AF 447 Thread No. 7

[Landroger]

ChristiaanJ

These are the boards you showed us on the "Concorde Question?" thread, I think, CJ? Nevertheless, they are good looking boards and bring back a lot of memories, but by gum they look dated now! :D

A33Zab

Thanks for posting those images - the top ones look just like my CT Renewal Parts manuals :D but the bottom one - the A320 Pitch channel logic - is 'positioned' rather oddly in my Medical Electronics experience. It is rather crude and a 'level' below most of the block diagrams I use, while being more than a level above the logic diagrams I used to use back in the day.

As CJ puts it:
Terminology has obviously gone out of the window since "my days". That's not a 'logic' block diagram, but a 'functional' diagram.... and near-useless (except as an intro) to anybody called to maintain the system.

You couldn't 'chase ones and zeros' through that and I wish I had a pound for every hour I've spent chasing them through page after page of logic diagrams. :ugh: :D

[roulishollandais]

@ChristiaanJ
#750
I totally agree with you.
The ATEC Series 6 testbench is a very bad choice who does the pilots blind.
The pilot must be able to understand very quickly what goes wrong in the flight to take the good decision.

The FCSC CMM with 2000 pages is a BABEL ATLAS.

[ChristiaanJ]

The ATEC Series 6 testbench is a very bad choice who does the pilots blind.
I don't quite get your point....

An ATEC is a huge computer-controlled automatic test bench, used for initial reception of the equipment, and for testing and fault-finding of equipment "thrown off the aircraft as suspect".
I think most pilots have never even seen one......

ATLAS is a specialised programming language for (mostly) avionics and similar aircraft equipment.
Describing ATLAS here in detail is really a bit too much O/T, but any old computer freaks will find some vague similarities with BASIC.
It really is a neat way of writing a full test specification for a piece of equipment in a format that can be understood directly by humans (and even performed on a manual test bench), as well as by fully automatic test equipment (such as the ATEC, but also ATEs from other manufacturers).

The pilot must be able to understand very quickly what goes wrong in the flight to take the good decision.I agree, but that's not the same context....

The FCSC CMM with 2000 pages is a BABEL ATLAS.What do you mean with that?
I believe the 2000 pages (ours were a bit smaller), but not all of that would be the ATLAS spec.... (unless the ATLAS progs for the individual boards were also included in the CMM, which I doubt), some would be intercon, wiring lists, circuit layouts, diagrams, IPCs, etc.

Anyway, all this is not too relevant, but a nice 'blast from the past'.

[roulishollandais]

Hi ChristiaanJ,


[QUOTE=roulishollandais]
Originally Posted by roulishollandais http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/buttons/viewpost.gif (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-post7045019.html#post7045019)
The ATEC Series 6 testbench is a very bad choice who does the pilots blind.

I don't quite get your point....

An ATEC is a huge computer-controlled automatic test bench, used for initial reception of the equipment, and for testing and fault-finding of equipment "thrown off the aircraft as suspect".
I think most pilots have never even seen one......



Testing software or equipment is a very strategic action. ATEC is a good choice for EADS... If something is wrong or missing in ATEC it is the whole responsability if something gets wrong or missing in an EADS aircraft. But, seeing the ATEC advert. it seems to be an commercial product, that B could use too and B will then not be able to see something will get wrong or false in his aircraft or equipment... :suspect:

I agree, but that's not the same context....


The flight engiener is no more in the aircraft. If some hydraulic or electric failure happens caution or warning light and call happen, and a check-list is used. If a software failure happens, nobody knows it in the airplane : the pilots are blinds, get unmotivated, and have behaviour like in AF447.
They get idiots.:eek:

2000 pages (ours were a bit smaller)
2000 pages of Basic : nice to write them, but too big to extract anything useful of such a FBW system for the pilot when things get crazy. :E

Before beeing a pilot, I had to organize computer math methods and software in a national research center. After that and due testing, the software was given to twelve regional centers. Some of these softwares concerned human life (dikes). They were running three years (you read well) at the same time that traditional method, without any difference in the results, and without changing anything in the software...

[ChristiaanJ]

roulishollandais,

We seem to be on slightly different wavelengths.....

A CMM is aimed at the maintenance engineer who gets a supposedly faulty piece of equipment dumped on his bench, and has to find and fix the supposed fault, and then recertify the equipment as airworthy.

It is not aimed at either a pilot or (in the olden days) at a flight engineer, who don't necessarily have the specialist engineering background to 'decipher' electronic circuit diagrams or test specifications in a document like the CMM.
They refer to the functional documentation (aircraft flight manuals, etc.).

Testing software or equipment is a very strategic action.I think you're confusing testing during development and 'operational' testing....

The ATEC is strictly a production and 'operational' piece of test equipment. It has no relation with the equipment used for software and hardware testing and validation during design and development.
And indeed, ATECs have been sold to other clients, exactly like Honeywell, HP and SFENA ATEs.

[RR_NDB]

Hi, ChristiaanJ


Automated and automatic testing was a passion during many years. I faced very interesting challenges designing for adequate testability at Module level (set of PCB's), Board level and Component level(LSI). Your comment on ATE made me ask you something:

Testability is a serious issue in a complex System as you know. A simple example may show why we need strategies to perform an effective test:

Suppose a VERY SMALL memory of just 64 bits. If you test it to all combinations of zeros and ones in the array at 10 Mhz the time required is prohibitive. The solution is to apply a checkerboard pattern, invert it, galloping ones, galloping zeros, all zeros, all ones, etc. And stil you may have a pattern sensitivity.

In a complex machine the Test Engineers use a multitude of Test Strategies at different phases (design phase, prototype testing, etc.)

My question is:

How you compare the ability to test thoroughly an A/C like a current FBW versus e.g. a Concord where Systems were less "Finite State Machines" equipped.

But highly complex and with "feedback loops" that creates formidable challenges when trying to locate for example, an intermittent failure. :E

I am always concerned with Complex Systems due the "testability issue", so this is the reason of my question to an Engineer from the Concorde era. :)

It comes to my mind something i heard on A330: To adjust the real Time Clock you have to lower the flaps a little bit. :rolleyes:

[A33Zab]

It comes to my mind something i heard on A330: To adjust the real Time Clock you have to lower the flaps a little bit. :rolleyes:

Well, nothing to do with a software bug...

Once a day (Flight Phase 9 = after landing) the wing tip brakes are automatically checked, if test fails to initialize for 10 days, this test should be performed by maintenance through MCDU.

When -incorrectly- setting the clock date (manual) you would go beyond those 10 days and trigger the FLAP TIP BRK FAULT and SLAT TIP BRK FAULT messages.
To reset these situation you have to reset the system through CMS AND cycle flaps opposite to the direction when it locked up.
If F/S are in the full up position you only have one way (=DOWN) to go for automatic reset. (and manual reset of the devices becomes necessary when a F/S Up command is required)

To prevent this situation you would lower the F/S a little bit so you can reset (by MCDU) in both directions.

With the GPS clock setting option this would not bring one into this trouble.

[RR_NDB]

Hi,

A33Zab

Well, nothing to do with a software bug...

The context of my post was Testability, maintainability, etc.

Once a day (Flight Phase 9 = after landing) the wing tip brakes are automatically checked, if test fails to initialize for 10 days, this test should be performed by maintenance through MCDU.

When -incorrectly- setting the clock date (manual) you would go beyond those 10 days and trigger the FLAP TIP BRK FAULT and SLAT TIP BRK FAULT messages.
To reset these situation you have to reset the system through CMS AND cycle flaps opposite to the direction when it locked up.
If F/S are in the full up position you only have one way (=DOWN) to go for automatic reset. (and manual reset of the devices becomes necessary when a F/S Up command is required)

To prevent this situation you would lower the F/S a little bit so you can reset (by MCDU) in both directions.

With the GPS clock setting option this would not bring one into this trouble.



Fine biz! Some friends also will benefit from your explanation.

Rgds,

[RR_NDB]

Hi,

A33Zab,

Is this a concern in order to understand reasons of PF persistent NU?

Mismatch between sides are recorded?

BEA published information mentioned this?

If existed a mismatch how we could learn what PF saw?

If this specific point was covered earlier, please inform the link, if possible.

[HazelNuts39]

BEA published information mentioned this? See for example BEA Interim #3(en) p.44 "1.16.6 Reconstruction of the information available to the crew".

[A33Zab]

Unfortunately ADR 2 (RH PFD) is not recorded.

As mentioned in PAR 1.11.3 Interim report #3 the non-volatile memory in the salvaged computers
could give some more information.

From the FD engagement FDR traces and the information mentioned by HN39 (Page 44),
a little information about the status of ADR2 can be extracted.
(as far as I understand the sytems)

Before that one should know that a FMGEC needs at leats 2 valid ADR inputs to engage the FD.
-besides other AP/FD Common conditions -

Before @02:10:05 AP2 was engaged, this means (by engament logic)
FMGEC #2 was master, #1 was slave.
@02:10:05 AP drops off, Air speed of ADR 1 and ISIS(#3) are normal; FMGEC switchover is visible at the peak in FDR trace (FD2).
Suspect ADR 2 was the median speed at this time and lost (also due to other events at this time)
~02:10:10: Both FD (FMGEC) not available, also ADR#1 60Kts and ISIS(#3) 140Kts are to far apart.
~02:10:20: FD's available because ADR#1 and ISIS(#3) are nearly the same (but wrong) value 90Kts.
~02:10:25: FD's for a brief moment unavailable (although ADR#1 and ISIS(#3) are nearly equal (but wrong) at 110/100 Kts.
~02:10:30: FD's available, ADR#1 and ISIS(#3) in agreement (still wrong). Status ADR#2 (RH PFD unknown untill:
@02:10:40: There's a peak in both FD FDR traces, meaning they both switch over to
the other FMGEC, ADR#1 and ISIS(#3) are far apart, this means ADR(#2) must have been available again and its value in agreement with ADR(#1) = 215 Kts OR ISIS(#3) 120 Kts,
to become the 2 valid sources for FMGEC.
Unfortunally at that time they switch over to ADR#3 as faulty source for RH PFD!

From 02:10:47 untill 02:11:35 ADR#2 must have been available but not displayed on the RH PFD.

~02:11:45 the captain is entering the cockpit and would have seen 35 Kts on the LH PFD, 0 Kts on ISIS and SPEED FLAG on RH PFD.

After that all the speed indications where going up and down, FLAGS etc.

[roulishollandais]

@ChristiaanJ
I understand your argumentation, and I don't want to worry anybody.:hmm: But today our forum wants to understand what was wrong in the AF447, and the Crew actions seem so crazy, that we must get sure that nothing wrong stays in the first levels inside of inside ... and that the BEA will be able to search the solution (if exists :rolleyes:) there too .

roulishollandais,

We seem to be on slightly different wavelengths.....

A CMM is aimed at the maintenance engineer who gets a supposedly faulty piece of equipment dumped on his bench, and has to find and fix the supposed fault, and then recertify the equipment as airworthy.

