Alaska to put new pilots through a 4hr upset recovery training

[Guest]

How Does A Boeing 737 Handle On A Full Stall?

Aug 19, 2016John Croft  | Aviation Week & Space Technology

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Alaska Airlines will begin putting new pilots through a 4-hr. upset recovery and prevention indoctrination that includes full stalls and a host of other potential loss-of-control scenarios. Aviation Week senior editor John Croft demonstrates recovery from several full stalls during his sampling of the training in Alaska Airlines’ Boeing 737-800 simulator.

And don't miss our report on air safety technologies.

[Don Hudson]

And for a bit of history, same author, same subject in 2014.

One of the comments below the article brought up the subject of "stall data", and where is it, how is it obtained, (one can't derive it or model it, if it is to be a real, (simulated) stall and recovery - this was the problem of using the AF447 accident in training scripts, although the real value is in experiencing the loss of airspeed information, not recovery from a stall.)

 

Full-Stall Simulators Take Shape

Stall-capable simulator traits due soon

Mar 24, 2014John Croft  | Aviation Week & Space Technology 

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It will be summer before an FAA preliminary rule to upgrade full-motion simulators with extended models to handle full stall training hits the streets, and nearly five years before airlines have to officially put the updated machines to work. Despite the long grace period, the industry is taking a proactive stance on the safety improvements triggered by new flight-training rules, finalized in November and designed to help pilots recognize and recover from fully developed stalls and attitude upsets, often caused by stalls. 

“We're finding that there are a variety of different airlines and training organizations trying to do some of this work in lieu of formal requirements,” says Jack Ralston, president of Bihrle Applied Research, a developer of extended simulator models for civil and military aircraft. “A lot of actual users are anxious to get started.” The FAA will issue a preliminary version of the formal requirements, known as the Part 60 rule, this summer, but a final rule could take a year or more to complete. 

In the meantime, industry has some fairly solid clues from the FAA in terms of what will be required of simulators in 2019 when the flight-training rule goes live. In January, the agency's National Simulator Program (NSP) published preliminary guidelines to qualify a simulator for the full-stall maneuvers. Simulators today must correctly represent an aircraft in the “approach to stall” regime, where recovery is initiated at the first indication of the stall, typically at the activation of the stall warning system or stickshaker, occurring at or below the stall angle of attack. 

 

The NSP says the 2019 full-stall simulator models should mimic the actual aircraft to “at least” 10 deg. beyond the stall angle of attack and exhibit the same degradation in pitch, roll and yaw stability as the actual aircraft in a stall. Judging how well the simulator performs will be a subject matter expert (SME) pilot “with relevant experience in the aircraft,” typically a test pilot who has performed many stalls. 

Guidance on the types of stall models that might qualify comes from an FAA study last year. The agency brought nine SMEs—test pilots with stall experience—to its Boeing 737-800 simulator in Oklahoma City to evaluate stall models of varying complexity, hence cost to develop. The group evaluated the standard as-delivered 737-800 simulator model, but with a more pronounced “buffet,” the rumbling that occurs as airflow separates on the top of the wing near stall; a Bihrle-developed “representative” model built from computational aerodynamics, wind-tunnel data and input from a test pilot with “extensive” stall experience in the 737; and a “specific” model Boeing built from 737-800 flight-test data from “hundreds” of fully developed stalls, including turning stalls. Given the flight-testing required, a specific model will be more costly to develop than the representative model, which could be built to emulate a variety of aircraft with similar characteristics (low- and under-wing engines, and conventional tail). In some cases, flight data may not be possible to obtain for aircraft that are out of production. 

On average, the test pilots “somewhat agreed” that any of the models could be used for stall-recovery training, but “wide differences of opinion arose between the particular models,” say the authors of the study, including Jeff Schroeder, FAA chief scientific and technical adviser for flight simulation systems. It could be that more than one model is needed, Schroeder concludes.“Some preferred to be challenged by what could happen in a stall. Others preferred the more benign, typical responses,” he says. “This is an important training question; do you show what could happen or what happens on average? Perhaps the best answer is to show one of each.” The tests confirmed what Birhle's and other experts had suggested, that representative stall models are feasible when flight data are not available. 

