Once again if you lose airspeed and are in level flight flying fine why not just stay in level flight, make sure the thrust is reasonable, pull out the unreliable airspeed checklist and truck on. I wouldn't pull up for no reason just because IAS went away. Would you?

He has released the sidestick, for less nose up, but to point the nose down (negative pitch), that won’t be the FD command if the goal is to reduce the V/S to a still positive 1500 fpm. What could have helped to point the nose down and let all the problems behind was for the PF to promptly request to his PNF to select a negative V/S on the FCU (probably at least minus 1000 fpm …), if his goal was to benefit from the FD directions of course, but for that, he would have had to realize first that the present vertical command was unrealistic.

To be honest, I know little about the Boeing FBW.

No, my suggestion is simply the result of many years of observation. If you reduce the laws and the complexity, you end up with something more straight forward and simple for the pilot thinking. It means that for every single simulator session, a way or the other, the pilots will automatically be exposed to direct law with the necessity to manually trim if in manual flight (why AP could not be avail in direct law ?), and a clear thinking of what is available or not.

Is it such an handicap to fly direct law after all ?

You most probably know much more than me regarding the B. FBW, but what I can say is that up to now, and the triple 7 is flying for a while, I simply never ear about it – Something must be good.

You’re talking here as an engineer, not a guy who regularly seat in a simulator and has to deal with the amount of malfunctions and emergencies.
Also, I have never read in an official documentation that touching the wheel when autotrim was operative, was prohibited. But shame or not, as RF4 mentioned, interfering with the autotrim is not a procedure, nothing to encourage a pilot to do so.

Houston, I think we have a problem!
 

This really isn't news fresh off the presses, but the the incident mentioned in the thread "An other AF 447 avoided?" over in Rumours & News has resulted in a BEA report on the incident. For those English speakers who have not seen the BEA report, there is an repost of an informal translation by Simon Hradecky here: http://www.pprune.org/7199637-post311.html
Retired F-4 has already plucked out the salient facts and the implications are chilling.
http://www.pprune.org/7200167-post314.html

The thing that really gets me is this statement:
The thing that helped save the day here is that the aircraft was still in Normal law.
The crew of AF447 was even more confused than these guys and were flying in Alt2.

In my day, I had to develop a mental mechanism to cruise at my assigned altitude. A part of my brain was continuously noting altitude and continuously striving to work out a strategy to "lock on" to the assigned altitude. This mechanism ran at a subconscious level. Not really very different than the effort to keep the wings level and nose at cruise attitude which also ran at the subconscious level.

It is clear that some pilots are losing this mental mechanism, or even worse, not developing it in the first place. There is only one way to keep this mechanism active, you must exercise it regularly.

Do we really just want to put another squawking computer nag in the cockpit just to declare this problem solved? Wouldn't it be better if we just insisted that pilots actually fly their aircraft for a percentage of the time aloft.

I've heard the explanation that the requirements of RVSM airspace preclude pilots from actually handling their aircraft. Maybe that should be reviewed. I could hold within 200 feet of assigned altitude while hand flying about 99.9% of the time, and the worst I ever saw was 300' off due to distractions, and this was in a single pilot fighter. Is that good enough for RVSM airspace?

A pilot should never be so mentally disengaged from the aircraft that it takes almost a minute for him to realize he is seriously off altitude. This was the initial piloting problem leading to the downfall of AF447. :mad:

Am I being unrealistic?

Dozy:
it's not either / or. That same check/cross check is required even for fancy fighters. Also, most modern fighters, F-16 to present, have considerable redundancy built in, for both reliability reasons and the operational environment the planes will be in: likely something hits you that takes out a system, or degrades is. Not a lot of single point failure systems hitting production, and that's been true for a while.

HazelNuts39
As I look at MM43's chart, he's already been stalled for a bit (~32 seconds) before he realizes that he has lost the ability to control the aircraft, or at least he feels that way.

OCF (Out of Control Flight) is roughly defined as
"You make a control input and the aircraft doesn't do what it is supposed to do, or what you expect it to do."

At 32 seconds into being stalled, per mm43's graph/picture, the pilot says to his cabin mate "I've lost control" and finally acknowledges that he is in OCF. What doesn't get added up and understood is that he is in OCF, and he is OCF because the aircraft is stalled ... even though the warning that he is approaching stall (and also in stall) has sounded quite a bit in the last minute or so.

