Long experience with the perversity of aviation accident causes makes me extremely suspicious when I see anomalous behavior.
While I absolutely agree that the 8 degree initial bank was no big deal, I am not so comfortable in describing the PF's initial wing wobbling as minor gyrations. PF was using a substantial portion of the aircraft's lateral control authority to drive this oscillation, and any pilot with high altitude handling experience knows that this is a bad idea for a number of reasons. Although the bank angles achieved were not very spectacular until after the stall, the roll rates were very high. I do not believe an experienced pilot would have exceeded 1/10th of these lateral control inputs in "normal" Alt 2 flight. (But I have to provide the caveat that I have never flown the 'Bus) http://home.comcast.net/%7Eshademaker/RollAmplitude.jpg
From this chart I provided earlier, the first 4 roll half oscillations were on the order of 15 degrees each. Each one was accomplished in just over 2 seconds and PF then accelerated his inputs to drop his average time between reversals below 2 seconds. This is too much movement for the average pilot to calmly ignore.

I suspect his initial difficulty in controlling the wing roll attitude grabbed his full attention. There are hints of this in the type of strategy he used to control the oscillation. Instead of backing out of the loop for a moment and letting things calm, he accelerated his inputs to "get ahead" of the oscillation. You can see this by just graphing out the reversal intervals. As I have said a few times before, he actually got so far ahead with his large inputs that he caused at least two phase reversals of the oscillation. Yes, he did finally get the aircraft under a semblance of control- but he did it with high gain inputs. This is very indicative of an agitated mental state (IMHO) at the point just before the stall. You don't fly smooth when the adrenalin is pumping.

This second sentence is very concerning to me. From observing the posts of others, I know that stuffing the nose down is avoided like the plague in airline flying-and for good reason when you have people in the back of your aircraft.

For a tactical experienced pilot, there is a concept called unloading the wing. If you establish a ballistic trajectory with your aircraft, you do not require lift and this allows your aircraft to accelerate much more quickly than it would while maintaining high AOA. In a ballistic trajectory, your aircraft will not stall. This is the core idea behind many tactical maneuvers. In airline use, you would not have to fully adopt a zero g ballistic flight to recover from a potential low speed excursion. 1/10th g is sufficient to keep most things stuck to the floor and still provide almost all the benefit of zero g. Unloading is a concept that every jet pilot should have in their back pocket through practical (airborne) flying experience. (You cannot do it in a Sim). A pilot who understands the concept won't have difficulty getting the nose down to get flying. The only limitations are likely those built into your flight control system.

Very refreshing and sparkling post
 

Hi Maching Bird,

Unloading the wing :D, was one of the art of Henri Giraud, who did it once... to land in the mountain, "like a bird on the branch", on a 40% slope with fresh snow, who had two times the length of his tail-dragger... The most difficult for him was to turn his aircraft 180° to take-off toward the valley of Grenoble : That way he saved the life of a skier who had fallen, very near from the death, from a cliff.

This art of Giraud has never been and will never be teached :mad::mad::mad: officialy in France : Henri Ziegler for his confidants put the hand on the airspace administration, after he tried to send Giraud to the "STO" during the WWII : Giraud prefered to enter in the french Resistance :cool: (he was the chef-adjoint from the 7th camp du Maquis du Vercors during two years). After the war he became the fabulous glacier pilot:ok::ok::ok:, alone to land on the top of the Mont-Blanc with an aircraft (june 23. 1960).... and landed 53 five times on the "Mont Aiguille":suspect:. He died in his bed :D.

The french aviation is just totally unable to do that... near of the ground.
She is also unable to do many other things that Monsieur Giraud did !

Maching Bird, teach that to your students, AF and Airbus will never teach that. They are just unable !

Thank you so much for this very refreshing and sparkling post in the middle of the despair of this modern ... AF447 crash and crew (I dare not to say "pilots" :\).

Interesting discussion on "unloading" the wing - thanks Machinbird and roulishollandais.

One thing I have mentioned before is the obvious 1.5g as the PF loaded the wing shortly after taking the controls, during which the two brief bursts of SW occurred. At the top of the initial climb the wing was unloaded and 0.75g resulted as the aircraft went over the top in ballistic fashion, to be loaded to 1.15g as he pulled into the final climb and triggering the SW continuously.