What the test pilots did largely agree on was that the correct buffet response is important to training. “Even after more than doubling the buffet response [of the unmodified simulator], most of the test pilots believed the buffet cue was less in the simulation than in the aircraft,” says Schroeder. 

Along with developing representative models, Birhle also has come up with a technology to upgrade simulators without changing the basic system, an external “stall box” the FAA used for the model testing in Oklahoma City. Ralston says the stall box overwrites the existing simulator model when the aircraft reaches certain thresholds near and beyond the stall, and would not require the basic simulator to repeat its qualification. The system can also drive tablet-based displays of yoke, throttle and attitude positions, and g-force envelopes to help instructors keep pilots within valid bounds of the extended simulator model and to replay pilot performance afterward. 

For the stall box, Ralston envisions a two-tiered system where airlines would pay one price without the box active and a higher price for an activated stall box. He says, “You would not have to dedicate a single simulator for full stalls.”

[boestar]

When I was working in Flight test on the Global Express we had access to an EICAS page FOR FLIGHT TEST ONLY that displayed the Angle of atttack of the aircraft in real time.  This was used during certification flights when the aircraft was testing the envelope.  I often wondered why there was no AOA indicator in the cockpit as a rule.

 

[Don Hudson]

boestar - just to add to the discussion:

The Airbus can display AoA using a maintenance MCDU feature, (maintenance display of aircraft parameters).

A rough AoA can be quickly viewed by using the FPV symbol and comparing it to the pitch attitude. If the pitch is say, 12deg, and the FPV is showing -6deg, the AoA is, very roughly, 18deg. It's not as good as an AoA indicator; - a positive pitch attitude with a descent rate of say -15,000 fpm is a better indication of a stall...

Frankly, I don't think the industry has demonstrated the need for an AoA indication in the cockpit, and I don't think it would have made a difference to the AF447 A330, AirAsia A320 outcomes.

We have used the relationship between pitch and airspeed forever and it works, even though it is very much an indirect relationship and does not apply in abnormal attitudes. In my view, recent stall accidents speak to inexperience, training priorities, oversight (including FDM programs) and a dumbing down of requirements under the impression that automated aircraft fly themselves. I know that these ideas have been around a very long time and some carriers are actually requiring one sim session per year with purely manual manoeuvres.

Distantly related, I think the advent of autonomous vehicles will see a rapid rise in accidents just as the aviation industry did 28 years ago when the A320 was introduced. It doesn't appear that they are examining, or willing to examine the human factors behind automation and risk.

 

[Don Hudson]

Agree with you entirely on teaching AoA and its importance, particularly at high altitudes.

Discussion:

The BUSS system is a visual presentation of the pitch-thrust charts. Yes, it's based upon AoA not airspeed, but it's use has been discouraged by Airbus, (Note: but not prohibited), above ~FL250, ostensibly because it is Mach No. not airspeed which governs stall AoA.

From an A320/A321 QRH:

AFFECTED ADR IDENTIFICATION
PROBE/WINDOW HEAT........................................................ ..............................ON
ALL SPEED INDICATIONS................................................. ......................X CHECK
ADR3 and STBY speeds use the data of the same probe.
- If at least one ADR is confirmed reliable:
RELIABLE AIR DATA........................................................ ........................... USE
UNRELIABLE ADR P/B(s)........................................................ .................... OFF
- If affected ADR(s) cannot be identified or all ADRs are affected:
- When above FL 250:
ONE ADR......................................................... ...............................KEEP ON
TWO ADR P/Bs.......................................................... ............................. OFF
This prevents the flight control laws from using two coherent but unreliable ADR data.
For flight continuation, Refer to Pitch/Thrust Tables.
- When below FL 250, if speed still unreliable:
ALL ADR P/Bs.......................................................... ............................... OFF
SPD......................................................... ........................... FLY THE GREEN
NAV ADR 1+2+3 FAULT Procedure................................................... APPLY  

The recommendation in the QRH drill above is the same as prior to AF447 - pitch/power.

