AF 447 Thread No. 8

[mm43]

@ OK465

I tend to agree that the various colors of ALT Law are not well documented, but can only assume that Airbus Industrie have determined in their wisdom that full divulgence will conflict with their KISS policy.

Best I can judge is that the switch to ALT2B was due to diverging CAS data which set up the ADR monitoring sequence with ADR2 being voted the "median". At the end of the monitoring period the new CAS "median" was not within 50KTS of the initial "median" value. Now that certainly matches the UAS criteria, but whether that should have been displayed or annunciated is debatable. The PNF announced, "We've lost the speeds", but then failed to check the QRH for guidance and the game was lost before reaching first base.

The following discussion between HazelNuts39 and Takata in AF447 - Thread No.5 (http://www.pprune.org/tech-log/456874-af-447-thread-no-5-a-17.html#post6572321) should give you an insight into why the law change was ALT2B, and the implications for the remainder of the flight.

I do think that Clandestino summed up ALL the ALT Law states quite succinctly:-Most important is to recognize that all the technical jargon about laws signifies that the safety nets are no longer there. and this could be quantified by the "bucket is half full" approach which is eminently preferable to the "bucket is half empty" scenario when DIRECT Law is applicable.

[wozzo]

@A-FLOOR:
Well....no, sorry. That's the very first time I've heard that one, after following these threads closely since 6/09. This Der Spiegel article is full of other mistakes, misrepresentations, and inaccuracies as well. Forget it.

For the record, SPIEGEL reporting concerning AF 447 usually reflects the thinking of Gerhard Hüttig, a professor from Technical University Berlin and advisor to the lawyers of the families of German victims (E.g., he thinks Airbus A330/340 are dangerous & should be grounded because he "proved" in the sim that they can't be recovered from stall). I'm pretty sure he or the lawyers are also the source for most of the "insider" information.

[Lyman]

"Now that certainly matches the UAS criteria, but whether that should have been displayed or annunciated is debatable. The PNF announced, "We've lost the speeds", but then failed to check the QRH for guidance and the game was lost before reaching first base."......from mm43, above.

How is it debatable? Are you comfortable hand flying without speeds in these conditions? For thirteen seconds, now the ship is climbing? Now you will wait for UAS determination causing serious control changes in mode until 2:10:22?

What am I missing here?

The game was lost before crew had a chance to troubleshoot.

[A33Zab]

ALT1A:
As ALT1 but Stall protection is lost.

ALT2A:
As ALT2 (Stall protection is lost)

...as if stall 'protection' (wrong term) is available in ALT2, but not lost until reconfig to ALT2A?? In any case both stall 'protection' & theta protection take a hike in all laws other than normal, so 1A, 2A are what exactly?? Just vanilla 1 & 2??



Flavours:
'Vanilla' 1 = Normal Lateral law
'Vanilla' 2 = Roll DIRECT law & Alternate Yaw law


For ALT1/2A 'alternate stall protection':


The ALTERNATE stall protection is based upon Vc.
When Vc < Vc prot a SS pitch order is a DIRECT! elevator deflection order, a stability order with limited authority is added to the SS order.

My question regards the difference in failure modes that would create one or the other level of reconfig. I would have thought that 2A & 2B are a function of how many ADR's get flaky, i.e.

1 flaky ADR = continued Normal Law
2 flaky ADR = ALT2A
3 flaky ADR = ALT2B



Ok, but not exclusive to ADRs only. (e.g. loss of weight information)

I guess I'd like to know how do I then get into each of these conditions and then how do I recognize which one I have, which ones 'latch', which can be recovered to a different level of reconfig, or do I even need to know any of this?



I can list them for you (from fragmented data) but don't know the latched state or possibility to recovery to a higher level.

Simulators generally only provide a limited range of constrained failures to achieve one or the other reconfiguration level for training, so does the available documentation need to be enhanced?


Don't know, I am not a pilot, but from the side I would say you need to experience the difference between NORMAL & DIRECT SS manipulation and consider everything what is available to you as a bonus.

[OK465]

Thanks A33Zab & MM43.

In case of UAS, What you will have instead is the red flag "SPD LIM" (see report previous page) without Vmax, VSL nor VSW and... It will last for the remainder of the flight like ALT2! (read me well: even if the airspeed come back to normal after a while...

This quote is from Takata, and if I understand it correctly, raises an interesting point about the 'latched' state of ALT2B and addresses some of the recent discussion about VLS availability and other displays.

It indicates to me that when speeds returned to normal at the apex at 5.6 degrees of pitch, that not only was VLS not available, but there was no red & black zipper (VSW) displayed either. Just a valid speed value (~215k) and speed tape and a SPD LIM flag.

So when the FD's returned, there was no visual indication of VSW, i.e. no real good visual indication of stall proximity or the inadvisability of pulling up again at this point. And without the classic aircraft response, a source of confusion in correlating the audio SW to the actual flight conditions.

I think this is why, at least I think, knowing what actually gets 'latched' may be of some use to the drivers.

[Lyman]

"It indicates to me that when speeds returned to normal at the apex at 5.6 degrees of pitch, that not only was VLS not available, but there was no red & black zipper (VSW) displayed either. Just a valid speed value (~215k) and speed tape and a SPD LIM flag."....OK.

Whether the stall bug returns with speeds or not is unclear, the BEA say that with ADRs out, the bug is not available, HazelNuts39 pointed that out, it is in #3.

[OK465]

Apologies if I'm going over old territory. Just trying to relate it to available documentation. :)

[CONF iture]

I'm afraid I can't follow your argument here. The issue whether or not the memory items apply was not addressed in the Air Caraibe Memo. Airbus said they would think about a modification of the checklists to address ACA's problem which was that their pilots were 'intimately' convinced that the two stall warnings were 'inapproprié', and had decided to disregard the phrase "RESPECT STALL WARNING AND DISREGARD 'RISK OF UNDUE STALL WARNING' STATUS MESSAGE IF DISPLAYED ON ECAM"
You are correct to underline one aspect of the memo on which, by the way, answers are still to be developed, as mentioned here (http://www.pprune.org/6676111-post706.html) earlier.

But point in debate is more general, it is not only about the memory items but the overall applicability of the UNRELIABLE SPEED INDICATION PROCEDURE :
De plus, les ingénieurs Airbus ont bien compris toute la difficulté rencontrée par l'équipage pour une mise en application rapide et efficace de la procédure « UNRELIABLE SPEED INDICATION ». Ils ont convenu de la recevabilité de nos remarques et réfléchissent donc à une modification des check-lists. A suivre...

Have we seen that modification yet ?

[CONF iture]

Yes, that's correct, they wrote that in November, 2002 under the heading, "Immediate Pitch Attitude and Thrust Guidance" followed by an admonition to "Respect the Stall Warning" and, "When the Flight Path is Stabilized" -Attitude/Thrust - Adjust".

Admonition to respect Stall Warning but then part of the ACA Memo, everybody, Airbus included, thinks the Stall Warnings were inappropriate and the crew did well to ignore them.

A similar language is part of the AF info OSV :
here (http://www.pprune.org/7122035-post1302.html) and here (http://www.pprune.org/7129482-post2.html)

So, a lot has still to be clarified and we are certainly not at the last revision for the UAS drill/checklist.

Note:
I post here a few slides of a "NEW" UAS procedure but I cannot certified the date of that revision ?
To note the clear request for 5 deg pitch attitude in cruise phase.

http://i45.servimg.com/u/f45/11/75/17/84/ltop_a10.gif (http://www.servimg.com/image_preview.php?i=148&u=11751784)

http://i45.servimg.com/u/f45/11/75/17/84/ltop_a11.gif (http://www.servimg.com/image_preview.php?i=149&u=11751784)

http://i45.servimg.com/u/f45/11/75/17/84/ltop_a12.gif (http://www.servimg.com/image_preview.php?i=150&u=11751784)

http://i45.servimg.com/u/f45/11/75/17/84/ltop_a13.gif (http://www.servimg.com/image_preview.php?i=151&u=11751784)

[Clandestino]

What am I missing here?

The point.

Aeroplane did not pitch up out of her own accord but because CM2 commanded her to. It stalled because CM2 kept on pulling when she was alredy above her practical ceiling. Aeroplane performed as expected. Pilots not at all.

The game was lost before crew had a chance to troubleshoot. If the name of the game is "situational awareness", then you are right.

when speeds returned to normal at the apex at 5.6 degrees of pitchErrrr... not quite. The apex of first pull-up was 12°, zoom climb made vertical speed go up to 7000 fpm (at FL362!), both recorded airspeeds (ADR 1 & ISIS) were false. Nose pitched down slowly, following the order form the right sidestick, IAS 1 returned to normal while pitch was 11°. ISIS speed started showing the correct value just about the time the aeroplane exited envelope following the second pull-up. Pitch was about 16° and alpha about ten.

So when the FD's returned, there was no visual indication of VSW, i.e. no real good visual indication of stall proximity or the inadvisability of pulling up again at this point.For the time being, this seems to be the correct assessment. However, altitude display was available so why would anyone consider a good idea to pull, especially as MAX REC was discussed just a couple of minutes before and the aeroplane was very near it, or to pull while something is shouting "STALL STALL STALL" in the cockpit is something I find inexplicable in rational terms.

And without the classic aircraft responseResponse was completely according to the tired old cliche: To go up, pull back on the stick, to go down, pull back further.

[Machinbird]

Originally Posted by OK 465
So when the FD's returned, there was no visual indication of VSW, i.e. no real good visual indication of stall proximity or the inadvisability of pulling up again at this point.
For the time being, this seems to be the correct assessment. However, altitude display was available so why would anyone consider a good idea to pull, especially as MAX REC was discussed just a couple of minutes before and the aeroplane was very near it, or to pull while something is shouting "STALL STALL STALL" in the cockpit is something I find inexplicable in rational terms.
If you will notice, no where during the pull up was there ever a mention of actual altitude by the crew, only that weird "go down" recommendation from PM.

It would seem that this crew was already so stressed, that neither of them actually read the altitude numbers, and they only noted the scrolling of the altitude tic marks on the PFD.

What could cause this level of stress? Other than it was a black and turbulent night, and neither of the pilots had experience with UAS or Alt2 at altitude (which is enough to make most pilots edgy), it would appear that the initial overcontrol of roll caused an adrenaline flood when the aircraft refused to calmly follow PF's piloting efforts.

Something really got to these guys. What else is unusual about the first 30 seconds after the AP dropped that would set them on edge? How many of the 30+ flights that didn't lose control experienced roll oscillation?

Response was completely according to the tired old cliche: To go up, pull back on the stick, to go down, pull back further.
Yep!

[OK465]

Nose pitched down slowly, following the order form the right sidestick, IAS 1 returned to normal while pitch was 11°.

Clandestino:

You are correct that the CAS (which BTW is referred to in the report as "calculated airspeed' not calibrated nor IAS, the term you use) is actually recovered at 2:10:34 at 223 knots.

However, the FD's become available at 2:10:47, and as you correctly state, CAS 'has already been recovered' and is at 216k with a theta of 5.6 degrees at 2:10:49 at ~FL375, eventually topping out at an 'apex' of FL379.

The stall warning occurs 4 seconds after the FD's return (2:10:51) at a '6 degree' AOA (FD bars steady not flashing).

We may be splitting hairs here, I'm an old guy and get distracted easily. :)

Response was completely according to the tired old cliche: To go up, pull back on the stick, to go down, pull back further.

Entirely correct as far as vertical direction of flight. (I'm old and occasionally get tired also. :})

...or to pull while something is shouting "STALL STALL STALL" in the cockpit is something I find inexplicable in rational terms.

I think there's a considerable effort going on to make it 'explicable', and that effort unfortunately may indeed fail.

(I understand that pilots need to know the state of their airplane to control it, and those that do will perform well no matter. As you say, sometimes they don't, but as you also say (if I may paraphrase without going back and directly quoting), "pilots 'learn' their aircraft from reading their manuals".)

[CONF iture]

Straw man argument. It is supposed to be applied until QRH is brought out and correct values for weight found and set. If it takes five minutes of fumbling, it won't kill you in this five minutes. Or until the fuel runs out but that doesn't mean it should be applied indefinitely.
Typical Clandestino stuff here :
I write how illusionary it is to pretend to maintain indefinitely a 5 deg pitch in altitude but you find 5 reasons to state I’m wrong but now you feel the need to precise it is only for the necessary time to get the QRH out …
How long do you think it takes at CLB thrust from FL350 200T before the AoA matches the 5 deg given to the pitch ?
I have no precise idea just a guess it would not take much but I’m certainly not ready to test and validate or not your theory.

It's attempt at dumbing down the procedure to unachieavable level, no matter if it proposed by Airbus or some PPRuNer. Applying such a procedure for low level approach to stall can easily result in unnecessary deaths and damage to property.
No pprune in that, and not only Airbus.
And on the contrary, to not apply that procedure for low level has proved to be deadly, but then the procedure was not published yet …

[HazelNuts39]

How long do you think it takes at CLB thrust from FL350 200T before the AoA matches the 5 deg given to the pitch ?http://i.imgur.com/aXCVA.gif?1

[HazelNuts39]

You are correct that the CAS (which BTW is referred to in the report as "calculated airspeed' not calibrated nor IAS, the term you use) is actually recovered at 2:10:34 at 223 knots.If you allow me to 'split hairs' on terminology: The airspeed indicated on the display (corrected for instrument error, if any) is commonly referred to as IAS. If the ADIRU applies appropriate corrections for errors in pitot and static pressures, IAS is equal to CAS. If the pitots are blocked or at large AoA the indicated airspeed is not equal to CAS. The report refers to the captain's IAS as 'Vitesse conventionelle' or 'calculated airspeed' or 'CAS' when it means IAS.

Regarding the ACARS messages FLAG ON CAPT(F/O) PFD SPD LIM, BEA#1 says: "This message indicates the unavailability of the FMGEC's characteristic speed calculation function." There is no reference for Takata's assertion that it would be latched. IMO it could well be a temporary condition similar to the unavailability of the FD's - the SPD flag that occurs later is not latched (see IR#3 page 44). When the FD's return at 02:10:47, the F/O's airpeed (ISIS) is still 121 kt. The stall warning speed of 207 kt would have been off-scale on the F/O's PFD.

[VGCM66]

Vol AF 447 Crash: 01/06/09: Les Raisons D'un Crash (Reconstitution) - YouTube

I am guessing no subtitles yet on this French reconstruction anywhere...:ugh:

?

[CONF iture]

Interesting graph HN39
So in theory it takes about 3 minutes before both angles match.
Alpha SW is below Alpha Max.
Alpha SW is not even 1 deg above the 5 deg AoA.
Where would be Alpha Stall ?
What altitude would be reached when both angles match ?

[BOAC]

We are heading for 1300 posts now, and the oozlum burd is circling once again. SURELY wheter or not 5 degrees is 'right' or 'wrong' is immaterial in this accident? Had the crew maintained 5 degrees and crashed I would be interested!:ugh:

[OK465]

1301 BOAC, go play with NG guys...:)

There is no reference for Takata's assertion that it would be latched. IMO it could well be a temporary condition similar to the unavailability of the FD's - the SPD flag that occurs later is not latched…

HN39:

This is baffling to me. There's also no reference contradicting Takata. Having done some UAS work for sim lesson plans before I retired…

I can get a ‘latched’ SPD LIM flag with NO characteristic speed info on BOTH PFD’s by simply inputting a speed discrepancy of 50 knots, failing a single ADR in use (either 1 or 2, or 3 if switched), and then reviving the ADR and removing the speed discrepancy.

I will be in a ‘latched’ alternate law of some flavor (amber hash marks), both FD’s are back, but the absence of characteristic speed info is permanent, however the SPD LIM flag remains also???

I think I have ALT2”B” OCD.

[HazelNuts39]

Alpha SW is not even 1 deg above the 5 deg AoA.True, but do you need three minutes to get the QRH?
Where would be Alpha Stall ?The stall is not clearly defined. I would put it somewhere between 9.5 and 10.5 degrees.
What altitude would be reached when both angles match ? 37353 ft after three minutes.

[CONF iture]

True, but do you need three minutes to get the QRH?
No it should not, but don't forget you're here in the theory territory where everything is by the book, total control of the pitch, no turbulence, above average crew who will get the right data from the right page with no delay. In practice many distractions may interfere ...
It is bringing complexity where none is needed.

I restate my position :
IMO, the procedure for UAS in cruise phase should clearly mention to adopt the usual parameters for such phase of flight :

PF Maintain 2.5 degrees of pitch
PNF Set the thrust parameters as they are usually in CRZ
Wait for improvement

It is a suggestion that would clarify the situation ...

[PJ2]

I restate my position :
IMO, the procedure for UAS in cruise phase should clearly mention to adopt the usual parameters for such phase of flight :
1.PF Maintain 2.5 degrees of pitch
2.PNF Set the thrust parameters as they are usually in CRZ
3.Wait for improvement
"Do nothing" has been my position since July 30th 2009 in a response to Stepwilk, (Post #3990 (http://www.pprune.org/tech-log/376433-af447-200.html#post5093749)), and I have consistently maintained this position in the face of considerable opposition since.

HN39's work shows the effects of a slight increase in pitch, (2.5deg increase) and while slightly destabilizing, are benign in the short term. The point has always been, when in already-stable flight, why bother? It adds work, complexity as you say, and clearly most crews ignored the drill.

In my view, the opposition is primarily because the UAS drill and checklist is indeed confusing even to trained crews and was to this point that I have continually addressed myself, even re-designing the drill. Reverting to the simplest solution is also the safest one - do nothing - maintain pitch and power, remain calm and get out the books; even the video to which you provided a link now says this, yet the BEA maintains a position now at odds with this thinking from an ordinary A330 line pilot. What is to be done?

We're arguing the same point.

[NeoFit]

"Do nothing" has been my position since July 30th 2009 in a response to Stepwilk, (Post #3990), and I have consistently maintained this position in the face of considerable opposition since.
Undoubtedly, your position is right when UAS event occured in a "shinning blue sky tempest".

But would you please consider that at 02:10 UTC, the vessel was flying in ITCZ (also called F.I.T - Front Inter Tropical in another language).

[AlphaZuluRomeo]

+1 NeoFit

Also I remember one fellow poster (can't remember who precisely, sorry...), who said as a captain he sometimes asked his F/Os: "look at me, not the instruments, and tell me without cheating what is our pitch right now" (aircraft in cruise). IIRC many couldn't say precisely.

Perhaps that's one reason? (is it good or bad, I'm not sure)
5° & CLB, as a memory item. That is what you must know, for the time needed by the PNF to get the QRH at the right page, and crawl through the table for your aircraft current weight/alt.

