks of it.

Originally Posted by DoubleWasp
Uneducated hypothetical: Would opening the flaps and speedbrakes have arrested their over speed issue and locked out MCAS while giving them back electric trim, or would that have just opened a whole other can of worms?
Flaps would be ripped off at those speeds, maybe speedbrakes too. Flap deployment does turn off MCAS normally though.
Actually, if they would have turned ON the Autopilot, they would have been saved since MCAS turns OFF when autopilot is on. I think on this system the autopilot could stay engaged with AoA disagree, for speed on pitch modes, for example, or vertical speed mode, where the feedback control system doesn't use AoA.
 
umm, PIC had tried AP but it quickly kicked out due to anomalous AOA and airspeed inputs.
Ironically, the right side AP might have saved the day, since his data was good.
Had the crew thought to pull the throttles back from the insane levels they were at, airspeed would have declined to a level that would have allowed the trim wheels to become useable.
At the really insane speeds at which this flight was operating, the trim wheels were physically barely moveable.
Also, trim response does depend upon airspeed and going faster makes an out of trim situation worse.
 
Children of the magneta line indeed!
What if you hadn't been sitting in that jumpseat?
At what point would the PM have looked out of the window, say this isn't right, my airplane, call a missed approach?
Given the worldwide demand for pilots, which has lead to widespread pilot poaching, are we seeing too many pilots trained to operate by rote without any fundamental understanding of what's happening or why?
This rote learning works just fine until something unexpected happens, usually involving some type of identifiable and survivable equipment failure.
This is what you saw on the little Embraer, this is what happened with AF447 and this is also what happened with the thread topic flight.
Hey, we're doing what we were trained to do. Why isn't it working?
Given the huge deliveries backlogs of both A and B, this trend will only get worse with more birds needing more pilots to fly them.
 
Originally Posted by DoubleWasp
I'm starting to understand the philosophy of ignoring everything until the final report. The picture truly is different every day until then.Thanks again.

That is wise, although nothing has been surprising along the way except for the original design decisions:

(1) Boeing allowed only 1 bad AoA vane to pitch the nose down, persistently. (Fixing it with dual-signal comparison now.) How that got thru the FTA/FMEA hazard analysis like that is now the subject of certification inquisition & making lawyers rich too.

(2) Boeing doesn't use "yoke jerk" autotrim cancellation like they do on everything else. Philosophy of an easier yoke-pull override not followed.

Everything else seen in flight is more or less expected of confused and paniced pilots, trained or not. .................We've seen pilots forget to do the right thing in the air plenty of times in the past. The 'startle' factor. Even highly trained pilots like Sullenberger can forget to do the #1 airmanship task of tracking an airspeed, for example.
 
Originally Posted by fdcg27
Children of the magneta line indeed!
What if you hadn't been sitting in that jumpseat?
At what point would the PM have looked out of the window, say this isn't right, my airplane, call a missed approach?
Given the worldwide demand for pilots, which has lead to widespread pilot poaching, are we seeing too many pilots trained to operate by rote without any fundamental understanding of what's happening or why?
This rote learning works just fine until something unexpected happens, usually involving some type of identifiable and survivable equipment failure.
This is what you saw on the little Embraer, this is what happened with AF447 and this is also what happened with the thread topic flight.
Hey, we're doing what we were trained to do. Why isn't it working?
Given the huge deliveries backlogs of both A and B, this trend will only get worse with more birds needing more pilots to fly them.


Interesting question. I don't know what would've happened without me there. We were still IMC (in the clouds) when I said it. Had we been visual, it would've been obvious, between the PAPI and the way the runway looked.

Clearly, tower was watching, too. I didn't even know that they could see, or were watching, altitude on approach. That's a great safety cross-check, too, but I wonder how many air traffic controllers do this, or have the time to. Is it automated, perhaps?

I don't know...

I think, that without me there, tower's intervention would've kept them safe. Thus proving the "Swiss Cheese" safety model. The first layers (glideslope transmitter, pilot cross-check) clearly had holes that allowed this error to continue, but the next layer of Swiss Cheese (me. tower) didn't have a hole that lined up.

To be fair, we don't train to cross check barometric altitude during approach. I doubt that they do, either.

We identify navaids via the Morse (757, 767-300). We verify altitudes on the approach and are constantly cross-checking altitude during an RNAV/GPS STAR or approach, but nowhere (that I can find) are we supposed to cross-check altitude when flying an ILS glideslope.

So, I don't fault them for not noticing. Perhaps I wouldn't have, either, had I actually been responsible for flying, which is far more task-intensive, instead of simply observing.

But, I do fault the FO for not understanding. The Captain got it right away. Tower saw it. The FO was puzzled.

As you say, they were flying the way that they were trained.

Why do I look around and cross-check even though it's not required? I think because I was once trained that way.