It is not aimed at either a pilot or (in the olden days) at a flight engineer, who don't necessarily have the specialist engineering background to 'decipher' electronic circuit diagrams or test specifications in a document like the CMM.
They refer to the functional documentation (aircraft flight manuals, etc.).



Is this a concern in order to understand reasons of PF persistent NU?

Mismatch between sides are recorded?

BEA published information mentioned this?

If existed a mismatch how we could learn what PF saw?

If this specific point was covered earlier, please inform the link, if possible

[A33Zab]

Is this a concern in order to understand reasons of PF persistent NU?


Yes, before switching to ADR3 the speed information displayed on the RH PFD will be 'unknown'. thereafter the information could be extracted from ISIS (share the same Pitot and static lines).
Was he following -wrong- FD orders, when this was available?

Mismatch between sides are recorded?

No, LH and (ISIS or Standby) are recorded.*

*Edit: BEA#3


 Speed parameters

The calibrated airspeed recorded in the FDR is that displayed on the left-hand PFD, unless it is invalid
(if the speed is less than 30 kt, in which case the SPD flag replaces the speed
scale).
In this case, the airspeed recorded on the FDR is then that displayed on the righthand PFD.


BEA published information mentioned this?

Yes. PAR 4.3 of BEA Interim report #3

If existed a mismatch how we could learn what PF saw?

See previous post, I guess somebody can derive - possible FD orders-,
out of information from FDR traces.

If this specific point was covered earlier, please inform the link, if possible.

I don't know.

[ChristiaanJ]

"Flying the FD" (FD commands are computed in exactly the same way as the AP commands) just after the AP has disconnected seems, to me, the height of folly.
I hope pilots are aware of that.... several posters here seem to not understand that.....

[OK465]

Actually the 'FD commands' immediately available after an A/P disconnect under normal circumstances are intended to be valid. That is how you would normally transition to hand flying the aircraft.

A/P disconnect was not the cause of any erroneous or misleading FD commands. When the A/P disconnects as a result of 2 or more ADR's going on the 'fritz', the FD's are automatically removed, but the buttons NOT automatically deselected (even the light in the button stays on).

It's the intermittent default FD commands that that 'pop up' in a UAS situation like this that are not to be blindly trusted. That is why, in the interest of avoiding this source of confusion, the FD's are to be deselected manually in an UAS situation.

There are other situations, e.g. PRM breakouts, where the FD's are deselected, because the existing or default vertical guidance may not be compatible with the PRM breakout procedural requirements. Has nothing to do with the A/P being disconnected. Has to do with being a pilot.

This is not your "grandfather's" FD-109.

[Lyman]

Oke, howdy.

For the thick and the less than quick, like me, what do you have to describe as to the initial PF inputs post a/p? Bonin 'saw' (via BEA) ND and RR, to which he responded per report. PJ2 early on initiated a very important discussion that weeded out most here as to what the manual response should have been, eg, do nothing, maneuver, or deselect FD, and call the book. Arrest any poor trend? Attitude, Airspeed?? Pitch/Power?

I think, imo, Bonin did the right thing, which evolved, for reasons as yet undetermined, into a "climb" into the sea. There is a beginning to everything, where do you sense this point to be? For instance, the VS was "selected" by the a/c, at 5000fpm down. Since the a/c was rolling to the right, I assume the a/c was commanded so by the a/p, or the airmass was insinuating itself into the flight path. What gives?

[OK465]

Howdy Lyman,

I'm only speaking to the way the system works.

I have no idea what motivated the PF.

(The FMA is your friend. :))

[RR_NDB]

Hi,

Feedback loops are designed (and potentially capable) to improve a System.

For example, the AS probes in auto mode receives just the required electric power.

Feedback loops are designed with "time constants" and eventually with techniques like hysteresis. The engineering takes into account essential aspects like stability, etc.

I posted some comments assertively saying the AS probes the industry is still using, are "subheated".

I am based in several facts and i can discuss each one when necessary.

I have six questions to the Pilots (daily facing UAS threaths) and to the Technicians here:

1) Is the power being applied to the AS probes enough in order to their proper operation?
2) The delay between a sudden atmospheric temperature drop and the "reheating" of the probes could explain the "failures" leading to UAS?
3) The differences between US and FR probes may be explained by "different" time constants?
4) Is the max power sufficient to provide a safe operation in most environments?


5) Is there "recording capability" in current Systems in order to analyze the UAS incidents more precisely?

6) Could be better to enter WX using MAX instead of AUTO? (Operating "open loop")?


This content i posted first in another thread related to AF447.

[RR_NDB]

Hi,

One may ask:

What is the importance of this issue?

AS data affects the Stability of the System.


The importance is clearly recognized by the Designers in applying triple redundancy.

IMHO is unacceptable the FACT they are "failing" almost SIMUTANEOUSLY.

Redundancy is not the solution to elements that "fail together"

IMO this configures a SERIOUS and PERSISTENT "DESIGN FLAW" or even, ERROR

AND VERY PROBABLY WILL BE CONSIDERED THE TRIGGER OF AF447 CASE.

The industry was receiving persistent warnings on this and the crew of the previous incidents were capable to deal with and landed.

Murphy Law in this case used the "industry failure" and put other slices of the cheese in the "proper alignement" :sad:

[lomapaseo]

The importance is clearly recognized by the Designers in applying triple redundancy.

IMHO is unacceptable the FACT they are "failing" almost SIMUTANEOUSLY.

Redundancy is not the solution to elements that "fail together"



IMO this configures a SERIOUS and PERSISTENT "DESIGN FLAW" or even, ERROR



I do not agree

Redundancy is more than duplicating a single system (even though there are multiple similar components). It also considers multiple systems which can take over and mitigate the failure condition and still provide safe flight and landing.

[RR_NDB]

Hi,

Redundancy is more than duplicating a single system (even though there are multiple similar components). It also considers multiple systems which can take over and mitigate the failure condition and still provide safe flight and landing.
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-39.html#post7060039)
I fully agree with your comment above!

I do not agree

Please, clarify where is the discordance. Component level redundancy? Module level? System level?

[RR_NDB]

Hi,

Redundancy is more than duplicating a single system (even though there are multiple similar components). It also considers multiple systems which can take over and mitigate the failure condition and still provide safe flight and landing. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-39.html#post7060039) Did F-GZCP provide the resources to?
.
.

provide safe flight and landing. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-39.html#post7060039)

Did the man-machine interface provide the tools to allow the crew to even understand TIMELY the first priorities?

[lomapaseo]

RR NDB

Please, clarify where is the discordance. Component level redundancy? Module level? System level? Please, clarify where is the discordance. Component level redundancy? Module level? System level?


ans. System level

Did the man-machine interface provide the tools to allow the crew to even understand TIMELY the first priorities?

That is the most important part of the investigation's report to provide comparitive prevention strategies (in any aircraft) via system design and/or training against a repeat accident where airpseed is temporarily lost for any reason.

[Lyman]

If the redundance is at system level, and the three sensors are identical, redundancy is absent.

Thales had corrosion problems at the drain, I do not recall if they rose to the level of AD. Regardless, the probes performed sufficient to satisfy the certifications protocol, and that is acceptable. After the fact does not obtain to this crash.

Redundancy had thorough airing in BA038, where BOTH engines failed, within seconds of eachother. The Heat exchangers were found to be of insufficient design. Instead of changing engine manufacturers, the Heat Exchangers were modded. An AirSpeed sensing SYSTEM that relies on three identical probes is a single system. IF there are mitigating procedures that can provide AS in a transient system failure, well and good. However, focussing on the probes only is missing the point at large, eg: system FAIL.

[RR_NDB]

Hi,

However, focussing on the probes only is missing the point at large, eg: system FAIL.
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-39.html#post7060364)
Your comment and the one from lomapaseo (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-39.html#post7060346) motivates me to say:

A probe "failure" exposed a much more serious issue at System level.

:}

[Lyman]

I would suggest further, that in this particular case, had only ONE Pitot tube been installed, the outcome may have been different.

One only need review the computers trail, the Pilots' confusion, and the lack of a co-ordinated plan to conclude that in this case, had the system failed completely, directly, (and REJECTED, with prejudice) in transient fashion, a single probe would have come back alive and been correct, no "voting", no indecision?

The AS system here seems over-reliant on decision making made at the electronic level, excluding the handling pilots, and causing delay.

At the least, had a separate "system" been installed, one that had a shrouded probe that came alive when the first failed, a new and reliable sense of AS would be available.

The focus on redundancy is a fool's errand, when a "sequential system(s)" is a separate and independent source. Even BUSS fills this need, a separate system, one that can replace indefinitely a system that causes problems whilst one waits for it to become reliable.

The longer these UAS events pertain, the more foolish the authority appears.

[Organfreak]

Lyman sayeth:
The focus on redundancy is a fool's errand...

All I have to say is that it's a damned good thing there are two wings!

[RR_NDB]

Hi,

The longer these UAS events pertain, the more foolish the authority appears. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-39.html#post7060411)

Bureaucrats are prone to be lazy. Their "time constant" are much bigger than the good Technicians SELF MOTIVATED. :}

PS

Kelly Johnson put an angel to fly in 60 days. Yet taxiing:

The sailplane-like wings were so efficient that the aircraft jumped into the air at 70 knots (81 mph) (http://en.wikipedia.org/wiki/Lockheed_U-2)

[Lyman]

Hi Organfreak

At some point, system utilization must merge, or we end up with something, you know, Rutanesque.

Some would have said (and still say) "Thank GOD for two TRENT700s. (BEA038)." Where the neck narrows, there is the executioner's blade.

RR NDB. (re Kelly Johnson). Where are these giants today? Gone. What we have left are committees, ffs. risk/benefit. Over-reliance on the ability to disappear and blame others. COMMAND? gone.

Captain Hank, on his Stratocruiser, "This is not a god damn Democracy!"

[RR_NDB]

Hi,

At the least, had a separate "system" been installed, one that had a shrouded probe that came alive when the first failed,...

LOL,

I am sure the issue can be fixed without this...,

LOL

Anyway i maintain what i did write earlier:The design (in respect to AS) seems ridiculous

And maintaining this during many years was the trigger for System stability issues at that night *

(*)

K.I.C.S. Keep It Complex Stupid

M.I.C.S. Maintain It Complex Stupid

[A33Zab]

IMO this configures a SERIOUS and PERSISTENT "DESIGN FLAW" or even,
ERROR



Let's assume there is another - more reliable - system available.
wouldn't it be a great idea to have 3 or more of them iso 2 or 1 less reliable, just because they should not be identical?
They are still operating in 1 and the same environment.

Don't want to suggest the probe was reliable but there have been several modifications and upgrade options available before and since.

I agree with PJ2, just sit and wait (30 sec.) is proven to be the best strategy in case of UAS.

[Machinbird]

I agree with PJ2, just sit and wait (30 sec.) is proven to be the best strategy in case of UAS.Even better would be no UAS at all. It probably is achievable.