I wonder if it would not be better (and simpler?) if any crew member could tell what are the current stabilized pitch & power settings, in order to maintain those should the A/P and/or A/THR drop off, for whatever reason. But as the shared experience of the above quoted captain teached me, this knowledge seems not (enough) widespread...

[edit] would like to add that, even if this question is interesting, I see it as unrelated to AF447 where the crew neither maintained standard cruise pitch&power, neither set 5° & CLB as per the published procedure if they had condidered the safe conduct of the flight was affected, which I don't think was the cas, at this point.
(and BTW yes, I'm aware of the "unsafy condithingy" brandished by totally un-agended people, based on a memo from an avionic manufacturer ; this memo was twofold IMO: to alert about potential danger and (in the mean time) to cover said manufacturer's assets)

[bubbers44]

"Are there pilots that follow the flight director blindly? Didn't happen when I was flying"

Sorry to follow my own quote but when did pilots not become pilots but follow the magenta line?

I always looked at the flight director but sometimes it gets programmed wrong as in one of my previous posts when my check airman got it so screwed up I just ignored it and flew my flight plan. He eventually caught up. No you do not follow the flight director blindly. You verify everything it is doing. To just follow it with no verification makes you not a real pilot, soory.

[PJ2]

Neofit;
Undoubtedly, your position is right when UAS event occured in a "shinning blue sky tempest".

But would you please consider that at 02:10 UTC, the vessel was flying in ITCZ (also called F.I.T - Front Inter Tropical in another language).
Many of us here have flown in that kind of weather, (light to moderate chop or turbulence) and we know that the pitch will vary slightly as will the thrust...in most circumstances not much but it will vary. The requirement to "set" five degrees in the checklist may not be exactly the result in the aircraft but it will be close, while the other crew member gets out the QRH and the PF. Five degrees is about 2 to 2.5 degrees above normal cruise pitch and perhaps prevents the airplane from descending if the drill required, say, "3deg" and not 5, thus preventing a possible overspeed situation from developing - it guarantees that the aircraft will at least climb and not descend. So there are some reasonable reasons behind 5deg providing it isn't held too long.

My "do nothing" view means roughly the following: Once aware of the problem, (and it may take a few moments), call the abnormal so the other crew member is aware you're aware and is alert for next actions, wait for a few moments, observe the altitude, get the FMC onto the GPS page and see if the airplane is climbing or descending and adjust pitch accordingly. In the Airbus at least, "thrust lock", which occurs when the autothrust is disconnected involuntarily, will prevent any change in the power setting. If the thrust setting was lower than cruise power when the autothrust disconnected, that will be corrected with the QRH pitch-and-power tables. In the meantime, control is maintained even if the airplane wanders a bit. It certainly isn't going to lose speed fast if the thrust is a bit low. But like the training notes say, get on with the QRH checklist smartly. The checklist provides guidance on how to ensure that the correct pitch and power are set and it takes a while as the settings slowly affect airplane performance and it stabilizes with the changes. "Do nothing" doesn't mean literally just sit there!

AlphaZuluRomeo;
Also I remember one fellow poster (can't remember who precisely, sorry...), who said as a captain he sometimes asked his F/Os: "look at me, not the instruments, and tell me without cheating what is our pitch right now" (aircraft in cruise). IIRC many couldn't say precisely.
It's a good exercise. But not being able to tell what the pitch and power was does not mean that all is lost and "5deg" is the only answer.

To me, it means leave the airplane alone. By all means do what is obviously necessary to maintain stable flight, but having to change something in these circumstances would be extremely rare. The energy state of the airplane was fine using the pitch-power settings just seconds before the event. Unless sudden and unexpected entry occurs into turbulence that is severe to extreme, the pitch and power settings which existed just before the event are going to be very close to, if not exactly what is needed in terms of temporary pitch and power settings while the other pilot gets out the QRH. If the airplane starts to wander downhill, gently squeeze the stick back a tiny bit and wait for the input to take effect. Tiny movements on the stick is key, regardless of the method used.

I agree that five degrees is safe, providing the crew response is timely. But I think destabilizing the airplane when it was fine before, especially when almost no one is practised at high-altitude manual flight, requires some careful thought.

[bubbers44]

Why not just hold the pitch attitude of 2.5 and cruise power until airspeed returned. The altimiters were working fine. They would have been fine if they hadn't pulled up into the obvious stall. Experienced pilots would not have had a problem. Cheap new hire pilots will.

[mm43]

Probably worthwhile reminding the current punters that A33Zab provided a comprehensive spreadsheet layout of essential data back in AF447 Thread No.4 post#691 (http://www.pprune.org/tech-log/454653-af-447-thread-no-4-a-35.html#post6549447). Those with a screen resolution width of 1024 pixels or less should view the image directly here. (http://i474.photobucket.com/albums/rr101/Zab999/AF447Events3.jpg)

We don't know how long the UAS condition would have remained if the aircraft had maintained FL350, but at least they would have eventually "flown" out of the ITCZ.

[PJ2]

mm43;

Thanks for the link. IIRC, the time for the airspeed to return to normal was painfully short...less than a minute? but by that time the airplane was established in the stall. In the original sim exercise, (I did two), it took about 4 minutes to slow down from 270kts to about 186kts, in level flight. At the time I never contemplated the possibility of a pitch-up and it is remarkable how quickly the energy is lost. That said, Owain Glyndwr has posted data which posit a successful recovery as low as 6000ft. He readily acknowledges that few if any transport line pilots would point the airplane down the necessary -10deg pitch to do so but the higher-level scenarios, which still require just a -10deg pitch attitude, recover successfully.

bubbers44;

Indeed, why not just hold 2.5 and make that the target in the drill?

For almost all conditions that would be fine and that is how I have argued - perhaps not "2.5", but the last-known. Clearly it is what all other crews did, to a greater or lesser degree.

What I can see out of this extended conversation is a subtle need to at least protect the airplane from going downhill. What perhaps wasn't anticipated was someone pitching up to 15deg in cruise and that has motivated my argument all along.

To me, and perhaps to most transport pilots, if it started going downhill a bit we'd just bring it back up, hopefully gently, (but that assumes that the altimeters are working!...but there's still the GPS.

Five degrees caters to all weight/altitude conditions, but I know from having looked for years and years at the ACMS data in cruise flight (A330-300) that the pitch doesn't vary much from 2.0 to 3.0 degrees even in the kind of turbulence AF447 was in. So keeping it at 2.5 and then working from there, fine-tuning it just in case that was a transient pitch attitude or power setting, is very doable.

I'm pretty sure we have to look beyond the "cheap new hire pilot" notion here. A great deal of commentary has already been offered by a number of contributors on the topic.

[AlphaZuluRomeo]

It's a good exercise. But not being able to tell what the pitch and power was does not mean that all is lost and "5deg" is the only answer.
Certainly not, indeed. But 5°/CLB has apparently been deemed stable enough. Why not 2.5? Perhaps because you don't have an associated stable-in-all-conditions thrust setting?

I'm not advocating 5°/CLB should be applied at all time when UAS. Neither am I sure the authors of the procedure meant it that way.

If the safe conduct of the flight is affected => if above FL100 => 5°/CLB => QRH
If the safe conduct of the flight is not affected => maintain current => QRH

What means "safe conduct of the flight is affected" is, IMO, where the "problem" lies...

They would have been fine if they hadn't pulled up into the obvious stall.
Once again, this is not related directly to AF447 as we have no clear indication they tried to follow any (part of) procedure.
That doesn't mean the procedure should not be improved. It should.

[HazelNuts39]

HN39: This is baffling to me. There's also no reference contradicting Takata.It seems Takata is right this time. The Air Caraibe memo states that about 30 minutes after the UAS event the crew reset both FMGEC to get rid of the SPD LIM red flag and to regain VLS indication on the PFD.

RE 5°/CLB: The Air Caraibe crew used GPS altitude and groundspeed to maintain trajectory and speed. Prior to UAS they had disconnected the A/THR and set cruise N1 for the weight and altitude.

[PJ2]

What means "safe conduct of the flight is affected" is, IMO, where the "problem" lies...
Fully agree with you, AZR. This condition seems to have been introduced and incorporated into the memorized drill portion of the UAS response, around 2006.

In its "Unreliable Speeds; Latest Improvements (http://www.iag-inc.com/premium/AirbusUnreliableSpeeds.pdf)" document from September, 2006, it is indicated that the memory drill qualifying condition, "Safe Conduct of the Flight Affected?" will be "Defined in Training". But the guidance remains, if the safety of the flight is not affected, first step is to level off and troubleshoot. Prior to 2006 the drill had "Immediate Actions" and then "Immediate Pitch and Thrust Guidance" and then a "When Flight Path Stabilized" section which required the Probe Heat to be put ON and "Attitude/Thrust - Adjust".

The December, 2007 edition, (#5), of Airbus' "Safety First" an article entitled "Unreliable Speed" was published. The article is quite thorough and well-written, making clear many points. It states, in part:


1) If the safe conduct of the flight is affected, APPLY THE MEMORY ITEMS, i.e. fly a pitch with TOGA or CLB thrust,
2) If the safe conduct of the flight is not affected, or once the memory items have been applied, LEVEL OFF, if necessary, and start TROUBLESHOOTING,
3) If the affected ADR can be identified, fly with the remaining ADR.
4) If the affected ADR cannot be identified or all airspeed indications remain unreliable, FLY WITH PITCH/THRUST REFERENCES

The question, as always when such changes occur and the distribution and incorporation of infomation is involved is, how are these changes incorporated into training by airlines operating Airbus equipment? As with most editorial changes, these changes were ordinary in the sense that most changes in procedures, SOPs, checklists and so on go through a pretty thorough vetting process even at the airline and are then published, incorporated into SOPs and training scripts and regimes, all of which take time to make their way to flight crews.

Here again, as this is the way almost all changes to SOPs work, we have to be mindful of hindsight bias. We can see now, that there were at the time of these changes, already UAS & ADR events occurring. The 2006 documents speak to awareness and addressing of the issues.

According to BEA IR#2 Appendix 7, "List of events on A330/A340 attributable to the blocking of at least two Pitot probes with ice, identified by Airbus as of 3 November 2009" there were ten UAS events prior to 2007. So the information would have been "out there".

Since most crews appeared to have kept the aircraft level while troubleshooting, (we don't know this for certain but it appears so), it would be interesting though likely difficult to determine given the passage of time, if crews who had one of the listed UAS events had had either training in the changed procedure or were at least aware of the changes and knew how to do the updated drill.

[TTex600]

"Are there pilots that follow the flight director blindly? Didn't happen when I was flying"

Sorry to follow my own quote but when did pilots not become pilots but follow the magenta line?

I always looked at the flight director but sometimes it gets programmed wrong as in one of my previous posts when my check airman got it so screwed up I just ignored it and flew my flight plan. He eventually caught up. No you do not follow the flight director blindly. You verify everything it is doing. To just follow it with no verification makes you not a real pilot, sorry.

When? When Airbus intro'd an airplane that required the FD's be followed. If the FD's are not followed, it sometimes confuses the Autothrust system, etc. The only real way to "fly" the bus requires one to turn the A/P, A/T and F/D's all off. Otherwise, you're mixing things up and confusing both the co-pilot and FiFI/Henri/HAL.

[CONF iture]

AP is also lost if ADR DISAGREE, could it have been reengaged to also follow the reappearing FD bars ?
NO, all ADR speeds were below VLS after 02:10:08.
If 2 speeds would have been above VLS then YES,... See VH-EBA
But the Air Caraibes memo shows AP can be reengaged when VLS are not even computed ...

[CONF iture]

When? When Airbus intro'd an airplane that required the FD's be followed. If the FD's are not followed, it sometimes confuses the Autothrust system, etc. The only real way to "fly" the bus requires one to turn the A/P, A/T and F/D's all off. Otherwise, you're mixing things up and confusing both the co-pilot and FiFI/Henri/HAL.
But the Airbus procedure is quite clear : If you choose to NOT follow the FD, turn them OFF.

[OK465]

The Air Caraibe memo states that about 30 minutes after the UAS event the crew reset both FMGEC to get rid of the SPD LIM red flag and to regain VLS indication on the PFD.

HN39 (or CONF or A33Zab):

If I might ask (without going to the memo), how did they reset the FMGEC's and how did they know, procedurally, to do it?

(BTW: saw your earlier question, and yes you can get the same 'latched' SPD LIM situation by inputting two airspeed discrepancies with no failure. Using a single offside ADR failure is just quicker than typing on an IOS keypad, but at least one side must incorporate the speed discrepancy, 2 or 3 ADR 'failures' and revivals will not do it. Once on the ground, you can reset both the SPD LIM & FC law by cycling the generators off and on.)

[HazelNuts39]

OK465;
Sorry, I don't know more than the memo says: warnings "AUTO FLT FN1(2) FAULT" are recorded, and these are explained by the reset of the FMGEC's.

[OK465]

But the Airbus procedure is quite clear : If you choose to NOT follow the FD, turn them OFF.

Very important.

And a 'normal' op where this required is a PRM breakout.

It's interesting that if the PNF deselects both FD's first (as required) and then the PF elects to use TOGA rather than CLB on the breakout, the FD's reappear in TOGA (due to flaps extended) and must be again deselected by the PNF.

Making radio calls, watching a TCAS target, reconfiguring, resetting the FCU by the PNF, and hand flying raw data for the PF can all be quite challenging and must be a very disciplined drill.

When the FD's are reselected after the breakout, care must be taken to not fly them until proper FMA mode indications are verified, some modes not being selectable until after re-engagement.

(edit: BTW for B44, the same requirement to turn off the FD's on a PRM breakout exists in the automated Boeing's also, because sometimes people inadvertantly do dumb things, even in Boeing's. :})

[CONF iture]

If I might ask (without going to the memo), how did they reset the FMGEC's and how did they know, procedurally, to do it?
I think they would use the RESET OF COMPUTERS procedure from the QRH and were probably in touch with their maintenance through the ACARS. That reset was done 30 minutes after the initial event. 3 hours later ... PRIM1 was also reset, maybe in an attempt to go back to Normal Law.
It is also possible the maintenance was directly in touch with Airbus.

[Lyman]

In the initial discussions re: BUSS, I believe that once it activates, no more NORMAL LAW, til she's on the ground and tended to....

[A33Zab]

Someone knows if this memo is translated into english?

From the available documentation: (AMM FMGEC / EFCS)

AP Operational Conditions:


(2) AP engagement inhibition and disengagement logics



(a) Pitch and roll angle limits


- Roll angle
. AP engagement is inhibited when abs(phi) > 40°
. AP is automatically disengaged when abs(phi) > 45°.
- Pitch angle
. AP engagement is inhibited when theta < -10° or theta > +22°
. AP is automatically disengaged when theta < -13° or theta > 25°.
(b) AP engagement is inhibited in flight when CAS < VLS or CAS > (VMO/MMO or VLE/VFE).

(c) AP engagement is inhibited when the FMGEC receives the "pitch angle protection active" information from the FCPC.

[HazelNuts39]

Someone knows if this memo is translated into english?No translation I'm afraid, but I converted it to a
WORD document (https://docs.google.com/open?id=0B0CqniOzW0rjcHJ4SmdTRHFtanc). Hope that helps.

[A33Zab]

If I might ask (without going to the memo), how did they reset the FMGEC's and how did they know, procedurally, to do it?


FCOM Procedures 22-10


MANUAL FMGES RESET

MANUAL RESET OF FMGCS

On rare occasions, the FMGS may require manual resetting.
If this occurs in flight, reset one FMGC at a time.
The aircraft has two reset breakers per FMGC:
‐ The FM reset-breaker C/B resets the flight management part of the FMGC.
‐ The FMGEC reset-breaker C/B resets the flight management, flight guidance, and flight envelope parts.

Resetting the FM reset-breakers C/B or FMGEC reset-breakers C/B disconnects the onside autopilot.
The FM further resynchronizes to reset one or both FM.
Resetting the FM or FMGC reset-breaker does not increment the reset counter: There is no limitation to the number of reset-breaker resets.

[bubbers44]

I still think setting the attitude to what it was at FL350 and doing what the autopilot was at about 2.5 degrees nose up attitude and maintaining cruise power around 90 percent N1 or what ever your cruise power is with your conditions would be prefered to busting through altitudes because of a bad checklist. If the altimiters work, use them. Just get out the unusable airspeed checklist and don't repeat this error again. The 5 degrees nose up and climb power is still taught in some airlines. Pray for the airliners above them opposite direction. That procedure is only to be used in an emergency when control of aircraft was in doubt, not loss of airspeed.

[OK465]

Thanks once again A33Zab & CONF.

Using reset-breakers for a procedure makes it sound a little more like an 'old' Boeing.

Although, in the past, if you put breakers (reset type or not) on any flight deck (even as few as there are in a 330), some flight engineer would eventually figure out a valid operational reason for 'using' 'some' of them. :)

[AlphaZuluRomeo]

Vol AF 447 Crash: 01/06/09: Les Raisons D'un Crash (Reconstitution) - YouTube (http://www.youtube.com/watch?v=kXMsmPQKaps&feature=related)

I am guessing no subtitles yet on this French reconstruction anywhere...:ugh:

?

Hi VGCM66,

No subtitled version exists that I'm aware of.
But as there were questions about Mr Rosay's interview, I translated two parts where he can be seen:

On the loss of speed indications and the procedure to follow:

French transcript:
Le genre de situation qui a été rencontré est une situation qui n'a rien de... d'exceptionnelle.
D'ailleurs la... quand vous perdez les indications de vitesse, en croisière hein, je crois que c'est la procédure la plus simple à appliquer : il faut faire rien. Et il va continuer à voler comme ça pendant encore très longtemps.
English translation [& notes] by AZR:
The kind of situation that was encountered [loss of speed indication] is a situation that has nothing ... exceptional.
Besides ... when one loses the speed indications, in cruise eh, I think this is the simplest procedure to apply: one must do nothing. And it [the plane] will continue to fly like this for much longer.


On the (non) reaction to the stall warning:

French transcript:
Ce qui doit exister dans le cerveau reptilien de chaque pilote, le cerveau reptilien je veux dire ce qui est ancré au plus profond des réflexes de pilotage, c'est : j'entends un avertisseur de décrochage et je rends la main immédiatement. Vous voyez on a un manche pour piloter, lorsque l'avion approche du décrochage il ne faut surtout pas tirer sur le manche, il faut pousser sur le manche pour le faire sortir de la situation de décrochage.
La réponse à l'avertisseur de décrochage ça doit être quelque chose de fondamental que tous les pilotes doivent savoir tout le temps, dès le premier jour. On ne peut pas discuter là dessus. Et ce n'est même pas une question d'entrainement récurrent sur tel ou tel type d'avion, c'est vrai tout le temps, sur tout type d'avion.
English translation [& notes] by AZR:
What must exist in the reptilian brain of each pilot, by reptilian brain I mean what is rooted deep in the steering reflexes, is this: I hear a stall warning and I pitch down immediately. You see we use this stick to fly [showing it], when the aircraft approaches the stall it is important not to pull on the stick, but to push on the stick to get it [the aircraft] out of the stall.
The answer to the stall warning must be something fundamental that all pilots must know all the time, from day one. There can be no discussion about that. And it's not even a question of recurrent training on a specific aircraft type, that maneuver is true all the time, on any aircraft.