When we flew the instrument approach to the Carrier, known as a CASE 3 recovery, we often had no precision guidance. So, we would simiply fly a final bearing on the TACAN, and simply fly altitudes to arrive at a good position for visual transition for landing. In that case, with a 3.5 degree glideslope, it was 400'/mile, so, we would start our descent from 1,200' at 3 miles and keep working our way down at 700-800 FPM, cross-checking altitude every 1/4 mile (or about every 7 seconds). Because I have flown dozens of those (there is no real analog in the civil aviation world, it's like a non-precision, but all done manually, in our heads, to minima that are lower than a typical non-precision, or an RNAV/VNAV, or RNAV/GPS), I naturally cross-check baro vs. distance.

Too many pilots trained by rote? Too many children of the Magenta?

Yeah. That's exactly my point. Far too many.
 
Originally Posted by oil_film_movies
Boeing allowed only 1 bad AoA vane to pitch the nose down, persistently. (Fixing it with dual-signal comparison now.) How that got thru the FTA/FMEA hazard analysis like that is now the subject of certification inquisition & making lawyers rich too.


Boeing isn't going to ignore or shortcut the documented processes. There is most likely a document path that allowed them to use only one sensor, and if that's the case then the documentation needs to be changed to not allow this to happen again.
 
Originally Posted by ZeeOSix
Originally Posted by oil_film_movies
Boeing allowed only 1 bad AoA vane to pitch the nose down, persistently. (Fixing it with dual-signal comparison now.) How that got thru the FTA/FMEA hazard analysis like that is now the subject of certification inquisition & making lawyers rich too.
Boeing isn't going to ignore or shortcut the documented processes. There is most likely a document path that allowed them to use only one sensor, and if that's the case then the documentation needs to be changed to not allow this to happen again.
They are getting investigated for letting business pressures dominate, to complete the 737 Max8/9 sales with the benefit of "No Additional Crew Training" for this new verson of the ole 737. Some at Boeing (technical people mostly) were not on board with pushing through MCAS on one AoA vane, with no dual comparison & no warning light when it's lost. The FBI & others are trying to find out if any of the engineers producing the cert documents were pressured to push it through. Of course, we engineers have pressure all the time, and aren't supposed to cave, even when careers are threatened.
 
Does anyone really believe that Boeing and the FAA teamed up to allow certification and delivery of a potentially lethal design feature?
Flown by crews who actually understand flying and why planes do what they do, the quirks of the MAX appear to be quite manageable.
Flown by crews who've learned little more than rote procedure, the quirks of the MAX appear to be potentially lethal.
This is as much a failure of the pilot experience and training regime found in many parts of the world as it is any faults in the aircraft as delivered.
The plain truth is that there are a lot of pilots who wouldn't be able to operate outside of a highly automated environment. Take them out of their comfort zone and they're completely lost, like the pilots in this thread topic as well as those of AF447.
We need to insist on better and more skilled crews worldwide. The problems with this Boeing are a symptom of much deeper problems in the current airline pilot population. In this country, we have fairly strict experience requirements for those who fly airliners. In much of the world, this simply isn't the case, so we end up with crews who cannot deal with anything outside normal operating procedures.
 
Originally Posted by fdcg27
Does anyone really believe that Boeing and the FAA teamed up to allow certification and delivery of a potentially lethal design feature?
Flown by crews who actually understand flying and why planes do what they do, the quirks of the MAX appear to be quite manageable.
Flown by crews who've learned little more than rote procedure, the quirks of the MAX appear to be potentially lethal.
This is as much a failure of the pilot experience and training regime found in many parts of the world as it is any faults in the aircraft as delivered.
The plain truth is that there are a lot of pilots who wouldn't be able to operate outside of a highly automated environment. Take them out of their comfort zone and they're completely lost, like the pilots in this thread topic as well as those of AF447.
We need to insist on better and more skilled crews worldwide. The problems with this Boeing are a symptom of much deeper problems in the current airline pilot population. In this country, we have fairly strict experience requirements for those who fly airliners. In much of the world, this simply isn't the case, so we end up with crews who cannot deal with anything outside normal operating procedures.

+1. Piloting a plane is quite a skill. I would guess the military pilots are the best due to the conditions they operate in.
 
Originally Posted by oil_film_movies
Originally Posted by ZeeOSix
Originally Posted by oil_film_movies
Boeing allowed only 1 bad AoA vane to pitch the nose down, persistently. (Fixing it with dual-signal comparison now.) How that got thru the FTA/FMEA hazard analysis like that is now the subject of certification inquisition & making lawyers rich too.
Boeing isn't going to ignore or shortcut the documented processes. There is most likely a document path that allowed them to use only one sensor, and if that's the case then the documentation needs to be changed to not allow this to happen again.
They are getting investigated for letting business pressures dominate, to complete the 737 Max8/9 sales with the benefit of "No Additional Crew Training" for this new verson of the ole 737. Some at Boeing (technical people mostly) were not on board with pushing through MCAS on one AoA vane, with no dual comparison & no warning light when it's lost. The FBI & others are trying to find out if any of the engineers producing the cert documents were pressured to push it through. Of course, we engineers have pressure all the time, and aren't supposed to cave, even when careers are threatened.


