No, that was not the reason for posting. I referred to page 42 in the same post and at several earlier occasions.

I was wondering whether to dignify this with a reply, but I'm in a realtively good mood, so what the hell...

Aah... I love the smell of ad hominem in the morning - smells like, er, ad hominem.

Yes, and the TRE also failed the speed tape and altimeter on my PFD to simulate the conditions (the sim couldn't fail one or the other - only both), so I read the altitude from the standby. I wasn't giving Lyman an in-depth blow-by-blow account because I wrote about it in extensive detail on an earlier thread, I was simply giving an overall view.

Failing 2 ADCs switches to Alternate Law, as will a UAS event - that was the point I was making.

Now let's see - Alpha Max isn't a protection, it's a variable value indicating the maximum AoA an aerofoil can reach before it stops generating lift (this is simplified, but you catch my drift). AoA is determined by the coefficient of lift, the formula for calculating which includes airspeed/Mach as a variable.

I hope I'm more-or-less right so far, and incidentally, damn you to hell for making me revise algebra for this.

Alpha Prot is a layer of protection within the flight control logic and is the first protection triggered as AoA approaches Alpha Max. This protection inhibits further pitch-up, retracts speedbrakes if deployed and limits bank angle to 45 degrees.

Alpha Floor is a protection within the autothrottle logic and is triggered at a predetermined point between the onset of Alpha Prot and arrival at Alpha Max, and primarily sets thrust to TO/GA.

Neither of these protections are a direct function of airspeed, purely that of AoA - but because airspeed is a variable used in the calculation of AoA there is an indirect relationship. In short, because you can increase your AoA by increasing pitch and by bleeding off airspeed, the relative pitch of Alpha Max (and the protection triggers) will decrease if you bleed off airspeed.

Alpha Prot and Alpha Floor both activate just short of Alpha Max, so when you state that the logic prevents Alpha Max from being reached you are technically correct. However, the reason for holding just short of Alpha Max is because it provides a safety margin. If Alpha Prot triggered at Alpha Max itself, it would take only a small gust to stall the aircraft and the protection would be much less effective.

Well no, but let's not ignore the fact that a significant percentage of the fleet had already had the SB work carried out prior to AF447. And it's not about "killing" a type, it's about airlines kicking up a stink because their aircraft aren't making money while they're on the ground.

Your opinion, to which you are both welcome and entitled. In an ideal world I'd agree - but this isn't an ideal world. As I said, the risk posed by the Thales AA pitot tubes strikes me as considerably less than that posed by the 737 rudder PCU issue, and yet the latter was never deemed worthy of an AD with grounding to take effect immediately or otherwise.

Again with the presentation of your opinion as fact. A few posts back I listed four accidents just off the top of my head where the yoke cue was not acted upon. I'm not disputing that it *might* have helped, but it's a considerable stretch to claim it as a certainty (or an "elephant in the room").

I hate to use a driving analogy because it's not really the same, but when you've been driving for a while you rarely, if ever, *look* at the steering wheel. You're either looking out of the windscreen and reading the road, or glancing at your instruments - the latter of which causes you to look *through* the wheel, which after a time becomes automatic. I'd imagine it's the same for pilots, although they spent a much greater amount of time looking at the instruments and "through" the yoke, if there is one. I suspect this is one reason why there are so many incidents where the yoke position was not taken as a cue.

I'm genuinely curious as to why you think how he opened the door is so important.

Myself dunno if it's more or less important than all other movements .. actions and chatters of the pilots during this night
Anyways .. as this accident seem's very complicated ( flight deck and pilots matter) any clues can be important to find what happened ...
Actually we have ony the sparcely clues provided by BEA in the interim N°3

DW, in utter denial mode, wrote:
IMO, the 737 should have been grounded. This was a (poorly-decided) risk/benefit equation. There were, arguably, more than the three well-known accidents/incidents of rudder hardover/reversals. In hindsight, given the particulars of AF447, the Thales-equipped planes, too, ought to have been grounded. The crash sequence began there and ended hundreds of lives. "...risk...less serious"??? Oy veh! Here's how worried I am about airlines' profits: not one bit. If they can't be safe, they can jolly well fold their tents and get outta the business.