While I don't think he just means roll, roll is doubtless a problem for hims since the airfoil has been stalled for about half a minute.

Owain said it far more thoroughly, I was speaking from a pilot's point of view.

The line from Owain that gets me weeping ...
So: why didn't he know he was stalled?
That warning had been available as a cue.
Why didn't he believe it/
Why didn't PNF believe it?
If he was in fact trying to fly 15 deg nose up, on purpose, at that cruise altitude ... WHY?
I don't think he was just making up things to do for himself, he seems to have had the idea that "if I do this, my problem will be closer to solved."
Why did he believe that?
Provisional conclusion: training issue.

Dozy, and others:

When discussing degradation, maybe "gradual" might be a better way to think of it, than "graceful" ... since the odds of graceful performance decrase as degradation increases. ;)

No.

DozyWannabe (re: end of #802 & following):
I agree :)
We all should read the report about the Caracas A343 flight. Startle factor, very much more likely than this or that technical glitch not recorded on the FDR/CVR...

Machinbird (re : #845)
Having 100% "real" pilots is a nice thing. But is it achievable?
I think it's easier (and cheaper) to have an obligation to carry (and use) an A/P to this class of aircrafts, than to have a proficient crew.
In fact, it would be better to have both (as in the "part time manual flying" you evocated), but then the risk would be a manual "super pilot" out of a flight school not really up to what should be expected... this super pilot cannot hold his F/L within 200 or 300ft, but is cleared to fly in RVSM because his paper say he could.
It's far easier to assess if a "machine" works as intended or not, than to assess the proficiency (airmanship, SOP adherence...) of a human being.

I read Bubbers, 'bird, Retired, Okie et al and I, too, question the procedures.

The 'almost an AF447' thread shows what I see as a problem with the procedures, if not with the profiles the jets are flying. To wit, a fascination with overspeed. The reaction to pull up. But then, we see "what the hell are we doing climbing so far?".

Why are the jets flying so close to a mach limit?

Why is not the first step to get the throttles outta the damned "auto" mode?

Why not use same logic for the AoA probes as the pitot probes? If they all agree then keep using AoA "protection" ( how I hate that term).

Where's the PNF commenting about the sustained climb?

And at Doze.... if that's the control laws working "normally" and the standard procedures, then both need to be changed, IMHO.

Hi,

Not deep technical (no drawing or PDF) but I think that the procedure in case of overspeed is the high speed protection come in force:
The AP will disconnect .. high speed protection come active ... as an interdiction to go down and a command to go up and return to normal flight command when end of overspeed
Note that the ATHR still active and will go to TOGA (and so add a little more up movement)
The AOA will increase .. and if too much ... the AOA protection will be activated .. this will give some down command to keep alpha prot and the altitude will decrease
The aircraft will find a balance and will remain in that position and altitude reached if pilot(s) do not touch anything IMHO
DW know certainly better

In my opinion it is. We have enough time in the air to do all sorts of useful training. We just have to figure out how to accomplish the training given our operational constraints.
AlphaZuluRomeo, I think this viewpoint will lead us down the slippery slope leading to no one in the cockpit and when the unthinkable happens, the MBAs will have already factored in the loss into their financial planning.:yuk:

I am not sure why you are using the term "super pilot" except perhaps in a sarcastic vein. The expected level of altitude maintenance accuracy is achievable by properly trained pilots. Early in our advanced Naval pilot training sequence, my classmates and I could all hit this level of performance or we did not advance. Even if a new FO is a little shaky there are things that can be done that will allow him/her to build the necessary competence.

Let us think outside the box for a moment. Supposing we added in a manual flying training mode into our aircraft.

How did you learn to hold altitude? When you began to get a little off altitude, didn't your instructor cluck at you and if you continued to diverge, didn't he give the stick a nudge to put you back in the tolerance band. Why couldn't our aircraft with their sophisticated autopilots do something similar? No need to breech RVSM limits yet we can still get actual handling time and build a scan. Any pilot worth his salt hates having the stick nudged. When you get tired, you can let OTTO have the complete aircraft. Think of the potential to actually monitor a pilot's handling skill and to automatically record actual handling time! True, you won't get as much time to balance your checkbook or to read a magazine, but remember why you are sitting in the front seats!