The reduction in 'g' as he pulled for the second time was in direct relationship to the remaining CAS, i.e.

1.15 / 1.5 = 0.767 or,
265 * 0.767 = 203 KCAS.

That's not the real point, as it is the crossing into the stall during the 15 secs after 02:10:57, where the aircraft was "ballistic" and continued to gain height as the normal acceleration dropped to 0.8g, is where the real opportunity to change the AoA rapidly and recover airspeed existed. It wasn't to be, and the opportunity to do so became limited after 02:12:00 (IMHO).

Hi,

All this discussion on the roll of the AF447 is very interesting ...
Where the pilot see the banking angle (instrument) ?
Why when checking this instrument he (they) don't see the longitudinal angle (climb .. this must be plenty blue there .. with 15° and more)
Why they discuss (all 3 pilots) all the way down about keep the wings level and the speed.. but not about all the blue they must certainly seen on the instrument ?

Lost information?
 

Hi,

What kind of "inputs" they received?

PS

We have all, related to their "outputs".

What BEA have today would be enough to understand crew actions?

PS2

PF acted "immediately" when was suddenly inserted in the loop. Crew actions are to be based on reliable inputs.

AS was lost due A/C resources limitations (simply not measured) during a period.

The (relevant and necessary) information PF (and crew) received was also lost?

PS3

Are current FDR able to record all required information? In order to take into account everything necessary for the analysis? (e.g. ALL pilot inputs)

Human Factors

Blue/Brown. Neither color is reliable to show the Angle of attack, although at first, Pitch was not unreasonable. The BEA language make it unclear whether the ship climbed prior to, or after the ten degree 'plateau' right after manual control.

That is not to say the data are wrong, only that the Pilot was flying, not the autopilot. For all, did he realize LAW had degraded? The first we know the lack of NORMAL was at 2:10:22. Virtually all his experience was non ALTLAW, and STALL had been trained sporadically, without a syllabus that included High altitude upset leading to STALL. Say what you will, and the evidence is damning surely, but the fulcrum of recovery was immediate and positive reaction to manual control.

NOT ALTERNATE LAW. I must disagree with no less than PJ2. The ROLL was 'part of', not a singular challenge. We have the benefit of nearly three years of perusal. The Flying Pilot had one second. Well and good to frame the discussion based on trickle down data, and that parsed; we appear to have relinquished our initial hold on objectivity. The passage of time does not change History; it changes only opinions.

mm43. What about that 1.5g 'load'? I believe the report was 1.65g, and my question is how did it increase that high? Doesn't the Bus protect PITCH with One G commands?

Similarly, a maneuvering aircraft can't be felt in de-brief. Not accurately. ROLLING is a form of UPSET, regardless the parameters. I think that might be what Machinbird is on about. All three axes were quite active, and the a/c was in turbulence. Quoting the book, and emphasizing how 'easy it is' to recover UAS is misleading, borderline dishonest.

I will rely instead on the report of post wreck simm. For one only line pilot to have crashed '447', is too many. For several to have failed remains a benchmark for those who prefer to frame the discussion as problematic, not simplistic.

regards

BTW, re: damage and config. At least one FLAP track is referred to as "extended", in BEA's damage inventory.

It's in there. At some point, did they wish to "recover" the Rudder's authority with a F/S select?

Simple answer to this question. When the bank became excessive, the sensation of down became well off to the side. If the Captain was standing between the seats, holding on to head rests, he would have trouble remaining there. The wing was no longer carrying much of the aircraft's weight. The missing lift was replaced by the drag of the fuselage so that the aircraft was at a relatively stable speed (but velocity vector pointed very down).
To summarize, it was as if the fuselage had rolled partially onto its side while on the ground. Hard to maneuver inside like that. That was having an immediate effect on everyone's ability to function.

Similarities with Thiells 727 crash (HF issue)
 

Hi,

Some days ago Clandestino mentioned similarities (buffet misleading) between both cases.

Yes, there are many similarities:

1) UAS was the "trigger factor"
2) Both planes stalled
3) Crew perception failed
4) Recovery was not possible
5) Crew errors were present
6) HF factors "played important role"

The Pitot heater was the cause leading to UAS (Alt and Climb, indications) degrading the man-machine interface and misleading the crew.

Subsequently the buffet "confirmed" (a wrong perception) of "overmach".

