A33Zab

A late reply on Your post #506 concerning the BUSS.
I'm behind with all the posts.

Maybe this image is of some help?

AFAIK, there is no MACH compensation and amber/red area is not changed for speedbrake.

Lyman

Dozy

This argument is not to do with pilots, right, wrong, or indifferent. It has to do with the a/c, and what it is doing, strictly. AoA aside, my point is that there is room to entertain sensing/sussing anomalies with the autoflight, and the a/c basic modes to include Vselect, and work done prior to the Early June surprise sprung on the crew. This accident had its roots deep in the time frame prior to handoff, irrespective of ICE, turbulence, and Degraded Law. A working theory of Ice occluded probes suits me fine, but there is wiggle room in there for other sources of danger.... RetiredF4 I must say thank you for your work, your frame of PNF as a human, and not a foil for nothing more than a guess at CRM, well, thanks. There was ample confusion, and no less than two qualified pilots felt thoroughly in the weeds from the gitgo. If for no other reason, I will keep my objective view alive. There had to have been more than off target competence in play.

And HazelNuts39 thank you for a finer point on airmass/AOA. Five degrees? What was I thinking?

DozyWannabe

Lyman,

This is the definition of "Moderate" turbulence, but the bolding is mine:

From : Tutorial: wind shear and turbulence

Note that Moderate doesn't even come close to the equivalent of 100kts (50fps = 29.6kts).

Outside of the numbers, I sat in the sim - I saw it happen and I *heard* it happen. I experienced an infinitesimal fraction of the concern and fear those pilots felt as the aircraft ran away from me. I stand by the assertion that the climb, warning and deviation from assigned altitude were predominantly caused by deliberate action by the PF.

I can't convince you - of this I'm sure. But I've gone to further lengths than I ever have before - assisted by people to whom I am in eternal debt - to prove that I'm not talking out of my ar*e here, and I'm as certain as it's possible to be that the aircraft did nothing to make things harder for them.

jcjeant

Some off topic
Indeed this failure mode was not considered at the time the aircraft was designed
And for this kind of failure .. it's not possible to apply a procedure (pilot is not able to go plug the holes in F.O tanks) this failure required a structural correction ...
The problem is that along the life of the Concorde .. one of his main problem was the tires (many events) and so the design has to be reconsidered seriously (certainly after the important accident of Washington concerning tires and F.O tanks)
Another flaw design was the position of the tires relative to the engines ducts .. (this one was pratically impossible to correct .. lol)
But it was a possible solution for the dangerous tandem tires-F.O tanks ... and the solution was put in force .... after Gonesse ... unfortunately again too late for some people ...
Return to topic ...

Lyman

Dozy

Be careful not to extrapolate from guesswork. Initially, the Airline reported "turbulence fortes". We were not there, and the accelerations on the airframe leave some important data out. Why would the airline make such a statement? Who knows, and we do not know if there is data that is available, from the line, that is not released. Met based on satellite IR? Hmm......

Some cells can exceed 60000 feet in height, and contain monster cylinders of highly energetic vertical air. The crew inter briefed "somewhat more intense than that we just experienced, etc" . Once accelerated, the airframe can report calm accelerations, but be moving rapidly Up, or Down. Besides, I am not interested in turbulence, but in well developed symmetrical, and independent air mass, mostly, Up. Imagine an a/ c that is rising vertically, but with a reasonable Pitch, and consider that an airliner can climb whilst essentially level. Rapid climb....

I am suggesting the discrepancy in AoA and Pitch suggest such a thing. A thirty second bonus of climb, that paid out, and left the a/c hanging on her Fans, basically, all the way down. PostStall, I think it is a reach to get too critical of anyone on deck.

I am a fan of this a/c; whatever happened, look elsewhere for bias against this airframe.

DozyWannabe

BA made an alteration to the MLG deflection guard - AF did not.

True - nowhere else to put them.

Well, BA altered the MLG setup, so one solution to that particular problem was in place on half the fleet years before Gonesse. However after Gonesse both operators did everything possible - and then some - to make sure the problem was completely resolved.

But there were only a dozen or so serviceable Concordes - it's a very different proposition compared to a type where the aircraft in service number in the hundreds or thousands.

But the point is that we're talking a catastrophic failure in which there is nothing any pilot could do to resolve the situation. This is very different from a UAS incident which is trained for even when there is no problem known on the type.

All data was released. The Airline reported "fortes" to the press, which makes sense if you bear in mind that most passengers - even frequent fliers - rarely encounter anything more than what is considered "light" turbulence to pilots

This one didn't though - the pitch change preceded the climb according to the FDR.