Good pilots will be able to hand fly and stay at altitude just fine. Computer operator pilots won't. Unfortunately the latter are taking over right now. It is the future in aviation unfortunately. The Bob Hoover types who really know how to fly are scarce. It didn't use to be this way but it is now.

you are right, straight and level flying and maintaining a specified flight level is not rocket science. It has been done before.

Our ferry flights to goose bay / Labrador and back lasted around 8 hours each. The KC135 or KC10 tanker aircraft did the navigation part, and 5 phantoms flew in formation along, when weather closed in even in close fingertip formation. Our autopilot was not useable that close to other aircraft, everything was manual flying including the 8 air-refueling phases. With O² masks on and orange juice self served with a straw. After a 7 hour flight i had to lead my wing man down to landing (he had complete com failure) in marginal weather conditions (rvr 1000 meters, ceiling at 200 feet, no ILS only PAR talkdown). No modern gadgets where available, no FDR and no copilot, just a weapon system operator in the backseat. All pilots of the wing could do that, thanks to lots of training we didn´t need to be skygod.

As often mentioned, it comes down to the will of the management to have trained pilots and not system monitors.

@Machinbird
I like your thinking out of the box, but doubt that the industry can look that far.

Machinbird, I was indeed sarcastic.

I'm sure that having correctly trained pilots is achievable, in the sense that we know how to do that seriously. My concern is about economics for one part (all over the world), and "over there" second/third rank companies for the second part.
How do you assure that all crews are trained as they need to be?
How do you assure that all planes meet requirement criteria?
The latter is far easier to assess, even from a third party (other country...)

As said by bubbers44, because they are not so much needed (in normal ops), pure flying skills are seen as less essential by many (including some crews). With today's planes, a rookie crew can manage a normal flight "full auto" without wetting its pants. It's not good because, as we know, when !!!! hits the fan skills & training remain essential. But they do. That's why I prefer that those untrained crews stay in auto. Not that I will go in their plane (if I can avoid it) but because in RVSM, if such a crew screw it, it endanger its plane and other ones, even if those other ones have a perfectly trained crew.

Your idea of a plane helping the crew to gain certain competences, with instructor-like clues/help for keeping the assigned altitude manually is an interesting one :)

All pilots of the wing could do that ...

ah, but that was in an era when pilots saw the pleasure .. nay, even desired the skill ... of being able to fly .. well.

it comes down to the will of the management

indeed .. but, if most of us have no great trouble taking a chap of modest competence and, in the space of a longish sim session, get him to the stage where he can perform a blind landing to a stop and then, when vis is returned, observe that the aircraft is on the centreline ... surely it is not all that big an ask to desire that pilots might have such a basic level of stick and rudder skills ?

The same can be said of the I/F circuit and ILS recovery in CAT 1 or worse conditions with all pressure instruments having failed during the takeoff rotation into said critical weather conditions.

Yes, it is a cost .. but not an horrendous cost.

I'm not pilot and my uneducated perception about this tragedy is that if the pilot in question had fainted, probably everybody would still be alive. But I admit not reading the previous no doubt hundreds of excellent posts on this topic, so ..

Can someone please summarize the previous 854 posts in 1 or two sentences?

Thnx!

That's hilarious, keesje!

OK, I'll try:

These so-called pilots didn't know how to fly.

But probably the Airbus FBW is evil and succeeded in killing them.

OTOH, what're you, NUTS? Of course, the AB is perfect in every way!

No it isn't!

That is all. Did I leave anything out?

Orangefreak
 

Well summarized !http://images.ibsrv.net/ibsrv/res/sr...ies/thumbs.gif

keesje.
Very infrequently, though more times than acceptable, this type aircraft experiences rare circumstances, generally weather oriented, that cause it to drop out of autoflight (autopilot). In these circumstances, the pilot(s) are required to fly "manually", a more and more infrequent concept. The results can be loss of control, uncommanded excursions of flight path, and other disconcerting and unnecessary events.

Necessary competence on such occasions has been found wanting, and incidents and accidents have resulted. The maker of the aircraft, and the pilots, both have work to do.

And the regulators.

But in this case there was no apparent "confusion" over laws. The drop to Alternate was called by the PNF, but the PF either didn't notice or disregarded the call. At no point does the PF question why the aircraft is respnsing the way it is and at no point does he quesiton the fact that the aircraft is clearly not in a protected mode.