In F-GZCP a sophisticated "interface" seems not helped the crew in their perception (perception relates to survivability). Despite (or because it?). PF put (diligently :}) the plane into an stall (through persistent NU).

In CVR there is a mention to "crazy speeds". This shows they were receiving conflicting indications. From interface? From cockpit "environment", certainly: Noise (probably a different noise) and buffet (post stall).

The similarity probably is not with the meaning of "buffet misleading" interpreted as overmach buffet. In 447 the buffet, i suppose was clear after the stall (high AOA descent). In 727 the buffet (low speed stall buffet) "led to the full stall". In 447 the "misleading" Clandestino suggest, as a possible reason for "nose up" after plane was stalled. But i ask: During many minutes? From apogee to FL100 or lower?

As i understand your rationale was: Overmach buffet requires climb the plane. As an explanation for not lowering the nose. (misleaded by an overmach stall "thinking")

Is it possible? This could partially explain what crew "maintained" after apogee?

IMO there was misleading, by at least, lack of reliable information (scan failure, HF, etc.). Aggravated by Noise and high AOA buffet. In a turbulent environment (outside) and in a "stressing" cockpit (man machine interface aural and visual outputs)

A recipe for serious HF issues.

But, i agree, in both cases there are several similarities.

PS

I didn't find my post when i commented the Thiells case.

Machinbird

That is what I was trying to say. A maneuvering a/c is disorienting.

Disoriented, on an airliner, is (can be) disastrous.

Hi,

I agree .. but what is the sense of vision is reduced or affected or impaired by such feelings?

I can tell you this: Situational awareness is not overdone, ever. Once the status is lost, (forget the instruments), the odds go long. Recovery from upset is taught, and tested, ab initio. As is STALL. When the important instruments go sour, and the airplane is not recovered, quickly, the rest is guesswork, random.

It boils down to "Sit on your hands" or "recover the bank angle and PITCH."

This flight was doomed well before the STALL. At least one pilot, the one flying, was done in rapidly, he lost his grip on the situation. The second one shortly thereafter. (Else why the frantic call to Captain?). The folks who continue to claim this was business as usual are holding an illusion. The a/c needed correction, at least in the mind of the PF. Can that be argued? To what point?

The Captain had to climb up the aisle at quite an angle. One g, in the pilot's seat, is quite different than having to ascend a ramped aisle.

He entered to STALLSTALL, and a confused crew. "Er, What are you doing?"

Shortly thereafter, he lost the plot. Check that, he never had it, and it was not forthcoming.

Bend over in the crosswalk, tie your shoelace, get flattened by a truck. Same-o.

"vario" / vertical speed
 

I can teach you nothing : I may only answer to the french half of your question :
1. For the instrument/system mesuring vertical speed, in french, we use the common acronym VSI only in airliner, to be easely understood for maintenance papers and books. We use it also on small aircrafts to be pedantic !
2. IVSI is the instrument/system too, mostly used in gliders or by paragliders for the instantaneous vertical speed indicator with accelerometer.
3. "variomètre" is the prehistoric world ... still used for the instrument, as french aviation is still on Mermoz century, and stopped with Concorde...
Despite the word seems to refer to the meter, it may be calibrated in FT/mn as well as m/mn. (~meter refer to latin word for mesure and not to metric system)
4. French speaking pilots use "vario" or "Vs" or Vz for the name of the information showed by the system/instrument. It is shorter to say "vario" then "vitesse verticale", or "vitesse ascentionelle".

I hope a english speaking linguist/pilot will answer to the second half of your question, and despite my user name I am not dutch...

Perhaps not the sense of vison, but the management of priorities. If the roll is making it hard for the crew to even hold their position in the cockpit and to maintain a semblance of control, then the roll attitude takes priority over the pitch. With a nose up pitch, the crew is being cradled by their seats. With a nose down pitch, gravity is trying to take them off the front edge of their seats. If PF was not using his shoulder harness, there was nothing for him to lean into, and he would find it was easier to hold himself in the seat in a nose up attitude.

From the Captain's perspective, the aircraft generally follows the nose in all his past experience. If the nose is above the horizon, then even though the attitude is not optimum, it shouldn't be falling out of the sky and he can concentrate on trying to make sense of the instrument displays. But if the roll was excessive and if he was not properly seated, he would be almost unable to function in any useful capacity.

Initial "crisis" management
 

Hi,

Machinbird:

Makes a lot of sense.