If the PF had kept her on a relatively level pitch angle then I'd be happy to entertain your theory, but this is not the case. He pulled up and continued to pull up throughout the sequence. As I've said, this climb was commanded.

This isn't about bashing the crew. Sure, they made mistakes - but even if they did, the fact that at least two of them were placed in a position beyond their knowledge and experience is not their fault.

Lyman

If the PF had kept her on a relatively level pitch angle then I'd be happy to entertain your theory, but this is not the case. He pulled up and continued to pull up throughout the sequence. As I've said, this climb was commanded.

Yes, Yes, Yes..... It was commanded. Yes there was a Pitch Up command. What evidence do you have that shows the PF's input was the only thing happening? How do you eliminate that some of the ascent was due airmass?

They are not mutually exclusive. See? The rate may have been in excess of PF's command? Additive, but masked in his Pull?

bubbers44

Highly unlikely since his full up commands were during a high climb rate from FL350 to 380 when it of course went into a full stall as all aircraft do handled that way.

Lyman

Yes. But remember "full up commands" doesn't net him any more than one g.

So actually the 7000 fpm lends credence to an assisted ascent (U/D). What is your opinion on melding 7k fpm with One G?

DozyWannabe

Not true. The system will allow anything up to 2.5G.

Lyman

In DIRECTLAW...... Pitch in AL 2 is g limited?

bubbers44

I think 1 G means you can not climb because as soon as you climb you will have to exceed it. Just a simple law of physics.

Lyman

I think max g in the climb was 1.68? One g in unaccelerated flight, yes. But accelerated rate (limit) is one g, ok?

CONF iture

Why don't you take a rest Dozy, you're writing nonsenses one after the other. It is getting hard to know which one to comment :
You fail 2 ADRs to switch to Alternate Law, not to simulate UAS.

I have seen that before :
You understand nothing about Alpha Max, you understand nothing about the protections, you didn't read the Habsheim report, and obviously understand nothing about aerodynamics ...
But please comment further, I'm curious to know how deep you'll go in this nonsense.

Absolutely not. After the crash, EASA issued an AD, did it kill the 330 ?
Obviously the overkill has been to not treat the situation seriously enough before.

RetiredF4

.

Do I understand your insight correct, that the BUSS indications are not compensating for MACH or configuration and therefore the accuracy of the underlying AOA is therefore similar to the AOA indication we had in second generation fighter jets (F4)?

post of Owain Glyndwr
and
PJ2

HazelNuts39

RetF4,

The BUSS 'Slow' indication is adjusted for configuration as per the 'VSW-BackUp table'. (Second Table A in PJ2's post)

Since use of the BUSS is limited to FL250, the Mach at Vsw does not exceed 0.525 and therefore the threshold at 8.6 degrees is reasonable.

Owain Glyndwr

BUSS/AoA

To be strictly accurate the actual AoA doesn't need to be compensated for Mach, but if you mean that the surrounding limits are no better than you had on your F4 then yes, I think BUSS is no different. In fact it cannot be otherwise; to get stall AoA for the display in all flight conditions you need at least some estimate of Mach number, which is in principle not available in a UAS situation. It might be, as gums sort of suggested, that you could get by with an approximate value of Mach derived from (for example) inertial speeds and barometric altitude - this would probably be good enough to give the sort of protection one is looking for in an AF447 situation but this is not, AFAIK a feature of BUSS as currently offered.

Otherwise, as I see it, BUSS functions exactly like your F4 AoA indication. In particular it gives a good guide for approach, or anything below about 0.4M and apart from the mechanics of the display BUSS does exactly the same job on approach as did your indexer lights.

Clandestino

Gentlemen, thank you for quite useful discussion on AoA gauges. I don't have definite opinion on the matter of necessity of equipping the airliners with them and anyway I spent about 150 hours warming up the front right seat on A320 of mid 200s S/N vintage, that had AoA indicators; small, round, analog, mechanical, pretty devoid of markings on dial face (just some units which might have been degrees or indices or whatever, no bugs or typical AoA markings) and set outboard of PFDs. There was description of the way system works in our manuals but there was not a single procedure based upon them. They did provide some inflight entertainment, especially in CONF 1 as they were not config compensated.