Because the system works differently to other airliners. Traditional layouts have the AP designed with hard limits, whereas the Airbus design has those limits as part of the flight control logic. In any case, it's not a good idea to use AP when there is a pitot/static failure as the AP limits can take an aircraft right up to the edge of stall (see the Birgenair 757 case).

It's more of a jump from Normal to Direct than it is via Alternate, that's for certain - and because autotrim is designed to replace manual trim by feel (because there's no backdrive), a systems failure in the middle of bad weather is not a good time to be made to do it for real.

A lot of lay folk (and indeed the press) are unaware that the T7 is in fact full FBW, because the fact was not publicised as widely when the T7 was launched. The T7 computers *did* come under a lot of scrutiny during the BA038 investigation - especially in the early days before the AAIB ruled them out as a contributing factor.

I've said this before, but the Boeing system is in fact more complex than Airbus's from an engineering standpoint because of the backdrive. In fact it would have been unwise to attempt backdrive on the A320 because of the immense amount of extra complexity involved - the almost decade-long gap between the A320 and B777 projects meant that the hardware could handle the extra load safely.

The most concise way of describing the difference in approach to protection is that the Boeing system significantly increases resistance to yoke movement when the safe limits are reached whereas the Airbus system simply holds the aircraft in the maximum commanded attitude deemed safe.

Comparing the systems statistically is difficult because the Airbus system is applied across the range where as the Boeing system was applied to only one model (two now that the B787 is in service).

Totally - I was referring to failure modes only. Because one can egress from a fighter in mid-air, a failure mode in which the system can regress to a single data feed if necessary is workable. In an airliner it's simply not reliable enough because there are more lives at stake, and they don't have banng seats.

"Graceful degradation" is an engineering term that simply means that the system is designed to keep the remaining system components functioning in a way that can assist the operator, rather than dumping them in the cacky at the first hurdle. It has no bearing on the way the operator uses that system in a degraded state!

The myriad failure modes are grouped into "Laws" simply to aid understanding. In this case, Alternate Law exists to keep the aircraft handling as close to the way it does in Normal Law as it can, so that a pilot is not thrown into a situation where the aircraft is suddenly handling differently across all axes of movement. The pilots only need to remember one thing really - outside of Normal Laws the aircraft is effectively unprotected and needs to be treated as such. Which is not to say that it's not a good idea for pilots to understand the control laws - they should. But the only need-to-know golden rule is that out of Normal Law you need to be careful with manual control inputs.

Airliners do - it's in the nature of the beast.

That happens automatically - autothrust disengages with AP in this situation.

Because there's a worst case scenario failure mode where the failure is in the hardware logic rather than the sensors. If the aircraft is attitude-limited in an inappropriate way because of this then a situation can arise where the aircraft cannot be recovered.

Trust me - no procedures were followed here, standard or otherwise. My personal feeling is that the PF was in the grip of a startle response at AP disconnect from which he never fully recovered. At no point does he talk about control laws and at no point does he acknowledge the information that is in front of him - he simply grabs the stick and starts heaving on it.

If the systems behaves as advertised it will stay within all limits up to the edge of that limit if the pilot tries to exceed them.

There are technical questions that need addressing - the Stall Warning design needs looking at, as well as a backup system that will disable and latch FD in the case of UAS where Normal Law is not recovered among other things. Similarly organisational issues - why the UAS procedure was not drilled into these pilots, why it was the norm that two pilots who had no high-altitude manual handling training or experience were in a position that cut safety margins a little too fine - again, among other things.

But the psychological/human factors investigation is where the heart of solving this accident lies and I'm loath to even try to unravel that.

@ keesje
Just read ! the best posts are at the beginning ! Start with thread 1... (3 short sentences):O

@ AZR
Your cyniscism is out of acceptable limit.:=
Which is the price of your life, of your childrens' life, of the pilots' life ?

As he said, he wasn't being entirely serious - he also said that if an outfit was known to be deficient in training that he would not fly with them (and presumably by extension would not allow his family to fly with them).

The first page of the first thread seems to be largely taken up with discussion of finding the flight recorders using their pingers - are you talking about a different thread?

y PNF
 

Hi Doze,

But in this case there was no apparent "confusion" over laws. The drop to Alternate was called by the PNF, but the PF either didn't notice or disregarded the call. At no point does the PF question why the aircraft is respnsing the way it is and at no point does he quesiton the fact that the aircraft is clearly not in a protected mode.

What a wild statement to make!