Hope it helps, and my english is not too bad...

[NeoFit]

Mr Rosay @ 29:15
When the aircraft approaches the stall it is important not to pull on the stick, but to push on the stick to get it [the aircraft] out of the stall.
Easy to say, i hope everybody is aware of this. But in really life ...

Unfortunatly, the reptilian brain has sometimes a snooze.
BEA wrote (1994 Tarom YR-LCA serious incident report (http://www.bea.aero/docspa/1994/yr-a940924a/htm/yr-a940924a.htm)):
The statistical data shows that, when confronted by a stall, in 80% of cases, pilots pull back the control column, in a sort of reflex movement, which continues the loss of control.
Terrifying, is'n it.

[bubbers44]

I know hundreds of pilots and not one would pull back in a stall. The only pilots that pulled back in a stall are the AF new hires and one Bonanza pilot who lost an engine out of Burbank trying to return after an engine failure in front of my eyes. Of course all died in that crash too. None of my hundreds of students died by pulling up in a stall. Rethink your 80% theory.

[Lyman]

bubbers44, that appears not to be NeoFit's theory at all, but statistical data published by BEA.....Oddly, I am speechless.

[sevenstrokeroll]

I agree with bubbers.

I was also very lucky in flying...I read, reread, and reread again "STick and Rudder" by Langweische. In it, his constant refrain was , in trouble? push forward on the stick.

and its important not to say: lower the nose...pushing forward on the stick reduces angle of attack (ok, maybe not in inverted aerobatic flight).

I drummed this into my students and one of my proudest moments was when one of my students came up to me saying he had a near midaircollision with someone at Truckee Airport (near lake tahoe california usa)...the other plane was on the wrong side of the depicted traffic pattern...they were head on converging on base leg. Mind you field elevation is 5900'msl...he avoided traffic , got the stall warning and PUSHED forward even though the mountains nearby were filling the window. an incorrect thing to do would be to pull up to avoid the mountains...but not when you are stalled or near a stall.

He landed safely, having recovered from a stall in a difficult situation.

he told me I saved his life and the lives of his family. I told him to thank Wolf gang langweische, the author of 'Stick and rudder".

[Machinbird]

From the BEA report on the Tarom incident:
Just before the stall, the Captain pulled the control column fully back, bringing the elevator to 23 degrees nose up. He then pushed it fully forward, while continuing to counter the roll of 75 degrees to the right with the ailerons. The statistical data shows that, when confronted by a stall, in 80% of cases, pilots pull back the control column, in a sort of reflex movement, which continues the loss of control.It occurs to me that the Captain may have been momentarily uncertain of the direction to the nearest horizon. They were 60 degrees nose up after all.:eek:

Add a little roll and he may not have been able to see the horizon initially. This might explain the otherwise inexplicable pitch control motions.

[Organfreak]

My Dear Sirs, Mesdames, (and Any Others),

It has come to our attention that this article (posted previously) bears repeating.

Technique: The 'Panic Pull' (http://www.aopa.org/members/files/pilot/2011/october/technique.html?WT.mc_id=111028epilot&WT.mc_sect=tts)

Thank you for your attention to this important matter.

Yours Ever,
Etc., etc. (Ret.)

[bubbers44]

Stick and Rudder was one of my favorite books learning to fly. Yes we all needed to know what to do and that book was very helpful. Most of my flying through commercial pilot was reading books, no ground school. I taught my self aerobatics by reading Roll around a Point by Dwayne Cole. I ended up teaching Art Scholls aerobatics class at Flabob airport in Riverside California with a one hour brush up with Art. He did the inverted spin scene or tried to in Top Gun when Goose was killed. He crashed into the Pacific off of San Clamente doing the filming. Notice at the end of Top Gun this is dedicated to the memory of Art Scholl.

Bob Hoover was a good friend of Art's. He would land at Flabob on one wheel in his Shrike just because he wanted to see him. What a great guy Bob is. We see him every year at the Reno Air Races.

I have been blessed with many legends in aviation knowing them personally.
I couldn't be happier with how my aviation career went from crop dusting to aerobatics to corporate jets and finally wide body international flying.

[bubbers44]

I thought I should add my last flight out of Miami to Tegucigalpa, Honduras with my FA wife in the jump seat. Flightlevel350.com: Free Aviation Videos, Airplane Videos and Cockpit Videos (http://WWW.flightlevel350.com)
search mhtg and look about 6 videos down with a cockpit view out of a 757 for my final 6 minutes. What a great career. This is claimed the most dangerous airport for jets in the world but I flew in there over 600 times and loved it. Never had a problem.

[OK465]

First wife?

[Machinbird]

The most interesting part of the Rosay interview was this:
English translation [& notes] by AZR:
The kind of situation that was encountered [loss of speed indication] is a situation that has nothing ... exceptional.
Besides ... when one loses the speed indications, in cruise eh, I think this is the simplest procedure to apply: one must do nothing. And it [the plane] will continue to fly like this for much longer.I read this as: When one loses the speed indications in cruise do nothing (except keep the aircraft trucking on down the line.) It doesn't mean sit on your hands however.

[Organfreak]

Congratulations on an enviable (by me anyway) career. Very impressive.

The video scared the crap outta me. You did that 600 times and lived!? :D

[bubbers44]

No, second but took 20 years to find her she was not a FA when I met her, I talked her into it..

[bubbers44]

Yes, I lived and loved every bit of it. That is the most fun airport in the world. You just can't get sloppy on the approach. Just do it right.

[DozyWannabe]

*de-lurk*

Bubbers - I understand what you're saying, but if we're honest you're talking a different generation here, with a lot more ex-military flyers. I realise this is something of a generalisation, but from what I've read and been told, the pros of which include a tendency for better stick-and-rudder skills and knowledge of aeronautical fundamentals, the cons including occasional issues with CRM. In the US, you're also talking about a lot of pilots who came up through the crop-dusting route and the like, which comes with a lot more hands-on experience.

The fact is that over time the demographic has changed, and the explosion in numbers of jet transports and jumps in technology since the '60s means that less time is spent learning the basics and more on operating and managing the systems - which has led to a significant increase in things like "panic pulls" from line-qualified pilots. When talking of pulling into a stall, don't forget Birgenair 301 and Palm 90, neither of which involved AF or Airbus. This is an industry-wide trend and always has been.

That said, your career makes for great reading, and it's clear that you've always striven to do the right thing - for that alone my cap would be doffed.

I was wondering - I realise it's a UK document, but did you ever read Davies' "Handling The Big Jets"? I'd be interested to know how it compares with the material more prevalent in the US from the same period.

Lyman : You were asking about the sim experience a week or so back. I can't really add anything to what I originally wrote, so for convenience I'll provide the links here:

http://www.pprune.org/tech-log/460625-af-447-thread-no-6-a-85.html#post6793521

http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a.html#post6794612

http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a.html#post6794908

*re-lurk*

[HazelNuts39]

I have deleted this post pending correction of an error. Apologies for any confusion.

[Machinbird]

Yes, I lived and loved every bit of it. That is the most fun airport in the world. You just can't get sloppy on the approach. Just do it right.
Bubbers, you would not have any trouble with day aircraft carrier qualifications.:ok: Did you also fly in at night?

[grity]

HN, be intrested! what means NoseDown faktor 0.85?

if every spring in the SS was right and his seat in a good position, than he just shorted his arm for 20 sec with a lot of adrenalin....

[HazelNuts39]

HN, be intrested! what means NoseDown faktor 0.85?The ND side stick angles are multiplied by this factor to account for an apparent sensitivity difference ND versus NU (see graph in earlier post). The resulting SS characteristic is shown in red below. The blue points are from a graph posted by A33Zab in post #852 on page 42 of this thread.

http://i.imgur.com/QVWuc.gif

[bubbers44]

Handling the big jets was always with me. I learned a lot from it. All of my knowledge came from books through commercial license and aerobatics. I took an instrument course but it was pretty pathetic. That was the first ground school I attended. As I said I had an early interview with united with less than 200 hrs and am so glad I didn't get hired. I would have missed out on learning how to fly. I learned how to fly by gradually going up through the ranks, not as a 727 FE, Going from single engine to multi engine to charter jets to corporate jets finally airlines, I was prepared.

[NeoFit]

Sorry, coming back too late!

My previous post # 1296

Bubbers44
None of my hundreds of students died by pulling up in a stall.
Rethink your 80% theory.

And sevenstrokeroll
I agree with bubbers.

Please, would you try to understand what I am trying to say

Lyman , Machinbird and Organfreak
Thanks a lot understanding my post.

Even if I wrote in a previous message <<stupid pilots >>�, notice that quotes are very important.
(and -please - obviously replace this in the context)

In fact, pilots never understood the vessel was stalled.
' we have engine thrust ! '
In fact, the vessel, with 13 degrees THS NU, was ' Âœparachuted '.

For me, Tarom report raised very important points (As QF72, Perpignan ...).
Did you read Tarom BEAs report?
In its analysis of this accident, the commission has been led to note deficiencies in the effectiveness of the display to the flight crew of the various active modes, the references used, actions in progress and targets pursued with regard to the Autopilot devices, notably in the vertical plane. Most particularly, in the opinion of the commission, the total information presented is inadequate in terms of its likelihood of alerting a crew, who at a given moment have an incorrect mental picture of the state of the automatic devices.
In practice, a good number of observations made by the commission apply to one degree or another to all new-generation aircraft
Consequently, the commission recommends that for all new-generation aircraft:
- consideration should be given by the competent authorities and organizations with a view to improving, in a standardized fashion on an international basis, the presentation and the symbols for displays and information relating to the different Autopilot active modes, notably in the vertical plane.
[/I]

HN39
Your graphic is very interesting.
It recalls me <<Owain Glyndwr - THS Equivalent Elevator Angle>>
(sorry, I am not able to put the link at this time)

Regards

[Linktrained]

When giving "Joyrides" ( pleasure flights ) my first flying job, I used to be asked to "Loop-the-loop" by bolder holiday makers. No-one asked for a Bunt, perhaps they did not know the word. If ever I was slightly harsh in putting the nose down, there would be squeals - never if I pulled the nose up by the same degree. ( I was not cleared for aerobatic flights by my employer and neither was the aircraft. It was a very new Licence - precious to me !)

I believe that around 1916, Frederick Lindemann had asked a number of Royal Flying Corps and Royal Naval Air Service pilot trainees, who had crashed, but were now in hospital being mended after crashes ( many aircraft of that era broke up on hitting the ground). A number reported that they had stalled and /or spun whilst holding back on the joystick as hard as they could, to avoid hitting the ground...

Does anyone know the logic used by the makers of lifts (Elevators) to control the rates of acceleration both up and down, particularly in very tall buildings ? ( I would expect that the rate going down might be more gradual than going up.)

[bubbers44]

I wish the new pilots could learn how to fly like we did back then. They are missing out on some very important experience that is hard to get now. We all want to be the best at what we do.

The new pilots have a difficult time getting the experience we got. With the automation even when they get their first job they probably rarely hand fly so become autopilot monitors. Flying skills deteriorate rapidly monitoring autopilots. I have been there so shut them off to maintain pilot skills. I have been told airlines discourage hand flying automatic airplanes, that is sad.

Pilots, do not let automation control your airplane, you control it. Disconnect everything and make sure you are really in control. If you don't you become an autopilot monitor, not a pilot. I am not kidding on this one.

[bubbers44]

We were not authorized to land at TGU at night or take off. We had to visually avoid the terrain so couldn't operate then. General aviation aircraft could. My buddy who opperated our airline emails me all the time from Tegucigalpa runs another airline now out of there but don't think they can land at night either.

[sevenstrokeroll]

dozzywanabe

you mentioned "handling the big jets'

I read it about 30 years ago...still have a copy and even wrote to the author...he was kind enough to write back and I still have his letter to me.

you mentioned a US equivilent...I would say: "Fly the Wing" by Webb is every bit as good...maybe a bit more oomphy and less british...but he was an american (eastern airlines) pilot. Flew DC9's. I had the great good fortune to track him down and spoke with him for over an hour on the phone...he echoed many of the things that bubbers and I have been saying. he paid me the supreme compliment saying: 'you get it.

if money permited, I would take up a perspective pilot...tell him to fly from Pittsburgh to Chicago in a plane he had never flown. I would tell him I would handle the checklists and systems..he had to navigate and aviate.

and NO FREIGGN auto pilot.

hand fly at the max authorized altitude (remember when we called it the service ceiling?)

I would see how he could trim her up at altitude...that tells me alot about a flyer!

[Lyman]

Per graph, post 1310, by Hazelnuts39...

Howdy. I do not understand why SS angle associated with Climb is shown on the graph as in the negative (below Zero). It feels counter intuitive to relate "Positive climb" to a negative (opposite) descriptor. ?

Thanks HN

[DozyWannabe]

I do not understand why SS angle associated with Climb is shown on the graph as in the negative (below Zero). It feels counter intuitive to relate "Positive climb" to a negative (opposite) descriptor?

*de-lurk*

Which direction do you move the SS to increase pitch angle and induce a climb (if airspeed is sufficient and the aircraft is shiny-side up)?

*re-lurk*

[HazelNuts39]

Lyman,

How about the sign convention for elevator and THS position? The ATSB uses the same sign convention, but plots it upside down:

http://i.imgur.com/drZiU.jpg?1

[Lyman]

The tail works opposite the wings. Its Pitch Up makes the aircraft Descend, lowering the nose, hence it is understandable for elevator movement to be described contra wing....

Presenting the two in the same way is misleading. ?

Dozy, one pulls to raise the nose, I have always associated Nose Up as a positive, an INCREASE, and a push (descent) as negative. AOA the same, an increase is a plus move, so why associate the control movement as the opposite of its result?

[Owain Glyndwr]

Presenting the two in the same way is misleading. ?

What HN39 has described is standard aerodynamic convention - TE down on the elevator (or THS) is a positive deflection. It would be understood by aerodynamicists anywhere in the world except Grassy Valley!

[PJ2]

Owain Glyndwr;
What HN39 has described is standard aerodynamic convention - TE down on the elevator (or THS) is a positive deflection.
Interestingly, for the takeoff setting, one does not see a negative THS indication on the A330 & A340 but one sees slightly negative THS settings on the A320 all the time. IIRC, typical settings for the A330/A343 would be 3.0deg while the A320/A319 would be -1.5deg...etc.

[bubbers44]

aerodynamicists usually are not pilots so of coarse grassy valley thought you had it backwards, I did too. We all know how the horizontal stabilizer and elevator works. It has a down thrust to make the aircraft stable. Speed up and the down thrust increases and brings the nose up. I think it makes it confusing when talking to pilots in your aerodyamicist way of looking at it. We need to keep it simple so even we know what you are talking about. Just a suggestion to keep us simple pilot guys in the loop.

[One Outsider]

The resident of Grassy Valley had already asked the same question before and had it answered before.

Short memory or just the usual FUD.

[AlphaZuluRomeo]

The most interesting part of the Rosay interview was this:
English translation [& notes] by AZR:
The kind of situation that was encountered [loss of speed indication] is a situation that has nothing ... exceptional.
Besides ... when one loses the speed indications, in cruise eh, I think this is the simplest procedure to apply: one must do nothing. And it [the plane] will continue to fly like this for much longer.
I read this as: When one loses the speed indications in cruise do nothing (except keep the aircraft trucking on down the line.) It doesn't mean sit on your hands however.
Thanks Machinbird, that was indeed the point IMO, due to many questions re: UAS procedure and the "choice" re: following memory items or skipping them.

At last for Mr Rosay, it seems clear that there was no need to set 5°/CLB.

[bubbers44]

Maybe I just should have gone back more than four pages. I am busy getting my boat ready, OK? Dolphin fishing this week.

[bubbers44]

I agree with AZR, if it was flying fine on autopilot just keep the same attitude and power and maintain altitude, don't do anything stupid like some airlines and go to climb power and 5 degrees nose up and bust through everybody elses altitude with a stupid checklist.

[TTex600]

I need some help. Somewhere in string 6 or 7, someone posted a link to an airbus document that gave expanded actions for UAS. I initially downloaded the document but lost it (thanks microsoft) and now can't find it again. What I look for isn't in the normal manuals. i.e., AOM, COM, etc

Thanks in advance.

[mm43]

TTex600... someone posted a link to an airbus document that gave expanded actions for UAS.I wonder if it was the Airbus 2010 Upset Recovery (http://www.mediafire.com/?jrkvp2ysl7aea25) document that you are thinking of?

There are 2 documents included in the above ZIP file.

[mm43]

AZR, Machinbird;At last for Mr Rosay, it seems clear that there was no need to set 5°/CLB.Yep! But will everyone remember that, and do the right thing? The "startle factor" seems to have an ability to cause a "memory crash" and a strange reversion to the "pull up" as the BEA noted in the Tarom incident.

The F-GLZU incident (http://www.bea.aero/docspa/2011/f-zu110722.en/pdf/f-zu110722.en.pdf) on 22 July 2011 was even stranger ... not only did the PNF not remember his NU on the SS, but neither pilot noticed the FD bars on the PFD, nor the AH, the ALT and +5700 fpm VS until after going through FL364. Then busting FL380 before getting things sorted.:uhoh:

As Rosay has said, and PJ2 has been saying here for 3 years, the "do nothing" really means "recover" from any initial A/P hand-off condition and set CRZ pitch and power.:ok:

[jcjeant]

Hi,

mm43
As Rosay has said, and PJ2 has been saying here for 3 years, the "do nothing" The chief pilot of Airbus Mr Rosay can maybe be expected to show prudence when he made ​​statements to the press .. for if we make an extreme assumption
Mr Rosay seems to be sure the response to the event AF447 was "do nothing"
If he knew this before the tragic event of AF447 (and consequently his employer Airbus) .. this is a problem because no instructions of Airbus or AF before the accident do not offer clearly this procedure (do nothing)
This Rosay "do nothing" can be used in a court trial by some parties
If he deduced this procedure after the accident AF447 ... it has no more merit than others

[VGCM66]

What's really scary is to see that the crews don't know how to work together. Each one goes to do something the other one is completely unaware of it. Have they heard about CRM? Altitude, Speed and Attitude, do they think they went out of fashion, style or something? Complete madness. :ugh:

[AlphaZuluRomeo]

mm43, rest assured I didn't forget the startle factor. In fact, I believe its the key to the "why", but that's a personal opinion, that I didn't want to mix with the translation of Mr Rosay's ITW.

jcjeant, please, I know you can read & write french, I assume you understand it well. Listen carefully to Mr Rosay. He didn't say "they should have done that". He said "I think this is the simplest procedure to apply".
I read that as a reference to an existing (at the time, at last) published procedure. You can (rightly IMO) argue about the clarity of the said procedure :) but not on its existence :=

[Lyman]

Hi AlphaZuluRomeo.

