1. Lift control
Thank you Gums ! :D
Now it is very clear that French aviation and Airbus were guilty to stop the use of the Klopfstein HUD ! Pilots were deliberately deprived gradually since the HUD was on the Air Inter A310. :(

2. Unloading the wing to recover, stalling deeply
And they had already been deprived from beeing able to come out of stall, as Machinbird and Hazelnuts39 showed us that.

Thank you to you, all three,:ok::ok::ok:

Deprived how? You push the nose down, reduce AoA, the speed builds up and when the wing is flying again you level out. This is piloting 101 - no HUD required.

Hi,

DW
Indeed ..
I wonder why this is an HUD on the F-16 .. and many other planes .. ?
Maybe they are piloted by "amateur pilots" who don't know "piloting 101" :)

There is no debate in my mind that a HUD is a valuable tool for the pilot. :ok:
More so if it includes energy state cues. :D

Now, OTOH, the absence of HUD on most airliners is not a "french" or an "Airbus" thing AFAIK.
Nor does the absence of HUD prevent stall recovery (I wouldn't be there if that was true ;)).

@ Doze My point was that a flight path marker based upon inertial data would have illustrated that old adage "pull back to go up, pull back further to go down". It would have shown the climb and it would have shown the aircraft vector then decrease until it was caged at the bottom of the display. It would have shown the plane in level flight at the loss of speed occurrence and that existing pitch was sufficient and no further back stick was required.

I have discovered an error that resulted in erroneous values for the C* parameters presented in my post #1310.

Please accept my apologies for any confusion caused.

Are there plans to fit a hud in the F35 or is the helmet mounted sight going to do it all?

très pourrait confondre indeed.:E

Hi Hazelnuts,
No problem Hazelnuts39 ! An open and large community is usefull in the fact that we can crosscheck and find a better shorter and optimized way toward solution. So would have been air safety and has not been before AF447. We are always doing errors, we just have to try to find them in the time we have before misuse. "We" not only one person. The greatest mathematicians and physicians did famous errors, conducting to progress.:ok:
Your graphs and calculations are always very welcome ! :ok:

HUD or not HUD !
 

Here are some important 1977's sentences I extracted from Gilbert Klopfstein (French test pilot and engineer who invented the HUD) :
I know no traduction, but you will perhaps understand it with translator ?

It is time to come back to a right conception of piloting our airliner , how Gums explains it very well.

link : headupflight.net/articles2/Securiteoumarketing.htm
( -il

SECURITE AERIENNE... OU MARKETING ?




par
Gilbert KLOPFSTEIN et René LAMI



Pour nous, " difficulté d'appréciation de la situation " et " insuffisance des instruments " ont la même signification, car les instruments doivent précisément permettre d'apprécier la situation dans toutes les phases du vol.

Or les principes mêmes utilisés par les instruments classiques de planche de bord, comme d'ailleurs ceux des " monstres " électroniques promis à les remplacer, les rendent complètement inaptes à ce rôle

[...]

Les principes traditionnels

Reportons-nous aux besoins principaux énoncés plus haut, et voyons comment l'instrumentation classique tente d'y pourvoir :
La sustentation
est connue par le biaisd'un paramètre indirect qui est la vitesse indiquée (en anglais IAS... en français " le Badin "). Malheureusement cela n'a pas grand' chose à voir avec la sustentation : par exemple, dans une ressource tant soit peu brutale à grande vitesse, on a vu des avions " décrocher ". C'est l'angle l'attaque (ou incidence) de l'aile qui est le paramètre de référence, et pour maintenir cet angle à une valeur choisie pour une phase de vol donnée il faut calculer la vitesse correspondante, laquelle varie avec la masse, les accélérations, les braquages de volets... d'où risques d'erreur et imprécision obligeant à prendre des marges de sécurité importantes.
La trajectoire,
dans le plan vertical, n'est indiquée par aucun instrument traditionnel. Tout au plus, si celle-ci est stabilisée, peut-on l'estimer par un calcul approximatif déduit des indications du " badin " et du " vario " (le variomètre, qui indique la vitesse verticale, et dont le temps de réponse est trop grand). Le pilote en est réduit à observer les fluctuations du variomètre pour savoir - à posteriori - si sa trajectoire a varié. ,Pour agir sur cette trajectoire, le pilote n'a qu'un moyen indirect : l'assiette (qui est l'angle de cabré ou de piqué de l'avion par rapport à l'horizon). Faute de mieux, cette " assiette " est devenue le paramètre fondamental du pilotage aux instruments, bien qu'il n'ait en lui-même aucun intérêt

[...]