What I'm saying is there are documented design standards that define the safety level each system must be designed to. I highly doubt al the people involved with the design, testing and certification of the system ignored design requirements and purposely circumvented required over-sight and approvals. There would literally have to be dozens if not hundreds of people collaborating to pull off something illegal.

My corporation experience is when that many people are involved in a womb to tomb process there will be many people who will raise concern when things are purposely being done to circumvent the official processes. Personally, I never "caved" to anyone, including high up managers, to do anything that could get the company or employees in trouble. There is lots of over-sight going on, and anyone could be a whistle blower with one anonymous phone call.
 
Originally Posted by ZeeOSix
What I'm saying is there are documented design standards that define the safety level each system must be designed to. I highly doubt al the people involved with the design, testing and certification of the system ignored design requirements and purposely circumvented required over-sight and approvals. There would literally have to be dozens if not hundreds of people collaborating to pull off something illegal.
It's a chain of command, not always a peer-reviewed committee, and sometimes business people can be applying pressure. See the Seattle Times article by Dominic, who interviewed my old friend at Boeing about this: "Assessed a failure of the system as one level below "catastrophic." But even that "hazardous" danger level should have precluded activation of the system based on input from a single sensor — and yet that's how it was designed. The people who spoke to The Seattle Times and shared details of the safety analysis all spoke on condition of anonymity to protect their jobs at the FAA and other aviation organizations." ---
Seattle Times Article Link

When I was working on flight control algorithms, we always considered ANY automatically-applied (autopilot, augmentation paths) nose-down pitching moment (torque; tail-lift) as deserving of dual signal selection and/or other mitigation, period. Nose down is serious. At some point, it looks like they were pressured into giving pilot Human Factors way too much credit, for hitting both Stab Trim Cut-Out switches and spinning the wheel, including the yo-yo trimming, no yoke jerk cutout available to get there.
 
Originally Posted by ZeeOSix
Boeing allowed only 1 bad AoA vane to pitch the nose down, persistently. (Fixing it with dual-signal comparison now.) Boeing isn't going to ignore or shortcut the documented processes. There is most likely a document path that allowed them to use only one sensor, and if that's the case then the documentation needs to be changed to not allow this to happen again.

I agree there has to be a documented path and if there was a decision to use one AOA sensor, there had to be a technical, documented reason. There IS a paper trail involved in the development process and I am sure this paper trail is being examined in detail.

Now the question arises as to whether the reason was valid in light of other factors such as crew management and proper training, and the use of only one conjectured AOA and FCC, etc.


Originally Posted by oil_film_movies
They are getting investigated for letting business pressures dominate... Some at Boeing (technical people mostly) were not on board with pushing through MCAS on one AoA vane...

You nor I know this for sure and is pure conjecture on your part with additional conjecture being generated by some in the media to garner readership/viewers.


Originally Posted by oil_film_movies
The FBI & others are trying to find out if any of the engineers producing the cert documents were pressured to push it through. Of course, we engineers have pressure all the time, and aren't supposed to cave, even when careers are threatened.

It appears as if you are repeating yourself wrt, "pressure." The FBI will be asking a lot of different questions of both management and engineering, among them the sign-off of documents with which you agreed or disagreed, and what were your reasons for doing so.

These interviews will be coordinated with the FAA for further consideration.


It will interesting to see the final NTSB report and to see what changes the FAA requires of Boeing and OTHER Airframe/Avioncs manufacturers.

Unfortunately, every transportation crash is a tragedy, but it usually results in some rethinking about controls and procedures in order to provide enhanced safety.

In most investigations we find there is usually no one single event, but a series of events that contributed to the accident.
 
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Originally Posted by MolaKule
The FBI will be asking a lot of different questions of both management and engineering, among them, the question to agree to, to conform to, or to sign-off on a document in which you disagreed, and what were your reasons for doing so.


It appears as if you are repeating yourself wrt, "questions." The FBI investigation is indeed real, despite your odd denials.

Originally Posted by MolaKule
Originally Posted by ZeeOSix
Boeing allowed only 1 bad AoA vane to pitch the nose down, persistently. (Fixing it with dual-signal comparison now.) Boeing isn't going to ignore or shortcut the documented processes.
Mola, You edited and mixed comments from me and ZeeOSix.


Originally Posted by MolaKule
Unfortunately, every transportation crash is a tragedy,
Uhhh, yeah. Guess you nailed that point.
 