[RR_NDB]

Hi,

A33Zab

PF applied large stimuli to the plane.

I agree with PJ2, just sit and wait (30 sec.) is proven to be the best strategy in case of UAS.
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-40.html#post7060893)

We may say this "technique" is an "hysteresis like" one. No reaction (in the loop) until a given threshold. In absence of other solution I AGREE this is WISE.

Even better would be no UAS at all. It probably is achievable. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-40.html#post7060915)

As a researcher i have to remove the "probably" in the phrase.

And i am not not focusing on the probes. I look to the System.

The whole "processing" of the probes data IMO should be reviewed.

As i understand the a/c operation degrades EXACTLY when you need most.

Who knows what PF saw in the transitory, just after AP quit?

But this is to be covered in another post i am preparing:

Transient in Feedback Systems (II)

[roulishollandais]

Hi to all the pilots and engineers,

I feel a great progress has been made with the help of these forums.

Despite existence of FBW, automation was still missing in the closed loop system "Pilot AND Aircraft":{. We pilots were not really ALLOWED to use these words "system", "PIO", "transient", "unstability", and we were not allowed to think them, to fly them... :\

Despite the best place in the armchair (on the ground) is on Lieman airlines (with 2 or 1 pitot tubes and no redundancy :* ) a great step [correction : flight] has been done to a new aviation with Machinbird and RR_NDB.

Thank you to both, the first as pilot, the second as system engineer
who have overcome the taboos, without falling into dreams.

[Machinbird]

While RR_NDB is working on his next concept, let me throw out one of my own.
There is no doubt that the best course of action with UAS in cruise is to do nothing while you size the situation up. With a little more smarts in programming, the flight control system could do the same thing.
Process runs like this:


Oh Oh, lost the airspeeds!
Wait, we are in cruise, instructions say do nothing and warn the crew that they may have to take over.
Power table lookup says cruise power for current flight environment is X, set power to X, maintain Normal law.
Monitor airspeeds to see if we can get a valid airspeed.
Airspeeds agree on 90 knots? Not in the acceptable range-disregard.
Airspeeds now say 271 knots. In acceptable range. Advise crew that we are resuming normal control.
End of allowable dead reckoning period (where control would then pass to the crew).

How you handle loss of airspeeds in climb and descent could probably be handled pretty well with a lookup table as well. That only leaves Approach and the transition right after takeoff to climb speed.
Can they build this reasoning into the computers? Can they certify it? If so, most of the problem is solved.

[rudderrudderrat]

Hi Machinbird,
Power table lookup says cruise power for current flight environment is X, set power to X,....
Can they build this reasoning into the computers? Can they certify it?
Yes & yes they did.
It's called QRH Unreliable Airspeed tables and the central processors are organic.

[Machinbird]

It's called QRH Unreliable Airspeed tables and the central processors are organic. Yes, but you have to wake up the organic central processors. Sometimes they use the wrong programming, sometimes they are slow. sometimes they jump to the wrong spot in the instructions. Lets keep the organic computers in the situational loop, but give them a chance to come up to speed before they are put on the line.:}

[A33Zab]

Yes, but you have to wake up the organic central processors. Sometimes they
use the wrong programming, sometimes they are slow. sometimes they jump to the
wrong spot in the instructions. Lets keep the organic computers in the
situational loop, but give them a chance to come up to speed before they are put
on the line.http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/badteeth.gif


Do you advocate to remove all organic material from cockpit?:O

[Machinbird]

Do you advocate to remove all organic material from cockpit?http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/embarass.gifGood sense of humor A33Zab.:ok:

At the rate they crash drones, that is not going to happen any time soon.

[HazelNuts39]

Process runs like this:

Oh Oh, lost the airspeeds!
Wait, we are in cruise, instructions say do nothing and warn the crew that they may have to take over.
Power table lookup says cruise power for current flight environment is X, set power to X, maintain Normal law.
Monitor airspeeds to see if we can get a valid airspeed.
Airspeeds agree on 90 knots? Not in the acceptable range-disregard.
Airspeeds now say 271 knots. In acceptable range. Advise crew that we are resuming normal control.
End of allowable dead reckoning period (where control would then pass to the crew).Very attractive at first sight. We just have to settle on a few details of implementation:
(1) Oh Oh, lost the airspeeds! >>> Based on a single speed (the median)?
(2) Wait, we are in cruise, instructions say do nothing and warn the crew that they may have to take over. >>> Do you mean what the system currently does - maintain current pitch and power and sound 'cavalry charge' - or keep A/P and A/THR engaged, so that A/THR will increase power to Max CLB?
(3) Power table lookup says cruise power for current flight environment is X, set power to X, maintain Normal law. >>> Maintain Normal law means maintaining protection for high AoA and overspeed. Both will not function when IAS drops to low value. High AoA thresholds at low IAS are too high for protection at cruise Mach. There will be no stall warning.
(4) Monitor airspeeds to see if we can get a valid airspeed. Airspeeds agree on 90 knots? Not in the acceptable range-disregard. Airspeeds now say 271 knots. In acceptable range. Advise crew that we are resuming normal control. >>> What is the 'acceptable range' ?
(5) End of allowable dead reckoning period (where control would then pass to the crew). >>> What happens here? Isn't the crew always in control within the flight envelope?

P.S.
What I agree with: When the system drops A/P and A/THR, it could initially set pitch and power corresponding to level flight in still air, and maintain wings level.

[Machinbird]

(1) Oh Oh, lost the airspeeds! >>> Based on a single speed (the median)?As soon as the system cannot figure out which one of the speeds, if any, is "telling the truth."
(2) Wait, we are in cruise, instructions say do nothing and warn the crew that they may have to take over. >>> Do you mean what the system currently does - maintain current pitch and power and sound 'cavalry charge' - or keep A/P and A/THR engaged, so that A/THR will increase power to Max CLB?
Keep A/P and A/THR engaged so that A/THR will be able to set the lookup table power.
(3) Power table lookup says cruise power for current flight environment is X, set power to X, maintain Normal law. >>> Maintain Normal law means maintaining protection for high AoA and overspeed. Both will not function when IAS drops to low value. High AoA thresholds at low IAS are too high for protection at cruise Mach. There will be no stall warning. Maintain Normal law means just that. Plug in last valid airspeed and Mach number. Live and die by that. This is a dead reckoning exercise. How long you feel you can safely fly while dead reckoning the airspeed determines the period before you dump control to the pilots. This is likely the key certification issue. 3 seconds sure, no big deal. 20 seconds yeah, why not. 60 seconds, I'm beginning to get uncomfortable. How did we fly in the old days before autothrottles anyway? I can tell you I was not jockeying the throttles in cruise.
(4) Monitor airspeeds to see if we can get a valid airspeed. Airspeeds agree on 90 knots? Not in the acceptable range-disregard. Airspeeds now say 271 knots. In acceptable range. Advise crew that we are resuming normal control. >>> What is the 'acceptable range' ? To be determined by test flights or using existing criterion if deemed acceptable.
(5) End of allowable dead reckoning period (where control would then pass to the crew). >>> What happens here? Isn't the crew always in control within the flight envelope? This is where you play the cavalry charge if no valid airspeed is found. A/P and A/THR drop.

[RR_NDB]

Hi,

Sounds as an evolution:

1) The "wait and see" ("hysteresis") has a time out.
2) The "Organic processors" would have some time to prepare carefully to enter (and act) when "inside the loop"
3) The "graceful degradation" of System + crew is improved during the transient (when the System is being affected by the disturbance)

Fine biz!

[PJ2]

Machinbird;

Re, "As soon as the system cannot figure out which one of the speeds, if any, is "telling the truth." "

It doesn't need to. A power setting and pitch attitude is all you need and as someone suggested here, a recent history if the automation is to do it, (but no thanks!). Speed indication is now irrelevant. An AoA would help but it isn't necessary.

As discussed by Owain Glyndwr and to HN39's point regarding autoflight system programming when the AP and AT drops offline, the A330 fails/failed 'gracefully'. When disconnected by the airplane and by the instinctive disconnect buttons on the thrust levers, the autothrust reverts to the thrust-lock mode, maintaining the power setting at disconnect.

Almost all the time the thrust is appropriate. Here, the thrust had dropped slightly but to no short-term effect.

The checklist requires that the autothrust be disconnected, (press the AT button on the FCU or the instinctive buttons and THR LK is removed), then move the thrust levers out of the CLB detent and set thrust according to the tables. About 88% N1 or 1.2 EPR would be a good start, if I recall.

In Alternate Law pitch must be manually controlled so there is perhaps room for some form of "maintaining pitch" but I think this is taking automation precisely where we don't want to take it..."more", to cater to reduced thinking and skill levels.

The airplane is eminently flyable at cruise altitudes even in heavy turbulence, (done it...it's like any other airplane including the DC8)...tiny movements on the stick, (or control column), wait..., set the thrust, wait..., read the checklist, wait for the airspeed to return, as it did within 30 seconds in all previous events. And if it doesn't then complete the checklists, ECAMs, STATUS pages and secure the aircraft for manual flight, call the captain and decide whether to return to RIO (or..?) or continue.

RR_NDB, this response isn't "the academice ideal", this is what crews are trained to do and is absolutely middle-of-the-road SOPs. That it isn't done sometimes is not a counter-example argument for a sense that this is "expecting a lot", nor is it an argument for further-reduced standards and more automation.

In climb/descent and except for close in approach (when dirty), one levels off, and does the same thing. The powerpoint presentation to which Turbine D provided us the link is a superb explanation of the "new" (2006) process. The powerpoint referenced by Turbine D is at http://www.iag-inc.com/premium/AirbusUnreliableSpeeds.pdf

BTW, I quite appreciate that typing this stuff out is SO much easier. Like others here I'm sure, I've had a few "events" and they are never straightforward and the adrenaline always comes.

[roulishollandais]

to level flight in still air.

oh I have severe turbulence... :uhoh:

... and maintain wings level.

Oups ! I was just turning to avoid the mountains in the clouds...:{

[roulishollandais]

Thank you to allow us to speek non-linear systems, transitory stages during the flight, closed-loop systems, normality of oscillations, pluridisciplinarity knowledge, etc.

Could we generalize the use of "effective :) aircraft" or "effective :)system" to refer to the system (pilot & aircraft) ? I find it very clear to the mind, without excessive simplification.

Congratulations for your next speed sensor. Did Pprune already found a manufacturer for your many inventions : I am impatient to see the advert !

Monsieur Henri Pitot will soon be allowed to sleep... :suspect:

[Lyman]

Yes, it is a leap from armchair to RHS in Bonin's shoes. Since BEA have not issued their Final, it is disconcerting to see so many verdicts of guilty. For that matter, BEA will issue data, and will not condemn. The data may, but BEA is not charged to place blame.

My over arching beef with the investigation is the length of time they take. Also the slim releases of data. To me, it is not for science, but for politics. Time not only heals, it shelters. When the stage has been arranged so completely with damning evidence, one wonders if it is a true picture, or merely a cynical attempt to protect some survivng interests.