Les informations visuelles

Ilest bien connu que, lorsque la visibilité est bonne et s'il n'y a pas de problèmes dus au vent et à la turbulence, tout avion peul être posé manuellement et à vue sans difficulté. C'est donc la preuve que ce qui est vu dans le pare-brise contient toutes les informations nécessaires de guidage et de stabilisation du pilotage, en particulier dans la dernière partie de l'approche qui est la plus difficile à réaliser sans visibilité en pilotage manuel utilisant les instruments classiques, ou en pilotage automatique.

[...]

Les principes nouveaux

qu'il convient d'appliquer à une nouvelle génération d'instruments sont basés sur des lois aérodynamiques ou physiques connues depuis fort longtemps, mais qu'il faut utiliser correctement. - La sustentation est déterminée par l'angle d'attaque ou incidence de l'aile - c'est donc ce paramètre qu'il faut préférer à la vitesse. - La trajectoire est déterminée simplement par la direction d'où vient le vent relatif... on serait tenté de dire " par définition ". Supposez qu'un beau matin vous soyez transportéen Corée (vous savez, " le pays des matins calmes ") et que vous fassiez un petit tour de bicyclette : vous sentirez le vent arriver sur la figure, bien que le vent, à l'arrêt, soit nul. Mais si vous êtes capable de pédaler, assis sur le guidon, en roulant à l'envers, vous sentirez du vent vous arriver derrière les oreilles : vous roulez, par définition, dans la direction d'où vous sentez venir le vent.

L'angle d'attaque
(incidence) est tout simplement l'angle formé entre la direction du vent relatif à l'avion et celle d'une référence fixe, choisie sur l'avion (la corde de l'aile, ou l'axe du fuselage, si l'aile a un calage fixe).

Cet angle va nous donner deux informations fondamentales : celle de la sustentation et celle de trajectoire.

[...]

Le Vecteur-Vitesse

Le seul moyen logique est un système optique approprié (collimateur) reproduisant à la même échelle le déplacement angulaire du détecteur d'angle d'attaque (une simple girouette d'axe horizontal convenablement placée sur l'avion par exemple) et montrant ainsi un repère lumineux dans la direction où va l'avion. Ce repère s'appelle le " vecteur-vitesse " (air) qui montre la trajectoire de l'avion par rapport à la masse d'air dans laquelle il vole. Nous le qualifions de " bon côté " de l'angle d'attaque (fig. 2), par opposition à l'autre côté que nous appelons le " fixe-avion " et qui est tout juste bon à servir d'index de mesure de l'angle... mais que, faute de mieux, on s'obstine à piloter et à faire piloter aux pilotes automatiques (... pourtant mon petit doigt m'a chuchoté que certain constructeur français serait en train de copier la méthode du collimateur, mais pour une fois on ne le grondera pas, au contraire !).

[...]

Le gradient de vent

Ce terme est utilisé chaque fois que la composante de vent, le long de la trajectoire d'un avion, varie. L’avion, du fait de son inertie, tend à garder sa vitesse par rapport au sol, de sorte que c'est sa vitesse indiquée (badin) qui change la première : pratiquement d'une quantité égale à la variation de la composante de vent. Cela se produit soit par rotation de la direction du vent, accompagnée généralement d'une variation de sa vitesse ou de mouvements verticaux à proximité de cellules orageuses, mais le plus souvent, il s'agit d'un " gradient vertical " où la force du vent varie avec l'altitude, les couches de vent glissent en quelque sorte les unes sur les autres, d'où le terme anglais de " wind shear ".

Ce qui nous intéresse ici ce sont les effets produits sur un avion, et pourquoi les pilotes humains " affligés " des instruments traditionnels, aussi bien que les pilotes automatiques qui agissent sur les mauvaises références, réagissent mai et trop tard aux effets des gradients de vent.

