View Full Version : 737 Stall Training - Alaska Airlines Sim
Put up for interest
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plhought
2nd Sep 2016, 01:58
These guys did it for real 15 years ago:
https://vimeo.com/8511733
It was part of some sideslip testing.
Interesting. The Alaskan video says this training will be mandated by for all FAA airlines by 2020. What is EASA's policy on this? It also suggests a full 4 hour (2 hrs each pilot) training session for 15 manoeuvres of upset prevention and upset recovery. Good news and a marked expansion from the 20 min, 3 stall, stick shaker recovery exercises now included. The 15 min upset recovery refresher during the 3 year recurrent training cycle might have to be expanded also. That will alter the training courses quite significantly. I hope the training syllabus allows for more basic handling of normal manoeuvres before this training session.
Nightstop
2nd Sep 2016, 09:15
Recently did A320 high altitude stall recovery in the Sim, a very useful excersise. Interesting that a few turns of forward (nose down) Stab trim was required to get the nose to drop, in addition to full forward sidestick (with takeover pushbutton pressed too...).
vapilot2004
2nd Sep 2016, 09:29
What is EASA's policy on this?
Unless they have changed their collective minds recently, last I heard, EASA, unlike the FAA, does not believe full stall training is a useful exercise, yet, in agreement with their US counterpart, they do understand the importance of upset recovery for both type rating and recurrent training scenarios. Perhaps they will change their minds, eventually.
Fursty Ferret
2nd Sep 2016, 10:22
Two points:
It's interesting that on the video the autopilot was used to fly the aircraft into the stall on each occasion, which strikes me as appalling design now we're well into the 21st century.
Secondly, Airbus are emphatic that the simulator should not be used to demonstrate, nor attempt to recover from, a full stall owing to lack of aerodynamic data in that region. "Approach to stall" (audio warning or buffet) is all that's approved IIRC. Do Boeing have a different view?
With regard to Boeing, and B737NG in particular, does anyone have a TR syllabus that demonstrates the pseudo stick nudger? It's still there, I believe, but with little information about it. When I wrote a TR course I used to go past the stick shaker to demo the system. It's part of the a/c systems. With other later TR's everything is at the stick shaker. Is the system still installed? If so, why is it not known about?
bburks
2nd Sep 2016, 18:23
Boeing has provided validated flight test data of full stall up to 10 degrees beyond critical AOA to provide an accurate model, for the 737NG fleet only. The Bihrle company has produced engineered data that also provides a representative model. Both models have been assessed, evaluated and approved by the FAA and by thorough testing by SME's with hundreds of actual stalls in the 737NG. The first full stall demo is accomplished on the Auto-Pilot so as to allow the pilots to observe all of the cues preceding stall up to full stall (the A/P will not dis-connect like the 777, 787). In addition, to manually fly into the full stall requires so much elevator back pressure on the column, as to make it quite un-realistic for the first demonstration. Later, the pilots will manually fly into the full stall.
bburks
2nd Sep 2016, 18:29
The Elevator Feel Shift (EFS) is installed and active. It is rarely seen in flight training, as it becomes effective after stick shaker AOA is reached, just preceding critical AOA. It was designed to address FAA Part 121 requirements for the B-737NG fleet to exhibit a positive nose drop behavior in stall. As the NG has a super-critical wing, and as the lift curve of the wing does not fall aggressively at and beyond critical AOA (it is a rather flat line), the nose drop is rather benign. Boeing designed the EFS as an additional cue to the pilot of full stall, by forcing the control column forward. You will notice this behavior (if the simulator is properly qualified) in stall training now, particularly when manually flying into full stall.
vapilot2004
2nd Sep 2016, 19:39
Secondly, Airbus are emphatic that the simulator should not be used to demonstrate, nor attempt to recover from, a full stall owing to lack of aerodynamic data in that region. "Approach to stall" (audio warning or buffet) is all that's approved IIRC. Do Boeing have a different view?
I have been told this, informally by more than a few 'insiders', but was not sure of the veracity of their claim regarding EASA and Airbus. Do you have a source Master Ferret?