As for CONFiture's opinion, I (as well as others far more qualified) fully agree. Some opinions are more informed than others. It Just Make Sense. Your opinion seems to me to be arbitrary and capricious, with no offense intended, sir. Once more, with feeling, just because it didn't prevent some accidents proves nothing. As we all know, one cannot prove a negative.

Organfreak, please note the part where I said that in an ideal world, I'd agree with him re:ADs and grounding.

You're as free to believe what you wish about yokes as he is, but the fact is that he stated flat out that the yoke position would automatically have been noted. I provide evidence to refute that, while noting that it *might* have made a difference, and *I'm* the arbitrary and capricious one?

Look, I know that a popular conception among some has the Airbus FBW control system being dreamed up by a bunch of us computer geeks, none of whom had ever set foot inside a flight deck, but it just isn't true. I've mentioned this before, but the system was overseen by none other than the late Captain Gordon Corps, who was not only one of the most respected pilots of his day but also a colleague (and briefly the successor) of the late D.P. Davies, who wrote the seminal book on heavy jet operation still in use today. In terms of informed knowledge on the technical and operations aspect of airliners you simply can't get much more clout than that.

As for "It Just Makes Sense" - just about the most subjective statement in existence, because what makes sense to one individual may very well not make sense to others, and in terms of qualitative appraisal is about as useful as "My Dad Always Said", "It Stands To Reason" and "Some Bloke In The Pub Told Me".

[EDIT : Think for a second about the knock-on effect of grounding the 737. In a matter of days you'd be looking at a significant number of airlines - even the safest - folding completely through no fault of their own, if they couldn't find some way of making alternative arrangements. The only recourse they'd have would have been to seek compensation from Boeing, and before long you're looking at a collapse of a large chunk of the industry.

The A330 and A340 are not as widespread, but they make up a significant percentage of long-haul fleets these days.

As safe as air travel has become, the simple physics of what it involves means that there will always be an inherent risk even when everything is plain sailing. Mitigating that risk is a careful balancing act, and sometimes that means making a call that is not only cutting things finer than many (including myself) would like, but also has every potential of blowing up in your face. Real life by definition means compromising ideals and balancing risk on the occasions where the alternative would definitely be worse.]

DW:
I was afraid you'd point out the "in an ideal world" part. I saw it; I should have addressed it. When it comes to air safety, I think we should strive for the ideal, even tho we all know that perfection is unattainable (something I learned long ago as a musician). "Good enough" is the friend of shoddy.

It is obvious that CONF's contention was an opinion-- good writing guidelines tell us that an opinion is obvious and the statement ID-ing it as such should be left out. But it the opinion of someone with a great deal of piloting experience, unlike yourself, or me for that matter. He did not state it as fact because it can't be fact, only a very-informed opinion.

As for the rest of your answer: it doesn't apply. When premier experts design things, we still have to look at mistakes made, ones that could not have been foreseen by any designer-god.

I think we're talking at cross-purposes here. I agree.

Me too.

This wasn't a case of "good enough" as much as "the best that could be done in the circumstances". In this case guarding as much as possible against the risks inherent in doing things one way which could potentially have a bad outcome because to do things the other way would inevitably have a bad outcome.

Whoever wrote those guidelines had clearly never encountered an internet forum before...

Certainly, and if we were talking about airline operations, aeronautics and the like then I'd be all ears. But we're discussing an opinion he formed before he got that piloting experience on political grounds and one he has rigidly stuck to since. The equivalent with me would be over a decade of software engineering experience having no effect on the fact that I find Apple a loathsome company and have done since 1994 - not that it seems to have done them any harm over the last decade or so, so make of that what you will.

Capt. Corps didn't design it, he was responsible for making sure that the system provided a safe and effective way of operating the aircraft, and doing so in a way that a majority of pilots would find relatively natural. By any objective measure, he succeeded. Seeing doing away with the yoke as a "mistake" is very much a minority opinion - and a dwindling one at that.

DW:
Just for fun, and something completely different (I'll never win this argument with you anyway), I've picked out the one part with which I entirely agree! Don't even let me get started on that!

@Organfreak

I'm not trying to win any arguments, I assure you. I'm just presenting rational evidence-based counterpoints to sweeping statements that we're expected to take as gospel.

Just as anyone asking me about Apple needs to take into account my visceral (to put it mildly) dislike of the company and their products when evaluating my words, so it goes with CONF iture and Airbus.