The drop to ALTERNATE was called by PNF seventeen seconds after loss of AUTOPILOT. You claim there was no "confusion"? It is more likely PF thought he remained[/I] IN NORMAL than that he thought the LAWS had changed. Evidence would be his ham handed handling of the a/c in manual. One could say he was merely rusty in ALT, but one could also say he thought NORMAL LAW still obtained for flight, and the ship still responsible for smooth.

If PNF was seriously asking "What was that?" re: STALLSTALL, and PF did not even mention it, why would you say he saw amber "ALT LAW" on the screen? One can make no suppositions in the absence of even basic conversation re: CRM.


As to why he did not question why the a/c was "handling different", are you serious? He didn't know it was "handling" at ALL and I suggest he was unable to discern the simple matter of LAW differentiation on the "fly".....

Then he should have been listening.


Just as logically explained by the fact that he had no training or practice in manual handling.

Then - again - he should have been listening

Indeed - we don't even know if "What was that?" referred to the stall warning.

He didn't need to - he should have made small, gentle corrections. Instead he bashed the stick around like he was attempting a crosswind landing. Even in Normal Law this would have brought the aircraft to the edge of stall - those inputs were not only in excess of what was required, but also in excess of what was sensible. Discussion of control laws is a red herring, because it has absolutely no bearing on why those inputs were so inappropriately excessive in the first place.

First and foremost - even if he was in Normal Law, the attitude he was trying to command was completely inappropriate at cruise level.

Laws
 

Just for the record concerning confusion about Laws, it´s not that easy like DW sees it. Look for yourself and call it simple if you like.

@Franzl :

The point I was making was that you don't need to know the specifics as far as Alternate Law is concerned - fly the thing as you would normally fly it, just don't expect the protections to be there.

Is there anything in what you've posted that contradicts the above summary?

Yes, if you are a pilot and understand, how flying itself and management of abnormal situations is functioning in a human brain in opposition to an electronic gadget designed by engineers you will find some points to think over.

And the main problem is, that you normally don´t fly that thing, but you are being flown while monitoring. Except when the !!!!! hits the fan.

Doze.

Even in Normal Law this would have brought the aircraft to the edge of stall - those inputs were not only in excess of what was required, but also in excess of what was sensible. Discussion of control laws is a red herring, because it has absolutely no bearing on why those inputs were so inappropriately excessive in the first place.

Early on, we were treated to closeup video of short finals/touchdown, the pilots handling were stirring mayonnaise, yet the camera outside showed the a/c virtually on rails, very impressive, to see such stickwork. Now that means they were: Johnny Ace, able to fly through anything on a rail, or a forgiving a/c, smoothing stck to find a stable path.

All due respect, the stick was excessive, and the a/c shone brightly as a sweetie.
So I am calling mayonnaise on Bonin, him thinking the ship would smooth his "whatever" stickwork into grease....e thought he was in NORMAL, and made no effort to modify his stick inputs to a LAW of which he was unaware?

LAW has everything to do with everything, in those first twenty seconds. it took the a/c some seconds to load up, and go up, and once committed, no one would be able to suss her attitude. So think DIRECT in roll, and ask: Would this pilot, aware of his AL DIRECT ROLL, act as if he was low, and the a/c made him look good? I say no, and so I conclude his handling bespoke NORMAL, with protections. At 2:10:22, when PNF says "....ALTERNATE LAW", I think he was preoccupied, no, I KNOW he was preoccupied. Why? A pilot who does not know whether he is climbing, at Mach .80, or descending, has not thought of which LAW obtains. So my case is based on: STARTLE (agree?), loss of scan, loss of orientation, and loss of the plot.....This in the first twenty seconds, max. The only save was for the PNF to take over. He didn't. The rest is merely interesting, but the game was over quickly. The PNF and later the Captain, failed, for whatever combination of reasons, to call off the jam, send the RightSeat to jump seat, and fly the plane.

How many times can I say this before it sinks in? The Airbus FBW system was designed by a group that included pilots.

And you're not answering my question. You've got five failure modes there (you didn't bold "In the event of temporary loss of all electrical control:"), only one of which is relevant to the case we're discussing and two or three of which have never actually cropped up on the line. From a piloting perspective the only significant failure mode that requires a different approach entirely is mechanical reversion (i.e USE MAN PITCH TRIM ONLY).