You say...."I read that as a reference to an existing (at the time, at last) published procedure...."

You well may read it that way. If you could provide the link to this "procedure"?

PJ2's long standing comments are the standard....the only discussion I see around his wise words are that the aircraft (447) needed correction, this is explained in the attitudes reported by the DFDR.

The only "experience" PF had in this sort of airmanship was.....none. Airmanship transcends the book, no volume can encompass all airwork, much is assumed to have been acquired to have been given the certificate. Even with Sim training for this result at high altitude, the responses by the handling pilot would have been a part of some "syllabus", which did not exist.

"Do Nothing Stupid" can be easily written down, and some version of it may have been a "procedure", if anyone at the airline or at Airbus had exercised the foresight necessary to write and disseminate it...But they didn't.

"Doing Nothing" is doing something. It is a decision, same as doing anything else, and is instructed by whatever mental process the pilots had at their service.

Clearly we have been discussing what's missing from the responses PF made, and lack of training, or lack of a published procedure are in the front..... When such a profoundly poor response to a life threatening occurrence is made, the cause is there. We will not ever know the nuances, the pressures, the void of help available to the crew, nor their desperation. Repeating a thousand times "Why so much climb?" ignores the plainly obvious conclusion, and BEA will not miss that. The harridans who harp on the obvious, and blame, miss the point.

[HazelNuts39]

The procedure is on page 70 of BEA#1:
1.18.4 Procedures to be applied in case an unreliable speed indication is detected
On the date of the accident, the operator’s procedures mention that the following actions must be carried out from memory by the crew when they have any doubt concerning the reliability of a speed indication and when control of the flight is “affected dangerously”:
(...)
If conduct of the flight does not seem to be affected dangerously, the crew must apply the UNRELIABLE SPEED INDICATION / ADR CHECK procedure (see appendix 9).

[jcjeant]

Hi,

And in the appendix N°9 (Page 121 BEA*1)
My translation from french
If conduct of the flight is affected ...all speed indications are false .. (and this is the case of AF447) apply this procedure:
Apply the emergency procedure and this is the case of AF447 (my addition)
And so .. do NOT "do nothing"

[Jazz Hands]

Just a minor observation on that Tarom incident, referring to the tendency of pilots to pull back the stick when confronted by a stall. The A310 has a yoke control. Where does that leave the "sidestick feedback" argument?

[roulishollandais]

@HN39
Thank you for your graph and edit.;)
Do you know from where the airspeed information is coming in case of ADRs failures ?

[HazelNuts39]

Roulis,

The C-star law does not depend on airspeed information. From Favre, C.(1994) 'Fly-by-wire for commercial aircraft: the Airbus experience', International Journal of Control, 59: 1, 139 — 157 :
(http://dx.doi.org/10.1080/00207179408923072)http://i.imgur.com/osVOR.jpg?1

The load factor comes from an accelerometer and the pitch rate from a gyro. I don't know where these are located, but my guess is in the ADIRU's under the cockpit floor.

[Organfreak]

@Jazz Hands,
Doesn't disqualify the SS issue from consideration at all. Other yokes have been pulled back to stall as well. Not logical, sorry, BZZZZT!

[Turbine D]

Regarding the occurrence of UAS at cruise and what information may have been available on June 1, 2009 refer to the BEA IR3, pages 63 and 64. It would appear to me that Air France provided (distributed) information to their crews regarding the ongoing investigation of six UAS incidents and made some recommendations. The 4th recommendation pointed out that corrections made should be "fabiles" or feeble in nature, meaning delicate or gentle. I assume this recommendation would apply to both roll and pitch corrections.

[Organfreak]

I'm beginning to think that those pilots (447) never read anything, much less advisories from AB or AF. Ignorance is not, in this case, any kind of bliss.

Should it be mandatory for F/Os to take a quiz on everything that's handed out? Yes it should.

[CONF iture]

Just a minor observation on that Tarom incident, referring to the tendency of pilots to pull back the stick when confronted by a stall. The A310 has a yoke control. Where does that leave the "sidestick feedback" argument?
Very much alive.
The PF did not insist as he then fully pushed it forward.

[roulishollandais]

Hi HazelNuts39,

Sorry to come back to C*, :{ the speeds which keep my interest are V and Vco, as I readed these two documents, in post #1 Thread8 AF447
Thank you for your help... Perhaps I misunderstand something, but were ? what ? why? ...


C Star
C* (pronounced "C Star") is the popular name for a control law in which Nz (g) and pitch-rate feedback are blended. (In the late 60s and early 70s, Nz feedback was called the C law. NASA space shuttle approach studies added pitch-rate feedback, which was called C*.) At low speed in a C* airplane, pitch rate is primary;at higher speeds, g is primary. The changeover is transparent and occurs at about 210 knots in the A320 ("Fly-By-Wire for Commercial Aircraft: The Airbus Experience," C. Favre, 1991).
C*U ("U" represents forward velocity in flight equations) is a modified C* control law used in the B-777 to provide apparent speed stability. The trim switches set a reference speed that is summed with the actual speed in the feedback loop in such a way that the pilot feels conventional control force cues as speed changes. You "trim a speed," not the stabilizer (weight off wheels). Because the max trim reference speed is 330 knots, you would have to push on the control wheel to further increase speed toward Vmo. This provides a tactile high-speed cue.

Fly-by-wire allows designers to optimize the effective dynamics for different flight tasks--for example, an approach mode or a flare mode. This is called task tailoring and produces a multi-mode FCS.
In both the A320 and the B-777, the control laws are not fully active during takeoff until after liftoff because the sensors used for feedback would sense a lot of vibration and "noise" during the ground roll. Landing requires other transitions. Accident investigators should thoroughly understand mode transition points and effects.


c*= Knz.nz + Kq.q (2)
q= (nz.g.Ttheta2/V) (s+1/Ttheta2) (3)
qSS=nz.g/V (4)
Kq=Vco/g (6)

[AlphaZuluRomeo]

jcjeant, re: your #1339

I'm happy we agreed on the existence of the procedure. :)
Indeed, we can safely assume that all speed indications were false on AF447.
On the other hand, the condition for "doing nothing" is :
Si les informations erronées de vitesse ou d'altitude n'affectent pas la sécurité du vol (trajectoire stabilisée)
If the incorrect informations of speed or altitude do not affect the safe conduct of the flight (stabilized flight path)

One can argue that, coming from an A/P ON (in cruise) situation, the path was stable enough to skip the memory items. Apparently, that's the position of Mr Rosay (perhaps with his employer's interests in mind, too). ;)

My position remains unchanged:
1/ I read the condition as "if you don't know what to set, then memory items for the time needed to pull the QRH"
2/ but even a crew which won't have the same understanding as Mr Rosay won't put its aircraft at risk by following the 5°/CLB memory items (re: excellent HN39's graphs :ok:)
3/ given all the previous discussions, for a safer world, the "if" condition in the procedure should be clarified (perhaps it's already done, I hope so)
4/ all of this is barely related to AF447, as this crew didn't follow one (do nothing) or the other (5° and CLB) possibility.

[HazelNuts39]

roulishollandais,


The application of a C* flight controllaw to large civil transport aircraft
c*= Knz.nz + Kq.q (2)
qSS=nz.g/V (4)
if Knz is set equal to 1, (...):
Kq=Vco/g (6)

If Knz is not set equal to 1, equation (6) reads:
Kq/Knz=Vco/g

V in equation (4) and Vco in equation (6) are not airspeeds but are kinematic speeds. Equation (4) applies equally in space without air, usually written as an=ω*V, for any body moving along a curved path and maintaining its orientation relative to the direction of movement.

[roulishollandais]

thank you HN39
it means that kinetic speed information comes from inertial data after integration '?

[HazelNuts39]

it means that kinetic speed information comes from inertial data after integration '?No, speed information does not appear in the C-star law as such. Airspeed affects the response of the airplane (in terms of pitch rate and normal acceleration) to changes of elevator and THS positions, and therefore may enter in the 'gains' used to calculate elevator and THS commands:
A homogeneous law, ensuring aircraft behaviour independent of the flight conditions and, in particular, independent of the centre of gravity location, is achieved by tabulating the gains as a function of the computed air speed, high-lift configuration and centre of gravity location.

If you are referring to my post #1310, I didn't use airspeed either, just vertical speed and integrated SS angle to calculate pitch from:
Pitch = Pitch(0) + Ks/Kq * ∫ Sdt - Kn/Kq*(Vz - Vz(0))/g,
where S=side stick angle, Vz is vertical speed, and Pitch(0) and Vz(0) are the initial values of pitch and vertical speed.

P.S. About the cross-over velocity Vco.

The 'steady state' relationship between nz and q:
qSS = nz*g/V (4) may be written as:
Kn*nz = V/Vco * (Kq*q) and shown as:

http://i.imgur.com/dsJZT.gif?1

Section8.3: The cross-over velocity defines the ratio of pitch rate and normal acceleration feedback gains. (...) it had been argued that the cross-over velocity chosen had no apparent relation with the existing flying qualities specification (...) and so is open to question. By relaxing the definition of the cross-over velocity it becomes possible to specify feedback gains independently ...

Based on the data posted in #1310, the A330 control law uses a cross-over velocity of ...(EDIT).

[gums]

Thanks to 'nuts and Rouli for bring up one aspect of the control laws that is independent of all the "autopilot" functions.

Part of the quote mentioned by Rouli strikes home, as it was inplemented operationally years before the shuttle entered drop tests and so forth:

Originally Posted by a) Alpa FBW Primer
C Star
C* (pronounced "C Star") is the popular name for a control law in which Nz (g) and pitch-rate feedback are blended. (In the late 60s and early 70s, Nz feedback was called the C law. NASA space shuttle approach studies added pitch-rate feedback, which was called C*.) At low speed in a C* airplane, pitch rate is primary;at higher speeds, g is primary. The changeover is transparent and occurs at about 210 knots in the A320 ("Fly-By-Wire for Commercial Aircraft: The Airbus Experience," C. Favre, 1991).
C*U ("U" represents forward velocity in flight equations) is a modified C* control law used in the B-777 to provide apparent speed stability. The trim switches set a reference speed that is summed with the actual speed in the feedback loop in such a way that the pilot feels conventional control force cues as speed changes. You "trim a speed," not the stabilizer (weight off wheels). Because the max trim reference speed is 330 knots, you would have to push on the control wheel to further increase speed toward Vmo. This provides a tactile high-speed cue.

The biggest thing we did not have was the airspeed feedback loop. The Nz and body rates ruled! Only thing dynamic pressure did was provide values for the "gains" that determined how much the control surfaces moved to produce the commanded Nz or roll rate ( gear up). AoA was much more important than speed, and it limited us from about 15 deg to 27 degrees with respect to gee. Figure about 15 degrees at 9 gees and 27 degrees at 1 gee ( draw the line yourself). Gear down blended AoA with the gee command and body rates. Gains were still a function of dynamic pressure. So we had the "feeling" that we were trimming for speed or AoA and not Nz as with gear up. Wasn't a real strong "feel" compared to conventional control systems, but better than a pure body rate or gee command.

Interestingly, if dynamic pressure was lost or deemed unreliable, the system used "standby gains". So gear up was 300 knots or so, and gear down was 180 knots. Simple deal, and landing gear handle switch provided the changeover. The biggest thing was the system used AoA intil the bitter end. The one example I provided was the guy who lost most of the radome due to a bird strike. This included the AoA probes. So he flew for 7 or 8 minutes using nothing but Nz and body rates and standby gains.

I am glad to see that some of our primitive control laws were improved for the Shuttle and later FBW planes.

[roulishollandais]

Thank you Gums and Hazelnuts39 : ;) PPrune has the best specialists !

Reading you, Gums, i understand that it is airspeed (or an equivalent information as dynamic pressure) who determine the gains and not kinetic speed . It seems to me very logic.

Reading Hazzelnuts39 i don't understand that A330 (edit : add "does not use", del "used") does not use standby gains in case of loss of dynamic pressure, unlike the F-16. And that VCO=1200 KT.

The biggest thing we did not have was the airspeed feedback loop. The Nz and body rates ruled! Only thing dynamic pressure did was provide values for the "gains" that determined how much the control surfaces moved to produce the commanded Nz or roll rate ( gear up). AoA was much more important than speed, and it limited us from about 15 deg to 27 degrees with respect to gee. Figure about 15 degrees at 9 gees and 27 degrees at 1 gee ( draw the line yourself).
but on the F-16 HUD (this of Gilbert Klopfstein) you have the speed vektor himself.

You are right to say and repeat that airspeed is not very important, much more is the Angle of Attack with adequate training.
But AF447 lost the PF (and the headdown Pilot managing !) without speed nor AoA. (Sure they still had pitch and power who were enough to save their lifes : but i let to other the Rosay discussion about the pitch, despite having had an ice-clogged pitot tube I guess for the "do-nothing" not written in the procedure).

It seems easy for engineers to explicite and display anywhere the inertial speed information in UAS case. K/s is not very expensive...

I will try to find the Favre's book and understand better why this C*,seems so unusefull and inadapted to transport aircraft.
Still a question, gums : why had the Pelican F-16 finally a PIO/APC

[HazelNuts39]

this C*,seems so unusefull and inadapted to transport aircraftThis is baffling to me.

[mm43]

HazelNuts39... the A330 control law uses a cross-over velocity of 1200 kt (in alternate law)Is that a typo? Was it meant to be 210 kt?

Thanks for all your good work on C*, and am slowly working my way through the references. I note that Boeings patent was dated 1989, which is a clear indication that "change" happens very slowly in the aviation industry.:cool:

[HazelNuts39]

Is that a typo?Not a typo, but the value of Kq/Kn is in error.
Vco = Kq/Kn * g = Kq/Kn * 32.17 ft/sec

Apologies for the confusion.

[mm43]

Now it makes sense!!:ouch:

Thanks.

[HazelNuts39]

Did a similar exercise on QF72, which stayed in normal law, and Vco=400 ft/s seems to give a reasonable fit:

http://i.imgur.com/hJU7D.gif?1

[gums]

Good curve fit, 'nuts.

A year or more ago I raised the issue of "standby gains" to use a given value for dynamic pressure should the normal sensors go off to wonderland or the system deems the values FUBAR. Unfortunately, the 'bus laws are not designed to provide the AoA/speed "feeling"most pilots are used to. Only time we had that in the Viper was gear down, and even that mechanization was a kludge.

The 'bus laws are primarily a Nz command ( just as ours were, and best I can tell) and looks to me that AoA and other inputs only come into play when approaching a stall AoA. And then the system appears to ignore AoA if the dynamic/static pressure inputs are deemed to be unreliable ( and the infamous 60 knot deal), or we are in sub-mode "c", of mode "b", and the beat goes on.

As 'doze has pointed out over and over, and on end, our FLCS was designed for a different mission, but I can tell you that we would like to have had an airspeed/dynamic pressure feedback when gear up to "feel" more like a normal jet. Our feel was strickly biased according to the commanded Nz we had set using a roller wheel or the hat switch on the stick. let go of the stick and the jet assumed the "trimmed" gee, and rather aggressively, heh heh.

@ rouli

Probably the best flight instrument ever invented for us was that flight path marker in the HUD. Ooooops, the 'bus didn't have one. We had it back as far as 1968 - 1969 in the A-7D. No air data required. The sucker used inertial data only, and showed where the jet was gonna impact the ground or climb above the ridge or.... Invaluable for an instrument approach. And with AF447, it would have shown that the aircraft velocity vector was approaching zero pitch well before they flew into the stall. My lef failure video shows the ILS "cross bars" which I used to help in the dubious WX I had to deal with. You can also see where I mistakenly had my vector slightly short of the runway, as I expectd it to move down the runway when I got close and "flared". Hell, was 30 knots above approach speed, but happy I still had roll control.

http://www.sluf.org/warbirds/lef-landing.m4v

For now, I can still see a procedure change and maybe a tweak to the 'bus flight control laws and reversion sequence.

[roulishollandais]

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. :(

@ rouli

Probably the best flight instrument ever invented for us was that flight path marker in the HUD. Ooooops, the 'bus didn't have one. We had it back as far as 1968 - 1969 in the A-7D. No air data required. The sucker used inertial data only, and showed where the jet was gonna impact the ground or climb above the ridge or.... Invaluable for an instrument approach. And with AF447, it would have shown that the aircraft velocity vector was approaching zero pitch well before they flew into the stall.

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:

[DozyWannabe]

And they had already been deprived from beeing able to come out of stall, as Machinbird and Hazelnuts39 showed us that.


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.

[jcjeant]

Hi,

DW
This is piloting 101 - no HUD requiredIndeed ..
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" :)

[AlphaZuluRomeo]

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 ;)).

[gums]

@ 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.

[HazelNuts39]

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.

[glad rag]

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

[roulishollandais]

Hi Hazelnuts,
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.

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:

[roulishollandais]

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 (http://www.headupflight.net/articles2/Securiteoumarketing.htm)

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.

[...]

[Lonewolf_50]

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.

[Turbine D]

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?


Night Landing at LAX in a Boeing 737NG - YouTube


Cockpit View Emirates Airbus A380 Night Landing Dubai - YouTube

[OK465]

...when the autos quit along with the computers.

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.

[AlphaZuluRomeo]

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?
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.

[DozyWannabe]

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.

[gums]

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.

[roulishollandais]

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.

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:
For us, "difficulty of assessing the situation" and "inadequate tools" have the same meaning, because the instruments must accurately can assess the situation in all phases of flight.


So HUD is (was!) "the" solution !

[Machinbird]

But the AF447 had possible difficulty of assessing the situation...
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.

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.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.

[mm43]

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.
AOA is a long-standing subject that is broadly known but one for which the details are not broadly understood. While AOA is a very useful and important parameter in some instances, it is not useful and is potentially misleading in others.


