High Altitude Stalls – how well do you understand them?

[Boris Badenov]

Certainly an interesting article, and thought-provoking. I'd be very interested to see the correspondence between seagull and Jimmy.

And I've ~2000 hours in turbojets, mostly as PIC...zero formal training on high altitude stalls. But I've done plenty of V1 cuts! Discuss!

 

[Cherokee_Cruiser]

Certainly an interesting article, and thought-provoking. I'd be very interested to see the correspondence between seagull and Jimmy.

And I've ~2000 hours in turbojets, mostly as PIC...zero formal training on high altitude stalls. But I've done plenty of V1 cuts! Discuss!

Exactly. By law we are required to practice the statistical chance of not only losing an engine, but losing at the very instant defined in time by a certain speed. The chances of both occurring simultaneously are next to nil (that having been said, we had a crew recently at VX that had a real life V1 cut).

Still, point being that the feds have demanded controlling an aircraft with a failure of the critical engine at takeoff decision speed and continuing airborne, and coming back single engine hand-flown ILS.

And yet, cruise flight, where we spend 90% of our time and has been the phase-of-flight for the last several crashes (Air Asia, Air Algiers, Air France), we don't want to mandate high altitude upset recovery and stalls with the same importance as V1 cuts and single-engine handflown ILS. Now that's rondonculous.

 

[PeanuckleCRJ]

I am not sure you have those "stabilities". Where did you get that information? I appreciate the feedback, and will correct that if accurate. For reference, my friend, Clive, who "chopped" this article was chief aerodynamicist for Concorde as well as chief UK engineer on the A330. I would think he would have caught an error like that, but I will make some inquiries just the same. The French chief engineer on the A330 is also an acquaintance of mine.

As for the 17 degrees, true, but I don't think it is as salient as you might expect, particularly when the FD is pitching upwards. I think the HF issues in my article on Salient Symbols and the HUD are applicable to this issue.

Stabilities exist in most flavors of alternate law, however if it is due to an airspeed unreliable situation (ADR disagree or failure), the high and low speed stabilities do not exist due to the fact that the plane isn't sure about its speed. So in this situation, there likely wouldn't have been high and low speed stability.

Getting target fixated and following the FD during a situation like this (as the probes iced over) is very much a danger! Much better to just get the FDs off and revert to basic pitch and power.

 

[TwoTwoLeft]

Aerodymamics for Naval Aviators is interesting but not exactly an easy read, especially for the Math challenged.

I've flown with guys who couldn't average two numbers on a performance chart, no way in hell they're understanding anything here.

The math is only there to quantify the concepts, not explain them. While not the easiest reading, it is organized well with fairly straight forward explanations. If anything, it makes you aware of things you might want to look into farther from a different source that is easier to comprehend. That, I'd rather get this kind of information form those who have actually done it, and literally wrote the book on it.

 

[Boris Badenov]

Getting target fixated and following the FD during a situation like this (as the probes iced over) is very much a danger! Much better to just get the FDs off and revert to basic pitch and power.

This is a problem that I *have* actually seen. A lot of guys seem to be unable to look through the FD, even under far less trying circumstances. I'm not one of those dudes who uh "instructs" other ATPs on technique, but I really have to bite my tongue when some unexpected instruction comes and the other dude is fiddling with the FD controls for longer than a few seconds. Turn it off, grab the great big handle bar thingie in front of you, and make the plane do stuff. Fix the bars later. They're a tool. You don't fiddle with the guide on a circular saw when you hit a knot and it goes all catywampus, do you?

 

[cmhumphr]

Good read. Thanks.

 

[CoffeeIcePapers]

This is a problem that I *have* actually seen. A lot of guys seem to be unable to look through the FD, even under far less trying circumstances. I'm not one of those dudes who uh "instructs" other ATPs on technique, but I really have to bite my tongue when some unexpected instruction comes and the other dude is fiddling with the FD controls for longer than a few seconds. Turn it off, grab the great big handle bar thingie in front of you, and make the plane do stuff. Fix the bars later. They're a tool. You don't fiddle with the guide on a circular saw when you hit a knot and it goes all catywampus, do you?

