BOAC

I am confused by this comment. Do you mean that this belief is correct? That it cannot be stalled in Normal Law. Or that they they correctly understand the material they are given but this is incorrect.

Can you clarify whether you are saying they are right or that they are misguided in this belief.

Thanks

"Do you mean that this belief is correct?" - as I understand it, yes, it is correct, but I am not Airbus qualified. Sorry - I thought it was clear.

So, they are right to just pull back in Normal Law then! That's a long way from believing your aircraft magically can't stall which is what you seem to be claiming.

Not in my opinion. What I posted was "and full back stick can be the way out of trouble".

But now I'm confused! Can you clarify? Are you saying you can stall an Airbus in normal law? You would never catch me just pulling back on the stick and trusting in the machine, Airbus or not, despite what any TRE might tell me.

......and by the way, I am not claiming "your aircraft magically can't stall" - I would not be that foolish. Merely stating what I understand from many comments on many fora and excited, breathless words from AB pilots over the years.

An airbus can stall in normal law, although the only normal law, no failure incident that I am aware of is a severe windshear that momentarily outpaced the EFCS. The crew pulled back in sheer terror and this action along with the EFCS saved the day. The EFCS quickly unstalled the wing then maintained max alpha to rapidly recover the A/C from a 4000 fpm descent below 1000 aal.

As this example shows in a huge number of cases simply trusting the system IS the right thing to do. For example, Airbus FBWs can carry out terrain avoidance maneuvres that are simply impossible on other types. An outfit I am 'familiar with' had just such an incident, full back stick on receipt of the hard 'pull up' just saved them (rad alt at the peak around 40ft). They trusted the system in this instance as they are rightly trained to do and it saved them. Had they pulled to some other less restrictive parameter or not just got on with it (as you suggest) it is highly likely the A/C would have been lost.

In very many circumstances crews are quite right to trust the EFCS to help them out and I believe a number of A/C and pilots) are still flying today because the system helped them. There is a training issue around educating crews when to trust it and when not to and what to do if it isn't doing what it should. But that is entirely different from the claim that 'children of the magenta' as so many ignorant (in the literal sense) posters have it, only know how to fly a computer.

There is training, and then there is experience. In a perfect world the experience does the training and tries to pass it along.

Unfortunately for a long time Airbus didn't train from experience, but TO the lowest common demoninator.

FBW is great. But it doesn't make up for a lack of experience and training in the extreme.

On a Bus, or any other aircraft with a FPV (bird, velocity vector, etc), drop a perpendicular from the pitch bars to the FPV. That is your AOA. If you are less than stalling AOA, you are not stalled. \

Airbus doesn't teach or train this. They should. If they had, AF 447 would have had a lower probability to happen.

This isn't Boeing vs AB. Boeing doesn't teach this either. Fighter guys with HUDS know this as gospel.

- since you seem to be on a different topic and seeing things I have not posted, I think I will bow out of this discussion with you. I actually asked "Are you saying you can stall an Airbus in normal law?" which is a different issue, and I did post "I am not claiming your aircraft magically can't stall". I do not recognise your supposed quote "not just got on with it (as you suggest)" by the way.

Anyway - moving on - for 3holelover (post #34) - there you have it. The answer from someone who says he/she is an AB multi-type TRE. I think we can distill the opinion there that it is taught that (as I understood) it is impossible for a pilot to stall an Airbus in normal law, but obviously as with any flying machine, dynamic un-commanded events can take a serviceable AB into a stalled situation from which it will self-recover given sufficient margins. The question of how you disabuse the 'absorbent' pilot of this instinct when all is not well has not been answered and indeed may well be pivotal. If this belief persists the fault lies fully with the training system, as I have said for many years.

Just clarify as it seems some are finding this difficult.

AB pilots are quite rightly trained that the EFCS can be trusted in NORMAL LAW, to protect the A/C from stall. In the overwhelming majority of cases, (e.g. EGPWS), using the edge of the protection such as pulling full back without hesitation is precisely the right thing to do. In the TRTO that I work for we are at considerable pains to make sure crews understand that this is not effective in degraded scenarios.