Also, approach to stall, with identification of cues is the classic ATPL training scenario. We are hoping to move beyond that.
Bburks: Thank you kindly. Thus it disturbs me that a type rating course does not educate the student pilots that this system exists and does not let them experience it. I am, perhaps, being idealistic in believing that a type rating course should educate you in all the options and aspects of the aircraft you are being certified to fly as PIC, and as Commander. Silly me.
Secondly, Airbus are emphatic that the simulator should not be used to demonstrate, nor attempt to recover from, a full stall owing to lack of aerodynamic data in that region. "Approach to stall" (audio warning or buffet) is all that's approved IIRCFursty this is simply not true. Both high level and low level stalls are part of Airbus Syllabus. On the other hand there is a presentation by airbus on stall recovery. The old recovery procedures with emphasis on minimum loss of height has been discarded after commuter crashes in the US where the thrust vector prevented the pilot from decreasing angle of attack. The video emphasises on the reduction of angle attack first and when aircraft unstalls only then increase thrust but not slam TOGA as before but as required. It further explains that previous recovery method was based on approach to stall condition but it is difficult even for a test pilot to recognise whether it is full or incipient stall condition. What airbus doesn't want is jet upset training because of device constraint and not stall training. I read it somewhere that the first simulator(not airbus) for UPRT has been built.
vilas,
What airbus doesn't want is jet upset training because of device constraint and not stall trainingMay I disagree with you? Please see OTT ref.: 999.0077/16 released 20th June 2016
Fursty Ferret
7th Sep 2016, 09:12
What airbus doesn't want is jet upset training because of device constraint and not stall training
Ahhh... I see. I was told that beyond the deterrent buffet and initial nose drop in the stall Airbus lacked the data to say how the aircraft would react other than to the correct pilot response.
Your point makes more sense.
ZFT
Can you paste the OTT? Doe it want upset/stall training or doesn't?
It does. I will try and paste later but it is long ZFT
Can you paste the OTT? Doe it want upset/stall training or doesn't?
Zaphod Beblebrox
7th Sep 2016, 22:07
Two issues come to mind in my limited experience with stall training. The 737 and A320 series may not demonstrate a significant "stall break." I was trained in light aircraft and they tended to have a very definite break which identified the stall. The movie shows only limited nose over. The second issue, which has been discussed in depth and which I have experience in our simulators is, It can take 3000 feet to recover from a high altitude stall. Less if you don't try to recover too soon. The airplane is slow to recover and you have to give up significant altitude to regain energy. So no break and even if the stall is recognized, not holding a full corrective input with reduced angle of attack for long enough can lead to trouble as recent accidents have demonstrated.
ZFT
Can you email the OTT please?
Yes, PM me recipient ZFT
Cyan you email the OTT please?
Mad (Flt) Scientist
8th Sep 2016, 17:55
Can I caution people to be careful when using the apparently simple phrase "full stall" as this means different things to different people. A full aerodynamic stall can be rather different that a full (certification/demonstration/flight test - pick your term) stall, especially on an envelope protected aircraft. So whether a specific OEM supports a "full stall" may be very dependent on what EXACTLY you mean.
There is no difference between envelope protected and unprotected aircraft as far as stall is concerned because unless protections are removed the aircraft won't stall. The difference can be in aircraft behaviour between flight path stable and speed stable aircraft.
Clandestino
1st Oct 2016, 16:01
Unless they have changed their collective minds recently, last I heard, EASA, unlike the FAA, does not believe full stall training is a useful exercise,Given the amount of altitude required to get the jet airliner outta full stall, its usefulness might be limited to scaring pilots of ever approaching the fully blown stall on line.
Good thing I did full stall on my last type rating sim. Possible cause might be I was trained by the Dutch, rather than the Europeans.
The old recovery procedures with emphasis on minimum loss of height has been discarded after commuter crashes in the US where the thrust vector prevented the pilot from decreasing angle of attack.Could you please provide reference to these accidents?