The relationship between AOA and airplane lift and performance is complex, depending on many factors, such as airplane configuration, Mach number, thrust, and CG.
AOA information is most important when approaching stall.
AOA is not accurate enough to be used to optimize cruise performance. Mach number is the critical parameter.
AOA information currently is displayed on Boeing flight decks. The information is used to drive the PLI and speed tape displays.
An independent AOA indicator is being offered as an option for the 737, 767-400, and 777 airplanes.
The AOA indicator can be used to assist with unreliable airspeed indications as a result of blocked pitot or static ports and may provide additional situation and configuration awareness to the flight crew.

The rest of this article is in a SmartCockpit (https://docs.google.com/viewer?a=v&q=cache:Z1fOUC2Y20kJ:www.smartcockpit.com/data/pdfs/flightops/aerodynamics/Understanding_The_Angle_Of_Attack_%28Part1%29.pdf+b737ng+aoa +display&hl=en&gl=nz&pid=bl&srcid=ADGEEShPSqNrBhwo1kANuzRQBO_mXDIGrEWbXF334lKq69cjahxAk6 keJ35aBLH7Zt6uYgRstfRGWQmhqMWfTSw58iXtqxStQq7YiOa15BELBmtaU9 q3Uyzb-IuUz6EQt0AMaFNFAoBD&sig=AHIEtbRUYBZN1IEwPcVqU0U-4DxmZr2e3Q) document.

[BOAC]

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:

[mm43]

Giving them AoA or a HUD would, in my opinion, be like giving a monkey an Ipad.Now, you do know that some monkeys have been trained to use them! :D

They know them as iPads.:E

[BOAC]

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

[Machinbird]

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

[BOAC]

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. 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:

[OK465]

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

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:

[RetiredF4]

machinbird
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.

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.

[roulishollandais]

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 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.


(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...

[OK465]

Isn´t that the basic problem of missing airmenship here?

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.

[RetiredF4]

OK465
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?
You know what they call the guy who graduates last in his medical school class..

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

[OK465]

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. :))

[fantom]

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

[Machinbird]

I would recommend a spring-loaded boxing glove inset into both P1 and P2 main panels with an associated audio 'alors, stupide'
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?

[RetiredF4]

Machinbird
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?

[bubbers44]

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.

[Organfreak]

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

[Ian W]

Machinbird
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.

Interestingly, this problem has been foreseen but largely disregarded. If you read https://docs.google.com/viewer?url=http://csel.eng.ohio-state.edu/productions/xcta/downloads/automation_surprises.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:

[RR_NDB]

Machinbird::

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. (http://www.pprune.org/tech-log/482356-af-447-thread-no-8-a-70.html#post7260122)

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"

[gums]

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

[BOAC]

Post#1390 - refer 'Retired F4' Post#1391.

[mm43]

Imho it´s not a question what we can expect, but what we are entiteled to expect.As RetiredF4 says, it is the bottom line!:ok:

[Tableview]

3NKh7gRJdGQ

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.

[HazelNuts39]

The data used for the following chart are the traces of pitch attitude and normal acceleration from the Airbus simulation shown on page 42 of IR#3(EN), and the traces of longitudinal side stick angle on pages 29 -31.

While there is possibly a relation between side stick angle Ss, pitch rate q and incremental normal load factor nz of the form:

a*Ss = b*nz + q

it is not possible with the available data to establish the coëfficients a and b with any certainty. There is a wide range of a&b combinations that provide an acceptable match between the calculated and simulated pitch angles. The coefficients chosen for the following chart give the best 'fit', but should be regarded as an example only.

http://i.imgur.com/FJjHE.gif?1

[pcoletti]

Dear PPRuNers,

With the publication of the final AF 447 report by the BEA on 5th July I'm wondering if any current or retired Boeing or Airbus pilots would be interested in a debate for Newshour on BBC World Service Radio about the role of automation in commercial passenger flight?

We'd be looking to record this on the 5th July itself sometime after 2.30pm Frennch time (when the report is published).

If you're interested then whatever side of the automation debate you sit on I'd love to hear from you. It would be in English, 2 people (maybe 3), probably about 15 minutes duration. Logistics/connections TBC.

I'm on [email protected] or +44 7770820056 if you wanna get in touch.

Paul Coletti
Newshour
BBC World Service Radio

[Machinbird]

Quote:
Originally Posted by Machinbird
Post#1390

- refer 'Retired F4' Post#1391.
BOAC
I do not disagree at all with Retired's post. We do deserve aircrew with better qualifications than impressively starched shirts. What I have suggested regarding a cueing system for pilots who are looking at the wrong mouse hole would also help non-automation dependent pilots. Do you think they don't have lapses of situational awareness too?

The problem is that the regulators appear to have ignored the problems created by automation dependency. The flying game has changed. It is time they stepped up to the plate.

[BOAC]

Do you think they don't have lapses of situational awareness too? - from what we know so far, 447 does not represent a 'lapse of situational awareness' but a complete failure of any awareness by the crew. It is difficult for me to contemplate, even if woken from a deep sleep, that I could ignore what we think the signs were. This is the reason so many of us are concerned at the quality or mental attitude of 'new' pilots.

I also become increasingly concerned for the prominence given to all the 'psychological' work on human factors in aviation. I am not denying that all this work is important and of great value, it is just that there is a constant stream of pdf's and other papers thrust down our throats at every opportunity, and I personally believe this is conditioning Mr/Mrs 'Average' pilot into thinking "It's not my problem, it is human factors/design/management/training/CRM - you name it - and instead of making sure they have, and exercise, the basic flying/logic skills to deal with a situation, they will be conditioned into a subconscious state where it is someone else's problem - eg focussing on calling the Captain back to the cockpit to the degredation of monitoring the flight path.

I don't have the answers, but someone needs to get them PDQ. Another sheaf of papers will not help a rookie crew in the ITCZ with IAS failure in the middle of the night. Basic skills will.

[roulishollandais]

I personally believe this is conditioning Mr/Mrs 'Average' pilot into thinking "It's not my problem, it is human factors/design/management/training/CRM - you name it - and instead of making sure they have, and exercise, the basic flying/logic skills to deal with a situation, they will be conditioned into a subconscious state where it is someone else's problem
I agree 100% :p

[Lonewolf_50]

Dozy
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".
I tend to agree.

BOAC: well said, in re the mountain of published material from the shrinks and psychologists. Some one must still "do it" in terms of "do it" being "fly the machine."

[Clandestino]

topping out at an 'apex' of FL379.Sorry, I have mistaken your reference to trajectory apex to be referring to pitch. My bad.


How many of the 30+ flights that didn't lose control experienced roll oscillation?No idea how many of them banked to the whole 11° right / 9° left but I find interesting some of them went through stronger turbulence than AF 447 (0.2 / 1.9 compared to 0.7/1.6)

I write how illusionary it is to pretend to maintain indefinitely a 5 deg pitch in altitude but you find 5 reasons to state I’m wrong but now you feel the need to precise it is only for the necessary time to get the QRH out …You are mistaken about the source of what you call "precising". It's not me, it's all written in the procedure - the one a whole bunch of PPRuNers malign while displaying enviable ignorance.

Why 5 degrees and climb power?

It's to be used when pilots' primary concern is staying within the envelope while level bust takes back seat. It is preferable to keep flying on your assigned FL when speed goes AWOL but if you are unsure if you can make it, go for memory items, they 'll keep you flying. That is not to say it is the only combination of attitude and performance that maintains one unstalled and this side of the Macrit. 5° ANU was clearly marked on any AH/ADI I've ever flown so it would be safe bet it is so on the large majority therefore making it easy to set the aeroplane symbol against the mark. Climb power is there for all the pilots who can't remember exact cruise power for their weight when proverbial hits the fan at 4 AM. Especially if they are involved in mixed fleet flying - CFM A320 with IAE A321 can be pretty interesting mix, not to mention SA/TA combinations.

5°/climb thrust works for every aeroplane except:

1. low mach limited, high trust to weight ratio, turbojet powered ones, of which none flies passengers anymore.

2. those which stall below 5° AoA in steady, low Ma flight. None of these has successfully taken-off so far. Such a machines can be safely omitted from further consideration.

to not apply that procedure for low level has proved to be deadly, but then the procedure was not published yet …Reference, please.

When you are low & slow, option of trading potential energy for kinetic is unavailable. As it is policy to train for the most critical failures (V1 cut, anyone?), during approach to stall recovery practice it is assumed that it happens very low, that's why minimal loss of altitude is emphasized. Of course, the ignorant then wrongly assume that minimum loss of altitude is applicable for every approach to stall recovery or stall recovery itself.

It is preferable to miss the obstacle, even if by the narrowest of margins, at 1.1 Vs than hit it at 1.3. Knowing when the situation is so desperate to grant using up the normal margins is the part of what we call "airmanship". Avoiding such situations is another part of it.

There is absolutely no recovery from low altitude, low speed stall that would not involve hitting the ground in the process. Only pilot with realistic chances of survival is the one strapped to high-performance ejection seat, who doesn't hesitate much when time comes to part the company with the aeroplane.

The question, as always when such changes occur and the distribution and incorporation of infomation is involved is, how are these changes incorporated into training by airlines operating Airbus equipment? My last flight on A320 was in January 2009. No mention of "if safe conduct of flight affected" at the time. We were using company customized manuals.

Since most crews appeared to have kept the aircraft level while troubleshooting, (we don't know this for certain but it appears so),
We don't know that yet. Interim 2 mentions variation in altitude remained within 1000 ft or so while not mentioning what was the exact distribution. Five cases of descent following the stall warning are mentioned.

The only real way to "fly" the bus requires one to turn the A/P, A/T and F/D's all off. Otherwise, you're mixing things up and confusing both the co-pilot and FiFI/Henri/HAL.Exactly! I'm pretty sure I've heard it before my first hour in groundschool has expired.

There is no debate in my mind that a HUD is a valuable tool for the pilot.Absolutely, but we'll get it only if it's valuable for management. I got mine only because it reduced ILS minima to 200/50 from 300/100. Our Airbi are 75/NO DH so no gain there.

It would have shown the climbAs altimeter and vario did. If they believed whole air data system went tits up, they could have flown attitude+power. They said or did nothing that would indicate it was the case. Only coherent picture from FDR and CVR is of total confusion on both sides of the cockpit. If just one pilot kept the presence of mind, chances are PPRuNe discussion regarding the UAS on A330/340 would make it barely to the second page.

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?Yes. Absolutely. Interim 2, chapter 1.16.3 refers.

As with many here, I have serious problems with the airmanship of the new cropNot me. Not with the whole crop, that is. All of my F/Os confirm DP Davies maxim that the enthusiasm about flying is one of the best things a pilot can have. Most of them affirm it positively.

I am not denying that all this work is important and of great valueNot all of it is important and of great value. It's easy to sell well sounding psychobabble to people who are mostly trained in technical stuff, such as pilots.

our old rhino had nothing of those gimmicks and we did the job and survived like others did.That's a very nice example of survivor bias. Spare some thought for your colleagues that did not make it to retirement through no fault of their Rhinos or lack of good intentions.

They were not bad pilots. They did not intend to make that last mistake.

It can happen to anyone. It's just the matter of reducing chances.

[RetiredF4]

Global strategy envisions training all air carrier pilots in airplane upset prevention and recovery.
Flightsafety.org (http://flightsafety.org/asw/jun12/asw_june12_p16-19.pdf?dl=1)

[bubbers44]

gums and I are about the same age so flew with seasoned pilots, not 300 hr wonders. I flew with a few that had ins when I was a brand new 737 captain and it was single pilot. I don't think anything has changed.

We are now in a new generation of automation so to get cheap help the start up and regionals are hiring them. The majors, thank god, are not yet. Eventually they will be good pilots but not in the beginning. The captain will have to help and if they came from this same group we are in trouble. They don't have the experience required to fly single pilot with the new guy occupying a seat like I did. He could not copy a clearance, fly or talk on the radio. One of our check airmen got him in and expected us to teach him how to fly an airliner as brand new captains on a new airplane. That is not right. I flew charter and corporate before so could do both jobs but these guys can't, trust me.

[mm43]

This link to the high altitude operations power point file at flightsafety.org (http://flightsafety.org/files/Appendix_3-E_HighAltOperations.pps) has possibly been posted previously, but well worth a look. It was revised in November 2008, and incorporates everything that has been discussed here in relation to AF447. A pity that AF didn't bring it into their training syllabus sooner - assuming they have done now.:hmm:

[RetiredF4]

Clandestino
Originally Posted by Retired F4:
our old rhino had nothing of those gimmicks and we did the job and survived like others did.
Clandestino:
That's a very nice example of survivor bias. Spare some thought for your colleagues that did not make it to retirement through no fault of their Rhinos or lack of good intentions.

A Typical clandestino answer, taking one sentence out of context , reading something into the lines what´s not there and commenting on it. What for?

Be sure that i remember my close comrades and others who lost their lifes in combat aircraft. In 5 years we lost 5 aircraft in my squadron with 11 dead crewmembers. We looked detailed into those accidents, and none of those gizmo´s i mentioned would have saved their day, not saying they are superfluous though. Airmanship and common sense (with or without those gizmo´s) would have. That did not make them bad people or bad pilots, but it got them killed unfortunately.

They were not bad pilots. They did not intend to make that last mistake.

No, but they did not recognize, that they were doing that final mistake.

It can happen to anyone. It's just the matter of reducing chances.

With more gizmos or better training, what´s your answer? If it´s both, that´s fine with me. At the moment we have the unfortunate situation that all the gizmo´s and asociated regulations seem not to favor thorough training and built up of long lasting airmanship and expierience.

If your statement is something like sh*t happens, then that is not something i can accept as accident prevention handling.

[roulishollandais]

@Turbine_D

Thank you for the videos ! :)

Would anybody be able to have a video from simulated AF447 with HUD ?

[CONF iture]

A Typical clandestino answer, taking one sentence out of context , reading something into the lines what´s not there and commenting on it. What for?
The guy needs full attention on him - In need to correct or lecture each and everyone - Just glad I don't have to share a flight deck with that type of character ...

(an 'ignorant' among others)

[DozyWannabe]

Actually I've always found him (Clandestino) a very useful contributor. I may not always agree with what he says, but he's always been honest, upfront and willing to cut through the bull and get to the point.

In this case I think he was right to pull Franzl up for extrapolating a general theory from individual experience. Franzl himself makes a false dichotomy here:

With more gizmos or better training, what´s your answer?

Because a belt-and-braces approach would include improvements to both. We're back to the false idea that technological advances are intended to reduce the role of the human pilot when they are in fact intended to augment the information available to said human pilot.

(Well, we're almost in July... :E)

[RetiredF4]

Dozy

In this case I think he was right to pull Franzl up for extrapolating a general theory from individual experience. Franzl himself makes a false dichotomy here:

My full post
With more gizmos or better training, what´s your answer? If it´s both, that´s fine with me. At the moment we have the unfortunate situation that all the gizmo´s and asociated regulations seem not to favor thorough training and built up of long lasting airmanship and expierience.

We're back to the false idea that technological advances are intended to reduce the role of the human pilot when they are in fact intended to augment the information available to said human pilot.

I disagree, this is a wrong interpretation of my posts.
We are still at the practice (which has unfortunately nothing to do with an idea) that technological advances are used to degrade training and expierience from piloting to monitoring, which might be not intended, but it´s happening. Not everywhere, but even if it´s only 10% it´s 10% too much. Or do you turn a blind eye there?
It´s not my position to get rid of those technological advances,or to hinder new ones, but the crews have to be trained to handle an aircraft when those gizmos go on leave and they have to be allowed to gain expierience with those situations and manual handling skills. Therefore the first step is not to cry for aditional elo-helpers, but to improve training and expierience and with it airmanship firsthand.

[gums]

I can tell you what the AF447 HUD display would have looked like.

- UAS happens. No change in FPV, sucker is on the horizon line and bank angle oscillating.

- Gradual pull up reflected by FPV increasing "x" degrees" above the horizon line and pilot can see exactly how many degrees.

- Inertial vertical velocity decreasing as FPV slowly descends back to horizon line.

- FPV eventually reaches lower limit of the HUD. Meanwhile, pitch attitude remains way up there. Some shuddering from the stall. No spin or violent attitude changes, just a slow right turn until impact.

[DozyWannabe]

I'm aware of what your full post was - however the way it was phrased was leading, and somewhat indicative of the opinion that it was the technological advances themselves that caused a drop in airmanship, which isn't true.

I don't think the regulations care one way or another (except in the case of hyper-accurate positioning in RVSM airspace) - the issue is that the *airlines* seem to in some cases have misinterpreted the advances in technology and used them as an excuse to skimp on revision of basic airmanship. Given PJ2's excellent outlining of the trend towards managerialism as an end in itself, and the decline in industry specialisation at management level, I'd be prepared to wager a fair amount that if they hadn't used technology as an excuse, they'd have found something else.

Even then, that's just considering the reactions of this one crew (with a very distinct HF profile) - the 30-odd successful recoveries from the problem indicate that we're looking at an anomaly here.

[RetiredF4]

Even then, that's just considering the reactions of this one crew (with a very distinct HF profile) - the 30-odd successful recoveries from the problem indicate that we're looking at an anomaly here.

How about that one? (http://www.pprune.org/rumours-news/462918-other-af-447-avoided-16.html#post7200167)

Another anomaly?

Its like an iceberg; most of it is underwater.

To spend more and more money on technology and neglecting the required training to the aircrews (because no more money is available for that task) is the wrong approach.

[roulishollandais]

Thank you Gums.

What do you think of the oscillations of the two last minutes ?

Machinbird said us the importance of his AoA information immediatly after cat shot for the vital decision : fly or pull the ejection handle ! Could you compare the "best" raw AoA and the HUD AoA information in their qualities of time delay ,speed, liability, sensitivity, robustess, other...? Thank you

[DozyWannabe]

To spend more and more money on technology and neglecting the required training to the aircrews (because no more money is available for that task) is the wrong approach.

But are they spending more on technology? I'm not in a position to do the maths, but taking inflation and airline profitability into account I'd be surprised if modern airliners were a great deal more expensive - relatively speaking - than their counterparts of four decades ago.

Don't get me wrong, I'm in total agreement that the state of airmanship training needs a thorough going over, I just think that blaming technology is an overly simplistic viewpoint.

[mm43]

Its like an iceberg; most of it is underwater.The 'other one' and this 'one' have some common features such as complacency (http://www.pprune.org/rumours-news/462918-other-af-447-avoided-7.html#post6694640):suspect: but obviously different outcomes.

Addressing all the known issues such as "startle", "human" and "cultural" factors may be politically correct and gives everyone the "feel-good" warming of the blood. However, IMHO the ultimate use of automation comes with some well known restraints;


It is an aid
Treat it with respect
Understand its operation and limitations, and
Don't let it lead you, where you in your right mind wouldn't go.

For the "other one" and this "one" have one initiating factor in common, i.e. each aircraft was lead benignly into a situation that could have been avoided.

[RetiredF4]

Don't get me wrong, I'm in total agreement that the state of airmanship training needs a thorough going over, I just think that blaming technology is an overly simplistic viewpoint.

It´s not about blaming technology, it´s about setting the necessary priorities. If money i tight and more training is expensive, then the solution to this problem is not a new gadget.

[DozyWannabe]

If money i tight and more training is expensive, then the solution to this problem is not a new gadget.

I don't think anyone is saying that's the case - I'm certainly not!

That said, I think "more training" in a generalised sense will only go so far. There needs to be a thorough re-examination of the challenges inherent in civil aviation in modern times, and an understanding on the part of management that MBA cost-control tactics are inappropriate in an industry where a serious mistake can leave you with several hundred paying customers dead.

[gums]

While I continue to point out all the benefits of a HUD that was operational back in 1968 or so, I agree for the most part that we have plenty of information to use when things turn sour.

The thing about our HUD in the SLUF and Viper was it complemented the steam gauges. And since we had a combination of air data and inertial data, it was a lifesaver when the pitot-static system failed. Someone mentioned that the PF could tell he was climbing by using the altimeter. My understanding is that "all" air data was unreliable except AoA, and AoA ( separate probe) was deemed unreliable due to low airspeed. BEAM ME UP! The baro data was FUBAR! So there goes stall warnings and such based on AoA.

When our air data froze, that's what we saw. Frozen scales or blank scales. The flight path vector was still good, as was bank angle for the pitch lines. We could also select groundspeed for display versus CAS or TAS.

Most useful basic use of our HUD was landing in 100 and a quarter. Not that I never did that back in the 60's using primitive steam gauges.

[DozyWannabe]

The thing about our HUD in the SLUF and Viper was it complemented the steam gauges.

Let's be pragmatic though, the primary reason HUD is considered essential in fighters (and is therefore cost-effective in all cases) is not because of the fact it can complement the primary instruments so much as the fact that in a fighter you're going to have people shooting at you, and when that happens a split-second glance at the panel can mean the difference between life and death.

Someone mentioned that the PF could tell he was climbing by using the altimeter. My understanding is that "all" air data was unreliable except AoA...

As far as I know, altitude information was OK - certainly on the recorded instruments.

Remember that the engineering logic was designed around the idea that the failure of all three pitot tubes near-simultaneously was considered out-of-scope, and indeed it didn't happen until this particular model on this particular type encountered conditions with which they could not cope. The whole point of having the pitot and static information as separate "quorums" was so that the system would be able to determine where the failure was and disregard only that which was unreliable, and as such a failure of the pitots would not affect the static data and altitude data would have been OK at all times.

In any case the system was designed to preserve as much valid information as possible, with traditional pitch-and-power settings determined as contingency

and AoA ( separate probe) was deemed unreliable due to low airspeed.

Not until so late in the sequence that a recovery would have been difficult, if not impossible, and at that point the airspeed data was back.

[roulishollandais]

1992 : I discovered an error in pitch and power for the MD83, Max Landing Weight, 3000 FT, landing configuration ! 66.8% N1 instead 76.8% : my airline refused my analyse,as the figures came from MacDonnell ! After two months I obtained from the Chief engineer of my airline that he sent a fax to MacDonnell. 48h later he recieved a fax in return with thanks and congratulations he showed me immediately. My chief pilot and sector MD83 chief pilot have been angry against me... BOEING may confirm! Every information has to have sense and must be crosschecked each time where possible (see discussion about redundancy,different sources of information have to be used, as gums, klopfstein,others said it.
roulishollandais

[OK465]

...the primary reason HUD is considered essential in fighters...

The military fighter HUD's primary function is to aid shooting AT or bombing some poor disadvantaged adversary. If you become the 'shootee' instead of the 'shooter', a military HUD itself at that moment is of reduced value.

Military-wise, HUD instrument approach capability has always been secondary, and in fact in the early small HUD F-16, when you got to the 'rabbit' in thick, wet fog or snow, IMO you were better off going true heads down on the instruments due to the disorienting reflections and glare off the big curving scenic canopy. Even better was to have the sequenced flashers turned off when possible, something you generally realized after the fact. But I guess HUD is really valuable around the boat.

Civil aviation HUDs (or now more correctly HGS), though providing a range of functions from the mundane to the critical, are optimized for low visibility instrument approach capability. A couple of operators have already added IR capability, gaining a credit which effectively gets you even lower minima.

However, constantly flying nothing but HUD can also create a new species of technological dependents, the 'HUD cripples'. HGS, as a system, or components can fail...

So there we are again. That said, I personally would rather have one than not. :}

[Clandestino]

This link to the high altitude operations power point file at flightsafety.org has possibly been posted previously, but well worth a look.It absolutely is worth far more than a cursory look! Its salient points 1) there's a lot of difference between approach to stall recovery and stall recovery, 2) mach tuck and coffin corner are no longer factors on modern turbofan transports 3) most of the high altitude upsets are pilots induced, get cheerfully ignored during a many PPRuNe discussion, not just AF447.

In 5 years we lost 5 aircraft in my squadron with 11 dead crewmembers. We looked detailed into those accidents, and none of those gizmo´s i mentioned would have saved their day, not saying they are superfluous though. Airmanship and common sense (with or without those gizmo´s) would have. That did not make them bad people or bad pilots, but it got them killed unfortunately.

(...)

No, but they did not recognize, that they were doing that final mistake.

Any similarity between your fallen comrades and the crew of AF447 is not coincidental. There's very, very little doubt that CM2 felt he was doing the right thing just as he was putting himself and everyone else on board just in the fate's line of sight. That's the stuff of what Greek tragedies were made.

If your statement is something like sh*t happens, then that is not something i can accept as accident prevention handling.
Problem with some pilots are that they are spoiled and lazy. They never take the time to learn statistics properly. If every pilot understood it well, we would never have to discuss minima busting or taking off with snow on the wings and opportunities of having to learn from the colleagues who went from AME's objects of interest to pathologist's, would have been greatly reduced. AF447 was inevitable but there is a whole world of practical difference between once-a-year inevitable and once-in-ten-thousand-years inevitable. Statistics!

With more gizmos or better training, what´s your answer?

Neither alone and not just that.

StEx has shown better understanding of A330 than many a PPRuNer decrying the beast's design when he said: "The machine does not isolate us from the great problems of nature but plunges us more deeply into them". All the fabulous acronimous stuff such as: EFIS, GNADIRS, FBW, AP, FD, ATHR, etc. are absolutely incapable of separating us from nature, bot human and in general sense, a little bit.

The panic pull is old and known quantity, for pilots wiling and able to face their enemy. Wolfgang Langewiesche has described it accurately in "Stick and Rudder". Adolf Galand himself was its prey at the very early stage of his career. Saving grace was he kept stick pressed hard against the backstop as the ground contact finally put an end to his spin and very low wing loading of his glider resulted in impact RoD so low to make the crash survivable. Lucky for him, not so for the allied pilots who strayed into center of his aiming reticle during WW2. Just shows it can happen to anyone and pilots who succumb to it are not necessarily the ones with "the wrong stuff".

Better training? Sure! Improve training in such a manner to assure that every pilot really understand what is trained. Make better initial pilot selection, both before first flying lesson and at joining the airline. Give no credit for experience, lest you want 27 000 hrs pilot getting so excited about his first real emergency that he runs out of fuel while preparing the landing or 25 000 hrs pilot failing to do basic crosscheck, putting his trust in the sole failed instrument and spinning his passenger jet during climbout.

That's pretty uneconomical, eh?

The guy needs full attention on him - In need to correct or lecture each and everyone - Just glad I don't have to share a flight deck with that type of character ...
The guy tries to get as least personal as practicable. To this end, he tries to argue the points raised, not the people making it. He tries not to waste bandwidth by discussing completely unfounded arguments, just those that have some merit.

How about that one?AF definitively has training problems but then some AF crews have successfully negotiated AF447-like scenario in real life. Methinks problem lies with assuring that the pilots really understand what is trained and accept the training as useful and something to be relied upon when real life proverbial hits the fan. Basic airmanship might be an issue too. As once was said:

You can always lead the pilot to the right path, but you can not always make him follow it.

What do you think of the oscillations of the two last minutes ?Oscillation after AP went offline is very significant... in radically different matter than some here suggest. CM2 has countered it quickly, decisively and successfully - proving he was looking at functioning attitude indicator at the time.

These days no captain should argue in the moment and may even thank the F/O later for saving the airplane, the headlines and the heartbreak for families.For Finnegan's sake, it was always so! We just didn't call it CRM in the days of yore! Good captains needn't be told what CRM is and how it's good for them to practice it! They just filed it under "airmanship"!

Clearly I don't mean just when the F/O feels slightly uncomfortable with something the captain is doing, but in clear and present circumstances that warrant the actionBest advice, as usual, can be found on PPRuNe.

If you think somethings not right, say so. If you think it's not right, it probably isn't. If it is right, you've just learnt something.

However, current state of AF447 CVR transcripts indicates the major CRM problem was no crew resource to manage.

My understanding is that "all" air data was unreliable except AoA, and AoA ( separate probe) was deemed unreliable due to low airspeed.True, but it's not whole truth. It got unreliable when the aeroplane passed 41.5° alpha as the stick was held obstinately aft. Thirty seconds before that everything was valid, even the airspeed.

I'm speculating now, but my money is on the final findings being similar to Peter Garrison's take on Colgan 3407. (http://www.flyingmag.com/safety/accident-investigations/aftermath-mystery-colgan-3407)

[Turbine D]

@ Dozy,
Your Quote:
Let's be pragmatic though, the primary reason HUD is considered essential in fighters (and is therefore cost-effective in all cases) is not because of the fact it can complement the primary instruments so much as the fact that in a fighter you're going to have people shooting at you, and when that happens a split-second glance at the panel can mean the difference between life and death.
- Wrong...
I think you are somehow stuck in a time warp regarding HUDs, as if it were the old movies of dogfights in WWII or the Korean war when HUDs were not available. The purpose of HUDs had nothing to do with being shot at, but everything to do with accurate shooting at a target. Some American & British history regarding HUDs:

In 1955 the US Navy's Office of Naval Research and Development did some research with a mock HUD concept unit along with a sidestick controller in an attempt to ease the pilots burden flying modern jet aircraft and make the instrumentation less complicated during flight.

HUD technology was next advanced in the British Buccaneer, the prototype of which first flew on 30 April 1958. The aircraft's design called for an attack sight that would provide navigation and weapon release information for the low level attack mode. There was fierce competition between supporters of the new HUD design and supporters of the old electro-mechanical gunsight, with the HUD being described as a radical, even foolhardy option. The supporters won. BAE Systems thus has a claim to the world's first Head Up Display in operational service.
In the United Kingdom, it was soon noted that pilots flying with the new gun-sights were becoming better at piloting their aircraft. At this point, the HUD expanded its purpose beyond weapon aiming to general piloting.

Gilbert Klopfstein created the first modern HUD and a standardized system of HUD symbols so that pilots would only have to learn one system and could more easily transition between aircraft. Klopfstein pioneered HUD technology in military fighter jets and helicopters, aiming to centralize critical flight data within the pilot's field of vision. This approach sought to increase the pilot's scan efficiency and reduce "task saturation" and information overload.


Aircraft HUDs generally contain:


boresight or waterline symbol—is fixed on the display and shows where the nose of the aircraft is actually pointing.


flight path vector (FPV) or velocity vector symbol—shows where the aircraft is actually going, the sum of all forces acting on the aircraft. For example, if the aircraft is pitchedup but is losing energy, then the FPV symbol will be below the horizon even though the boresight symbol is above the horizon. During approach and landing, a pilot can fly the approach by keeping the FPV symbol at the desired descent angle and touchdown point on the runway.


acceleration indicator or energy cue—typically to the left of the FPV symbol, it is above it if the aircraft is accelerating, and below the FPV symbol if decelerating.


angle of attack indicator—shows the wing's angle relative to the airflow, often displayed as "α".


navigation data and symbols—for approaches and landings, the flight guidance systems can provide visual cues based on navigation aids such as an Instrument Landing Systemor augmented Global Positioning System such as the Wide Area Augmentation System. Typically this is a circle which fits inside the flight path vector symbol. Pilots can fly along the correct flight path by "flying to" the guidance cue.


Until a few years ago, the Embraer 190 and Boeing 737 New Generation Aircraft (737-600,700,800, and 900 series) were the only commercial passenger aircraft available with HUDs. A HUD is standard equipment on the Boeing 787. Furthermore, the Airbus A320, A330, A340 and A380 families have undergone the certification process for a HUD.

So if you want to be pragmatic regarding HUDs on most commercial aircraft today, I think Clandestino gave the correct answer, it all has to do with money, ROI and such.

[DozyWannabe]

@TD

I was referring to the duplicated instrument displays on the HUD, not the ordnance aiming capability - which as you correctly state goes all the way back to wartime gunsights and bomb-aiming reticles.

At any rate, the importance of HUD increases significantly in a combat environment where time spent looking down at a console would result in a significant disadvantage - not so for a civil environment (as demonstrated by the piecemeal take-up of the HUD option in the airliners you mention).

[gums]

Most of the folks here have pointed out that our HUD's in the Sluf and Viper and Jaguar and Tornado and Tomcat and Eagle and Hornet and Typhoon and Harrier and, and and, and........... were there primarily for increased combat effectiveness. No argument there. But as Turbine's article rightly points out, the doggone thing became a lifesaver when landing in poor weather and weapon delivery was not a factor. It definitely reduced workload for we folks that didn't have to deal with "CRM". Simply said, "Self, get your act together, and follow the approach plate and ILS steering cues".

@ OK The canopy distortion was negligible over all 360 degrees of view we had, and was optically reduced to near zero ( like a fraction of a milliradian) within the HUD FOV. See my landing in snow showers with the LEF folded up. That's the smaller HUD in the Block 10 or 15 Viper.

http://www.sluf.org/misc_pages/lef-landing.m4v

http://www.sluf.org/misc_pages/rightwing.jpg

You may call me a Hud cripple, as I used the thing 95% of the time when IMC, and cross-checked the steam gauges to ensure we were all a happy family. I have been far-sighted since a teen, and if I stared at the steam gauges for longer than 2 minutes, everything was blurry when I looked up - not good when breaking out at 200 feet and 190 knots as I did in the VooDoo. Learned not to focus real hard and survived easily.

For well over a decade USAF refused to call the HUD a primary flight instrument. As it seems some here are, 40 years of tradition unhampered by progress. Sheesh, if I have a relatively cheap display ( now that GPS, INS, FMS, etc are highly integrated via data bus and computers). what's the big deal?

As far as the Brits leading the way, they fly in poor weather most of the time, and their instrument skills are the best I ever saw. A HUD was a natural for them when landing in poor weather, regardless of the enhanced tgt acquisition and delivery capabilities. So my HUD time in both jets was courtesy of Marconi.

I continue to feel that a flight path vector display or symbol for the AF447 dudes would have helped a lot.

[BOAC]

I continue to feel that a flight path vector display or symbol for the AF447 dudes would have helped a lot. - I have said this before and it need saying gain. All this talk (1400+ posts now) about 'HUD' in relation to AF447 is a waste of time.

No-one will deny a HUD is a superb asset, of great use both in tactical aircraft and commercial aircraft. HOWEVER, to suggest that retrospectively it would have helped 'save' AF447 is nonsense. This crew appear, for whatever reason, to have been unable to interpret even basic 'so-called steam gauges' ie attitude and altitude. To have seen a HUD fitted in 447 would probably simply have meant even more electronics smacked into the South Atlantic. There does not appear to be a snowball's chance in hell that this crew would have taken in ANY FPV, AoA or any other EXTRA information they had in front of them.

FPV etc would certainly be of great use to a trained operator in extreme conditions, BUT the emphasis must be on PREVENTING these extreme conditions in the first place. To do that required no FPV, HUD, AoA - just an absent basic flying skill.

[AlphaZuluRomeo]

BOAC: :D:D

[OK465]

HOWEVER, to suggest that retrospectively it would have helped 'save' AF447 is nonsense.

It might have resulted in a fortuitous early positive switch of control to the 'guy' in the left seat since that's where it would have been located. :p

(@ gums: I'm not talking about canopy coefficient, I'm talking about the effects of those incredibly bright flashing strobes on the ground [particularly at night in moisture]. I believe they lost one at Shaw under these circumstances.)

Right, apologies, and now back to the rigidly enforced and universally accepted guidelines for this discussion...:}

[BOAC]

It might have resulted in a fortuitous early positive switch of control to the 'guy' in the left seat since that's where it would have been located. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/tongue.gif - er yes - I see the big grin there. You ARE joking, aren't you?

[OK465]

'The butterfly effect' :)

I don't believe an HGS would have saved 447 either, but only because of the logic underlying the selection & display of the FPV.

I tend to agree with gums in the sense that an 'NG style' PFD FPV might have made a difference at the very beginning.

Maybe not, but it's the 'next' time that counts now.

[BOAC]

Yes - indeed 'next time'. I firmly believe it is a 'quality' issue in Air France that needs sorting. No need for FPV etc. Just ensure basic skills are in place and crew comms/monitoring are employed correctly.

[A33Zab]

Loss of control training:

Project Supra / desdemona. (http://www.tno.nl/content.cfm?context=overtno&content=nieuwsbericht&laag1=37&laag2=2&item_id=2012-06-26%2011:08:50.0&Taal=2)

Desdemona (http://www.desdemona.eu/)

[mm43]

A33Zab;

Thanks for the link to the Desdemona simulator project. I noted a link hidden in the article leads to an EU Research & Innovation (http://ec.europa.eu/research/infocentre/article_en.cfm?id=/research/star/index_en.cfm?p=a20&item=Infocentre&artid=24174) page that includes a comprehensive write-up and video. Some may be interested.

[HazelNuts39]

From page 41 of Interim report #3:
At the request of the BEA, Airbus conducted a simulation of the operation of the flight control computers, which involved recalculating the movements of the elevators and of the trimmable horizontal stabiliser (PHR) based on pilots’ inputs and compare the results against FDR parameters. This simulation could be continued up until the end of the flight. The recalculated deflection angles for the elevators and the PHR are consistent with the parameters recorded.

At the request of the BEA, Airbus conducted a simulation of the aircraft behaviour based on the theoretical model and on the actions of the PF (sidestick and thrust). The validity of the model is limited to the known flight envelope based on wind tunnel and flight tests data. Consequently, it was possible to conduct the simulation to mirror the period from 2 h 10 min 00 to 2 h 10 min 54. However, in view of the complexity of such a simulation, it was agreed that, initially, the simulation would be confined to the longitudinal axis, without introducing turbulence. The lateral parameters used are those recorded in the FDR.Shortly after the publication of that report, I queried the presence prior to A/P disconnect of variations in elevator position, angle of attack and normal acceleration. What causes these variations in the absence of turbulence, and why are the AoA variations not accompanied by corresponding Nz variations (1° of AoA corresponds to 0.28 g) ?

In my search for a correlation between side stick angle, pitch rate and normal acceleration, based on the C* control law, I started comparing the elevator positions to the side stick commands, and am surprised to find that the elevator seems to be leading the side stick:

http://i.imgur.com/ZjO44.gif?1

[john_tullamarine]

.. as a sideline, should anyone be wondering why I haven't started the next thread, I'm leaving it until the report comes out .. as I suspect that the posts will be coming fast and furious for several weeks after that ..

[Machinbird]

In my search for a correlation between side stick angle, pitch rate and normal acceleration, based on the C* control law, I started comparing the elevator positions to the side stick commands, and am surprised to find that the elevator seems to be leading the side stick:
That sounds like a data reduction problem with the original data to me. Something likely caused a delay artifact in the side stick position data.

[bubbers44]

I have never used a HUD so don't know if it would have helped them or not. Attitude indicators, altimiters, Vertical speed indicators and stall warnings didn't, so doubt if HUD would have helped either. They just needed an experienced pilot flying, not them. Sorry. That is how I see it. Monitoring an autopilot for thousands of hours does not make you a pilot.

[Lyman]

HN39

In the first extreme, the stick follows acquired angle of elevator by eight seconds?

What is wit that?

Mach... Or a lead in the elevator data? If it is real, what could cause such a discrepancy?

Was the a/c hunting, the pilot chasing? Sounds like an abnormal.

[Organfreak]

Thanks for the link to the Desdemona simulator project. I noted a link hidden in the article leads to an EU Research & Innovation page that includes a comprehensive write-up and video. Some may be interested. New flight test to keep pilots out of a spin (http://ec.europa.eu/research/infocentre/article_en.cfm?id=/research/star/index_en.cfm?p=a20&item=Infocentre&artid=24174)

Mr. 43,
(Since nobody has remarked on this)-- Thanks, that was superb. The soundtrack of the video is the same as the article text. A large download people, but highly recommended! The new simulator really is a centrifuge. :yuk: Stupendous.

[HazelNuts39]

That sounds like a data reduction problem with the original data to me. Something likely caused a delay artifact in the side stick position data. In the simulation also?

[DozyWannabe]

In the simulation also?

Possibly, depending on how the collected and processed the data. It might be worth seeing if they correct it in the final report.

[grity]

HN In the simulation also? (in direkt law HALis in front of the PF and know what the PF will do the next 8 sec.....)

the time delay can and will be a non accurate start-time in the simulation or in the transfer from the simulation to the report,

they searched for bigger effects than you

[HazelNuts39]

I don't get it. If you do a simulation with the side stick as input and the elevator as output, how can the elevator get ahead of the side stick? If there was a delay artifact in the elevator or side stick position data, wouldn't the simulation have revealed it?

Yes, I'm looking forward to seeing that explained in the final report.

[OK465]

In one specific hypothetical case, over a given period of time nose high somewhere in that 6-15 degree pitch range, airspeed decaying, if you were to graph a hands-off 'neutral' sidestick, would that not be a 0 degree deflection integrated over a particular time period (flat line)?

But you would end up with a constantly increasing value of nose up elevator deflection over time attempting to hold the FP which I guess in a way could be considered as 'elevator leading sidestick'.

Now the SS is physically moved nose-up...

The same existing pitch rate (=elevator position) required for airspeed decay and in effect for the flight path is continually input over a range of increasing SS angles as the deflected elevator holds the FP until the SS rate command catches up? Would this give the appearance of elevator leading SS?

This may not be what you're getting at. :)

[grity]

HN what is your surce for the integral of the elevator position??? the graph on s.41 of the interimreport(en), capter 1.16.4.2 ???

[HazelNuts39]

grity,

No, it's the blue line on page 42, section 1.16.5.1.

With thanks to free Engauge Digitizer (http://digitizer.sourceforge.net/) software.

[grity]

HN
"Airbus conducted a simulation of the aircraft behaviour based on
the theoretical model and on the actions of the PF (sidestick and thrust)" (s.41)

"2 h 10 min 23 The N1 start to increase and reach around 104 % in 12 seconds." (s.90) and (s.113)

is there any automatismus for the elevator to reakt against the moment (--->pull) of the increasing engines ???

[A33Zab]

French investigation authority BEA appears likely to rekindle the smouldering conflict over the loss of Air France flight AF447 when it releases the final report into the accident on 5 July.
Air France and the main French pilots' union, SNPL, have previously clashed with Airbus over the circumstances of the crash and whether the fundamental reason for the loss centred on pilot competence or the design of the Airbus A330's flight-control and warning systems.
As expected, Airbus has submitted substantial comment to the inquiry following the release of the draft version of the report.
SNPL has already reiterated its concerns over aircraft functions and the alerts given to the crew, in a document published in February.
Airbus declines to comment on the AF447 report ahead of publication, but has previously strongly defended its aircraft and pointed out that three pilots appeared unable – despite clear warnings – to recognise the aerodynamic stall which downed the jet in June 2009.
Although the draft did not include recommendations it featured analysis by a human factors panel established to look into the crew's response to the stall.
But a source familiar with the situation indicates that the airframer is concerned whether the conclusions will focus too narrowly on the human-machine interface.
"If there are things to improve on the aircraft, [Airbus] won't try to escape in any way," says the source, but adds that the manufacturer “would like to see a report in which all the issues are being dealt with”.
The source also suggests that Airbus is likely to "become vocal" if it feels the breadth of the report is too narrow.
Former BEA deputy chief Jean Pariès - who heads human factors consultancy Dédale and took part in an Air France safety review - told an operations forum in Oslo in April that current safety models assume pilots will recognise and identify abnormal situations, then implement relevant procedures.
However in reality, he said, emergency situations generate surprise, causing momentary loss of cognitive control as well as resistance to recognising a loss of comprehension.
Pariès cited 16 events similar to AF447, all of which showed poor understanding, rare implementation of unreliable airspeed procedures and stall warnings which were "perceived but mostly not believed".
He suggests the problem cannot simply be reduced to "automation complacency" or loss of basic skills. Pariès claims crew training aims to prepare pilots for anticipated emergencies, not the unexpected, and highlights the irony that the competencies needed to cope with the unexpected "are those that are lost in a continuous effort to anticipate and respond to all potential threats".
Investigations into a strikingly similar event to AF447, involving an Air France A340 in July 2011, recommended that pilot training include shock and surprise elements.


Flight Global 12:00 28 Jun 2012 (http://www.flightglobal.com/news/articles/final-af447-report-set-to-re-ignite-safety-feud-373527/)

[jcjeant]

Hi,

Investigations into a strikingly similar event to AF447, involving an Air France A340 in July 2011, recommended that pilot training include shock and surprise elements.Shock and surprise are virtually impossible in a simulation cession ... unless you make suddenly appear on top of the dashboard .. a tarantula or a poisonous snake or even a mouse when female pilots on training ... :)

[Turbine D]

Hi HN39,

I was reading an old post by Chris Scott (#1060 7/9/11 AF447 Thread #4)
I don’t think much would happen to the THS during the initial rotation from level flight, as it would have required little up-elevator to enter the climb. Once the 7000ft/min had been achieved, the trajectory would be maintained by the EFCS even with no back-stick. As the speed started to drop, more up-elevator would need to be introduced by the EFCS to maintain 1g, and it would then start to trim the THS a bit to retain full elevator authority. Once the aircraft got on to the back end of the drag curve, however, this process would proceed rapidly.

In fact the PF arrested most of the climb at FL375, by “nose down control inputs...”, so some down-elevator may have been used briefly by the EFCS at this point. This partial recovery was to be short-lived, as the PF seems to have reacted to a stall warning by selecting TOGA (causing a pitch-up) and resuming “nose-up inputs”. Resuming the climb at that point, on the wrong side of the drag curve, was when the EFCS had to start using up-elevator and nose-up trim (THS) in earnest, in order to try and maintain the trajectory it thought the PF wanted.


I wonder if this could explain your graph findings of the elevator leading the SS?

[HazelNuts39]

Turbine D,

No, it doesn't. But thanks anyway.

[Turbine D]

Hi jcjeant,
Shock and surprise are virtually impossible in a simulation cession ... unless you make suddenly appear on top of the dashboard .. a tarantula or a poisonous snake or even a mouse when female pilots on training ...:)
:D:D:D

Actually, I have a family member who is working on the development and installation of two new nuclear reactors for electrical power generation here in the US. In order to take in account human psychological factors when things go wrong, they have a computer program they follow as it relates to S & S.

She calls it Human Risk Analysis, and they use an HRA calculator from EPRI as the tool. They go through plant operating procedures and identify human actions that could be a pre-initiator to an event or a post-initiator that could inhibit mitigating systems. They also identify operator actions necessary to mitigate an accident. They can quantify Human Error Probability (HEP) with the HRA calculator knowing various environmental factors, the approximated stress level of the operator/operators, the complexity of the procedures that must be followed, and the time window available to perform the action. All of these inputs are combined using various statistical methods in the HRA calculator, resulting in in a human error probability. If the analysis depicts a high HEP, the controls, control panels and procedures are reviewed and reworked to lower the HEP within acceptable levels.

She thinks that responses to aircraft accident scenarios are also highly proceduralized and imagines that similar methods could also be used in the aviation industry.

Just some food for thought....

[NeoFit]

#1453
Former BEA deputy chief Jean Paries - who heads human factors consultancy Dedale and took part in an Air France safety review - told an operations forum in Oslo in April that current safety models assume pilots will recognise and identify abnormal situations, then implement relevant procedures.
However in reality, he said, emergency situations generate surprise, causing momentary loss of cognitive control as well as resistance to recognising a loss of comprehension.
Some details here (http://www.flyoperativtforum.no/Foredrag/FOF12/AF447%20accident%20-%20some%20deep%20lessons%20-%20Jean%20Paries.pdf)

[Owain Glyndwr]

Hi HN39

In my search for a correlation between side stick angle, pitch rate and normal acceleration, based on the C* control law, I started comparing the elevator positions to the side stick commands, and am surprised to find that the elevator seems to be leading the side stick:

I think TurbineD has it right. Surely the whole point of the C* law is that there is no direct relationship between sidestick and elevator deflections? (and therefore no correlation of their integrals either).

A sidestick movement commands a 'g' level and the control system moves the elevators as much as it thinks is needed to fulfill that command. If the stick is held at a constant position the elevators will still move until that 'g' level is acheived - i.e. they will 'lead' the sidestick. If the 'g' is not what the pilot wanted then he would add more stick and the process would continue. Seems to me that is what was happening here.

[HazelNuts39]

Hi Owain G,

Thank you for your explanation, I'll go along with that.

Didn't read that in Turbine D's post though.

BTW, speaking about the C* law, if anyone is still interested, I did another exercise. The graph below shows the calculated side stick angle to maintain a constant pitch rate of 1°/second from 2.4° to 12° pitch attitude, with nz feedback, and compares it to the AF447 DFDR side stick angles averaged over 2-second intervals.

http://i.imgur.com/VJFeO.gif?1

[A33Zab]

No sign of 'leading' elevator here:

http://i474.photobucket.com/albums/rr101/Zab999/ss_Elev.jpg

[HazelNuts39]

A33Zab,

Yes, I agree with you, Thank you.

The curve of integrated elevator angle gives a misleading impression because:

(a) At 02:10:18 the elevator changes from nose-up to nose-down while the side stick is still nose-up,
(b) At 02:10:40 the elevator changes from nose-down to nose-up while the side stick is approximately neutral,
(c) The elevator is slightly nose-up between 02:10:00 and 02:10:06,5, i.e. prior to any side stick action, and
(d) The graphical scales presenting the two parameters.

I've accepted Owain Glyndwr's explanation for (a) and (b) and am hoping to get an explanation for (c). I've edited post #1439 to rectify (d).

Apologies for causing "a storm in a glass of water" (as we say in dutch).

[grity]

(c) The elevator is slightly nose-up between 02:10:00 and 02:10:06,5, i.e. prior to any side stick action.
AP2 was engaged till 02:10:05
elevator was up-down-up in this time
???

[HazelNuts39]

grity,

the elevator positions controlled by the autopilot are the purple dots. They do not seem to be part of the simulation which assumes zero turbulence. Perhaps I should have included the variations in AoA and normal acceleration in my item (c).

[grity]

IMO the intention for the simulation was just to control if the flightpath of the climb and stall was controled (consistent) from the action of PF and system, or from outside like broken wing or elevator, extrem turbulences, hand of the lord, rocket or metorit...

not more

[A33Zab]

"Don't sit down by the packages":ok: (another dutch saying)

From the C* schematic below (Don't know the airliner it belongs to, but in principle it is valid for any FBW airliner) the SAS control has a inner f/b loop based on qmeas (thru wash out filter and Kq gain).


http://i474.photobucket.com/albums/rr101/Zab999/C_Star.jpg

[Machinbird]

The majority of you must have missed this since there was a distraction about pitch control.:) You would be talking about it otherwise.

In post 1453, A33Zab posted the content of a Flight Global article relating to the AF447 human factors. This was based on an April presentation by Former BEA deputy chief Jean Pariès who heads human factors consultancy Dédale.

In post 1458, NeoFit posted a link to the actual presentation by Pariès but it was not particularly obvious.

Here it is again:http://www.flyoperativtforum.no/Foredrag/FOF12/AF447%20accident%20-%20some%20deep%20lessons%20-%20Jean%20Paries. (http://www.flyoperativtforum.no/Foredrag/FOF12/AF447%20accident%20-%20some%20deep%20lessons%20-%20Jean%20Paries.pdf)pdf (http://www.flyoperativtforum.no/Foredrag/FOF12/AF447%20accident%20-%20some%20deep%20lessons%20-%20Jean%20Paries.pdf)
The presentation is entitled AF 447 ACCIDENT: SOME DEEP LESSONS.

Somehow I believe this will largely represent the BEA human factors thinking on this accident.;)

[mm43]

Machinbird;

From the Jean Pariès paper -
Underlying assumption of the current safety model


Pilots, while focused on their current preoccupations, will...

recognize any abnormal situation
Implement "memory items" or "basic airmanship" response if relevant
(then) identify the situation, and implement the relevant procedure





...through their monitoring of instruments, their perception of warnings, their awareness of the situation, and their "airmanship":

So, dealing with AF447, it has been established without too much doubt that other than "recognizing they were in an abnormal situation" the crew failed on all other counts. Does this mean that the HF response will be a complete re-write and a re-jig of the aviation industry's approach to safety?

I somehow doubt that will happen overnight, but adaption of current technology will most likely be used to lessen the "startle factor" and lead/prompt for the correct response. If that doesn't work, then the "technology" might just have to vote the "HF" out of the loop.:}

[Owain Glyndwr]

the SAS control has a inner f/b loop based on qmeas (thru wash out filter and Kq gain).

That inner SAS loop is just an old fashioned pitch damper.

[Linktrained]

Sim Shocks
Reading a number of PPRuNe threads it would appear that Simulators are used by a number of different airlines in different ways.
One pilot commented that he had done the same series of routine checks on TWENTY different occasions.
China Airlines use them to keep their F/Os in flying practice, because with their 747SPs flying their very long sectors ( which require four pilots) it must mean that each pilot would only have a limited number of opportunities of T/O or Landings available per month.

There were some interesting contributions by FRYBURG on 8th June on the Humbling Sim Experience thread.

I have never used/ seen a Simulator - they were not around, then !

I read of one where to keep the pilots alert, having found that the airfield was not getting closer at something like the right G/S, one found that the
B737 was on short finals for an aircraft carrier.

I might have been better with a " F/O Dead Drill", a one hour hold at Nantucket before landing at JFK. ( The F/O had been flooded with R/T from the replacement ATControllers, due to their industrial action. I took him to a briefing place before departure. He was all right.)

A Simulator Check of "Engine failure on Overshoot" before it happened to me would have helped on a heavy twin. My Chief Pilot said that "It had never happened before..." Two months later it happened again... To a different crew, who were killed. After that, that system was switched OFF, except for heavy T/Os.

[roulishollandais]

I have been very very estonished to read Mr.Pariès, heading the human factors consultancy "Dédale SAS France", and also the "Former BEA deputy chief"! in AF 447 ACCIDENT: SOME DEEP LESSONS !

Reading the text (april 2012), clearly concerning AF447 as Machinbird , mm43, A33Zab, Neofit, iself, have seen it, it was even worse.


The fact of a person holding public authority or discharging a public service by a person or a public elective office, take, receive or retain, directly or indirectly, any interest in a company or in a transaction for which it has, at the time of the act, in whole or in part, responsible for providing supervision, administration, liquidation or payment, is punishable by five years imprisonment and 75,000 euros fine.

Where is the independance of the BEA ???!!!

[Turbine D]

Hi roulishollandais,

Relative to your post #1471, I don't see how the French criminal code cited would have any bearing relative to Jean Paries. If he were still an official of the BEA and also CEO of Dedale, it certainly would. It seems to me that Mr. Paries is an expert in what he does (and has done) and besides the AF447 presentation he gave, he has given dozens of others to various audiences around the world pertaining to aircraft safety.

If I were examining the human response aspects of the AF447 accident, I would want to hear him out on his thoughts, observations, recommendations and any other pertinent information that would be helpful in the analysis and/or recommendations offered going forward. There may not be many credible sources of this type of information to draw from, but I sure would like to hear from as many as possible leading to the final report out.

Also, didn't most or the entire upper echelon of the BEA turn over prior to the AF447 accident? Isn't this a new BEA organization team doing the AF447 investigation?

Just my opinion...

[NeoFit]

roulishollandais

I agree, absolutly

Nowadays, it's very fashionable to appeal to external consultants :)

I am so sorry coming back with Tarom event:
If the conclusions of the 447 HFG are of the same order as that of the Tarom thesis (sponsored by the bea), then, obviously, I wait for nothing of 447 HFG :=

Tarom report (www.skybrary.aero/bookshelf/books/680.pdf) (Engl.) or try also here (http://www.bea.aero/docspa/1994/yr-a940924a/htm/yr-a940924a.htm)

Tarom HFG thesis (http://www.headupflight.net/Documents/Th%E8se%20LAA/These.htm) (french)
('Fiche Nr 3 : incident A310 - Declenchement de la protection de vitesse en approche')

[jcjeant]

Hi,

Turbine D
Also, didn't most or the entire upper echelon of the BEA turn over prior to the AF447 accident? Isn't this a new BEA organization team doing the AF447 investigation?The investigation chief of BEA for AF447 case ( Alain Bouillard ) is the same as for the investigation of the Concorde ....
The only significant change after the AF447 event was the replacement of the BEA chairman (Paul-Louis Arslanian replaced by Troadec) and the depart of Arslanian was already scheduled prior the AF447 event
http://i.imgur.com/Fc827.jpg

Bouillard (left) and Arslanian

http://i.imgur.com/nSw9y.jpg

Troadec

[DozyWannabe]

If the conclusions of the 447 HFG are of the same order as that of the Tarom thesis (sponsored by the bea), then, obviously, I wait for nothing of 447 HFG

Why?

An objective view of the evidence - even going back to 1988 - proves conclusively that BEA did *nothing* to protect or shield Airbus, and all accusations of such behaviour were lies concocted by the defence team of M. Asseline and those who followed him.

[IGh]

Another topic -- a new thread --

Above, in slots #1471 & #1473, there seems a skepticism about the _investigation_:

So -- for that discussion of investigator-err, bias, misconduct, and fraud, see:
http://www.pprune.org/safety-crm-qa-emergency-response-planning/489479-bias-independent-investigating-authority.html#post7273383

[DozyWannabe]

Really, IGh - "Hoot" Gibson again? Didn't he retire sometime around the last Ice Age? (not to take anything away from him...)

[Lonewolf_50]

From the briefing, I noted that there had been one or two stall warnings roughly a minute before the upset.

I hadn't grasped that before.

It fits the vague idea I had that the pilots were initially, and in the end fatally, inclined to believe that the stall warnings were spurious, or perhaps as unreliable as the airspeed.

[NeoFit]

DozyWannabe
Why?
An objective view of the evidence - even going back to 1988 - proves conclusively that BEA did *nothing* to ...
I am not belonging M. Asseline team and those who followed him, but, AFAR, it seems to me that pilots must be informed about the specificities of the vessel they are handling.

Did you never heard something about "The reasons of State" ?

It has been discussed of Concorde on this (or a previous) AF447 thread.
After one of the Concorde Washington tire event, you probably remember that NTSB sent a letter to BEA (links or scans available within some deadline).
It others one terms, NTSB needed to open the umbrella and protect his back.

Which was the answer of BEA?
I summarize: everything is under control.

Okay, no problem .... till Gonesse Concorde Crash.

Now, what's new about pitot probes ?
No problem (and don't take care with near of 50 previous UAS events?) :ugh:


IGh
Investigator Bias ...
Another topic -- a new thread --
Thank you very much for this new subject.
At the time I read it : only two posts ... but two Scuds !


Why Tarom report ? It and only an example to show the slowness.
At last but not at least: Tarom from french BEA report:
4.2 Recommandation intermeiaire
A la suite de plusieurs accidents pour lesquels le Bureau Enquetes-Accidents avait participe, la recommandation suivante a ete emise le 24 janvier 1995 :
...
4) Consequences:
* la reaction des systemes automatiques de vol entraine des configurations potentiellement dangereuses : hors trim, poussee moteur(s) incompatible avec la trajectoire souhaitee par le pilote, ...
* L euipage, soit ne se rend pas compte de la situation, et donc ne peut pas prendre les mesures correctrices, soit constate la configuration de l avion sans en comprendre les causes. Cette incomprehension (egalement liee a une connaissance limitee des systemes) entraine une perte de temps dans l analyse de la situation, voire une analyse erronee, generalement associees a un deficit de communication entre les membres d equipage

3 Un rapport preliminaire a ete publie le 3 novembre 1994.
Ceci a entraine des attitudes tres dangereuses: assiettes ou roulis tres importants, perte de vitesse (jusqu au decrochage) ou vitesse excessive, etc.

En consequence, le Bureau Enquetes-Accidents recommande:
- qu une etude soit lancee pour que la priorite du pilote sur les systemes automatiques de vol soit maintenue en toutes circonstances.

Ceci pourrait se traduire:
a) par la deconnexion des systemes automatiques de vol (pilote automatique et auto-manette ou auto poussee) en cas d antagonisme entre les actions du pilote et celles du systeme automatique de vol ou du directeur de vol.
b) et/ou par une information claire en cockpit (eventuellement une alarme) alertant l equipage d un tel antagonisme.

[bubbers44]

I have never fllown with a side stick but no Boeing pilot at FL350 would pull back to the stops if he lost his airspeed and autopilot, why would an Airbus guy do it? No monitoring pilot would let the pilot flying do it either. Is this really how Airbus pilots normally fly?

[gums]

@ bubbers, et al

Yep, beats the hell outta me. Hold what ya got and analyze the situation.

maybe the "boldface" or whatever the commercial folks call it was not a good idea - like pull to 5 degrees of pitch and so forth.

For others, re: elevator versus stick inputs

Good grief, we've been thru this. The position of the control surfaces on a FBW jet do not reflect the pilot inputs via sidestick, wheel or whatever. They move to achieve the commanded gee, AoA or roll rate. The rudder will move to help roll coordination, with no input from the pilot.

In the 'bus, the THS will gradually move one direction or the other to reduce the amount of control input to achieve the "commanded" gee.

Waiting for the final and the immense amount of comments from we in the peanut gallery shortly thereafter.

[mm43]

The BEA's English translation of the recommendations issued following their report into the Tarom incident is as follows:-Following several accident investigations in which the Bureau Enquêtes-Accidents participated, the following recommendation was issued on 24 January 1995:
Various incidents or accidents (see list below) involving public transport aircraft show the following common characteristics:


Configuration: Automatic Pilot and/or auto-throttle lever (or auto thrust) in operation.
Circumstances: pilot flying overrides (voluntarily or involuntarily) the Automatic Flight System, or acts contrary to the indications of the Flight Director.
Aggravating circumstances:

the pilot flying is not always aware of his action in opposition with the Automatic Flight Systems and never perceives the consequences thereof,
the pilot not flying (even instructors) is not aware of the conflict between the pilot at the controls and the Automatic Flight Systems.


Consequences:

the reaction of the Automatic Flight Systems leads to potentially dangerous configurations: out of trim, engine thrust incompatible with the trajectory chosen by the pilot, etc.
Flight crew,

either is not aware of the situation, and thus cannot take corrective measures,
or observes the aircraft configuration without understanding the causes. This incomprehension (also related to limited knowledge of systems) leads to a loss of time in analyzing the situation, or even to an erroneous analysis, generally associated with a lack of adequate communicationmbetween crew members





This has led to highly dangerous attitudes: extreme attitudes or rolls, loss of speed (including stalls) or excess speed, etc.
See preliminary report, published 3 November 1994.

As a result, the Bureau Enquêtes-Accidents recommends:
- that a study be launched so that the pilot’s priority over all Automatic Flight Systems is maintained in all circumstances.
This could be done :a) by the disconnection of Automatic Flight Systems (automatic pilot and auto-throttle lever or auto thrust) in the event of conflict between the pilot’s actions and those of the Automatic Flight System or Flight Director.
b) and/or by clear information in the cockpit (possibly an alarm) warning the flight crew of such a conflict.As far as I can ascertain, those basic recommendations have been fulfilled, e.g.Auto Pilot :-
Auto OFF if abs(φ) >45°, or θ <-13°, or θ >+25°, or CAS < VLS, or CAS >(VMO/MMO or VLE/VFE), or Pitch Angle Protection ACTIVE.

Auto Pilot:-
Unavailable if abs(φ) >40°, or θ <-10°, or θ >+22°, or CAS < VLS, or CAS >(VMO/MMO or VLE/VFE), or Pitch Angle Protection ACTIVE.



The A/P and A/THR disconnected when a couple of ADR's had a disagreement over speeds.
The THS trim continued the way it was designed to, though due to a change in the control law, it would appear that the crew had no idea that the Alpha protections had been lost.

Except when the Abnormal Attitude Law has been triggered, auto trim is still functioning and a constant stick NU/ND command will cause the THS to follow in an attempt to maintain a load factor of +1g - be aware!


The Stall Warning operated correctly while the aircraft was within the Normal Flight Envelope, but wasn't heeded.

In short, the visual and audio clues/warnings provided, possibly added to the cognitive overload. Would a pseudo artificial feedback to the SS helped?? Perhaps the centrifuge simulators of tomorrow may help to reinforce what it feels like when the aircraft is maneouvered in abnormal conditions.

[DozyWannabe]

... but no Boeing pilot at FL350 would pull back to the stops if he lost his airspeed and autopilot...

Bubbers, that's *precisely* what the Birgenair 757 captain did.

[infrequentflyer789]

Bubbers, that's *precisely* what the Birgenair 757 captain did.

Not at FL350 he didn't. which maybe means bubbers wins on a technicality.

The point, however, remains that LOC accidents, and specifically mishandled stalls, are happening across range of types/mfrs/airlines.

If it was just 'buses falling out of the sky I'd be clamouring for investigation of the bus specific sidestick and fbw etc. - but that isn't what is happening.

If the effort were focused on the bus stuff only, then we could only ever fix part of the problem and risk fixing nothing if in fact the causes are elsewhere and common across types. Far better to try and identify common causes, surely ?

[RR_NDB]

Pariès cited 16 events similar to AF447, all of which showed poor understanding, rare implementation of unreliable airspeed procedures and stall warnings which were "perceived but mostly not believed".

[DozyWannabe]

Not at FL350 he didn't. which maybe means bubbers wins on a technicality.

Granted, but in that case the Birgenair jet never made it to cruise level. While it doesn't satisfy all of the criteria Bubbers set, it satisfies the important ones - namely doing precisely the wrong thing minus speed indications and with autopilot behaving erratically. It also puts a dent in the "other pilot would see the inappropriate control deflection and take over", because in that case the F/O did not. The Stony Point NWA B727 was at FL 248 when exactly the same thing happened.

[Organfreak]

Dozy:
It also puts a dent in the "other pilot would see the inappropriate control deflection and take over", because in that case the F/O did not. The Stony Point NWA B727 was at FL 248 when exactly the same thing happened.

You keep on saying that, and I keep on countering that your premise is based on false logic. One or two cases proves nothing at all. One could (I do) also speculate that, if one had a data base of, say, 100 such incidents, equally distributed between SS and yoke aircraft, it might be more appropriate to draw the conclusion that you do IF there was no difference in the associated statistics. I.E., if we're going to make guesses on this issue, I would guess that in 100 cases of LOC-to-stall, MORE pilots would notice the inappropriate input when it was a yoke. But....I have no more proof for that than you do for your opposite conclusion. :ugh:

True, I can't fly, but I can think! :\

[SeenItAll]

... but no Boeing pilot at FL350 would pull back to the stops if he lost his airspeed and autopilot...

But this guy was an Airbus pilot, and under Normal Law, isn't pulling the side stick to the stops quite permitted because Alpha Protect would limit any pitch change to prevent LOC? (Indeed, I thought such such flight protections were one of Airbus' avowed selling points.)

So what about the possibility that the PF simply did not process/comprehend that when the A/P went into Alternate Law, that Alpha Protect was no longer active -- and that he would need to use the side stick more like a Boeing yoke than an Airbus joystick? Thus, it wasn't that he was dumb, just that he had a brain freeze in not fully comprehending that his protections were gone (despite this warning being given on the ECAM).

[SRMman]

Just catching up on the discussions.
I found the Jean Pariès presentation very interesting. In the conclusion he recommends an "Overall paradigm shift" in design and training. Well, how about giving the crew a synthetic view of the aircraft generated from the sensors, something like the MS Flt Sim outide spot view, say 3/4 rear view. We see this kind of display on visualisations of FDR readouts. It would give the crew (when at their most 'startled') an immediate understanding of the aircraft's pitch/roll attitude relative to the horizon, and also (if it were possible to generate) their FPV in 3D.

[Turbine D]

Dozy,

The Stony Point NWA B727 was at FL 248 when exactly the same thing happened.

The same thing did not happen except for the end result. There was a different reason. The NWA B727 crew forgot to turn on the pitot heaters. So when they iced over, all indications were that they were all of a sudden speeding up, therefore they reduced speed. There was nothing to tell them they were at the right speed in reality. The speeds they were seeing on the instruments were erroneous, they didn't go away and they appeared real to them sadly.

I think caution needs to be applied when comparing accidents of this type, one 3 years ago and one ~ 40 years ago.

[RR_NDB]

Hi,

SRMman:

"Overall paradigm shift" in design and training. (http://www.pprune.org/tech-log/482356-af-447-thread-no-8-a-75.html#post7275653)

Long time ago some of us raised the issue. A very serious one.

Unfortunately i am too busy to do more in this Thread:

http://www.pprune.org/tech-log/481350-man-machine-interface-anomalies.html

[infrequentflyer789]

Dozy,

The same thing did not happen except for the end result. There was a different reason.


Initial cause of the pitot failure was not the same but after that it's all depressingly similar.


The stall was precipitated by the flight crew's improper reaction to erroneous airspeed and Mach indications

loss of control of the aircraft because the flight crew failed to recognize and correct the aircraft's high-angle-of-attack, low-speed stall

The flightcrew continued to increase the noseup attitude of
the aircraft following the operation of the stall warning stick shaker.

You could write those statements about either accident.

Yes, there is a big difference in aviation between 40yrs ago and 3yrs ago but that doesn't mean history provides nothing to learn from. The problem of crews failing to recognize stall, pulling up into stalls, pulling back through stall warnings, and failing to correct the other guy doing it is not new and didn't start with fbw and sidesticks.

[Organfreak]

IF789 said:
The problem of crews failing to recognize stall, pulling up into stalls, pulling back through stall warnings, and failing to correct the other guy doing it is not new and didn't start with fbw and sidesticks.

You're sure right about that, but some of us are suspicious that sidesticks could make this problem harder to suss out under pressure, since the other guy can't see them.

=this has been a pre-recorded announcement=

:ugh: :ugh: :ugh: :ugh: :ugh:

[DozyWannabe]

You're sure right about that, but some of us are suspicious that sidesticks could make this problem harder to suss out under pressure, since the other guy can't see them.

Admittedly that's a good point taken in isolation, but as you so eloquently put it, the amount of evidence available is not sufficient to make a statistically valid conclusion. "Suspicions" based on an assumption that something stands to reason are just that - opinion and conjecture.

The fact is that whether you can see the sidestick or not (and FWIW in the sim I could get a good idea of what the guy in the opposite seat was doing with the stick based on his posture), a combination of monitoring the aircraft's response plus timely and effective communication with your colleague in the opposite seat should nullify that potential problem.

[Organfreak]

Admittedly that's a good point taken in isolation, but as you so eloquently put it, the amount of evidence available is not sufficient to make a statistically valid conclusion. "Suspicions" based on an assumption that something stands to reason are just that - opinion and conjecture.

Good! Then I'll stop maintaining that yokes would have helped, if you'll stop saying that they wouldn't. :p The only thing for sure is that we don't know.

....a combination of monitoring the aircraft's response plus timely and effective communication with your colleague in the opposite seat should nullify that potential problem.

Indeed it should, but back to the real world-- that just didn't happen this time. Even if some pilots shouldn't be fools, the fact remains that some are, so "foolproof is better." If one outta 100 pilots need a situational icon showing attitude, let's just give 'em one! Hang the expense.

=I HAVE SPOKEN= :8

[Flyinheavy]

@DW

As far as I remember the Birgen Air accident was mainly caused by failure of shutting off the A/T system, which by design took thrust to idle because of the false overspeed sensed by blocked pitot. The FO very well was aware of the situation, but it seemed to be also a cultural issue that he did not take control.

So IMHO this has very little resemblance with a yoke versus SS issue.

Why do I sense some reluctance throughout all your postings to realize that humans not always react the way that engineers plan and sometimes design the human - machine interface the way that the human has to configure himself to the machine instead the other way around?

[safetypee]

Re Overall paradigm shift" in design and training.
Pariès expands paradigm shift elsewhere as “the change from safety through conformity, to safety through variation management”. Variation is described by Hollnagel:- http://ipac.ca/documents/The_resilient_organisation%5B1%5D.pdf


"… other pilot would see the inappropriate control deflection and take over"
I doubt that there would be a fair range of data to support either view, but anecdotal evidence suggests that pilots don’t ‘see’ a control input as inappropriate, particularly where both have similar but erroneous situation awareness. Aspect of this are discussed in http://www.pprune.org/safety-crm-qa-emergency-response-planning/478368-monitoring-intervention.html.

In addition, it would be poor practice to train pilots to use an input as a measure of aircraft control, where the really important aspect is the output - what the aircraft is doing – what has the control input achieved.

[DozyWannabe]

As far as I remember the Birgen Air accident was mainly caused by failure of shutting off the A/T system, which by design took thrust to idle because of the false overspeed sensed by blocked pitot.

Not what I read. The blocked pitot tube caused all kinds of problems for the autoflight systems. The autopilot's manouvering limits kept the aircraft from stalling while autoflight (A/P and A/T) were engaged. The automation made no change to the thrust setting - that was set by the Captain when he pulled thrust back in response to the warnings. By pulling it back the autopilot could no longer prevent stall, but regardless, the captain pulled back on the yoke repeatedly throughout the follwoing sequence.

Why do I sense some reluctance throughout all your postings to realize that humans not always react the way that engineers plan and sometimes design the human - machine interface the way that the human has to configure himself to the machine instead the other way around?

Well now, let's break that down a little. Engineers do not design aircraft in a vacuum and expect the pilots to cope with decisions made in isolation. In any development process there is a constant dialogue going on between all interested parties.

I've said this before, but there seems to be a persistent rumour that the Airbus FBW design was the work of engineers and management alone with no pilot input - which is categorically not true.

The difference between the Airbus and Boeing FBW designs is solely down to the dialogue having different conclusions (because the pool of engineers and pool of pilots was different). As Organfreak says, there is insufficient evidence to prove that one design is any safer or more intituitve than another, so all we have to go on are our own conclusions based on the information to hand.

Remember that the yoke design grew from the requirement to have cables connected to all flight surfaces, and until the late '80s was a de facto standard that reached acceptance over time - it was not designed to be the ultimate piloting interface, nor was it ever so.

Good! Then I'll stop maintaining that yokes would have helped, if you'll stop saying that they wouldn't. :p The only thing for sure is that we don't know.

I never said it wouldn't - I said that there's a roughly equal probability that a connected yoke or stick would have helped versus the probability that it wouldn't. I've only ever taken exception to posts which state that it categorically would have made a difference when the evidence is not there. :)

[HazelNuts39]

A german translation of the accident report is available here (http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/ComAndRep/PuertoPlata/bericht.html).