[...]

Les palliatifs

Les insuffisances des systèmes actuels, tant instrumentaux qu'automatiques, ayant été illustrées par les exemples cités, il est bien évident que les milieux dirigeants, dans l'administration comme dans les compagnies, sont conscients de ces problèmes, mais les solutions proposées ressortent plutôt d'une volonté inébranlable de ne rien changer à la doctrine. Ces solutions vont de la révision de règlements pointilleux et détaillés sur l'organisation des tâches dans le cockpit jusqu'à des... élucubrations parfois assez effarantes.

Il est exact qu'une bonne répartition des tâches et le respect d'une discipline de travail dans les phases cruciales de l'atterrissage permettent de mieux s'accommoder de L'instrumentation classique. C'est déjà beaucoup moins vrai lorsque la méthode imposée par des non pilotes au nom d'une administration toute-puissante conduit à des erreurs manifestes (ex : " changement de main " au moment de la transition entre Pilote-Commandant de Bord, ou Pilote Automatique-Commandant de Bord, ou au moment de la remise des gaz).

Mais que dire de la " Méthode " que la FAA [...]

[...]

Tout se passe donc comme si, par volonté délibérée, on refusait ces instruments aux pilotes pour démontrer que seul le système automatique doit être utilisé.

[...]

Dans les milieux officiels, il se trouve, Dieu merci, encore des responsables préoccupés de sécurité et qui ont un peu plus " les pieds sur terre " que les visionnaires du grand puzzle.

[...]

Ceux-là sont avec nous et nous espérons bien qu'ils partageront aussi les vues des pilotes pour le système simple qu'est le collimateur.

Car les pilotes sont de plus en plus nombreux dans le monde à réclamer des " HUD " : non seulement l'ALPA et d'autres, mais l'IFALPA qui regroupe toutes les associations mondiales et en a fait sa doctrine; et en France, bien sûr, le SNPL, et l'APNA qui l'a demandé au Ministre récemment.

Si les journaux français sont étonnamment discrets sur les résultats du collimateur chez nous (bien que nous soyons les premiers au monde à l'utiliser en ligne), la revue Aviation Week, dont le représentant en Europe est un pilote qualifié, a consacré un excellent article (malgré quelques erreurs mineures) au collimateur expérimental TC 121, dont Icare a parlé, et cet article a déjà suscité des réactions favorables de pilotes américains.

[...]

Comme il est précisé dans ces lignes, si des réticences violentes se manifestent encore dans certains milieux, il est significatif que, depuis le voyage aux USA de l'avion N. 262 n° 55 en 1972, on a constaté que les avions de combat de la nouvelle génération sont tous pilotés en tête haute. Le TC 121 a effectué cette tournée de démonstration.

[...]

le TC 125 n'utilise que deux capteurs pour chacune des données nécessaires. Il doit être connecté à deux systèmes inertiels, à deux sondes d'incidence, à deux récepteurs ILS, à deux radioaltimètres. Il comporte deux ensembles de calcul séparés et donne une image de pilotage sur deux têtes de visée. Il utilise les deux postes de pilotage. Chaque tête peut être connectée à chacun des calculateurs, etc., etc.

[...]

Car il ne faut pas oublier que l'erreur la plus grave au point de vuetechnique, et économique, est d'utiliser la technologie actuelle pour refaire ce qui était fait auparavant : vouloir représenter un tableau de bord classique avec ADI, HSI, altimètre, badin, vario et directeur de vol en utilisant des visualisations trichromes conduit irrémédiablement à un produit ayant des performances à peine supérieures mais beaucoup plus cher et de maintenabilité plus difficile. Il ne faut pas craindre de repenser complètement la totalité de l'opération aérienne avec un œil nouveau. Les circuits, la distribution de l'information, les boites de commande, les fonctions et modes dupilotage automatique peuvent en être considérablement simplifiés.

[...]

Dozy, it never seems to have crossed their minds that they were stalled. If you don't think you are stalled, odds are, you won't implement stall recovery. That isn't flying 101, that is understanding pilots 101.

Why they were unable to discern "we are stalled" is hopefully covered, in depth, in the final report. There's been sufficient speculation, to include my own, in these PPRuNe discussions that I'll not add to it.

