The memory items have been eliminated on the legacy Boeings on the stab trim runaway non-normal is my point. The 2013 QRH runaway stab checklist for the 737 300-500 posted above has no memory items (bold face or boxed items at some airlines). I doubt that the MAX Boeing QRH has memory items for the runaway stab either. Anybody know for sure?

On the other hand, I've certainly seen airlines modify manufacturer's checklists for standardization with other fleets. I remember a couple of decades ago the Boeing company B-767 before takeoff checklist had only one item. Delta's '76's however had maybe a dozen items on the before takeoff checklist (e.g. instruments - checked, aligned and set) I'm told as a legacy of the mighty DC-8.

Airbubba,

The Runaway Stabilizer NNC shown above DOES have memory items. According to the checklist instructions:

I bet my ass the MAX QRH is the same.

Thanks, you are right, I was expecting boldface, shading, octothorpes or a box but it indeed seems to be memory items to the dashed line unlike the current procedures for uncommanded stab motion on the 777 for example.

Our 777 QRH also has memory items for uncommanded stabilizer motion, namely:

They are denoted exactly the same way as the 737 QRH above, ie with the dashed horizontal line beneath the second item.

Thanks again, very similar to the 727 checklist three decades ago.

In the U.S. for several reasons the memory items have become minimal in recent years.

For example this Delta 777 QRH from a decade ago has the same procedure you cited with no memory items on page 9.10:

http://www.aviationforall.com/wp-con...ng-777-QRH.pdf

As stated on page CI.2.1:

Just to clarify for the benefit of non-US readers, US airworthiness regulations are contained in one of the 50 titles of the US Code of Federal Regulations (specifically Title 14, usually referred to as "14 CFR"). The parts of 14 CFR dealing with aeronautics (it also covers space) are also widely known (including by the FAA here) as the "Federal Aviation Regulations" - so I'm not quite sure why the FAA apparently gets upset when they're called that.

Within 14 CFR/FARs are sections that most of us are familiar with, so airworthiness for example is in 14 CFR 25 (usually referred to as "Part 25" or simply "FAR 25").

EASA has taken the line of least resistance and adopted the same chapter numbering for its own airworthiness regulations covering aeroplanes and rotorcraft (but not engines), for example CS-23, CS-25, etc.

What a silly comparison!

Dispute arises among U.S. pilots on Boeing 737 MAX system linked to Lion Air crash

United Airlines pilots do not need to know the details about how their planes work ??!! oops...

Insler said many systems on an airplane work in the background without the pilot’s knowledge

perhaps he should have said many non-safety systems work.. like do you know how the toilet flush mechanism works, how the cabin entertainment works etc? Other than knowing what circuit breakers to pull to isolate the system, I don't believe pilots need to know about a lot of the above other than a general overview. For any flying, safety system then yes the Pilot needs to know everything there is to know about the mechanics and electronics and interactions and design decisions made.

The job is more system engineer than flyer these days..

G

I'm absolutely speechless about the attitude of a pilots union head.

One of the issues lurking in the background of this sad accident is common to all manufacturers, namely that there has been a race to the bottom on TR and differences training requirements. Everything has been reduced to the absolute minimum because that is what the customer/operator wants ('best price'), and it has been allowed by the regulators. Compared with the unit price for a new airframe, the training cost is small but it is an easy target when it comes to shaving a few $$ off the bottom line. Time for a re-think?

The automation doesn't land on icy runways with strong crosswinds, nor does it thread it way in breaks in lines of TRW.

True there. Odd & tragic & stupid how just ONE AOA (alpha) sensor can cause nose down pitch trim. One can argue about the Human Factors involved here concerning stress, panic, time to decide what to do, etc., but I tend to come down on the side of "don't over-stress tired human brains", from the Flight Controls Engineer viewpoint I have.