Further observations which support the point I'm making regarding the industry not demonstrating the need for AoA indication, (Qualifier: for experienced transport pilots) are:

One should intuitively know that just because one has lost airspeed indication that the airplane "doesn't care", and that what settings were fine prior to the loss are almost certainly going to be fine until the airspeed indication returns, particularly at cruise altitutudes. This knowledge was clearly evident in ~30 flights but not in AF447.

How would "BUSS" actually prevent a crew member from applying 15deg NU?

In the end, pulling a transport aircraft up to 15deg at cruise altitude is just something one absolutely never does because one knows, or should know on an intuitive level, (I know you know this...I'm speaking broadly about the industry),  that the reserve energy is tiny and that the AoA between normal cruise AoA and stall AoA is equally tiny, yet there it was in AF447.

I submit that most transport pilots do not know that the margin between normal cruise AoA's, ~1.5 - 2.5deg and the stall AoA is tiny - about 3deg or so, depending..., and that is the real point I am making - it's aerodynamics, not memorized book knowledge I'm emphasizing and the industry has failed to convey that understanding. There is no sense in having AoA if one doesn't know what conveys in all flight regimes.

For a transport pilot AoA is another indication of airspeed in normal operating regimes. If the "saves" are there like they are with EGPWS & TCAS, then I would agree with your view regarding AoA indications as a solid means of stall avoidance.

With the AF447 and Air Asia accidents, the crew's disconnect between the pitch attitude and the rate of descent which in AOMs is stated as one indication of a stall, would not have been aided by an AoA indication.

I have become convinced that "startle" will have played a greater role in both accidents than I had first given credit for.

[Kip Powick]

4 hours ago, Don Hudson said:

I submit that most transport pilots do not know that the margin between normal cruise AoA's, ~1.5 - 2.5deg and the stall AoA is tiny - about 3deg or so, depending.

Yup, we ex RCAF types called that area "coffin corner".....

The only place I think an AOA indicator would be advantageous to have is in the approach and landing phase of  a flight..... especially in bad weather.

 

[Don Hudson]

Thanks for the reminder of the term Kip - yes, I recall it from two sources - a set of DC-8 Manuals and introductory training materials given to me by a good friend of our family's at Canadian Pacific who flew the aircraft and who sometimes before his flight, got me into the cockpit at YVR, and D.P. Davies, (1967 edition).

I understand "coffin corner" doesn't really exist for modern transport wings in the same sense that it existed say, for 2nd generation transports, (B707, DC8, B727). The Airbus for example, just won't climb anymore, particularly with hair-dryers with which the -300 series was powered, but won't stall either.

Complex topic and I'm rapidly getting way out of my depth!

[Guest]

One question re the Alaska program, "why only new pilots"? Do they / we assume the "Old" crews are proficient in this regard? 

[DEFCON]

"I submit that most transport pilots do not know that the margin between normal cruise AoA's, ~1.5 - 2.5deg and the stall AoA is tiny - about 3deg or so, depending..., and that is the real point I am making - it's aerodynamics, not memorized book knowledge I'm emphasizing and the industry has failed to convey that understanding. There is no sense in having AoA if one doesn't know what conveys in all flight regimes."

That's a pretty scary observation when you think about all the potential consequences.

It's hard to imagine, but a serious loss of control event occurred fairly recently while a Q 400 was being flown 'manually' at altitude in turbulence.

It gets even better; in another more recent event, the crew of an E jet were apparently forced by circumstance to admit to ATC that they didn't know how to 'ident'.

It would seem that a very large piece of the safe flight equation is becoming substantially degraded.

 

  

[boestar]

Question:

If you are flying on a Transatlantic route (or pacific for that matter) and out of positive radar control.  What are the rules governing loss of altitude?

I am asking what the risk is in a loss of altitude say as a result of a stall recovery.  I would assume there could be risk involved.  

Would thos rules cause someone to "pull back" to maintain altitude as opposed to lowering the nose adn doing a standard stall recovery?

 

[rudder]

1 hour ago, boestar said:

Question:

If you are flying on a Transatlantic route (or pacific for that matter) and out of positive radar control.  What are the rules governing loss of altitude?

I am asking what the risk is in a loss of altitude say as a result of a stall recovery.  I would assume there could be risk involved.  

Would thos rules cause someone to "pull back" to maintain altitude as opposed to lowering the nose adn doing a standard stall recovery?