Hi Dozy,

I gotta agree with gums on the HUD.

Here are two night landing videos, one with a HUD, the other without. Now imagine all the ground light were gone and you were cruising at 350 looking out into the black when the autos quit along with the computers. Wouldn't the HUD be very useful in establishing a proper flight path among other things?

Depending on the failure, the same 'flags' show up on the HUD as are on the head's down stuff, and the same associated info is rendered unavailable.

However it's not just a head's down repeater (with the exception of the tapes & HSI), as the displayed is info is 'real' world, i.e. 10 degrees in any direction in the FOV subtends 10 degrees of real world viewing. This is why EFVS & SVS adapt so nicely to HGS.

The center piece of this FPV discussion is whether you can have a true, fully inertial FPV, without the requirement for air data inputs, or not.

You can fail both the ADR 'sections' of the ADIRU's on an NG and still have inertial FPV. The angular effect of any inertial drift is minimal and not even a factor on an ILS as far as the beams and steering command, although with inertial drift the FPV may not exactly visually overlay the instantaneous real world aim/impact point, but the steering command will be centered in the FPV on LOC & GS.

You can fail 2 ADR's on a 330 and still have an FPV, but not 3 ADR's, it's not a matter of being reliable or not, it is just flat taken away.

Notice the AOA in the upper right corner on the NG.

Hi
I don't think the HUD itself will be useful in the situation you describes.

The purpose of the HUD is to show parameters to the pilot who has his head up, allowing him to see outside in the same time.
At night, IMC, you don't need to have your head up, there is nothing to see out there.

What may be useful in the situation you describes is a velocity vector, or any other mean that shows the energy state of the aircraft.
An AoA indicator may help, too.
But none of those were required per regulation, nor required for the crew to be able to manage the situation they were in.

Let's just clarify what I said - which was that diagnosis of and recovery from a stall is something that *every* pilot *should* know and understand.

I also said that an HUD was not necessary for stall detection and recovery - I certainly did not say that an HUD would not be useful under certain circumstances. But in every circumstance I can think of an HUD falls definitively in the "nice to have" category rather than "essential". This is very different from a fighter specification where the likelihood of other fighters shooting at you means that going head-down on instruments can sometimes be a very bad idea.

I believe that HUD remains an option on airliners from both sides of the pond, but, possibly due to the expense and extra complexity involved, take-up has not been universal.

Good to see the discussion of the FPV, whether on a HUD or on the flat panels.

My point is that the sucker shows actual flight path regardless of the air data. Surely this would have allowed the pilot to see that he was climbing and not simply maintaining the existing flight path when the air data went FUBAR, and the system reverted to mode "b", sub-mode"III, and so forth.

As others have pointed out, flying in IMC or in pitch black darkness, that FPV related to the horizon line is very comforting. Talk to any nasal radiator that flew Scooters or Double Uglies off the boat at night. No visual references of any kind. Acceleration from the cat shot that forced you to fly instruments. The exchange pilots I flew with that went into SLUF's, Hornets or Tomcats will tell you that the HUD flight path marker and that horizon line were lifesavers. And then I had my own air data failure one day in IMC and did just fine using actual flight path data than attitude with no air data. The other thingie we had was inertial vertical velocity next to the altitude bar. Think that doofer would have helped the pilot figuring out he was climbing like a bat outta hell or finally descending after arcing ov er the top with very low speed and high AoA that he could not determine from the flat panels?

I realize that some here will re-state the requirement for our basic airmanship and instrument flying skills. We always emphazised the ability to fly using the steam gauges. But I gotta tellya that comparing the two types of data - inertial and air data, was the best crosscheck ever invented.

Excuse me, DozeWanabee, my post was effectively too short
1. In formal terms : if the crew had having some incapacity (big smoke, irritant vapors, hyjacking, seat problem, etc?) recovering quickly from stall when 50° AoA, needed the Machinbird "unloading the wing" method, not just push. I wanted to remember it is not just piloting 101. It needs to be able to fly as French pilots learned their job with aerobatics before the "nouvelle méthode" (1979)
2. In historic terms about DGAC and AIRBUS choices : just to remember for these one who know this story, it would be too long here.