Last edited:
Originally Posted by oil_film_movies
Originally Posted by MolaKule
The FBI will be asking a lot of different questions of both management and engineering, among them, the question to agree to, to conform to, or to sign-off on a document in which you disagreed, and what were your reasons for doing so.


...The FBI investigation is indeed real, despite your odd denials.


Where in any of my responses do I deny any FBI investigations?

My complete response was:
Quote
The [b]FBI will be asking a lot of different questions[/b] of both management and engineering, among them the sign-off of documents with which you agreed or disagreed, and what were your reasons for doing so.


To be accurate I was quoting a portion of ZeeOSix's response to which I was agreeing:

Originally Posted by ZeeOSix
What I'm saying is there are documented design standards that define the safety level each system must be designed to. I highly doubt al the people involved with the design, testing and certification of the system ignored design requirements and purposely circumvented required over-sight and approvals. There would literally have to be dozens if not hundreds of people collaborating to pull off something illegal...


My corporate experiences follow ZeeOSix's experiences.

In other words there has to be a paper trail from Concept to Flight and it would take many different Departments/Groups to engage in some kind of internal conspiracy.

Referring back to Post #5046176 for reference:

Originally Posted by MolaKule
Here is the usual High-Level and documented process, albeit somewhat simplified:

Aircraft Concept (General Requirements) > Detailed Requirements (written in DOORS or SysML) > Requirements Flowdown (to Hardware and Software Groups) > Design of Hardware and Software > Flight Simulation of Software > Simulation of Integrated MetaHardware and Software > Wind Tunnel Testing of Model > Structural Testing of completed structure > Hardware and Software Integration in aircraft > Instrumented Ground Testing > Instrumented Flight Testing > Modify Detailed Requirements if any anomalies are found in software, hardware, or flight characteristics.

Each of these steps are monitored either by the On-Site FAA rep or a DER (Designated Engineering Representative).

In addition to, and during all of the above steps, the Flight and Technical Manuals are being developed and modified.

A Documented and Strict peer review process is maintained during each step above.

I would conjecture that at this time the FAA, Boeing, and the NTSB are examining every Detailed Requirement and looking very closely at each and every modification done to the Hardware and Software during the complete development process.

I would also conjecture that there may be some process changes made both within Boeing and the FAA to improve flight safety.

With thousands of lines of requirements and tens of thousands of lines of code, it will be a long investigative process.


The only edit I would make to the above is that the DER situation is now covered by ODA:

Quote
...The Organization Designation Authorization (ODA) program is the means by which the FAA grants designee authority to organizations or companies. The regulations addressing the ODA program are found in Title 14 of the Code of Federal Regulations (14 CFR) part 183, subpart D, sections 183.41 through 813.67.

ODA holders are typically authorized to conduct the types of FAA functions which they would normally seek from the FAA. For example, aircraft manufacturers may be authorized to approve design changes in their products and repair stations may be authorized to approve repair and alteration data.

Regular FAA oversight of an ODA is accomplished by a team of FAA engineers and inspectors to ensure the ODA holder functions properly and that any approvals or certificates issued meet FAA safety standards...


from FAA ODA Site: https://www.faa.gov/other_visit/aviation_industry/designees_delegations/delegated_organizations/
 
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Originally Posted by MolaKule
I think this IG report will garner more attention now in light of recent accidents.

IG Report Regading FAA's ODA Oversight


So I'm wondering what all happened to address the report's Conclusions, Recommendations and Actions Required over the last 8 years.
 
Originally Posted by oil_film_movies
,,,It's a chain of command, not always a peer-reviewed committee, and sometimes business people can be applying pressure...


All companies have a chain of command.

Of the three Aerospace/Avionics companies I have worked for it has always been a Peer Review committee composed of engineers and Human Factors personnel that write the Systems and subsystems Specifications.

I have rarely seen a manager in one of those meetings and if they did come to a meeting it was to gauge the progress of the design, and not to technically influence it.

I think most companies realize that it is better to try and get the design as correct as possible the first time, even at a little extra cost, than to be sued later for cutting corners.
 
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I was at Honeywell for 25+ years and the bean counters always wanted to get in the act to run some 'value engineering'. That was taking something that worked and making something a little less so as to obtain more profit. More often than not, the result was something that just wasn't as reliable from the start or failed before it should. We ended up with a grumpy customer and ultimately had to do another redesign or go back to the original that worked. Of course, engineering folk always want to have the best and would want to work endlessly towards that goal='shoot the engineers and go to production'!
 
Originally Posted by DoubleWasp
I'm starting to understand the philosophy of ignoring everything until the final report. The picture truly is different every day until then.

Thanks again.


For sure.

Speculation may be fun but often inaccurate wrt the final reports.
 
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