Assuming the crash was caused by the AOA alpha vane ... continuing on:

"Analytical Redundancy" would have prevented this problem, as it would add a third alpha to the dual vane measurement to break the tie between 2 vane sensors. ... Note that alpha = theta - gamma, received through air data & inertial sensors apart from the alpha vanes. That caclulated third alpha makes the system triple redundant, along with using median value selection.

You could even apply a (fourth redundancy!) reasonableness test on the alpha vane's sensor values by writing more software that applies plain old logical common sense: --> Can that high alpha value, seen all of a sudden, and when the airspeed is good, and when g's aren't being pulled, be a valid value of alpha? Remember we have pitch rate sensors, accelerometers, pitot-static tubes, etc. to help the alpha fault detection out. Remember alpha-dot = pitch rate - (accelerometer / speed); we can use all the kinematic laws to do this.

All the above is what a very fast, sharp, smart pilot or flight engineer would do in a millisecond if they saw an alpha vane sensor measurement hard-over (high) all of a sudden. It would be obvious to an observer actually seeing the sensor values along with the trimmed aircraft state to decide it's a bad sensor. That is if a human could see & monitor the raw sensor values in real-time to make that clear judgement. Computers can.

Algorithms such as the above, along with complementary or Kalman filtering to filter out spectral noise and emphasize the short term estimation of valid alpha would also help. I won't go into the signal processing or kinematic blending algorithms here, but I will say you wouldn't need much.

And, finally, where was the FTA & FMEA in all this? I guess they thought the nose-down trim would be easily countered by pilots & was not deemed catastrophic. Again, Human Factors, and I'm on the side of "don't put the plane in peril and expected tired or paniced pilots figure it out".

quagmire (post #1364):

Excellent contribution to this discussion -- and your last para sums up a rather large issue: If two of the (supposed) most respected and capable organizations in civil aviation today (Boeing and the FAA) aren't doing thorough or appropriate risk assessments, what the heck has happened to our industry?

Fast big bucks.

Thanks. ... About the Fault Tree Analysis (FTA) & Failure Modes and Effects Analysis (FMEA), from what I saw in the industry, the avionics company, with oversight from the airframe maker, did the FTA & FMEA, and the FAA reviewed what it was at certification time. The Designated Engineering Representative (DER) at the avionics company gets their salary & pension from their own company, so has no interest in "causing trouble" by defying anything the avionics company and airframe maker wants.

I don't know how to solve this beyond actually having the FAA take a more active role. There were some comments above about Boeing effectively self-certifying the new versions of the 737, since Boeing is very powerful in this game. That could be the root cause of a bad FTA/FMEA getting through. Avionics companies & Boeing here don't like to admit there is anything wrong, until forced to.

Another of hundreds of speculative posts: It appears that their (Boeing and FAA) idea of what most pilots would do in such a situation was over-optimistic, a product of wishful thinking.

"You could even apply a (fourth redundancy!) reasonableness test on the alpha vane's sensor values by writing more software that applies plain old logical common sense: --> Can that high alpha value, seen all of a sudden, and when the airspeed is good, and when g's aren't being pulled, be a valid value of alpha?"

Well, I'm not a pilot but I have written a lot of laboratory/experimental software. Before a chunk of data is allowed into the record, it is compared with the expected value and trend over the last 5 minutes - if it is >(say)5x the expected value it gets discarded as anomalous and an interpolated value substituted. Inputs must be sanity checked before being accepted.

Having said that, writing more and more code can easily introduce race conditions and more corner-case results, so it is far from easy.

Mac

I think the problem with that, Mac, is that in rare cases a times-5 scenario would be real, and vitally important it be acted upon - even if only to warn.

The extremes experienced, especially in the last pitch up and dive, may well have been preceded by unprecedented in-flight streams of data, at least in civil flying. And yes, I'm taking into account the 447.


A by the way. Paniced. 'A combination of pissing ones pants whilst being in a panicked state.' I had to look it up, albeit in the Urban dictionary.

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