Right - let's get back on-topic.

[EDIT : Hostile? Nah - my natural manner is fairly jovial. Persistent almost to the point of being irritating? Guilty as charged, m'lud. ]

Your Honour, I submit that the witness is hostile.

Jobs and Boyd would have been buds. What makes Apple wildly successful is its genesis in product, and its disdain for tradition, and corporate corrosion, in Boyd's case "stale rank"....

Jobs..."Be Brutal, keep moving, and don't be satisfied..."THINK MOTION"

Boyd... "The victor is agile..."

Neither tolerated the status quo, and rejected explanations that took longer than two seconds...

The death of corporate agility started with the first committee.....

The evolution of the cockpit abandoned command in favor of democracy...

How precious....

Not at all. CRM may have been kryptonite to the "Captain God" philosophy, but in order to work effectively, a clear and well-understood command gradient is essential. Authority can be exercised without being a martinet about it.

In this case, both F/Os understood that they were under the captain's authority, but at least one of them seemed unsure as to his own.

If you pause, you will note that you may have affirmed my opinion. The flightdeck from BEA information, only, suggests a gauzy and illdefined working group. I like your summary of the PNF's intentions. I don't necessarily agree, but here, the format failed due surprise, mainly. Leaderless enterprises seldom succeed. There was precious little to hold on to, and the environment had an unfriendly ambience. It cannot have been as bad as it seems, per BEA #3.

It simply can't....

bubbers44: Yes, I know.

Dozy, your comment on the diagnosis bit misses the mark, handsomely.

The point of the AoA gage discussion over numerous AF 447 threads hinges upon how easy it is to see, on an AoA gage, if you are or are not stalled.

The other means of diagnosing pale in comparison when it comes to simplicity, though one must admit that a stall warning horn is usually a clue that one must pay serious attention to one's performance!
(I guess on this next bit, but I suspect that the pilots in the cockpit associated stall warning with Airspeed being unreliable, and for that reason ignored it as assumed to be spurious ... may be wrong on that).
While that is my feeling as well, I do appreciate the counter to any of us recommending that added indication:

the plane isn't supposed to be flown into stall, and pilots ought to be aware enough in their flying to take stall prevention steps when warning of impending stall (via scan or other alerts) tells them that they are about to stall. AoA would help that, but it is an additional scan item, as a supplemental scan, which takes us back to "if the scan is breaking down, or has broken down, what will the pilot look at next, and what will register?"

The requirements folks can make a decent case against. It takes something like AF 447 to demonstrate where that reasonable approach may still not account for how that gage helps when needed most.

Mainly?

If you had said, "The format failed due to lousy/non-existent training, mainly" then I'd completely agree!

OF,
-"Afflicting the comfortable since 1950"

They were surprised by their lack of training?

Comforting the afflicted, since.....

Maybe it would help some drivers if the warning stall, stall was replaced by the instruction stick forward, nose down.

Hi,

'NAV ADR DISAGREE : RISK OF UNDUE STALL WARN'

But
'AIRBUS incite les pilotes .... ne pas tenir compte des alarmes STALL'
= 'Don't take care with Stall Alarm'
Make your choice

Glad to hear from Cland that a few carriers are using a HUD.

His observations agree with mine to a large degree. That is, instrument approaches are much easier and safer. The down side is you can get spoiled and have to do the "human" reversion laws if the doofer fails. Just a few days until my digitized video is posted, and you will have no trouble seeing what was there to help.

I am not sure that any display should emphasize AoA in all flight regimes. However, even cruising, an AoA symbol referenced to the flight path marker would let you know within a second that something was gonna get bad and soon.

I have seen zero accident references to failed AoA sensors or inputs to the flight control system computers or even the old jets with basic control systems.

As some have pointed out, the basic airliners are much more sensitive to a mach stall than the jets I flew. Still, a display that shows a ridiculous AoA and low speed should be a clue for the pilot to use. You don't even need "bitching Betty" to tell you that you're about to stall. If that AoA bracket is way above the flight path marker, then....... duh?

Lastly, the solid-state HUD electronics were vastly more reliable than many old display systems. They either worked when you powered up or kept working unless you got hit by lightning.

Where was that quoted?

[AIRBUS encourages pilots to ignore the STALL warning]