As a right seater at a training facility, I saw a lot of this. It is really hard for people, especially ones without a strong background in flying without an FD, to step down the automation ladder.

 

[Boris Badenov]

As a right seater at a training facility, I saw a lot of this. It is really hard for people, especially ones without a strong background in flying without an FD, to step down the automation ladder.

To be fair, at every training facility I've ever been to, if you're turning the crap off, you've already pretty much failed. This isn't the fault of the instructors, or probably even the facilities. They're doing what the FAA mandates they do. Which is teach V1 cut after V1 cut, single engine approach after single engine approach, etc etc.

And don't get me wrong...it's absolutely essential that one know how to operate the automation on a modern jet. Even if it were legal, handflying a jet in RVSM is kind of silly, on a day-to-day basis. But what we're confronted with as "likely catastrophic events" seem to me to be, eh, not entirely likely. Or at the very least not anything near comprehensive of what is likely. *shrug*

I've always maintained that the best boon for safety that simulation companies could give would be one extra day of training wherein one is confronted with a "real-world" problem. It would be a non-jeopardy event, at least based on things that have actually happened, and you wouldn't know ahead of time what it would be. In the best case it would involve knowing the systems of the airplane and using that knowledge to affect a good outcome. But, you know, wish in one hand...

 

[PeanuckleCRJ]

To be fair, at every training facility I've ever been to, if you're turning the crap off, you've already pretty much failed. This isn't the fault of the instructors, or probably even the facilities. They're doing what the FAA mandates they do. Which is teach V1 cut after V1 cut, single engine approach after single engine approach, etc etc.

That is not the case at DL. If the crap hits the fan and the automation is giving bad info, if I see a guy recognize that and de-automate to get the aircraft into a stable state.... I'm doing cartwheels and setting off fireworks back at the IOS.

 

[Inverted]

You would think... This book has only been around for 50 years or so....

View attachment 30938

This should be required reading for any pilot, it's a very good book.

 

[ClearedForOption]

I am not sure you have those "stabilities". Where did you get that information?

Here's the info cribbed from my 320 crib sheet:

Low Speed Stability

A low speed stability function replaces the normal angle of attack protection, and is activated approximately 5 to 10 knots above the stall warning. With low speed stability, a gentle nose-down command is initiated which attempts to keep the speed from slowing further. This command can be overridden by the sidestick. The airplane can be stalled in alternate law. An audio stall warning consisting of “crickets” and a “stall” aural message is also activated.

In alternate law, the PFD airspeed scale is modified. While the VLS indication remains displayed, Vα prot and Vα max are removed. They are replaced by a red and black barber pole. The top of the pole indicates the stall warning speed (Vsw).

High Speed Stability

When flying in alternate law, a nose-up command is initiated any time the airplane exceeds Vmo/Mmo to attempt to keep the speed from increasing further. This command can be overridden by the sidestick.

ALTERNATE LAW WITHOUT SPEED STABILITY

With specific failures, the airplane reverts to alternate law without speed stability. When this occurs, the control laws are identical to alternate law; however, the low and high speed stability functions are lost. Only the load factor protection is provided. In addition, yaw damping is lost if the fault is a triple ADR failure.

 

[Inverted]

I've always maintained that the best boon for safety that simulation companies could give would be one extra day of training wherein one is confronted with a "real-world" problem. It would be a non-jeopardy event, at least based on things that have actually happened, and you wouldn't know ahead of time what it would be. In the best case it would involve knowing the systems of the airplane and using that knowledge to affect a good outcome. But, you know, wish in one hand...

This is how my current company trains on its PC cycles. FSI is expected to switch to this style of training for all fleets and companies within the next couple of years.

 

[Boris Badenov]

That is not the case at DL. If the crap hits the fan and the automation is giving bad info, if I see a guy recognize that and de-automate to get the aircraft into a stable state.... I'm doing cartwheels and setting off fireworks back at the IOS.