Recovery from stall
 

Hi,

Machinbird:

Supposing the limitations are disabled: Questions:

1) Using this "approach" AF447 could be saved? If so, the maneuver could still be decided (and initiated) at what minimum FL?

2) This stall recovery technique should be incorporated in (SIM) pilots training?

RR_NDB, unloading the wing is used to prevent entering a stall, even when the aircraft is well below its normal level flight stall speed.

You cannot effectively teach unloading the wing in a simulator. A key element of the training is the feel of near zero g. This type training goes hand in hand with use of AOA indicators. Once a pilot understands the idea, and if the aircraft is equipped with an AOA indicator, then some Sim reinforcement of the training can be performed by pushing to lower AOA indications to near zero actual AOA, (not necessarily indicator zero.)

Once you are actually in a stall, unloading the wing should break the stall and allow acceleration provided you do not progress into a spin. The sooner AOA is reduced to un-stalled ranges, the lower the likelihood of entering a spin.

Once a pilot understands unloading, the concept of pushing the nose down to get flying again seems natural. Then it is just a matter of do you have sufficient altitude to recover?:uhoh: Sometimes it is a delicate balance between getting the wing flying and not generating too much sink rate. In those cases, an AOA system or a system such as the Airbus Normal law protections is what makes the difference. If your 'Bus is not in normal law though, you are back to basic Stone age flying technique.

Mach

NORMAL LAW protections end up creating what 447 experienced. In NORMAL, the wing will not STALL, even with full back stick, held. It "merely" increases sink rate. It is a technical "NON STALL", only, for with increased sink, the result is what happened to 447. So Bus pilots are taught that the a/c will not stall, even with continued back stick. (In the Normal Law).

Is it just a trick of nomenclature? Do they believe that even with the STALLWARN, they are not STALLED?


For whatever reason, if the pilots are granted even minimal skill, they did not consider they were STALLED, in evidence in CVR. They knew they were descending, but could they have possibly believed they remained in NORMAL LAW? At the very last, they PITCHED down. They then increased PITCH before impact. On the face of it, it appears at least that they may have considered the STALL was not real?

Per your unloading description, they were 'flying', at one g, the wing is not "STALLED"? I have never experienced a one g STALL, developed, though I know you have. Had they? "How can we be STALLED, the NOSE has not dropped down?" ( No "0" g )

I suppose it is an aerodynamic exercise, help?

Unloading the wing
 

Hi,

Machinbird:

The concept is clear: Stall is a function of weight to be lifted (by the airfoil) and beyond a certain AOA there is a fast degradation. Unload means "help" the wing (to do the lift) "reducing the weight" using physics.

Let me put both questions a little different (better):

1) Using this approach nearing the stall could avoid the stall? Sure, Yes.

2) Using this approach after the stall could make you exit? As you put, Yes. In this case with a pilot trained (to "feel" the zero G) in an airliner (similar conditions of this flight) do you think the "day could be saved"?

3) In this case at what safe minimum FL the maneuver (by the same trained pilot) should be initiated (at what FL) to present reasonable chances to recover in time. (before SL :))

Obs. After a fully developed stall chances reduce fast due height loss, spin threat, noise (:}), etc.

Unfortunately the "zero G" feeling is impossible (for longer duration) in the SIM

Just "flying"* at high ROD?
 

Hi,

Bear:

Disturbing to imagine (a training could do) this.

May match elements we have so far.

(*) trajectory with HEAVY LOADED WINGS :E

In the AF447 case, they could have recovered if they had initiated somewhere around 10,000 feet, maybe even less, but there would be no room for secondary stalls. It would have to be done perfectly, and if you don't have Normal law, then you need an AOA indicator to do the recovery perfectly. Your flight control system can screw you up if it trims the THS too slowly.

Not only that, there is also a 'cornering' speed that you would not want to exceed either. If the aircraft got into g limiting, that would result in less than ideal results.
Once flying (un-stalled), you would want to accelerate using maximum thrust up to the cornering speed and then go to near idle to avoid exceeding it.

One of our aircraft performance guys can probably come up with some realistic numbers, but I have just described the basic tactical approach to the maneuver.

MACH:

You're looking at the glass half-full, which it is not, and pulling those numbers out of your glass.