BOAC

Your statement

strongly suggests that you wouldn't be 'just getting on with it' as a correctly trained crew would in most GPWS scenarios, for example. I didn't use your exact quote to avoid the rather cumbersome multi-quoted post look. If you would never just pull back then your FO would be quite entitled (indeed duty bound) to take-over for you and pull back while you did whatever you were doing instead of 'just pulling back'.

Another example why aviation morons will never be on the endangered species list:

.... just as Airbus can't stall in normal law and your grandmother can fly any Airbus.

Continue that BS and you are not only not helping Airbus's renommée, but actively encouraging stunningly stupid manoeuvres like this accident displayed. :ugh:

4 years after the event and (as an engineer) I am still annoyed by this.

1. AoA meter: yes would have been useful but any pilot capable of discerning its usefulness would be unlikely to be in this situation in the first place. Crucial to recovery and avoidance of secondary stall, but you need to get to the correct mental picture first. In a situation where the world seems to have gone mad, its output would have been condemned with all other indications.

2. Unusual Attitude Mode: well that turns out to be f' all use. How unusual do you have to get. How about an unusual dynamics mode (ie descending at 10000ft/min, nose in the air, engines at full thrust when 2 mins ago was crusing at 35).

3. Inhibition of stall warning. Well Ok, see where the designers where going...

4. Affirm mode by changing some colours on the FD ? In a crisis I am supposed to notice and swing my mind around to that ?

5. Let the THS go way beyond normal limits and not scream about it ?

6. Have a SOP which says blank FD when the software could automatically do it ?

Trouble is that in design you design around nominal conditions and then think about isolated excursions/perturbations. Need to crowbar the logic in some situations.

How about a 'Ghastly Silence' mode (combine it with Unusual Attitude) in which all noises and flashing messages are inhibited except for the crucial ones (OK a button push and you can have all you secondary and tertiary warnings and warblings back), such as what protections have been inhibited, pitch, descent rate, air speed, trim and any other thing you guys think are the first things that should be addressed.................

Gretchenfrage

Being able to fly a precise max-alpha DOES allow one to fly a terrain escape maneuvre that would be unachievable on a conventional aircraft. So where exactly is the BS. Perhaps you should restrict your insulting comments to areas you have knowledge of. Of which this is not one.

Perhaps the answer is that you cannot have it both ways. In that case you have to make a choice between one philosophy and the other.

It's easy enough to reset software. Not so easy to reset human beings. To get focus back, first thing is to deny as many opportunities to focus on the wrong thing as possible.

- is that not EXACTLY the problem I think lies here?

The pilots need effectively to understand 2/3 'philosophies' - slightly different 'rules of flying' in each law, and to be able to 'switch' seamlessly from one to the other, probably when the :mad: is hitting the fan. An easy task for a 'HAL' with loads'a lines of code, but for we mere mortals....................

That's not what I meant. The choice I referred to has to consider the probabilities. How often happen incidents like the two described in post #46, and how often does an Airbus get into alternate law?

Perhaps we need to remind ourselves that in AF447 the airplane did not stall due to 'full back stick'. That took place half-a-minute after the airplane was stalled.

I understand your point, but would also point out re "how often does an Airbus get into alternate law" - that on some occasions that it has, trouble has resulted.

Incidentally, I did not directly link 'full back stick' with 447 in my posts, but since you have raised it, and perhaps to complete a circle, why was the stick subsequently held back, do you think?

That's really anybody's guess, and I've given mine earlier. He had been*keeping the nose up at around 15 degrees, and applied full back stick when the nose dropped below that target.

bus TRE

1. An Airbus can crash, stall, CFIT etc. like any other aircraft.
2. An Airbus is not worse than any other design, but it is not better just because of its design either.

I don't want to enter the statistics debate again, but another FBW design has a better safety record. This is not to say that this one is better, but it simply anihilates the eternal myth that certain thing never happen or are much less prone to happen on Airbus.

In the mentioned case it might be true that flying precise max-alpha is the best way out of terrain trouble, but this can be done just as well without Airbus FBW. I have flown the AB, the T7 and the MD11. All of them FBW and they are equally good in flying out of terrain. Even the older stick-shaker mounted aircraft can fly out of trouble close to stick shaker and with average skills the pilot can get asymptotically close to what the Airbus admittedly does very nicely.
Your call that this is only achievable on Airbus is quite preposterous.