Knowing what those modes mean is helpful, but not crucial. The only thing that *is* crucial is that outside Normal Law there are no protections and as such, more care must be taken.

That is the fault of the industry, not the aircraft or the systems. Even then what you're saying is untrue unless you take a very narrow definition of "flying" to mean direct surface connection, because the flight computers will do whatever the pilot requests them to do (just as their electro-mechanical/hydraulic predecessors did) unless what the pilot requests threatens to damage the aircraft.

Most of the Airbus FBW pilots on here were of the opinion that the pilot in that video overcooked it slightly.

Law has nothing to do with it - even with traditional controls, high-altitude manual flight requires a defter touch than that at lower altitudes, because there's less air resistance.

You mean apart from the whacking great ADI indicator in front of both pilots?

It doesn't matter. Even in Normal Law those inputs would have been excessive. The crucial factor is that he didn't have any high-altitude manual handling experience.

Nor should he or she have to - that's the whole point of the law degradation process.

But will you still feel the same way tomorrow?

The PNF seems to have been entirely reliant on explicit instructions from the Captain to delineate his responsibilities. Once the Captain was there, rather that suggesting that he had an idea of what was going on, the PNF waited for the Captain to perform his own troubleshooting, which wasted valuable time.

I suspect that even after the final report is published, the HF and psychology experts are going to be poring over this one for decades - in terms of complexity it is every bit as morbidly fascinating as KLM4805.

Hi,

The final report will be certainly interesting (more than about thirty days to wait if the schedule of the BEA is respected)
It certainly will conclude with recommendations to avoid such accidents in the future
The trial has come (when ?) will be equally interesting .. but will concentrate more on what could possibly be done before the accident to prevent such a tragedy
The BEA will say what to do .. the trial will probably tell what it should have been done before and why

Machinbird,

I agree with your general comment made on post #850
But it is still interesting to note that on both events you refer to, each time a pilot by his initial action on the sidestick probably tried to correct an attitude that was at least 3 degrees below what the attitude in cruise usually is.

Also, in the AF447 case, a level bust could be understandable and considered as normal as the memory item for UAS states to initially adopt 5 degrees of positive attitude.

I think the disconnection with the altitude became flagrant just later on, when the FD bars reappeared. The crew just didn’t process the altitude when the PF instinctively decided to follow that unrealistic vertical command.

So I agree, if a guy, on a regular base, was manually leveling off at 350, he would deeply assimilate what is the necessary scanning and which level of inputs on the controls are acceptable.

@CONF iture

"So I agree, if a guy, on a regular base, was manually leveling off at 350, he would deeply assimilate what is the necessary scanning and which level of inputs on the controls are acceptable.

Absolutely. One cannot discourage manual control at altitude, and then, after something happens, blame the airman for less than sharp high altitude skills.

True and accepted. You didn´t understand my comment, let me explain my answer a little bit. A computer is doing a failure analysis in simple terms by comparing things in a yes or no system. Out of more possibilities the system will end at a clear decision based on all information and earlier programming in a sequential evaluation process. You can explain that one better than i can, therefore i stop there.
We human pilots have the tendency to grasp all available information at once and in a sum and draw the nearest conclusion out of the available information, the knowledge and our personal expierience. We start problem solving with the nearest probable cause, which might be wrong. The more possibilities there are, the greater the danger to start with the wrong conclusion.

Back to the different laws, if those are not displayed in detail by the system, the degradation of subsystems is not clearly recognizable in such a human thinking process. It´s not only normal and alternate and direct as you say, its complicated as the excerpt of the manual in my previous post clearly points out.

See above. I´didnt answer the question first, because your thinking into that matter is that of an engineer and not that of a pilot. But you are talking to those here and tell them it´s simple three cases and just do that and that. In hindsight you are right, but in reality the crew didn´t know in what kind of law they ended up, wether they had what kind of protections, wether it was ALt1 or ALt 2 or Alt 2b or whatever sublaws are possible and they didn´t grasp the consequences of this degradation and couldn´t base their decision making on that knowledge.

This statement is again not true. Knowing the mode you are in is not only helpful, it is mandatory at some point of the game, and not knowing of the consequences, of the amount of degradation might become crucial, because not knowing might agrevate an otherwise simple situation. Outside Normal Law there is a big variety of protections available or not available, dependent on the individual failure and the degradation the System deems necessary.