:)

I know it is not relevant to the discussion simply because the airplane is as it is, but if it had been a normal control column everyone would have seen the PF holding the stick right back in his lap, and nobody would have needed any flight instruments to see how very wrong that was.

No pilot would have tried to fly that way in the first place, and I would say that the design of the side stick lends itself to being misused in that manner.

What has/is being done to prevent a reoccurrence?

I have an aversion to robot airplanes and auto flight systems I guess. I will use an autopilot and am happy to do an auto land, but if I ever got to the stage where I could not do everything the autopilot could do, I would give up flying. Many of the pilots I fly with have never learned how to really fly an airplane, which is a pity and is a threat to the overall safety of aviation, and not just airline aviation.

This accident, I fear, will be repeated. And two B757 accidents with a loss of control by the pilot show that it is not an Airbus/Boeing, control column/sidestick problem but a problem with flying skills.

Well of course I am! ;)Are there any more reliable numbers in FCOM?

Just think about how much altitude your Super Sabre would take to recover if you stalled it but did not depart it under similar angle of descent and depth of stall figures.
I'll consider what my F-9, F-4 or A-4 would have done.

If you do not mess it up you would do surprisingly well. If you bobble it a bit, you could use up the whole sky. Now extend the results to a massive aircraft of rather high wing loading, low maximum g capability, and an overprotective flight control system.:}

The key determinants to altitude lost in recovery are smoothly breaking the stall without secondary stalls, promptly achieving Alpha Max, holding that AOA accurately while accelerating as quickly as you can to just short of the speed that g limiting commences and then not exceeding that speed until level.

Isn't that what they taught you in the AF?:):p

I may be able to do that, but first I have to explain that I don't necessarily agree with your proposed approach. I agree that you accelerate rapidly when you reduce the AoA to zero lift (or nearly), but that is not optimal if you're trying to recover with minimum height loss, and will also lead to high speed and "g". Intuitively I would expect that the minimum height loss, speed excursion and "g" is achieved by using all the lift that you can get without stalling. A more practical optimum would be the maximum lift available without stall warning, as illustrated by this phugoid:
http://i.imgur.com/QRe1H.gif?1
The AoA of 7 degrees was chosen to stay out of stall warning until at the bottom of the pull-up (the threshold is 10.8° at M.28, and 7.6° at M.53). An even better trajectory would be achieved if the pilot managed to stay on the threshold of stall warning:
Initial normal acceleration 0.73 g, and level off at FL 69, M.47, 276 kCAS, AoA 8.5°, and az=2,05 g.

The maneuver assumes constant total energy (thrust = drag), and begins after the airplane has been pitched down to unstall.

The fact that load factor protection is available in ALT2 is a bonus.

boofhead

Respectfully, sir, I disagree. Now that we all know where to look, the SS/Yoke kerfuffel is moot. If 447 had not been bobbing like a hula girl and had reasonable stability in the flightdeck, the RHSS might have tipped PF's "hand". The SS cannot be condemned, conclusively, here. Machinbird has shown how uncomfortable the footing/seating was on her Flight Deck. Restraints were not to spec. (from a user standpoint), and the Captain was holding onto the two seats like a sailor holds on to the bar, at 2 o'clock.

Just a thought.

And Presto! we have some numbers and they show that, Thank you HazelNuts:ok:.

The point about unloading relates to rapidly accelerating away from the zone where it is very easy to achieve secondary stalls. Once the stall is broken, the aircraft will accelerate rapidly, but if a human applies the g too rapidly in his haste to pull up, a secondary stall can result and snatch defeat from the jaws of victory.

Laying on g (in Alt2 law) without an AOA indicator while the airspeed is changing rapidly is tricky.

Just remember that HN39's chart has the following initial condition: We still have to consider how much altitude might be lost in pitching the aircraft down.

It hasn't been tested and therefore, in the absence of reliable data, it's really anybody's guess. In the TAROM A-310 incident at Orly the airplane pitched down at (more than) 5°/s, so perhaps 1100 ft (30° in 6 seconds at 11000 fpm) might be a reasonable guess?

As stated by someone way back in these discussions, I would venture that as you vary the CG across the allowable range you will see a significant variation in the response time to generate a pitch rate from 40+ AOA, and thence in the subsequent resulting altitude loss.