I can only speak to FlightSafety (a long time ago) and CAE or whatever they're calling themselves this week (more recently). It was all canned, and one was presented with more-or-less what the checkride would be on the first day. To be clear, it's not that I exactly disapprove of this. Any training that isn't counter-factual is good training, in my book. And the spaghetti monster knows that I don't know (yet) what a Hawker feels like on one engine. So, you know, all to the better if I do 5 V1 cuts. It helps me to understand the performance of the airplane, above and beyond the primate reflexes of what buttons or pedals to mash down on (or not), etc.

But, you know, these guys have boxes to tick, and them sims is tres precious to operate. So one tends to find themselves rushed through whatever disasters have little boxes on the FAA form from 1970. I don't even disapprove of a canned checkride...it doesn't seem quite cricket to have a checkride where the expectations aren't known, and it's obviously open to all sorts of Shenanigans from an IP who's having a bad day or doesn't like one's choice in sportswear, etc. if it's NOT canned. It just seems like maybe we could do both. Like, sure, test the poop out of me on the monkey-items. Because that learning transfers, too. But then possibly also give me a scenario that's a little bit more like what might actually happen. You know, three hours in to a five hour flight from the Teterhole to Grenada and woopsie you just lost two inverters. Whadya do now, Ace? Alternately, maybe you're descending in to Cabo and Jose just put you on a vector towards them mountains over thar, then got waxed by the Zetas because he had a little side-bidness. When do you say "screw it" and launch in to the stratosphere? You get the idea. I'm not advocating "real-world" training exclusively...just maybe a bit of both. *shrug*

 

[PeanuckleCRJ]

What you described as ideal is more or less the AQP that the airlines do, Boris. (with various flavors of course)

 

[BobDDuck]

You get the idea. I'm not advocating "real-world" training exclusively...just maybe a bit of both. *shrug*

Like Denny said, you are talking about AQP style training. I just finished up my yearly CQ two weeks ago and it consisted of three 4 hour sim sessions.

The first day is a warm up and first look day where we basically just do some maneuvers and try out the stuff that we have been "trained" on last year to see how well we've retained it. Here you knock out things like steep turns, V1 cuts, a few stalls and some approaches (including a SE approach). There is no jeopardy on this day.

Day 2 is a maneuvers validation. Basically most of the stuff you'd see on a tradition PC is "tested" although you can retrain and practice stuff you don't get correct, as needed. Also "specialized" operations like RAs, EGPWS escapes, windshear and some QRH work is covered here. Because it's a validation of just maneuvers, the instructors can reposition the sim as needed so you aren't wasting huge amounts of time flying from one maneuver and approach to the next.

Day 3 is "Line Operations Experience" or "Line Oriented Flight Training" (LOE/LOFT) depending on what your program calls it. This is a flight from point A to B (although it's rare that you ever actually land at point B) that incorporates hot button issues from FOQA, ASAP, FAA bulletins and other sources into a SOMEWHAT realistic flight.

The LOFT last year (we are supposed to keep the current year's scenario secret so crews go in to it cold) consisted of a flight to a nearby airport with some weather enroute and then an RA. A rainstorm dropped the visibility just before landing so you had to go around and then ask for (and get) an approach with better mins. After that approach doesn't work you had to divert to an alternate (your listed alternate was deteriorating so you had to work with Dispatch to get a better one) and then, while on route, your pressurization failed, requiring a quick trip through the QRH. It was slightly busier than any "normal" abnormal you'd probably see but it wasn't too bad. This year's was slightly more task saturated and unrealistic, but still possible.

After spending 8 years doing a PC/PT (although eventually the PT became kind of like a LOFT) every 6 months, I do like the 3 day setup and my only complaint is that the scenarios tend to be scripted to the point that there is very little decision making required and despite the fact that it is a choose your own adventure kind of test, there really is a very limited number of adventures you can actually take.