It is this myth of some invulnerability of Airbus that cultivates pilots who fly escape manoeuvres with full stick back in any situation.

Sure enough they have heard and were once briefly trained that in such and such law this and this does not work, however if you do such and such the system reverts to this and this, you simply have to switch that and that and consider this and this, then you will know that such and such manoeuvre does not work, however the this and this can still be applied.
You super TREs, Dozys and not to forget the Clandestinos, you astronauts might well know that at any given moment and at least one of you even knows how to do that in real time. But if you are completely honest, you might admit that when the s#!t hits the fan in real life (as opposed to the desk), for some awfully long moments your brain goes into shedding mode.
It is in those moments when the dumbed down assumption that Airbus will take care of everything takes over and the followers just pull and wait. QED.

That is what I call BS, that is what any common sensed pilot and TRE should fight. A start would be to stop with such dumb assertions that Airbus does this and that better than others. It is a fine machine, but that's it.

Another BS is the call for more protections, more automation, more gimmicks to check, recheck, countercheck and overrule anything a pilot does in the cockpit.
Anything can and will fail eventually, Murphys law is a present as Alternate or Direct law. Even such add-on gimmicks can fail. What if all screens go blank? It has happened! In what law are you then????

What we need is a simple independent back-up to all the electronics like i.e. a pneumatically (wind) driven gyroscopic horizon and a unprocessed access to the flight controls.
And then we need pilots who still are capable to fly an aircraft with that!!!!!

That should help in the first moments, not any pretension that the aircraft will do it for you.

Hi BOAC,
I think he was mistakenly performing this following procedure.

"Airborne, initial climb or landing
THR LEVERS AT TOGA SET OR CONFIRM
AP (if engaged) KEEP
SRS ORDERS FOLLOW
If necessary, the flight crew may pull the sidestick fully back.
Note:
Autopilot disengages if the angle of attack value goes above α prot.
If the FD bars are not displayed, move toward an initial pitch attitude of 17.5 °. Then, if necessary, to prevent a loss in altitude, increase the pitch attitude."

I guess he thought that since he was definitely airborne that it was necessary to pull fully back.

We dinosaurs were taught to "respect the stick shaker" during these manoeuvres. Airbus doesn't fit one - just another audio warning on top of constant "C chord" altitude deviation warning.

Posted one year ago:
http://i.imgur.com/QIX3o.gif

We probably could achieve a similar outcome with a less colourful description

Just need two AoA probes to freeze at a similar angle ... High angle protection no more but normal law still.

Surely a report must be somewhere ... or is it only AF to have their 'adventures' exposed ?

CONFiture

Yeah, I said an airbus CAN stall in normal law!

Don't know if the report is in the public domain. But I do know that the investigation team produced profiles for the escape maneuvre which included 'average' airline wide profiles for comparison which didn't clear the terrain.

and
I don't understand why you gentlemen think you do not need AOA indicators.

Of course you cannot fly as accurately by just triggering the stick shaker as you could fly with an actual AOA indicator directly in front of you, but if you had an AOA indicator and used it, your performance should not be far different than the EFCS max AOA performance.

In the situation just mentioned by CONF iture, there would be unreasonable AOA values staring you in the face as you decelerated. You would have to be asleep to miss it.

I used to fly Zlin 142 at 180° alpha (very briefly) with stall warning ringer silent, yet a couple of seconds later it went off quite happily as I botched the exit from Immelman.

Now, can we accept that alpha probes need to have some airflow to work reliably or do we keep on harping that they have to work perfectly from zero kt to Mmo, which is quite a wishful thinking?

Sigh. What was the initial crisis?

Sigh again. What is the normal THS limit? Did THS follow the pilot's stick order, yea or nay?

Fictional software. As developed and certified - can't.

When one's notions are both at odds with official documents and totally disproved by reality and yet still there is urge to promulgate them on internet fora, crowbaring the logic is quite appropriate.

Worked well around here until a couple of days ago.

Obviously, my umpteen attempts at explaining the protections were just too technical. Let me try it this way: why do you think Airbus pilot needs to understand what you have labeled "2/3 philosophies"? Why would the Airbus pilot need to know anything about protections at all (besides them being covered in FCOM and there being legal requirement to know one's manuals)?