 

Same as for emergency descent or descent due power loss (eng fail/fire). Turn 45 degrees off track and fly out 15nm then parallel track and descend. Delay descent until beyond 10nm if practical. Monitor TCAS. Broadcast position and actions on 121.5 and 123.45. Advise ATC.

[Kip Powick]

4 minutes ago, rudder said:

Same as for emergency descent or descent due power loss (eng fail/fire). Turn 45 degrees off track and fly out 15nm then parallel track and descend. Delay descent until beyond 10nm if practical. Monitor TCAS. Broadcast position and actions on 121.5 and 123.45. Advise ATC.

I hardly think that if a crew encountered an "upset" or stall, the last thing they would be thinking about would be turning off the NAT TRACK and following the loss of power or pressurization procedure.

Their primary thoughts would be to get control and establish a stabilized flight and then follow the recommended procedure once their heart rates became close to normal.

 

[blues deville]

8 hours ago, Kip Powick said:

I hardly think that if a crew encountered an "upset" or stall, the last thing they would be thinking about would be turning off the NAT TRACK and following the loss of power or pressurization procedure.

Their primary thoughts would be to get control and establish a stabilized flight and then follow the recommended procedure once their heart rates became close to normal.

 

Bad situation but if there's another aircraft 1000' below you on the same NAT, PACOT, or NOPAC it would have to be given some consideration or yours might not be the only upset event. 

[Kip Powick]

8 hours ago, blues deville said:

Bad situation but if there's another aircraft 1000' below you on the same NAT, PACOT, or NOPAC it would have to be given some consideration or yours might not be the only upset event. 

Fully agree and hopefully it never happens...again....however I would use standard stall recovery, (push forward...keep wings level...(rudder if required) .build up airspeed and when out of the stall add full power and gently climb away.

I have not flown the new breed of plastic and bundled-electrons aircraft, (777/787/etc), so perhaps they have a different mode of recovery,

Attempting to use ailerons or other wing devices and turn will only aggravate a stall....take my chances and fly straight ahead and hopefully the PNF would broadcast what was happening and all aircraft in the area would be keeping a lookout  

[DEFCON]

If you somehow manage to get into a stall on the NAT, I think your only reasonable action would be to recover the aircraft exactly as described by Kip. TCAS would be everyone's best avoidance tool at this point. 

[blues deville]

2 hours ago, Kip Powick said:

Fully agree and hopefully it never happens...again....however I would use standard stall recovery, (push forward...keep wings level...(rudder if required) .build up airspeed and when out of the stall add full power and gently climb away.

I have not flown the new breed of plastic and bundled-electrons aircraft, (777/787/etc), so perhaps they have a different mode of recovery,

Attempting to use ailerons or other wing devices and turn will only aggravate a stall....take my chances and fly straight ahead and hopefully the PNF would broadcast what was happening and all aircraft in the area would be keeping a lookout  

Recovery technique is the same. Still a swept wing jet. 

A few sim sessions ago they had us practicing high altitude stalls. Had never done this exercise before and I was amazed at how much altitude you will lose before fully recovering. I'd be curious to know how much of a warning a TCAS system will give with an aircraft falling out of the sky from above. As with many events in life, timing is everything!

[DEFCON]

"I'd be curious to know how much of a warning a TCAS system will give with an aircraft falling out of the sky from above."

I'd think the TCAS would probably work as expected, but the response time might be degraded during the short seconds it takes the pilots in the lower aircraft to get over the WTF startle effect.

 

[blues deville]

A good video of how much traffic is crossing the North Atlantic on any given day or night. 

 

[Guest]

'

Thanks "blues deville"

[blues deville]

2 hours ago, DEFCON said:

"I'd be curious to know how much of a warning a TCAS system will give with an aircraft falling out of the sky from above."

I'd think the TCAS would probably work as expected, but the response time might be degraded during the short seconds it takes the pilots in the lower aircraft to get over the WTF startle effect.

 

Agreed. However, my point is a TCAS event with one aircraft possibly out of control and unable to follow an "RA" climb instruction meeting another at an unavoidable closing rate.

 

. 

[DEFCON]

I agree Blues, things could get ugly.