 

[ppragman]

Like Denny said, you are talking about AQP style training. I just finished up my yearly CQ two weeks ago and it consisted of three 4 hour sim sessions.

The first day is a warm up and first look day where we basically just do some maneuvers and try out the stuff that we have been "trained" on last year to see how well we've retained it. Here you knock out things like steep turns, V1 cuts, a few stalls and some approaches (including a SE approach). There is no jeopardy on this day.

Day 2 is a maneuvers validation. Basically most of the stuff you'd see on a tradition PC is "tested" although you can retrain and practice stuff you don't get correct, as needed. Also "specialized" operations like RAs, EGPWS escapes, windshear and some QRH work is covered here. Because it's a validation of just maneuvers, the instructors can reposition the sim as needed so you aren't wasting huge amounts of time flying from one maneuver and approach to the next.

Day 3 is "Line Operations Experience" or "Line Oriented Flight Training" (LOE/LOFT) depending on what your program calls it. This is a flight from point A to B (although it's rare that you ever actually land at point B) that incorporates hot button issues from FOQA, ASAP, FAA bulletins and other sources into a SOMEWHAT realistic flight.

The LOFT last year (we are supposed to keep the current year's scenario secret so crews go in to it cold) consisted of a flight to a nearby airport with some weather enroute and then an RA. A rainstorm dropped the visibility just before landing so you had to go around and then ask for (and get) an approach with better mins. After that approach doesn't work you had to divert to an alternate (your listed alternate was deteriorating so you had to work with Dispatch to get a better one) and then, while on route, your pressurization failed, requiring a quick trip through the QRH. It was slightly busier than any "normal" abnormal you'd probably see but it wasn't too bad. This year's was slightly more task saturated and unrealistic, but still possible.

After spending 8 years doing a PC/PT (although eventually the PT became kind of like a LOFT) every 6 months, I do like the 3 day setup and my only complaint is that the scenarios tend to be scripted to the point that there is very little decision making required and despite the fact that it is a choose your own adventure kind of test, there really is a very limited number of adventures you can actually take.

Man, I would love to see this kind of training applied to FSI or just the 135 world in general. When I was doing training stuff for my old job, I'd try to get guys over to the FTDs that we had available and load them up with stuff like this, but it wasn't always practical to do so, and most guys were more interested in "what's on the checkride" than doing any extra curricular activities in the sim. It'd be amazing if it was more common in the 135 world.

 

[seagull]

Most of the time you will have these high and low speed stability protections in alternate law. There are certain flight control failures (Can't remeber which specifically) where you can lose these stabilities.

Ok, have confirmed my suspicions. The low speed term to the control laws are absent with loss of airspeed (no reference speed for it to use!). added that "the term is for compliance with 27.173 (a) ; the requirement that a pull must be required to obtain and maintain speeds below the specified trim speed and vice versa. The usual "g demand" laws do not give this. In normal law of course it is overtaken by the high aoa protection laws which do relate aoa to stick movement/force."

 

[Blackhawk]

A few thoughts.
1. I second what has been written about AQP. The one other thing my airline does is train specific maneuvers that have been IDed through the listed sources. For example, I know high altitude stalls (or "USA Today Stalls" as they are sometimes called), are covered at least once as well as dual relight.
While it takes a little research the same type of training can be done under 91 and 135. One of the things I cover in type specific training with students are some of the recurring accident themes in their aircraft type.
2. I was surprised at how minimal some airline training is. For example, after Pinnacle 3701 I was surprised to learn how little ground and sim those polots had- 1/2 what I had. They never covered a dual relight- not required.
3. Unfortunately with the quick upgrades and the scramble for regionals to find pilots I think we will have another Colgan 3407 event within a few years as we have relatively low experience pilots flying swept wing airplanes.

 

[Louie1975]

Agreed, there are better out there.

Seagull, what is a good Intro to Aerodynamics book that you would recommend?

 

[seagull]

The Flightwise series by Chris Carpenter are really good and easy to read, covers the topic well. Next would be Shevell's book, Fundamentals of Flight.