(Mach: the only aircraft I flew in my short, undistinguished AF career was a jet that I intentionally spun on a regular basis. I flew others with the militia and was very cognizant of the handling quirks of the 100, 105, F-4 & F-16. However, the A-7 I also departed on a regular basis, thanks to training initially provided by the USN. :)

The one thing I remember learning from the AF was to keep my hair neatly trimmed. :})

My experience in the A-4 Skyhawk which had a similar THS configuration to the A330, and the results of the Perpignan A320 accident lead me to believe that the THS trim is going to pace the recovery.

If that assumption is correct, then I'm guessing 20 seconds minimum of nose down stick would be required to recover to flying AOA, (based somewhat on how long it took to trim nose up). As the aircraft begins to nose down, the descent rate will increase to perhaps 15,000 fpm and the IAS will begin to increase. If those assumptions are correct, then you will use about 5000 feet in pitching the aircraft down.

With ~4400 feet to then pull out, that would seem to indicate that 10,000 feet is about the last point one could hope to begin recovery. But there are some BIG assumptions in there.:confused:

I did the ~250', zero airspeed, straight down data point once in a Luscombe, and I don't intend to repeat that experiment. I had 5' reserve altitude on completion.:eek:
The big question on the pullout was, "am I achieving all possible performance? " The consequences of exceeding the performance limits were rather stark. Fortunately, I felt the burble over the ailerons that told me there was no more performance available.

My big question that day would apply equally to AF447's potential stall recovery since they did not have AOA indicators.

Learning alot I am. STALL recovery, SIM replication, Douglas Aircraft, etc.

STALL recovery from UPSET at high altitude was not in the Syllabus, and will not be. A back up Speed scale was U/A, it was merely an OPTION. Angle of attack indicators, or even a back up Horizon? The a/c was not equipped to prevent STALL entry, or recovery, but the Pilots must be? How's that?

How many faeries can dance on a pin? I fear that this discussion will lead some to think that flight test will soon include STALL. It won't.

That this a/c behaved surprisingly "well" whilst on its unplanned descent into the sea is beneficial to, whom?

The evidence points to an early LOC, one related directly to the lack of equipment that may have prevented the STALL. If the reliance to prove the PF solely responsible, how is it the PNF hadn't any solutions other than to call the Captain back from rest? The loss of reliable displays were reported to the Captain when he entered, how was he to help?

"Here, Here, and Here, we climb, so go down" Eh? Pitch? V/S? A/S? There was no agreement from the outset, and this is entirely due poor CVR? How so? The PITCH numbers are from the DFDR, No? Where do DFDR data display to the pilots? One cannot fly the Bus by feel, the stick does not communicate "feel". Every response PF made to ROLL shows a chronic bias right by the a/c. What was wrong? If he was synching inputs via screen, were the displays correct?

Who would know, his PITCH prompts went unseen, else the PNF would have not felt the need to cue him to descend.

Three clear graphics show the a/c, its responses, and Pilot talk. Very helpful. The third and last one stops just as Captain enters. No more graphics, sorry. Just getting interesting, eh BEA?

A Korean MD11 out of Shanghai was pitched down some 20 degrees after takeoff when passing 2000 feet or so, and could not recover from the resulting dive.


And, Lyman, surely the reason the airplane was flying in such an unstable manner was precisely because it was being held deeply in a stall. Seeing the other pilot holding the control column back in his guts despite the shaking and pitching would have directly prompted any pilot that the airplane was stalled and that the control column should have been pushed forward, no matter what was indicated on the gauges. Without such an obvious clue, it was left to the pilots to interpret what they were seeing, and that was very confusing, to say the least.

However, as I said previously, two sets of crews on the B757 had similar indications of stall and did not respond to it, so nothing is guaranteed. I almost stalled a B737 at 35,000 feet and was amazed at the altitude loss I had to endure before I could get out of the stick shaker regime, even with full power applied. If it had happened at night and with most of my instruments under suspicion I might not have managed to recover either.

Aviation can be very humbling.

boofhead

Thanks for your kind and honest response. Aircraft are designed for varying roles, but all must adhere to best practice. I agree that after 109 years, the yoke is "best practice". Other than to merely be "different" I cannot state honestly what possessed the designers of Bus products to hide the SS one from the other.