Panic.

So sayst thou.

Not necessarily just because it's a FBW of different flavour. Part of it is certainly attributable to her price tag combined with date of service entry - she just didn't trickle down yet to lower tiers operators.

Since when LSAS counts as FBW?

Escape from what? Under what circumstances?

There is absolutely no realistic doubt that hard alpha protected aeroplane (such as Embraer) performs better in windshear/ground escapes than those with overridable prots. Why would anyone call assertion stemming from flight test results dumb?

Where would you power your pneumatic AH from with dual bleed failure? Why ISIS doesn't satisfy you? Did you ever hear about direct law, which is exactly what you propose but is in operation since 1988? Why do you feel the urge right now to denigrate alternate law?

Well, since you have so nicely copypasted the procedure 'tis a pity you didn't include the title of it.

It's low level windshear encounter.

What does it have to do with cruise, beats me. Lest you want to suggest that it is indeed difficult to tell the difference between low level maneuvering and cruise flight.

Even the report confirmed it is pretty superfluous as natural buffet is quite pronounced.

And it says : "STALL STALL STALL STALL STALL STALL". Pretty unambiguous, eh?

Pray tell, how did it occur?

Parbleu! Wasn't there any indication in cockpit something wasn't quite right?

A student pilot would not have had a problem recoverying from his instructors guidance.

Well, I'm not so sure you do. If the aircraft had remained airborne for another 2 seconds, the words the Capt was in the process of uttering would probably have confirmed the issue - one way or the other.

Another AoA disciple speaks
 

I welcome USMC to the fray. Seems to be from the "next generation" from 'bird and I, but has the same feelings/beliefs about AoA as RetiredF4 and other folks here that have used HUDs and AoA indicators for thousands of landings ( not hours, considering our mission lengths),

It is true that you can use the FPV relatonship to the ship's "boresight" to determine AoA. But why go thru that when you can have a simple display that shows your AoA WRT to stall or best approach AoA ( speed will vary depending upon gross weight and configuration)?. My leading edge flap failure video is old and grainy, but you can easily see it WRT to the pitch lines, and both are related to the real world via an inertial system, with no regard for frozen speed/altitude sensors. AoA doofers are still working. We can laugh at my mistakes near the end, but I corrected enough to save the jet and my skinny butt. The AoA is that braket below the FPV, and had I tried to reach the dersired AoA for normal approach, I would have lost roll authority, so I flew at a lower AoA. As with the A-7, F-14, F-16, F-15, AV-8, F-18, F-22, and now F-35 you pull to get the braket even with the FPV, or push. My upward FPV change near the end was due to extra power, as I had started down quickly when putting out speed brakes from habit ( not good).

http://www.sluf.org/misc_pages/lef-landing.m4v

So much for the basics of using AoA and FPV.

I'll guarantee that the AF447 troops would have noticed their FPV WRT to the pitch lines and realized that the FPV was not going up and that AoA was above the stall AoA. Pitch attitude be damned.

No doubt the unreliable speed was a factor, as was trusting the "protections" when in a back-up flight control law. But inertial vectors and operable AoA displays would possibly have saved the day.

- sorry, they still are - I do not understand the question.

Regarding AoA and the Oozlum bird. Forget the AoA. It would take enormous training input and costs no-one will justify, and can easily be 'missed' in a panic too - yet another gauge. All we need is pilots who understand basic flying, and that a PITCH attitude of 17 degrees at 38000' is just silly. I believe they never went below 5 degrees? 3 instruments already there, apparently working, displaying this, and used for 'basic flying'. End of? The challenge is 'why'?

BOAC

Agree. Introducing AoA would add a layer of complexity that will probably produce more problems than it solves.

Natstrackalpha

What utter balloney. You know nothing of the sort and how the hell do you know the real attitude was different from that on the ATT indicator? Please do tell.

It's embarrassing sometimes.

Show us the exact quote from the report

absolute c****n

Now read this carefully. WHERE IN THE REPORT DOES IT SAY THAT THE PFD WAS READING S&L WITH THE NOSE POINTING UP. Show me where it says that because I can't find it.