[Machinbird]

Re, "As soon as the system cannot figure out which one of the speeds, if any, is "telling the truth." "

It doesn't need to. A power setting and pitch attitude is all you need and as someone suggested here, a recent history if the automation is to do it, (but no thanks!). Speed indication is now irrelevant. An AoA would help but it isn't necessary.
PJ2, I am not sure you understood the intent of the procedure I posted. Its purpose was to basically outline the key functional elements of a computer program that would ease the transition between Normal law autopilot controlled flight and Alternate Law, pilot controlled flight. Rather than drop the aircraft into the pilots lap all at once, the transition could be spread over some time.

I know that pilots worry about their job security when computers are performing things that pilots consider their turf (such as emergency procedures.) I also know that sleepy pilots in cruise in the middle of the night can be slow to come up to speed. Best move is to provide all possible assistance to make the transition as painless as possible. If you get a little help doing your job, it isn't a bad thing, as long as the automatic help does not make things worse. 9 times out of 10, you will be alert and the help won't matter. It is that other time at 2:05 in the morning that you might appreciate the help.

The key thing to recognize is that the aircraft could probably handle the complete UAS procedure by itself for a period of time, assuming proper computer programming. The A330 is a fairly early version of Fly By Wire and despite its great success, does not mean it could not be made better. We need to pick out rough spots in the man-machine interface and improve them. This may be one of those.

[mm43]

Originally posted by Machinbird...
Rather than drop the aircraft into the pilots lap all at once, the transition could be spread over some time.That suggestion raises a deep sense of distrust in pilots that believe that when the automatics "fail", their own ability to take-over should not be questioned.:{

I'm not disputing that point, but when you are the air-frame manufacturer, your profit margin goes down the "big white telephone" every time someone stuffs up in that department. In that respect, I'm pretty sure that Airbus Industries will be moving (limited only by the time taken for regulatory approval) to do just as you suggest.

Perhaps I could refresh your memory to something posted eons ago in AF447- Thread No.4 (http://www.pprune.org/tech-log/454653-af-447-thread-no-4-a-31.html#post6547413). The wording might be different, but the intention is just the same.:ok:

[Machinbird]

The wording might be different, but the intention is just the same.:ok:
Yep, it was a good idea then and is still a good idea. :ok: This type adaptation of the FBW system is appropriate to improving the human interface.

The idea of the system suddenly shrieking, "I don't know how to compute this, YOU have it." rubs the flight instructor in me the wrong way.:*

[HazelNuts39]

Looking back at an earlier post (http://www.pprune.org/tech-log/466259-af447-final-crew-conversation-thread-no-1-a-66.html#post7019936) makes me wonder whether 20 seconds or so of dead reckoning to delay the cavalry charge would have made much difference in this case.

[Machinbird]

HN39, You mean the question, "Was he perhaps trying to maintain 15° pitch attitude?"

That is a perfectly reasonable question. No doubt BEA Human Factors Group is wrestling with this question still.

My feeling is that he was unintentionally catching a piece of aft stick during his lateral stick thrashing, and the characteristic of the pitch axis law is to basically add up (i.e. integrate) all those pitch input pulses. That is what caused the nose to rise, IMHO.
The man's scan was obviously broken at that point. He was not monitoring pitch! He was as far behind the aircraft as you can get (in the aviation sense of the word).

My reasons for concluding in this direction have to do with the notorious Occam's razor. Having found one plentifully sufficient for losing control of the pitch attitude, why introduce another? His pitch problems started when the wings started wobbling. He didn't actually have sufficient free attention available to implement a pitch attitude.

The delayed implementation of the handover to the crew might be considerably longer than 20 seconds. As long as the system knows the gross weight, configuration,operating altitude, and initial conditions, there is actually no reason it could not fly for hours like that, with only a small loss in fuel efficiency.

As I have said previously, how did we cruise our jets in the old days before autothrottles?

[Lyman]

HazelNuts39

"Was he trying to maintain 15 degrees NU?"

Fair question. I have another.

Was he trying to desperately keep the a/c tracking on a heading whilst keeping the wings level?

Your question has no basis in evidence. Mine does. The a/c has a demonstrable problem with YAW. What a/c behaviour might he have been trying to alleviate? A tendency to drop a wing? Slew to the right? Lose herself completely? Was the mush the only attitude the a/c could maintain and stay "airborne"? Did she have a desire to "lose it" with a ND?

Back to airloads. Her ROD touched 15thousand fpm. That is of course in addition to her forward progress. One hundred thirty knots down, plus forward, ~150? All her controls are working to put the mayonnaise in a carton, what were their loads? It is not pansy to entertain that this bird lost some feathers.

mach. "His Pitch problems started when the wings started rocking" qed. Were they "His" problems? Did they have possibly another genesis? BTW, the "Wings started to wobble" in autoflight, not after.

[Machinbird]

mach. "His Pitch problems started when the wings started rocking" qed. Were they "His" problems? Did they have possibly another genesis? Lyman, your reading assignment is here:http://www.mae.wmich.edu/faculty/Ro/ME540/FQ.pdf
and here: http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA319985

[Lyman]

Thanks. Your point? If I read and become a better man, I won't ask questions?
I am not stating facts, nor conclusions. It occurred to me that, the wings having started their wobble in autoflight, that PF's efforts at leveling them may have been related to the autopilot's failure at doing so.

[Machinbird]

Lyman, if you read it, you will ask better informed, more pertinent questions. That is the intended result.

[HazelNuts39]

The man's scan was obviously broken at that point. He was not monitoring pitch!If I may ask as a non-pilot: If you're struggling with roll control and your scan has narrowed to the ADI, is it plausible that you miss pitch altogether? Is it possible that he was aware of increasing pitch attitude, but didn't care because 15° was his target all along? Perhaps he only reluctantly and half-heartedly gave in to the PNF's urging "You're climbing, go down" until at 02:10:49 he changed his mind and went for 15° instead. Was there perhaps a similar mental process taking place at 02:11:32 when he admitted "I don't have control of the airplane anymore now (...) at all" and, after the PNF had taken control, abruptly took the controls back?

[RR_NDB]

Hi,

roulishollandais,

I adopted your suggestion in recent post:

of the "Effective System" (system + PF)
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-40.html#post7074246)

[RR_NDB]

Hi,

PJ2:

...this response isn't "the academice ideal", this is what crews are trained to do and is absolutely middle-of-the-road SOPs. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-40.html#post7073722)

We need to be practical and find a way to solve the issues when they arise.

I understand your position. It works and worked quite well with you and many others.

There are limitations on this procedure? Heavy turbulence, etc.?

[Turbine D]

RR NBD,

Normally, I don't like to comment on thing like you pose here, but this time I am going to.

Your Quote: We need to be practical and find a way to solve the issues when they arise.

I have been around this business for a long time as you can see by my age, in fact it was my entire working career. I am not a pilot as I think you are not either. But, I have great respect for pilots, especially those who spent their careers or a part of their careers flying fly-by-wire aircraft and the exact aircraft we have been discussing here for 2 years. Clearly, there are times and this was one of them, where a flight crew has to fly the airplane absent some of the luxuries normally provided by the sophisticated electronic control system currently in place. I haven't heard any A-330 pilot say this can't be done and so therefore, it can be done and has been done. A good experienced flight crew a Captain, a First Officer and an additional First Officer could have and would have dealt with this situation in a successful manner. It comes part and parcel with training and experience and team coordination supported by carrying out the written down recipes for dealing with specific situations like AF447 experienced. Unfortunately, this was the wrong flight crew, in the wrong location, at the wrong time, a flight crew which apparently had only part of the aforementioned attributes.

No amount of additional bell, whistles, electronic devises, etc., will ever make up for a flight crew's absolute necessity and ability to fly the airplane absent some of the electronics. Now there might be some things in the present electronic systems that can be made better, but they will never replace good piloting when the chips are down. Flying the airplane is what this has been all about in my opinion.

Never think that a new invention will substitute for the three attributes listed above as "Murphy's Law" will find a way to prove you wrong. Listen to what the successful pilots have said.

[Machinbird]

If I may ask as a non-pilot: If you're struggling with roll control and your scan has narrowed to the ADI, is it plausible that you miss pitch altogether? Is it possible that he was aware of increasing pitch attitude, but didn't care because 15° was his target all along?
I was reluctant to answer this too quickly. My basic training was half a century ago. I could fly instruments OK when I was a PPL and it saved my overly aggressive posterior one day as I was flying XC into lowering ceilings and snow showers (in mountainous terrain to make things even more interesting.) My subsequent military training was excellent and left me with an unbreakable scan. While instructing instrument students, I have seen individuals suffer dangerous scan breakdowns when fatigued, but if PF had a scan breakdown, it was as bad as it gets. The only reason a pilot with airline training would have a scan breakdown as bad as PF apparently had would be if confronted with an urgent problem that he did not understand. An out of control roll oscillation fits that description.

As to why he would apply additional nose up input at the second stall warning, he probably thought TOGA thrust would protect him from the consequences. This would then be a result of the obsolete stall procedure that was being used until recently (concentrating on minimizing altitude loss).

[RR_NDB]

Hi,

TD:

Listen to what the successful pilots have said.

I am not just listening. I completely agree.

I was confirming the "techniques" used for are in my opinion, wise, practical, time tested and effective.

My objective was only that!


Flying the airplane is what this has been all about in my opinion.

I agree.

Never think that a new invention will substitute for the three attributes listed above as "Murphy's Law" will find a way to prove you wrong.


I never did!

As a designer i consider impossible to substitute a creative, motivated and diligent professional when near limits.

I have the impression there was a misunderstanding of my post.

[RR_NDB]

Hi,

Machinbird:

The only reason a pilot with airline training would have a scan breakdown as bad as PF apparently had would be if confronted with an urgent problem that he did not understand. An out of control roll oscillation fits that description. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-41.html#post7076653)

So, elected this priority (acting as being at imminent risk) fighting a "completely new" problem? And wasting precious seconds neglecting the deadly pitch threat.

Makes a lot of sense for me.

[RR_NDB]

Hi,

Machinbird:

The delayed implementation of the handover to the crew might be considerably longer than 20 seconds.

Why not?

The current situation shows INCOMPATIBILITY between AS probes "recovery time" and System handover.

After 30+ UAS cases this IMHO is a "persistent design flaw"

[HazelNuts39]

As to why he would apply additional nose up input at the second stall warning,... The second stall warning came at 02:10:51, 2 seconds after he began pulling up again.

[Lyman]

On its face, the NU prior to STALL WARN is consistent with what Machinbird describes, and it is consistent with a Training failure and the PF's preoccupation with overspeed. Because it is prior to, PF had other indications that she needed not to be low in the NOSE?

If the warning is due increased speed into the realm of STALL WARN proper function, and not its disapearance at arbitrary "low" speed, the a/c is accelerating, and likely because the NOSE is dropping.

We've been there, but w/o the dropping nose. Inappropriate 'Approach to STALL training', and the PF's obsession with overspeed. No one it seems, including the Captain and LHS, wanted this bird to drop her nose and fly. From the stubborn reluctance of Bonin at first, and the pleas of LHS, to this NU at STALL WARN (!), to "Climb, Climb..." "No, don't climb..." "Pull, Pull, PULL..."

Complete unfamiliarity with a tail low STALL? Fear of overspeed? Could it be she became completely uncontrollable as she approached level flight? What would cause that? Was fear of airstream noise and its implications the driver instead of the crew?

Because if the single unknown factor that caused this wreck is the hidden RHSS, someone has some splainin' to do.

[Machinbird]

The second stall warning came at 02:10:51, 2 seconds after he began pulling up again.
That does establish the chicken and the egg, doesn't it. Looks like I'll have to do some additional head scratching.:ugh:

[Lyman]

Basically, something about approaching level attitude made PF pull up. It happened at a/p drop, and prior to STALL warn. (Both times).

Fear of overspeed? Possibly. I would not eliminate a/c behaviour. I say again, YAW? Bobbing, wing drop? To indict the PF without eliminating a/c damage or unflyability is wrong.

Directional handling problem is known. Captain mentions Rudder, and PNF says: "WATCH your Lateral". These two guys were not flying, but were seemingly content that PF was, so there may have been a problem undisclosed by BEA.

What would cause the a/c to slew about as she exits MUSH? It would be premature to mention, but some possibilities of handling problems v/v heading exist.

[roulishollandais]

:) Hi RR_NDB,

Thank you for your reply. I know you know this great loop :ok:!
I would like that all the airline pilots learn and use that expression , and that we no more have to add "(pilot & system)" . In this sense did I want to "generalize" it to all pilots, with your both benedictions ! (and Systemstech ;) where I found the word ! Thanks).

roulishollandais

[RR_NDB]

Hi,

I did study this issue and we could say the Systems placed in advanced planes like A330 are "somewhat" in this category.

These powerful mechanisms sometimes need a "Reset". There is the risk to enter some "States" and the Reset assures a "new begining".

My question is related to the need of "Graceful Degradation" on the planes, when submitted to anomalous "inputs" and requiring emergency manual "crew intervention"

Why A/P and A/THR are not "System designed" to "return" to the scene after an anomaly (like brief UAS) in this planes?


Mac

[Machinbird]

Why A/P and A/THR are not "System designed" to "return" to the scene after an anomaly (like briefly UAS) in this planes?
Graceful Degradation is an important concept, but you have to remember how quickly stuff can happen in an aircraft. First, that aircraft is changing position at the rate of ~ 8NM / minute and roll and pitch rates can also be pretty high, so anything more than a very brief interruption can cause too much variation for a reasonable reset.

Best approach would be to approximate what a human pilot should do under the circumstances and figure out how to automate those actions.

The good thing is that the computer can generally size up a situation in less than a second and apply all the corrective steps. No need to level off after a UAS during climb, just set a pitch attitude appropriate to the altitude and thrust available and keep on trucking after advising the crew of the problem..

[RR_NDB]

Hi,

Let me put slightly different: (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-42.html#post7082874)

Is there "technical limitations" not allowing the "slowly return" of A/P after the "inputs" became normal again?

My rationale is to provide crew ASAP a full set of tools in the order to make easier their task under difficult conditions.

I understand the "discontinuity" typical when automated resources enter or exit during "transitory".

Mac

[RR_NDB]

Hi,

Looking to the safety aspect we may say ii would be good to preserve some functions of the A/P after anomalies are presented to inputs of the System.

AS not valid during the transitory (when AS is not briefly valid by any reason) is not necessary to "roll corrections".

My rationale is:

Every effort should be made from the designers to "present a machine" capable to help the crew most of the time.

It seems the GIGO approach (used by IT professionals) could be better applied in an A/C for the sake of "Graceful Degradation" of the (effective) A/C, when PF is "suddenly inserted" in the "great loop".

The Stability of the System was affected by "tiny ice crystals" and IMHO the System could be designed (with about the same resources) to better "handle" similar situations.

Before, for example, better AS sensors are available. :}

(*) By "effective aircraft" or "effective system" we call the System + PF (when plane with it's automated resources has PF inserted in the "great loop"). Such occurred when PF started to hand fly F-GZCP that night.

[Lyman]

RR NDB

Howdy, you make a strong point (s). "Transitory". Not for nothing is the word "transition" heavily used in aviation. At the out set, the underlying focus is generally on the loss of autoflight, and the inability (apparent) of the crew to do some simple things, with skill and speed.

"Do nothing". Wise and elderly pilots here have said this is crucial. Do not start something that muddies the water, to eventually exclude knowing how the a/c is reacting.

Then, Set "Pitch and Power". Use a table, to select appropriate settings, if low, level and troubleshoot, if high, await the return of accurate A/S.

There is a stark chasm between the loss of automatic flight, and the manual control that followed.

For instance, the autopilot started to "do nothing" the moment it quit. It did not reset Pitch and Power, though of the two flight regimes, it was better equipped to do it. The protocol at the time was to set the two after consulting a table.

Does the computer not know the correct P/P? Of course it does, its memory is nearly foolproof. Whilst the computer knows the settings, the life of the a/c depends on pilots using a loose leaf reference, which they must locate, then consult?

So, the computer has already accomplished that which the designers have said the crew must now do, to save the flight path.

I had an instructor once, a Naval aviator whom I admired greatly. I asked him once what he disliked most about flying. He said.... "surprises".

Thus transition. RR NDB you eloquently state "graceful degradation". "Degradation" is an unfortunate term, no? The bottom line here, for me, is the apparent lack of attention and design invested in the transition between one regime and the next.

Should the computer handle the "middle ground" in a/p loss due UAS?

At this critical point, the a/c is left in the middle, to include the passengers.

It is easy to say the crew were not up to the task. Until the final report, and more important traces are available, I make no conclusions. I only ask that folks here try to remain doubtful of the entire context, and not judge ahead of time.

most respect to all.

[RR_NDB]

Hi,

Bear:

I had an instructor once, a Naval aviator whom I admired greatly. I asked him once what he disliked most about flying. He said.... "surprises". (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-42.html#post7082932)

I would include most surprises presented by "she". This includes A/C. :E

LOL

[RR_NDB]

Hi,

Bear,

apparent lack of attention and design invested in the transition between one regime and the next. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-42.html#post7082932)

And AFTER the transition, during the next "state".

For example:

From apogee to SL the man-machine interface did provide the (entire) crew the required information (in the proper way) to even understand they had an ETA (to SL) in ~4 minutes?

Apparently a "surprise" was presented (understood) after crossing 100. :}

[RR_NDB]

Hi,

Bear,

It is easy to say the crew were not up to the task. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-42.html#post7082932)

The task (mission) had to be accomplished not just by the crew. PF inherited a task he was not even (adequately) trained for.

HF study (being performed) could reveal why "mission" failed.

3 crew members tried hard and "barely understood only near the end".

[Lyman]

I seldom mention intuition, but here an exception. I feel there will be surprises in store that soften the blame on the pilots, and offer some mitigations that will help us understand. Noisy airstream, full power at 16 degrees NU for three minutes does not compute. Not even to a valet. There is something here, be it only hysteria/poor displays. HF indeed, it will be informative, and life saving.

It is clear they never grokked STALL. Last command......"Pull, PULL, PULL...."

[RR_NDB]

Hi,

"A half truth is a complete lie"

If what we learned (from BEA) is adequate to inform us, specially from apogee to SL, we must be impressed how the man-machine interface failed to provide reliable resources to allow the crew to just aviate.

The biggest surprise to me was this fact. During 4 minutes an entire crew (CPT partially) was not capable (or not well informed by the System) to do this basic and essential task.

More important than obsolete Pitot's, persistent NU from PF, inaction from PM, etc. is this fact, imho, in the analysis, in order to improve the safety of the equipment.

They worked ~4 minutes (man-machine interface and crew) with a near complete (*) fiasco (the interaction of the crew with the A/C through man-machine interface) and a total loss in the end.

We need to wait to conclude on the magnitude of this fiasco. We may receive additional info.

(*) When closing in to SL the imminent end was realized. Too little, too late.

[Organfreak]

If what we learned (from BEA) is adequate to inform us, specially from apogee to SL, we must be impressed how the man-machine interface failed to provide reliable resources to allow the crew to just aviate.


Not as if this hasn't been mentioned already, but let's not forget that, as far as we know, both pilots had very rapidly unwinding altimeters. Those who suspect that PF's displays were farkled have more ammunition for their beliefs thereby, but we really don't know, once again, what PF saw. But really, if neither of them had the altimeter in their scans, that would be shocking. I say this in opposition to the idea that they didn't have enough information to fly the plane.

[RR_NDB]

Hi,

Organfreak,

I say this in opposition to the idea that they didn't have enough information to fly the plane. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-42.html#post7083295)

When i comment on the man-machine interface i am looking to the "global picture" the crew were submitted.

My simple (K.I.S.S. one) feeling is:

The man-machine interface should be improved. "Bus drivers" would like. :)

I am not saying to replace SS, etc. Airbus SAS certainly knows very well what to do.

And authorities (based in HF group) should act.

For the benefit of the entire industry.

But really, if neither of them had the altimeter in their scans, that would be shocking.

We do not have enough factual info. on that. We need to wait.

I am just trying to be better prepared to evaluate the conclusions.

[Lyman]

Organfreak

Indeed, the altimeters. Their conversation from the beginning revolved around v/s. Especially at the end, they were quite aware of their rapid descent.

The only explanation is that they believed their nose was low, not high. How? The PF especially with his insistent pull. I think PNF eventually signed on to the Nose Low concept. Also Captain. So if true, the three of them reached the same false conclusion, though at different stages. One cannot dismiss the tacit power of the one with the controls. It is extremely difficult to justify a takeover, unilaterally, absent a plan, which none of them had. "Let me try" sounds cool, but given the stakes, all three acquiesced to the alpha dog, the PF. By default?

I doubt the "Lone Stick" theory, if they had instruments, they knew what was up with Bonin's SS. That alone may have helped convince the other two PF had a plan. It was not out of panic, wholly, that they all pulled, at the last. I believe they believed they were without a single cue upon which to base a recovery. Don't ask me how.

One thing. In ALTLAW2, the STALL WARN bug is absent from the speed tape. For what its worth.
adios O/f

[RR_NDB]

Hi,

Bear,

I believe they believed they were without a single cue upon which to base a recovery.
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-42.html#post7083376)
How? :)


You told to Organfreak to not ask you. :E

[Lyman]

Mostly from the lack of discussion re: the various instruments. PNF essentially was the last one to base his "get" on instruments, save Captain's Rudder comment, late. The scan may have been conflicting, or volatile. They set the stage for loss of trust on instruments at the outset. With help from the instruments, to be sure. Our picture has developed from data they did not have, accelerometers, traces, trends, graphs, etc. Can anyone say, that from this CVR data, that the instruments were reliable, and the Pilots proceeded as if? No.

I will be most disappointed in BEA should further data serve to explain their predicament to us, having allowed such condemnation to prevail thus far.

Hasta manana, amigo.

[HazelNuts39]

In ALTLAW2, the STALL WARN bug is absent from the speed tape.No, it isn't.

[Lyman]

HazelNuts39.

Yes, it is. I could have been more precise, sorry, but here is my reference.

"...In cruise at Mach 0.8, the margin between the flight AoA of the STALL WARNING is of the order of 1.5 degrees, but the STALL WARNING speed displayed on the air speed tape (in ALTERNATE or DIRECT LAW) will be around 40 knots below the actual speed. The value of the angle of Attack is not displayed directly to the pilots. The angle of attack is the parameter that allows the STALL WARNING to be triggered, but the activation threshold of this warnng is indicated by a marker on the airspeed tape. When the ADR are rejected by the flight control computers, this marker disappears." (my bold).

BEA #3 pp. 20,21.

Suffice to say that the time when this marker would be important, is when the speed window incorporates speeds (low) aroind the AoA for STALL WARN. The speeds are low because of FMC ADR rejection, so the marker is missing, just when it is imperative to be present?

[HazelNuts39]

Hi Lyman,
I'm impressed. Another quote from Interim Report #2:
1.6.11.3 Design and limit speeds
A certain number of speeds are represented by specifi c symbols on the PFD’s
speed scale (protection or design speeds – “green dot”, F, S, Vmax, Valpha prot, etc.).
Some of these speeds are calculated by the FMGEC, others by the PRIMs which
transmit them to the FMGEC for display. In the case where the three ADRs are
rejected by the PRIMs, the SPD LIM flag appears at the bottom right of the
speed scale. The current speed and the target speed remain on display. If at
least one ADR is valid in the FMGECs, the Vmax speed may remain displayed on
one side and/or the other. We don't know if and when all three ADR were rejected by the FCPC's(*), but IMHO it is unlikely to have occurred before 02:11:40. The (second) stall warning was triggered at 02:10:51.

In your quote the part that reads "but the activation threshold of this warnng is indicated by a marker on the airspeed tape" is strictly speaking only correct for flight at 1g.

(*) In my understanding that condition triggers the ECAM message F/CTL ADR DISAGREE, which according to the ACARS transmissions was generated in the minute commencing at 02:12:00.

P.S. When the stall warning began at 02:10:51, the right PFD was showing 121 kt. The stall warning speed VSW would have been close to 216 kt, the speed shown on the left PFD while the LF was close to 1. In other words, VSW would have been off scale for the right PFD.

[RetiredF4]

RR NDB
It seems the GIGO approach (used by IT professionals) could be better applied in an A/C for the sake of "Graceful Degradation" of the (effective) A/C, when PF is "suddenly inserted" in the "great loop".

I´m not saying that the discussion about improving the system to prevent those events is wrong, quite the contrary.

However, let´s not forget, that the crew should be in the great loop all the time, also when "George" is doing the handywork. At least that was the way pilots had been trained when the aircraft was designed.

[RR_NDB]

Hi,

RetiredF4,

...the crew should be in the great loop all the time... (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-42.html#post7083652)

When you are monitoring (PF before SS use) your entry in the loop should be done (ideally) with an understanding of why you are being called for. In order to allow you to have better chances to act precisely and fast enough to apply the right corrections (normally required). This was necessary (roll).

When i think on the man-machine interface i consider it's characteristics not just during abnormal situations or emergencies. IMO it should be designed to keep PF very close to the loop. In an effective "hot stand by" condition. And automatism must take into account HF related to how "hot" (aware) and prepared the crew is "put" (kept)

In summary, a professional must always be prepared to any scenario. (*) Even outside the (not acting) loop we should be "in the loop". In "parallel" :)

An analogy could be on the "synchronized processors" in certain fault tolerant Systems. They are working together in a "hot stand by condition" and can perform immediately if required.

In high speed vehicles (land) or near limits (e.g.aquaplaning threat) i learned it is better to "fully enter the loop" before any chance of LOC. This analogy is to agree with your rationale on the need to be "in the loop": I had an incident (with no consequences) in which i put myself in the loop, before. When the problem started (absolutely predicted and anticipated) i was yet in the loop (i started the maneuver applying a familiar large amplitude stimulus). After a surprise (vehicle reaction much different than normal) i performed perfectly the correction. But had no "maneuver room" to complete the task and eventually capsized (at very low speed) due a water drain hole at road side. When i left the vehicle (by the rear window i detected TWO flat tires (at rear) that explained the different behavior of the car (was not my one at this rainy night trip). This car had CG well ahead and used tubeless dangerous to detect when flat (difficult or even impossible to detect "on the fly" or even visually when parked) with low car weight in the back. This was my only "incident" (just testing the car after a previous LOC) since 1963, when started to drive cars at higher speeds.

In this case i remember i made an analogy of me as having two processors and their specific software (algorithms). When the 1st one didn't find the "car behavior" in the data base it dropped and put the 2nd to act. The second was used in a "emergency inside an emergency" and was capable (allowed me) to "calibrate" the correction stimuli. The adrenaline was enough to give me enough time to think (in "parallel" during the maneuver: How i would say to my friends i had two incidents in the same night? (because after not detecting the reason of the LOC (1st maneuver some 30 minutes before) i decided to understand why it happened. And later realized the first LOC was due just ONE flat tire. At cruise speed. And the 2nd with TWO under "test speed" some 50% lower.

In next day i concluded (in the local of the incident) it was fine to test because if i used the car (at cruise speed) with TWO (undetected) flat tires, the chances to suffer a serious accident would be enormous. It's possible to see all tire marks in the road (asphalt) very weak in next day (sunny) despite incident occurred at wet surface. (light rain)


(*) 5 Gorillas joke i learned in Silicon Valley in early 80's.:) on the Professionals.


One detail (available) was the reason of A/P and A/THR drop. IMHO this should be informed clearly to the crew ideally before. When AS began to show inconsistencies. If the System provide this info. (a "benign" event) the crew (PF) could enter the loop better prepared. But this is just a detail in a set of facts we don't know. And could not had helped too much.

[jcjeant]

Hi,

organfreak
once again, what PF saw. But really, if neither of them had the altimeter in their scans, that would be shocking.
At least they scan the vario ......

BEA report N°3
2 h 11 min 58
The vertical speed is around -
15,300 ft/min.

PF
I have a problem it’s
that I don’t have vertical
speed indication
Capt
Okay
PNF
I have no more displays

[roulishollandais]

But really, if neither of them had the altimeter in their scans, that would be shocking.

At least they scan the vario ......
2 h 11 min 58
The vertical speed is around -
15,300 ft/min.

PF
I have a problem it’s
that I don’t have vertical
speed indication

Capt
Okay

PNF
I have no more displays

Scaning vario 4 times in 4 minutes : Yes it is very schocking !

[Organfreak]

Mssr. Hollandaise:
Scaning vario 4 times in 4 minutes : Yes it is very schocking !

Please pardon my non-flying ignorance (again), but what is "vario?"

And, was your remark sarcastic, or serious?

[jcjeant]

Hi,

Vario ....
Variometer - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Variometer)

[Lyman]

Organfreak

Howdy. For context, imagine a human being in free fall, terminal velocity is about 120 miles per hour. This aircraft, at 15 thousand feet per minute descent, would pass our skydiver at 60 miles per hour! DOWN. Probably close to the jet's terminal velocity. Compare that picture with the apparent calm on the flight deck. Do you sense a disconnect? With an angle of attack of 40 degrees, the a/c is presenting an enormous amount of drag to the airmass, hence the : "I feel like we have some crazy speed". The noise must have been loud, and of course, unusual.

Even at the more consistent 10 thousand fpm descent, that is 120 mph. Even as a non-pilot, would you be concerned?

So I am expressing some surprise that others don't clamor for some more CVR.
The Flight deck was more animated, and noisy, than BEA would have us believe, No? Yet without a solution, the three pilots patiently await, what? In virtual silence? Nerves of steel? Ice water in the veins. I doubt it. "We are going to crash, this cannot be..." "Four spades? Double".

Eh?

[HazelNuts39]

... what is "vario?"
In the A330 the vertical speed indicator is to the right of the altitude tape and counter on the PFD. See for example page 48 of the second interim report. It consists of (1) an analog pointer that points to a vertical speed scale in white on a grey background graduated at intervals of 500 ft/min and (2) if the V/S is greater than 200 ft/min, a digital window showing the V/S in hundreds of feet per minute.

The analog pointer and the digital indication are normally green, but if the V/S is greater than 6000 ft/min they become amber and the pointer stays at the end of the scale.

[chrisN]

Vario, short for variometer, is usually used in English AFAIK only in gliding terminology. Our glider varios are sensitive to small changes in vertical velocity. The equivalent instrument in powered aircraft, from small single engine to airliners, is usually called a VSI (again, AFAIK) – Vertical Speed Indicator.

I suspect the same term for both is used in France – vario. If my surmise is correct, we have a translation from French to English of “vario” to “vario”, whereas it would be more usual to translate vario as VSI.

Hope that helps. If I have it wrong, and English usage in airliners is to call it a vario after all, I shall stand corrected (and have learnt something!).

[PJ2]

HN39;

Re, "In the A330 the vertical speed indicator is to the right of the altitude tape and counter on the PFD. See for example page 48 of the second interim report. It consists of (1) an analog pointer that points to a vertical speed scale in white on a grey background graduated at intervals of 500 ft/min and (2) if the V/S is greater than 200 ft/min, a digital window showing the V/S in hundreds of feet per minute.

The analog pointer and the digital indication are normally green, but if the V/S is greater than 6000 ft/min they become amber and the pointer stays at the end of the scale. "

The following image may assist:

Pitch: 10deg ND
Altitude passing: 33580
IVSI 20,100fpm

http://www.smugmug.com/photos/i-Vc8RFmq/0/XL/i-Vc8RFmq-XL.jpg

[OK465]

AOA: approx 28-29 degrees (+,- ambient wind, on the FPV)

FPV: barely visible with no trend information associated with it.

KIAS: 187 and increasing, trending to 209.

I would think that picture, itself, would sell a stand alone AOA gage for trend indentification (and possibly an ALT Law PLI, before the fact).

:ok:

[PJ2]

OK465;

Re, "FPV: barely visible with no trend information associated with it.

KIAS: 187 and increasing, trending to 209."

For clarification, "209" in ten seconds at that specific moment - the trend arrow is a real-time indication that changes as rapidly as the energy of the aircraft does and that varies with pitch, power and even external forces should there be any. Not saying you're not aware of this, I think you are but just for all who examine this..., caution is advised in concluding too much from a snapshot. As you're likely aware, the FPV is partially below the bottom limit of visibility for all PFD information. The "FLY UP" arrows, advising of a very steep ND pitch, are just coming into view. Clearly the AoA is greater than the FPV can fully display.

Regarding "AoA" indications etc, as a former A330 captain I don't know what to "recommend" anymore in terms of making this better. Clearly we can't just focus on "loss of airspeed" as 'cause' simply because when that's fixed, something else will arise. What would you advise we could learn from Islamabad, or Tripoli? Other than "understand the airplane", "fly the airplane", I truly don't know. And more automation?! Heaven deliver me, but I read that that exact solution is being touted and even planned, and it is SO wrong! I understand that a serious discussion is taking place next week at the RAeS, (The Aircraft Commander in the Twenty-first Century? (http://www.aerosociety.com/Assets/Docs/Events/674/RAeS_Aircraft_Commander_Conference_Programme.pdf)) on these topics.

The discussion on these nine AF447 threads has been so varied, so rich and so populated with perceptive thinking and suggestions that address the exact problem (how do we solve "loss of airspeed?") and the broader problem of human factors and automation, (I have written on this as well) that I think some 'distance' is needed from solutions to percolate and filter through to practicality, enhancement to safety and to cost including certification, training and so on.

[NeoFit]

Hello,

A FPV barely visibe yes, at # 847 above.
but Nr3 Interim Report En CVR transcript (p 89 to 100) points this:

FD 1 and 2 become --------- FD 1 and 2 become ------------ Comment
unavailable at ---------------- Available again at
=========================================================
2:10:08 ------------------------------ 2:10:17 -------------------------HDG & ALT CRZ modes
2:10:21 ------------------------------ 2:10:26 -------------------------HDG & VS modes
2:10:36 ------------------------------ 2:10:42 -------------------------Transitionally available (how ?)
2:10:45 (may be ?) -------------- 2:10:47 -------------------------HDG & VS modes
2:11:40 ------------------------------- 2:12:52 -------------------------HDG & VS modes
2:12:58 ------------------------------- 2:13:57 -------------------------Temporary (that is to say ?)

During more than half the time of the four minutes event, the two FD were not available. A graphic would give an easier visualization.
I have done it, but unfortunatly i don't know how to insert the picture.
Who will again dare to say that the pilots were stupid?

[jcjeant]

Hi,

but unfortunatly i don't know how to insert the picture.
Easy way to post a image :)
imgur: the simple image sharer (http://imgur.com/?noFlash)

[roulishollandais]

was your remark sarcastic, or serious?

Very very serious !
Normaly your eyes come to the variometer :rolleyes: (VSI) (in french variomètre) every two seconds great maximum. Not only to put your eyes on it, but to correct your altitude:rolleyes: and your speed :rolleyes:, that you scan in the same frequency, and as well as your heading :rolleyes:. When you have seen any of these three informations, you come back to look and correct your attitude:rolleyes::rolleyes::rolleyes::rolleyes: (pitch and roll). You have also to look outside :rolleyes: with your other eyes (!) and to crosscheck the other pilot :rolleyes: in the crew, to look the other instruments:rolleyes:, manage the warnings, cautions, cabincrew:rolleyes:, hijackers:rolleyes:, fire:rolleyes:, doc. etc.

[roulishollandais]

(Following : I had to many smilies for only one post !)

If anything is wrong, you have to say it to the other pilot:=. The two pilots (or three in AF447) are not independant.

In AF447, altitude,:\ attitude :\, heading :\ , vertical speed (vario):\ ... and speeds :\ :\ were wrong, and the CVR shows a crew totally disconnected from these basics .:ugh:

The crew managment in normal flight says that any of the two pilots has two main functions maximum and two subsidiaries functions maximum, under these four functions :
-pilot
-navigation
-radio-com
-mechaniks.

In case the other pilot cannot assume his functions, you have to do the four functions.

We pilots may be masochist ? We like that ! :rolleyes:

This eyes training does the pilot look so attractive !:):):)!! Your friends like to be looked by you really : they are indeed (here I am happy but it is real) ! hum... It was the case before the FBW and his seemingly sleeping on the control ! - (here I am sarcastic) Also the BEA #3 says the A330 cannot stall (p.26 french version) :mad:

[NeoFit]

jcjeant
Thank you very much.

Here is the picture, and I hope it's correctly resized :confused:

In my sens, ite missa est
@ 02:11:40
disapearence of the FPV (bird),
with FLAG ON (both) CPT & F/O PFD FD ( Interim #2 - Acars).

http://i.imgur.com/CYgs7.png

[Organfreak]

Thanks to all who answered my ignorant questions so kindly and clearly. What a great forum this is. I've learned so much about flying from you.

Lyman asked me a bunch of questions about what I think/assume, many posts ago. I was going to give him a detailed answer, but by simply being away from the computer for a while, the time has come and gone. Suffice to say, yes, I agree, there must be more to the story than what we have been told. And to your closing remark, "Four spades? Double," I simply say, "Redouble!" :p

[Lyman]

NeoFit

Thanks for the graphic, it is instructive. I consider this wreck to have two discrete phases, if not more. There is #1 the uncoupled a/p, manual control, and wild climb, leading to #2: STALL. Once STALLED, the a/c was in completely unknown territory, it was not "flying". It is fodder for endless speculation and dozens of "What ifs". Though these a/c have STALLED, they do so in other than NORMAL LAW, contrary to my friend ruolishollandais's statement that in French, the Report says STALL is impossible. Any a/c will STALL, and most have, with variable results.

One cannot fly this machine without instruments to inform. Not in these conditions. The Pilot Flying had none of his screen recorded. BEA does not go further. Was there anything to record? Did PNF call for Captain to sort a political discussion between the two seated pilots? That's provocative, but Occam would have it that Captain was called to help fly. There was no Captain referee, only Captain in attendance. "I have lost my vario" says Bonin, "Okay" says Captain.

No orders as to authority from Captain DuBois. None that are given us, in any case. So we are left with a narrative that I believe is lacking in data that would put in context what the conclusions are, or certainly at least suggested.

Mistake? BEA inadvertently included only pilot comment that leads to a definition of Pilot Error? Sure, pigs fly.

IR #2 has a description of previous UAS events to contextualize what happened to 447. It is instructive, and to me, estblishes that any UAS is fraught with risk, unaddressed SOP, and quite frankly, ignorance of the dangers by both manufacturer and line.

How do I know this? Because BUSS was not selected, and was "Optional" to the extent that pilot polling helped decide to deselect its presence in the cockpit.

An opinion poll to determine if pilots want to save their asses with a system that addresses a dangerous Condition? Blase? Perhaps, but it is so telling that UAS was not given the sort of attention it required.

Read IR #2 re: UAS. It describes a crapshoot, not a serious problem/address.

The conditions 447 found that night were severe, but not rare. To arrive at safety, risk is mitigated, not ignored.

Organfreak. Howdy, I mostly wanted to reframe the velocities for you. !5k fpm is 180 Miles Per Hour. That means in one minute, half of 447's altitude will be lost, and recovery will not be likely. That is why postSTALL events are not germane, imho. Once in the climb, and probably very quickly, the odds go sour for recovery. CRM is a relatively newly quantified concept, and arguments that say "Well,, PNF needed to...." Fine. However, if the last chance to live depends on politics, not command, well.........

adios.

[Machinbird]

Normaly your eyes come to the variometer :rolleyes: (VSI) (in french variomètre) every two seconds great maximum. Not only to put your eyes on it, but to correct your altitude
Well I am a bit ancient I guess, and the VSIs that I remember were not IVSIs.
We had to hawk the pitch attitude very carefully and note any trends on the altimeter, then apply a correction to pitch to hold altitude. There was too much lag in the VSI to use it for altitude maintenance. All I used the VSI for was to verify I had set pitch and power about right for a descent rate or climb rate.
It is interesting to learn that there has been a change in scan patterns as a result of new technology. :cool:

[Organfreak]

Lyman claimed:
Once in the climb, and probably very quickly, the odds go sour for recovery

Please cite an authorative source or support your contention with known facts. There have been hundreds of comments in these forums stating that the stall may have been recoverable. Is it just that you enjoy being a maverick? ;)

[Lyman]

Hey Organfreak

My comment comes from a point of view. It has to do with a body of facts, data, and evidence, plus the commentary of those here.

The Interim Report #2 discusses a foundation, a reference for the type of problem 447 had, and what others did, as well as the a/c reactions.
There could not be a worse place to lose instruments. There could not be a more lackadaisacal approach to AD, to training, and to command, by SOP and by culture.

From the OUTSET, something was wrong. Here, the evolution of opinion has landed on PE. I don't buy it. Neither pilot by CVR only, had the kind of demeanor one expects in such a situation, and for this I offer "Where is the Captain?". The entire contents of the releaes re: CVR could not have been better written by a soap opera show. Drama, personality, deviations from the expected, etc.

The two pilots were in trouble, and not because they did not get along. Here on thread, the popular drill is to claim discord, and incompetence. NO PROOF of either, merely a parsed verbal record, VERY parsed. What is missing? How about, "Where's the skipper, this bird is effed up, and we need him NOW." People have jumped, no, leapt to conclusions without listening for tone, volume, and idiom. Have you? Are you content with things as they are, without more data? Would your wife and kids be satisfied that you are painted as an incompetent dilettante, without as much as a complete record of events?

Three trained pilots, with a descent unarrested by any, with a mere position change on a stick. What DRAMA?

OPINION, MINE. It isn't for me to write the report. It was one thing when there was no evidence at all. Since recovery, what is available is parsed, limited, and censored. Should I get access to the CVR, I may have to apologize to BEA.

In the meantme, My opinion is not countered by evidence. Is it supported? I suggest it is, merely by noting the lack of evidence provided, when there is no reason to prevent its assessment. What gets no attention, seemimgly, is the utter lack of a case on which to rest Pilot ERROR, in the absence of a complete record. This is not obvious? Each of the actions can be explained, both to condemn and to clear. Is it odd that the context is lacking for any defense?

Not given what is at stake. Especially not now. BEA will never release any data that serves to condemn their actions. That became apparent when they caused to be released a PRESS memo, exonerating any "NEW" mechanical issues, and that language from the Airframe company. Of all the blatant political hand crossing, that was laughable.

In the absence of a complete record, neither of us can claim a conclusion, it is impossible.

be well.

[Organfreak]

Lyman, to be honest, I don't disagree with much of that. BUT, your claim (the one I quoted in my previous post) is the one I'm asking you to defend. "Odds"? I dunno about that, but I am of the impression that many/most pilots here would have sussed this stall and flown out of it, possibly without even spilling any peanuts. Any others want to jump in here?

[Lyman]

Sorry Goose, I got a little carried away.

"ODDS". Hmm....Odds are hard to quantify, but I'll try. Here on thread there have been Bus drivers who claim to have Simmed this ride, and the reason I believe at least some of that is that a fair number admitted they couldn't recover. KNOWING what was happening. Air Caraibes had a potentially deadly zoom, uncommanded. Can you tell me from the evidence 447's climb was not at least partially commanded by the computer? You can't, simply because the evidence is not available. The g up was 1.65 in a 1 g command control, how's that? I know pilots who have experienced anomalous behaviour in this equipment: "It started to turn...we selected HDG/ALT and corrected, but no one could ever say why she behaved that way."