But I agree with
Loss of airspeed => correct Pitch and Power,
Stall => PUSH

But the AF447 had possible difficulty of assessing the situation...
I remember the first cited sentence of Gilbert Klopfstein : :rolleyes:
So HUD is (was!) "the" solution !

We will have to categorize the AF447 crew as having evolved into the new generation of automation dependent pilots, no matter what their original background was.

When things went ugly that night, their adrenaline meters pegged, and their ability to rationally analyze the situation departed. They didn't know where to go to find a handle on their situation. They didn't even have a clue where to start looking.

When you do not have an ability to scan and then rationally analyze what you are seeing, you had better have a stone simple tool to lead you out of the mess you are in or else you are lost. Perhaps the HUD is that tool. Not ever having had the use of one, I really can't offer a recommendation.

I imagine so, but that AOA gage peek right after a night cat shot told me whether or not the catapult had done its job and whether I should fly or reach for the ejection handle.

For things with wings, you really need to know how well you are managing your alpha.

True, though Boeing are rather reticent in putting too much reliance on it when used in commercial aviation. Mainly due to large variations in CG and weight, along with the Mach issues.
The rest of this article is in a SmartCockpit document.

Round and round we go, HUD this and AoA that. Yes, AoA is good. Yes HUD is good - I have used both. I am 100% certain that this crew would not even have noticed either since they appear to have not noticed the extreme pitch attitude (x 3), the extreme Altitudes (x3) and the high Rate of climb, nor followed their trained responses. All such observations, of course, subject to the final report, but in essence this AF crew simply could not 'fly' or operate a cockpit correctly.

Giving them AoA or a HUD would, in my opinion, be like giving a monkey an Ipad.:ugh:

Now, you do know that some monkeys have been trained to use them! :D

They know them as iPads.:E

"Now, you do know that some monkeys have been trained to use them!" - not, apparently, in Air France:mad:

AF447's crew needed to have their attention drawn initially to their altitude and then to their pitch attitude. Later, they needed to understand their angle of attack, and finally they needed to understand their Flight Path Vector and the fact that it was pointed at the ground although the nose was pointed up.

I think we (collectively) can figure out ways to draw attention to a particular indication when computers recognize abnormal operation. What we might do to help pilots in general and automation dependent pilots in particular is have another system that helps direct their attention to crucial parameters that need correction. This could be a highly engineered system with the wisdom of a generation of 'old hand' pilots, built into its software. It would monitor the data bus on a modern aircraft and offer subtle cues (or even stronger ones) that would draw attention to out of tolerance parameters to enhance situational awareness.

To those who cry-No, not another %*(#@& system, I say that we are already marching down the automation road, and there is no turning back. Let us at least learn how to make automation more human friendly.

There is no sense in allowing the strong, silent partner in the cockpit to be unable to communicate key information.

possibly, but what is wrong with learning to fly as a system? As far as "subtle cues (or even stronger ones)" goes, I would recommend a spring-loaded boxing glove inset into both P1 and P2 main panels with an associated audio 'alors, stupide' and a glass case inside which could be a real pilot for emergency use only, of course. :ugh:

It would appear that they prefer the political blog sites and would be unlikely to post to PPRuNe.

But I guess you never know...:eek:

Isn´t that the basic problem of missing airmanship here?
Flying has to do with handling all those items and some others as well in unison, without "target fixation" to a single item. FD bars, FPV, betty bitch, a talking radar altimeter, TAWS, and all those other helpers in a daily pilots life should be exactly that, helpers and not substitutes for bad airmanship.
I know you are familiar with that, our old rhino had nothing of those gimmicks and we did the job and survived like others did. It brings us back to training and expierience. Both seem to be missing big time and will not be restored by another gizmo.

(bolds are mine)

Yes, as Gums showed us, with air data failure, inertial reference would have been enough to save the lifes.

It also concerns immediate corrections of the A330 software.

But modifications need sometimes more difficulties that seeing things "with a fresh eye" (=>HUD G.KLOPFSTEIN).

A more general problem emerges here : Who is responsible of the flight, the Captain, or the Chief engineer, or the automation analyst, or the manufacturer ?