Keep the joystick, no harm, ( wouldn't it be better between the knees?) but as you say, even with a yoke on the belly button, a/c still STALL. It happens generally because the second pilot is in a tight spot, politically, or he lacks self confidence. Early on, if one of my instructors had started a climb at low altitude, and held back wheel during the WARN HORN, I would not have intervened. "He knows something I don't". We may have crashed, and this happens yet.

It isn't the only problem that did in 447, but there remain more than a few puzzled by the "logic" of hiding life itself from the second pilot. That is quite literally placing your life in another's "Hand", blindly.

Thanks

Ain't that the truth!
Just for purposes of convenient reference, I am going to bring Hazelnut's Phugoid chart over to discuss how to possibly improve the results. To improve the results, we have to play with the assumptions.
Now lets look at piece of a Wikki article on BFM. The whole article can be found here: Basic fighter maneuvers - Wikipedia, the free encyclopedia
http://i.imgur.com/QRe1H.gif?1
One of the key assumptions in the chart is constant TE=total energy. Suppose we begin accelerating the engines from idle at T=0. (You probably will want to have the engines near idle to break the stall and negate the pitch up moment they would otherwise create.) By T=6 and later, you can begin to strongly increase CAS (Brownish line) and this will increase G available (Lift/Weight-The blue line). In the chart example. AOA is limited (somehow) to 7 degrees by the pilot. Using these conditions, we hit maximum structural g of 2.5 at the bottom of the pullout (321 knots). 321 knots is therefore our cornering speed.

But if we use the engines to strongly accelerate earlier, we have now created a problem. We are now hitting 321 knots much sooner. G limiting then keeps us from continuing to increase the turn rate and if we further accelerate, our turn radius increase will actually slow the turn rate.

Somehow, we have to avoid running through 321 knots. What tools do we have? Pulling the engines back would be one thing of course. What else might slow us? How about induced drag? We can continue to increase wing performance up to alpha max (and with it-Induced Drag). Finally, we have speed brakes available if we need them, but with wing mounted speed brakes, we may lose some of our wing lift performance (CL).

Using these parameters, we do not get into g limiting at all, so we are probably still leaving the thrust card on the table. (But you will still need some thrust to counteract induced drag and meet the TE=Constant condition).

The practical piloting problem during pullout is this: We do not have real AOA protection in Alt2 Law. We do not have a ready AOA indication. We do have a stall warning system, but it is either on or off-very hard to control AOA like that. Our flight control system is continually trimming off stick force, so a constant stick position causes an increasing AOA demand. There is significant risk of overpulling the stick and getting into a secondary stall-delaying the recovery still further.

You have to be very conservative in your approach to the pullout, particularly where g available is less than 1 g. But that early turn also gives you the most benefit because the turn radius is so small. This is a daunting problem for both pilots and aircraft performance engineers. All you can do is understand what your options are and know your corner speeds.

It will "BFM" better with the slats out.

There are hints that Bonin did deploy slats, and Flaps, as well. Doesn't thrust increase cornering speed without increasing speed? (Pull a tighter turn?) Doesn't drag replace Thrust in critical manouvering? So with maximum thrust and maximum drag (nibbling at the STALL), don't we have a relatively stable albeit somewhat ballistic a/c?

One thing that interests me is how Bonin's chronic pull can be explained. One way is to assume that the a/c was not controllable with her nose down. As he lowered her nose, she would want to drop it on her own, (completely, and quickly) and this is what he feared (overspeed), at least theoretically. So he was avoiding the Nose droping through, and maintaining "control". Was he cornered behind the curve?

TEN THOUSAND FEET ...
 

IT IS SAID AND WRITTEN : 10 000 FT ! Thank you USN ! Thank you Maching Bird, Thank you OK456 ! Shame to european "aviation".:mad:

RH:

I personally have great admiration for European aviation or any professionally oriented aviation system.

I, myself, have never said anything about '10,000 feet' as being necessarily germane and feel one should easily recognize that this type of conjecturing is purely hypothetical.

People associated with aviation, like yourself, enjoy discussing aviation and making their informal personal inputs, which may or may not be ultimately of any value.

:)

OK465, I bet !! :):)

dutchroll

Hmmm, key assumption?? The "on the threshold of stall warning" trajectory with specific excess thrust (T-D)/W = 0.15 results in level off after 15 s (was 18s) at FL76, Mach 0.51, 295 kCAS, az=2,24 g. An A330 is not a fighter.

@Lyman:
 

Where are those 'HINTS'?