Yes you did. It does NOT say this in the report and you are full of it.

- are you talking ("PFD diplaying S&L") about the brief interval between zooming up at several thousand feet per minute and zooming down at around 10,000 fpm? Yes, they probably were "S&L" for a moment or two - it is called the 'apogee'.

Hi BOAC,

I don't want to interfer to much in your discussion with HN39, abut still I'm puzzled by your comment about the different laws.

I mean, aren't crew supposed to be able to adapt to slightly different 'rules of flying'? Isn't that the very purpose of "keeping" crews and not letting computers alone in the front end?
- Crews are able to understand (and manage) an engine failure, resulting in slightly different 'rules of flying': less thrust available and dissimetry.
- Crews are able to understand (and manage) a fuel leak or a depressurization, resulting in slightly different 'rules of flying': range is shortened, altitude is limited (if depressurization).

Why would crews not be able to understand (and manage) the slightly different 'rules of flying' that some sensor failure may cause, such as the loss of protections caused by law reversion? :confused:

I fail to see the fundamental difference you seem to see between those different failures.

AZR

Its not the crew, the airlines or the training. All airlines train and all crews are trained - it is the type of training that needs to be reviewed.

AZR - I agree with NTA on that and have said it before many times. I don't know the answer to your question, but in the absence of any logical explanation for AB events such as 447 involving 'failure' of the protection systems, I am asking. A kind of Occam's razor, I suppose?

Quote:
Why would crews not be able to understand (and manage) the slightly different 'rules of flying' that some sensor failure may cause, such as the loss of protections caused by law reversion?
AZR

Its not the crew, the airlines or the training. All airlines train and all crews are trained - it is the type of training that needs to be reviewed


Quote:
Why would crews not be able to understand (and manage) the slightly different 'rules of flying' that some sensor failure may cause, such as the loss of protections caused by law reversion?
AZR

Its not the crew, the airlines or the training. All airlines train and all crews are trained - it is the type of training that needs to be reviewed
Re quote from Natstrackalpha about the type of training given.
Could not agree more!!!
Forget meaningless time in the sim and trying to land on the piano keys. Fully held off landings seem to be a thing of the past except on 2 airlines mainly crewed by "real pilots". WHY. Try landing an old taildragger without this method and watch the resulting bounce(s)! As a result the U/C gets a pounding. You might float down the R/W a bit but no worry.
In our budget restricted times who wants to shell out on tyres and U/C for clueless but highly educated individuals (poorly trained) who cannot fly.

Seems that all you need for a career is education. WRONG WRONG WRONG. A passion for flying is what you need. Go back to teaching basic piloting skills and not just fly by numbers and the world will be a safer place!!!

Hear endeth the rant:D

I wonder whether it is correct to say that the 'rules of flying' change with the FCS laws. It seems to me they depend on the urgency of the problem.

Situations like low level wind shear and GPWS warning leave no time for thought and just carrying out a drill without hesitation might save the day. In those situations being able to pull without fear of stalling must be an asset.

In AF447 there was no such urgency. The plane would have landed safely in Paris if the pilot had just sat back and 'done nothing'. In that situation there is no need to rely on any protection and the 'rule of flying' in alternate law is no different from that in normal law.

Natstrackalpha

You haven't the faintest clue what you're on about have you?

As I don't understand what NTA point is (perhaps because I'm under the impression he didn't get the facts right), I'll pass to comment on that.

OK, thanks.

I'm not aware of a long list of "AB events such as 447 involving 'failure' of the protection systems"... :confused:
About the logical explanation, there is one in the final report (as to why 447 crew, and more precisely PF, acted as he did) that looks convincing to me. This could led to technical modifications re: FD availability, but I fail to see how a modification to the protection system would be sensible. On that topic, and the existence of the alternate law (that some people judged misleading and/or dangerous), I just read "QF32" by Cpt de Crespigny and found his view on the matter reassuring.

Finally, if I understand correctly, the "go full back stick and trust protections" is teached *only* for low altitude, terrain avoidance events (e.g. CFIT trajectory, windshears...), *not* as a one-fit-all recipe to get out of trouble.
So AFAIK, HazelNuts39 has it right. :ok: