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Indonesian aircraft missing off Jakarta

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Indonesian aircraft missing off Jakarta

Old 17th Nov 2018, 00:39
  #1341 (permalink)  
 
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Here’s a screenshot of my training for the Max. As I’ve only flown around 10 flights on one, I forgot about this change.


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Old 17th Nov 2018, 02:22
  #1342 (permalink)  
 
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Originally Posted by b1lanc View Post
Well if the Max is simply the next-next-next-final gen 737 then you would think those items would be inherited - with one exception. I do believe Boeing introduced some automation that is not typical of a legacy 737 Boeing product - i.e. MCAS.
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.

Last edited by Airbubba; 17th Nov 2018 at 02:58.
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Old 17th Nov 2018, 03:10
  #1343 (permalink)  
 
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The memory items have been eliminated on the legacy Boeings is my point. The 2013 QRH 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?

Airbubba,

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

Checklists can have both memory and reference items. Memory items are critical steps that must be done before reading the checklist. The last memory item is followed by a dashed horizontal line. Reference items are actions to be done while reading the checklist.
I bet my ass the MAX QRH is the same.
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Old 17th Nov 2018, 03:33
  #1344 (permalink)  
 
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Originally Posted by BuzzBox View Post
Airbubba,

The Runaway Stabilizer NNC shown above DOES have memory items. According to the checklist instructions:
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.
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Old 17th Nov 2018, 03:43
  #1345 (permalink)  
 
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Our 777 QRH also has memory items for uncommanded stabilizer motion, namely:

1. STAB cutout switches (both) ............ CUTOUT
2. Do not exceed the current airspeed.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
They are denoted exactly the same way as the 737 QRH above, ie with the dashed horizontal line beneath the second item.
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Old 17th Nov 2018, 04:23
  #1346 (permalink)  
 
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Originally Posted by BuzzBox View Post
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:

Non-Normal Checklists can have both recall and reference items. Recall items
are critical steps that must be done from memory, prior to reading the checklist.
Recall items are preceded by a pound symbol (#). Reference items are actions to
be done while reading the checklist.

Each crewmember is required to know all recall items. However, bullets, notes,
and bracketed items within the recall box support action steps and are not
considered recall items.
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Old 17th Nov 2018, 06:51
  #1347 (permalink)  
 
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Originally Posted by tdracer View Post
For the CS regulations listed in that CRI, compliance must be shown separate to the FAA compliance (btw, the FAA doesn't call them FARs, they are CFR (Code of Federal Regulations) - and the FAA can be quite anal about it if you call them the FARs).
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.
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Old 17th Nov 2018, 09:19
  #1348 (permalink)  
 
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In an interview Thursday, Capt. Todd Insler, chairman of the United branch of ALPA, the Air Line Pilots Association union, broke ranks with his counterparts at American Airlines and Southwest Airlines who earlier this week publicly complained that this wasn’t disclosed to pilots during training or included in the 737 MAX pilot manuals. Insler said many systems on an airplane work in the background without the pilot’s knowledge. He compared it to watching television: “I don’t need to know how it works.”
What a silly comparison!

Dispute arises among U.S. pilots on Boeing 737 MAX system linked to Lion Air crash
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Old 17th Nov 2018, 09:47
  #1349 (permalink)  
 
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Originally Posted by gearlever View Post
United Airlines pilots do not need to know the details about how their planes work ??!! oops...
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Old 17th Nov 2018, 10:07
  #1350 (permalink)  
 
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I don’t need to know how it works.”
What a damming statement reflecting an attitude to safety. This taints all of us.

Unfortunately this attitude exists in other forms; “don’t tell us that, we will only be examined on it”. Quoted from a ground school of the initial cadre of instructor pilots, because the overseas manufacturer was deemed unsuitable to instruct line pilots. Perhaps that says something about regulation, but in this instant probably reflects unionised bias clouding the priority safety aspects.

Recognising that there might be systems or instances where working knowledge is not required, there is still always need of information when the system fails. There is as yet no specific drill, but when one is formally agreed, (even the interim one), then working system knowledge will be required to aid interpreting and applying the abnormal drill. e.g. how does the pilot interpret ‘un-commanded’ trim movement; MACS could appear to be doing that in normal operation; the difference between normal and failed might only be determined after 10sec of trim operation, - fly the aircraft, check for other combinations / confirming / confusing alerts.
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Old 17th Nov 2018, 10:47
  #1351 (permalink)  
 
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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
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Old 17th Nov 2018, 12:01
  #1352 (permalink)  
 
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Originally Posted by pax2908 View Post
United Airlines pilots do not need to know the details about how their planes work ??!! oops...
I'm absolutely speechless about the attitude of a pilots union head.
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Old 17th Nov 2018, 12:26
  #1353 (permalink)  
 
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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?
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Old 17th Nov 2018, 12:33
  #1354 (permalink)  
 
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Originally Posted by groundbum View Post
The job is more system engineer than flyer these days..
G
The automation doesn't land on icy runways with strong crosswinds, nor does it thread it way in breaks in lines of TRW.
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Old 17th Nov 2018, 14:38
  #1355 (permalink)  
 
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Originally Posted by infrequentflyer789 View Post
I still don't get how only one sensor failure can upset MCAS, I can't (or don't want to) believe they took a direct output from one sensor into the stab trim.

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".

Last edited by QuagmireAirlines; 17th Nov 2018 at 15:31.
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Old 17th Nov 2018, 16:16
  #1356 (permalink)  
 
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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?
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Old 17th Nov 2018, 16:20
  #1357 (permalink)  
 
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Originally Posted by grizzled View Post
quagmire (post #1364):

...what the heck has happened to our industry?
Fast big bucks.
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Old 17th Nov 2018, 16:49
  #1358 (permalink)  
 
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Originally Posted by grizzled View Post
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?
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.
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Old 17th Nov 2018, 16:49
  #1359 (permalink)  
 
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Angel

Originally Posted by gearlever View Post
Fast big bucks.
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.
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Old 17th Nov 2018, 17:29
  #1360 (permalink)  

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"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
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