Why are you always talking about fault? Any discussion with you ends in statements concerning blaming somebody. I didn´t mention anything concerning who is responsible for that fact concerning hand flying time, i only stated the fact, and you should accept it as ist stands. If you tell people to fly the aircraft in alternate law like you do it in normal law, then that statement is misleading. In normal law you only do takeoffs and landing and everything is done and monitored by the computers. In alternate law the roll yaw is direct, to point only one difference. The THS trim might work or might not work, and so on. It´s different to normal flying and it is differnet to manual flying in normal law (if you meant that one with your term normal flying).

When faced with a sudden failure the knowledge of the nature and detail of the failure and the consequences of failures is paramount. Under that view its best to keep things simple, limited to few cases to aid in a quick and effective decision making process.

At the moment it seems to be a graceful degradation (from the engineering point of view as you say), which keeps the system on the highest possible level, but it is prone to misunderstandings by the human monitor and operator called pilot. A gradual degradation with few and easy understandable steps could be easier understood and could reduce the error possibility.

Go back to the previous threads, how much we all discussed here the different laws and sublaws and their consequences to input and output systems (Autopilot, FBW-System, protections, flightcontrols...), how many wrong statements had been written about them, and we all learned from these errors.

But again, i only wanted to clarify, that the graceful degradation of the Flightlaws is not that easy to understand like you say here. My personal oppinion, all others are entiteled to a different one.

For once I do. I do agree with you, Lyman.
Now, if you would admit that the startle factor doesn't necessarily need (as shown is another AF widebody from Caracas, which made it to Paris) another aircraft malfunction (beside those we already know i.e. pitot freezing & consequences), it would be terrific.

roulishollandais, I was sarcastic at one point, but didn't try to show too much cynism. Perhaps a translation issue? My concern was about the idea about asking pilots to fly manually in RVSM space: With current mean flying levels, I'm afraid it will lead to mid-airs (or airproxes, at last) far too often to be acceptable. I would prefer it was possible to have every crew in the airliner world being able to do this (pretty basic, when you think about it), but when it come to be reliable upon a long period of time, and detecting/alerting as soon as reliability cannot be assured, I'm sorry but we must face it : a computer (never tired, never distracted) do that better than a human being.

Franzl
It all comes down to training and knowing you machine does it not? This removes any misunderstanding of the laws. Then you throw CRM into the mix and you have an solution

Absolutely correct.

But when we or the manufacturer comunicate like DW the asessment, that it flies in the gracefull degraded modes like in normal mode, then we will never get the management to improve the training and knowledge to the required standards.

That's not what I said, and it's not what Airbus say either. What *I* said was that the Alternate flight law was designed to handle as as closely to Normal Law as possible despite the failures that caused the drop to Alternate.

Obviously it can't be exactly the same because there's a failure.

OC I'll put it as simplistically as you have....

Airbus: Oversold, Undersupported. Grasp>Reach.


Doze: "That's not what I said, and it's not what Airbus say either. What *I* said was that the Alternate flight law was designed to handle as as closely to Normal Law as possible despite the failures that caused the drop to Alternate.

In this paragraph is the heart of the flaw in the architecture.....

To wit: "Hide the problem"......

More training especially simulator for those who fly and attempt to assimilate the complexity of the magic machine from Blagnac ... You have my vote !

How about your statement below? (Bolding by me)

Po-ta-to, po-tah-to. You can look at it as "hiding" the problem, but it's really just trying to make the problem more manageable for the person in control.

No-one has addressed the point I made that the inputs made by the PF were wildly inappropriate for the circumstances, whatever the control law. Getting hung up on control laws and degradation distracts from the far more worrying fact that AF (and probably several other airlines) was routinely sending crews up in which two-thirds of the flight crew had no training in high-altitude manual handling.

It's another of those rare occasions where we agree - although I would like to point out that the "machine from Blagnac" is neither magic (in fact it's quite long-in-the-tooth technology-wise these days), nor is it any more complicated than any other airliner designed in that era.

The whole point of the flight-deck design in cost-saving terms was purely related to streamlining conversion training between types - it was never intended to give airlines an excuse to cut back on any other type of training.

@franzl - I think something might be lost in translation. "Fly ... as you would normally" is not the same as "It flies the same as in Normal Law" - the first statement refers to how the human should approach things ("Du sollst") and the latter describes the aircraft's behaviour ("Es verhält sich") - albeit inaccurately.