In AF447 flight that may concern the Court...

Is this really a 'lack' of airmanship...or a lapse in airmanship...or just circumstantially 'unpredictable' airmanship on the lower part of the deemed acceptable bell curve?

Two of which are genuinely 'out there' at any given time in any given pilot group (or pick your professional group).

You know what they call the guy who graduates last in his medical school class...

Doctor.

As we talk about 3 guys in the same cockpit with the same symptoms, wouldn´t that qualify as an epidemic event , Mr. Doctor:)

Take 2 aspirin and call me in the morning.

(3 ex-Phantom guys & an ex-Harrier guy should not be allowed to discuss airmanship without a referee and a linesman. :))

But FOUR ex-Phantom guys beat 1 Harrier guy hands-down.

OK, that will work in French airliners. What will the English speaking crowd get?:}:E

Seriously, with guys flying intercontinental routes and bagging only 5-7 hours of actual stick time a year, do you really expect them to have the touch at 2 am after their handling skills have had a few years to atrophy?

Imho it´s not a question what we can expect, but what we are entiteled to expect. Those factors should be accounted for by the company, by the training departments and by the regulators. The situation you describe is not an unavoidable must, it´s the unfortunate result of negligence.

Would you like to sit in a cab, where the driver is not used anymore to operate the brakes and the steering wheel?

No would be my answer and letting 300 hr pilots be SIC isn't right, they know nothing about what is happening. Competent pilots would not have crashed that night. Would you pull up into a 17 degree climb at FL350 when your performance data said you couldn't climb? They did.

@ F4
 

Thank you. Common sense is always to be applauded. :D :D :D

Automation Surprise
 

Machinbird
Interestingly, this problem has been foreseen but largely disregarded. If you read https://docs.google.com/viewer?url=h...ises.pdf&pli=1
on automation surprises - you will see echoes of comments here and of the progress of the AFR447 incident. The research was done prior to the AFR447 incident - but as is the case with a lot of human factors research it was not fully believed. :sad:

This could be a highly engineered system ...
 

Machinbird::

To enhance situational awareness :ok:

R&D is required to help crew for an improved "scan" (scan of the situation)

IMO this is becoming more complex and AF447 could be a case of "canary in coal mine"

Bubbers said it. They didn't have "performance" data available. They had attitude and a myriad of control law reversions and loss of several of the so-called "protections"

I am a dinosaur like several here. I evolved. I never forgot my basic instrument training and drills and never forgot two thousand hours in single seat jets that had primitive instruments. I also found my HUD flight path marker and the pitch lines very valuable displays to cross check with the steam gauges. Now there was a true performance indicator. Actual flight path with respect to the earth. No need for air data or flight directors or auto-whatever. Keep the damned thing on that big "horizon line" and you didn't climb or descend. Over the ocean or the desert at night, that sucker was invaluable.

As with many here, I have serious problems with the airmanship of the new crop. As a nugget, my instructor would hand me "paste-on" doofers to cover all the intruments except the turn/slip indicator, airspeed and altimiter. Them make me fly an ADF approach at a field. True "needle, ball and airspeed". So I was not a pinball wizard, and I never flew a "flight director" system that provided course interception, bank angle steering, etc.( the A-7D doofer sucked, and no one used it) Even original Viper didn't have that. My HUD video shows what we had - a raw display of ILS centerline and glide path. Was up to me to center all the needles.

So I maintain that a simple HUD with pitch lines and velocity vector would be invaluable in IFR or at night over a dark ocean. It would be especially valuable if HAL deemed all the air data, including AoA, unreliable. Hell, I can still tell that I am climbing or staying level or whatever. Don't need AoA. I can see that I am level and can move stick and throttles to stay on that flight path.

Gotta go before I get carried away

- refer 'Retired F4' Post#1391.

As RetiredF4 says, it is the bottom line!:ok:

Has anyone seen this conspiracy theory about AF447 being shot down by an Iranian SAM? When I was sent the link I assumed it was a sick joke, I'm still not sure, but it seems this character is serious.

The relevant part starts at 1'20".

Edited to add : For the avoidance of doubt, I think this a load of bull and don't for one nanosecond believe in the theory.