Nevertheless, I am not convinced that AoA gauge would have been necessary or even helpful to get AF447 crew out of their predicament as 1) UAS was never recognized and prescribed actions were never initiated 2) 36 other crews managed to do just fine under similar circumstances just relying on attitude and power 3) CVR and FDR don't paint a pretty picture; it seems that both pilots got utterly confused simultaneously and did not realize what was going on. In my opinion the IFR pilot that is unable comprehend the implication of the attitude he's putting the aeroplane into and does not realize what is that synthetic voice shouting "STALL STALL" trying to convey has zero chance of understanding what AoA gauge is telling him.

No. The wording of the manual does leave many possibilities for creative misinterpretation but I am pretty sure I've spent about a dozen hours overhead Lambourne, watching it creep up during turns.

Another misconception is that low speed cues are g-sensitive. They are not. They are alpha sensitive, just as the Cl is, therefore change of AoA will simultaneously change low speed cue position and wing lift which leads to Nz (colloquially: G) change. Applying post hoc, ergo propter hoc one can come to fallacious conclusion you need inertial source to drive low speed cue.

Valiant effort, but if you tried to prove there was significant turbulence that has affected the flight, you needed not bothered. Interim 3, page 42 shows difference between control induced Nz and measured one - which is indication of turbulence. +/- 0.4 G is moderate. Also very short lived.


...but their PPS has sinister looking, dark figure of pilot on almost every page. Perchance compensating slight and not so slight distortions of facts with stage effects?

DGAC and EASA did know about far more than just AF's 9 pitot blockages. Consideration was given to changing SB regarding the replacement of Thales probes with Goodrich ones to AD somewhere in late 2008 but change was not effected. If it suits you, you may believe it to be a conspiracy. However, I have no problems seeing how the already more than twenty incidents that ended uneventfully could lead EASA to belief that every crew knows what to do when loosing IAS.

While Goodrich pitots perform far better than Thales, they are not perfectly immune from same type of clogging and their installation will not absolve the pilots from obligation to recognize UAS, know appropriate procedures for it and apply them. Law of self-preservation demands so.

Actually, for last three years, I have been earnin' my daily bread by staring through wide angle Head-up Guidance System grafted onto my Q400. It's a wonderful thing. It has flight path vector. It has inertially driven energy caret so you know you'll lose or gain speed before IAS makes a slightest movement. It has speed error column on FPV so you don't need as much as look left across the HUD to check your speed, let alone perform quick glances inside the cockpit to check ASI on primary flight display while maneuvering manually during final approach. It's not direct measure or readout, but vertical distance between aeroplane reference and your FPV represents your AoA. There are pitch limit indicators preventing you from whacking your tail on takeoff rotation, unusual attitude recovery help, flight path limit showing you margin to stickshaker, TCAS RA flightpath (instead of VSI) guidance and lots of other neat stuff.

Is there a downside to it? Of course there is; it's too good and too easy to use and aeroplane can be dispatched with HUD or IRS failed so you are back to classic instruments scan. It's easy to let your classic scan get rusty so I make a habit of using HUD only on about half of the flights, to stay in shape.

Did my company buy this neat gizmo to make my life easier? Of course not. Our base gets pretty foggy in winter and HGS enables us to perform low visibility approaches down to 200m RVR and 50 ft DH, rather than 300m/100ft we had before HGS. It was cheaper to install HGS then to develop autoland capable autopilot cum autotorque.

philip2412

i`m quite in line with DW.we do not know,what happend when the cpt gave command to bonin.
maybe there was a discussion,a look,a grumble.maybe there were some frictions.
ithink we will read a lot about the personal and prof-history of PF/PNF in the BEA report.he was afraid that it will look like he took the first opportunity to go at bonin and that it may reflect bad on him if it was not necessary.
that`s why he was so eager for the return of the cpt: "come back and see was your `wunderkind` has done."
but to his surprise dubois didNt have a clue too.so he was reluctant to tell the cpt what bonin did,because now he thought maybe i`m wrong .
and bonin was afraid to brief the cpt. because he knew or felt that he had made a miistake.

CONF iture

It is getting pretty sporty at Qantas these days ... but not unrealistic at all I must say.

No need to look, that's the first thing that will jump in your face : 2 yokes in that very unusual full aft position as soon as you enter the flightdeck. That's the first elephant in the room. Instruments reading only when get closer.

Second elephant in the room is the STALL WRN but that one unfortunately quits when the Captain is back. Still the Captain is fully aware of it as he could hear it when he was attempting to penetrate the flightdeck.

BTW who opened the door ? Did he have to use the emergency code to unlock the door ?
BEA, you have to produce much more that you did up to now.

For you Clandestino, too much to comment on your earlier post (467)
See you later.