Mind of her OWN? By definition, my friend.

mind how you go.

[RR_NDB]

Hi,

Organfreak

I am of the impression that many/most pilots here would have sussed this stall
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-43.html#post7086643)
:ok:

and flown out of it

:=

Too many variables to take into account (uncertainties)

For them (and for us) :confused:

[jcjeant]

Hi,

Lyman
Once in the climb, and probably very quickly, the odds go sour for recovery Organfreak
Please cite an authorative source or support your contention with known factsIn this video ... at time 46 minutes 18 seconds
AF 447 - YouTube
Pouvait t-on sauver l'avion ? ask the interviewer? ... on ne sais pas répond le chef instructeur pilote d'Airbus ....
Interviewer question:
It was possible to recover the plane?
We don't know answer the chief instructor pilot of Airbus !

[RR_NDB]

Hi,

Bear,

Can you tell me from the evidence 447's climb was not at least partially commanded by the computer? You can't, simply because the evidence is not available. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7086663)

Perfectly K.I.S.S.

Even BEA may not have all required info

[RR_NDB]

Hi,

Bear:

but no one could ever say why she behaved that way (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7086663)

Even the designers cannot explain all anomalies occurred since the introduction of these advanced planes.

Important information is simply lost. And FDR is not designed for that.

[Machinbird]

And FDR is not designed for that.
Is it proven that the Quick Access Recorder data cannot be resurrected from its time in the depths? I don't remember the answer anymore.:O

Personal opinion only, since the AP and A/THR dropped at the beginning of the AF447 event, it is extremely unlikely that any control inputs came via that route. Any surprise control inputs would then have to be through the basic ALT2 control structure which appears to have been debugged quite well.
(Although the aircraft must have 10000 times more experience in Normal law than in ALT2 law.)

[Hamburt Spinkleman]

The aircraft's behavior in pitch was consistent with stick input.

In really does take the cake to accuse BEA of manipulating data while doing so repeatedly oneself. While the aircraft entered alternate law, it seems some here entered alternate reality.

[Machinbird]

HN39 Post #807
If I may ask as a non-pilot: If you're struggling with roll control and your scan has narrowed to the ADI, is it plausible that you miss pitch altogether? Is it possible that he was aware of increasing pitch attitude, but didn't care because 15° was his target all along? Perhaps he only reluctantly and half-heartedly gave in to the PNF's urging "You're climbing, go down" until at 02:10:49 he changed his mind and went for 15°

HN39 Post #815
The second stall warning came at 02:10:51, 2 seconds after he began pulling up again. It would appear from NeoFit's chart that FD data became available just in time to be suspect as a cause for the second pull up leading to the stall.
http://i.imgur.com/CYgs7.png

[Machinbird]

In really does take the cake to accuse BEA of manipulating data while doing so repeatedly oneself. While the aircraft entered alternate law, it seems some here entered alternate reality.
I hold similar views to Mr. Spinkleman's and have discussed this with a prime offender via PM. I would be great if that person adopted the suggestions discussed.

It is now a free speech world, however, and we are all free to step on our lolly as many times as one can stand.:} Credibility? What's that?:ugh::ugh::mad:

[roulishollandais]

Hi Maching Bird,

We had to hawk the pitch attitude very carefully and note any trends on the altimeter, then apply a correction to pitch to hold altitude. There was too much lag in the VSI to use it for altitude maintenance. All I used the VSI for was to verify I had set pitch and power about right for a descent rate or climb rate.
It is interesting to learn that there has been a change in scan patterns as a result of new technology. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/cool.gif

Thank you for your scan instruction. What I have written in my post is the most academic manner to do which is learned for IR in France, on slower and less powered aircrafts that yours !

In all cases scan has to be rapid, effective, used,:rolleyes: and AF447's CVR shows a very different scenario !:sad:

What do you think about learning effective stall with aerobatics to all airline pilots (and not airline too) ?

Computer systems cannot help us to land when we have fire on board, no more electricity, no more system. A pilot must be able to try to do that, and bring the aircraft and the passenger on the ground.

That is only pleasure !:)

[RR_NDB]

Hi,

Machinbird:

...it is extremely unlikely that any control inputs came via that route. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7086746)

I agree!

We have to concentrate (first) on "elements" working in the "great loop". This includes PF (receiving "inputs" we don't have) and A/C "mechanisms" (all that had to work).

Other factors, IMO are to be neglected. Including: basic ALT2 control structure

[RR_NDB]

Hi,

Hamburt Spinkleman:

The aircraft's behavior in pitch was consistent with stick input. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7086748)

We can assume this, i agree.

While the aircraft entered alternate law, it seems some here entered alternate reality.

With some months (years) delay. :)

This happens in high profile cases. :}

As MB said: It is now a free speech world

[RR_NDB]

Hi,

Machinbird:

It would appear from NeoFit's chart that FD data became available just in time to be suspect as a cause for the second pull up leading to the stall. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7086751)

:suspect: , i agree.

[RR_NDB]

Hi,



no more electricity, no more system. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7086778)

fire on board

With current design this is "almost" impossible.

Smoke can be much worse:

See Dubai flight 6 (http://en.wikipedia.org/wiki/UPS_Airlines_Flight_6)

PF had no chances even to change comm to other ATC. The "element" suddenly inserted in the loop had no vision ahead. We may say: smoke from a cargo fire "broke the loop". :}

You need fresh air to be able to see ahead. This can be done with a hood. (http://en.wikipedia.org/wiki/Smoke_hood)

PS

The same (similar) effect that could explain AF447 PF actions. No valid and reliable inputs to him? Almost zero confidence in the inputs (them) received? This may explain what we learned so far.

[mm43]

Originally posted by Machinbird ...

It would appear from NeoFit's chart that FD data became available just in time to be suspect as a cause for the second pull up leading to the stall.Perhaps a graphic refresher (http://oi55.tinypic.com/vr55aq.jpg) of what the aircraft was doing around that time may help. Then answer what the FD data may have shown during the period in which the stall was entered and the SW sounded continuously.

[RetiredF4]

Organfreak

Lyman claimed:
Quote:
Once in the climb, and probably very quickly, the odds go sour for recovery

Please cite an authorative source or support your contention with known facts. There have been hundreds of comments in these forums stating that the stall may have been recoverable. Is it just that you enjoy being a maverick?
Last edited by Organfreak; 17th Mar 2012 at 17:30. Reason: HTML typo

I don´t know, whether you consider that as an authorative source.

http://www.pprune.org/7066105-post66.html

As for the AF447 accident: I am an instructor on the A320 and we are now doing high altitude stall demonstrations during recurrent training. When given similar circumstances as the AF447 guys, less than half of the pilots can successfully recover even when they know it is coming. It is not because the pilots do not know how to recover from a stall, it is because pilots at all levels have not been trained in the dynamics of high altitude stalls. High altitude stalls are very different animals. Recovery at high altitudes require significant nose low pitch, to be held for a very uncomfortably long time, and you have to accept a VERY high rate of descent (15,000fpm or higher). AFTER that you have to have a very slow pitch up because a secondary is very easy to occur. Historically when training stalls pilots are taught to lower the nose to the horizon and add full power and to minimize altitude loss. You cannot recover from a high altitude stall using that procedure. If you read what happened, and know how to correctly recover from a high altitude stall, it becomes clear that the AF447 guys were caught off guard because the aircraft did not recover in a way they were accustomed to when training lower altitude stalls.

I have a lot more sympathy for the actions of the AF447 guys having trained and demonstrated high altitude stalls in Airbus FBW aircraft.

It is not enough to look at the ability of the aircraft to be flown out of the stall, but to judge the success of recovery atempts in view of the knowledge of the crew (and not only of this AF crew) and the ability of the aircraft.

[HazelNuts39]

FD data became available just in time to be suspect as a cause for the second pull upWhat are your reasons for suspecting that the FD causes the second pull up, when the vertical Flight Mode is ALT CRZ, selected altitude is FL350, actual altitude is 37500 ft? I must admit that my understanding of FD commands is very limited, and I'm just assuming it 'mirrors' the commands that would have been given by an active autopilot.

[OK465]

MACH:

IF (big IF), in fact, the FD 'bit' him at any point, I 'spect it's the return at 2:10:47 when the CAS is 216k and aircraft vertical speed is +1500 FPM which is what the FD vertical command would have defaulted to because the FD buttons were still engaged. With the nose already having come down from 10-12 degrees to 5.6 degrees (1500 FPM) this would be a 'relatively' subtle nose up command initially that, if flown, could rapidly go full scale taking him back to the documented 13 degrees after 2:10:51 as airspeed continues to decay.

V/S 1500 would also have been annunciated on the FMA at this time.

The FD would indeed only default to ALT CRZ* if within FMGEC CRZ ALT altitude capture parameters (i.e. 34,976), and the FD would, at the earlier time of 2:10:17, have been in the process of providing a vertical command consistent with leveling off at FMGEC/FCU CRZ ALT. It was only available in this mode for 4 seconds before it dropped out again. By 2:10:47 they were well above FL 350 (default mode is V/S).

[RR_NDB]

Hi,

After saying "i have the controls" PF became (with the tacit concordance of PM and later the CPT, most of time) the "processor" and the "controller". He was put in the loop substituting in a difficult environment important elements, A/P and A/THR.

PF "output" (SS handling) was evidently based on uncertainties (as per NeoFit graph) (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-43.html#post7086487). His "inputs" are unknown to us and he expressed "high speed" suspicion. His "outputs" were not random, and soon showed a definite "bias to climb" the plane. A bias so strong, to put the plane in a steep climb going above REC MAX.

Probably this is not just explained by "lack of training", surprise, etc. Something very important, together the lack of "reliable" inputs may be was feeding his "processor" during important moments, leading (or misleading :} him to do that).

His "output" was not random. There was a pattern. This pattern was about the same during most of critical moments before stalling the plane.

After stalling, the reason could be partly explained by what was put in post #66 (http://www.pprune.org/7066105-post66.html)


RetiredF4::

It is not enough to look at the ability of the aircraft to be flown out of the stall, but to judge the success of recovery atempts in view of the knowledge of the crew (and not only of this AF crew) and the ability of the aircraft.
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7086879)

IMO, in this case is very important is to understand why the plane was put in the stall. Looking to all reasons that lead to this: Crew error(s), System anomalies (it's outputs, processing of UAS data), man-machine interface issues, etc. In order to learn from this crash this is absolutely necessary.

PS

The wreckage orientation in seabed proved later to be the coherent with A/C heading when hitting surface. When you have a "pattern" this normally "carries" important information.

[mm43]

His "inputs" are unknown to us and he expressed "high speed" suspicion. Using that simple description, the reality is that his "inputs" rejected the visual evidence in favour of the cockpit vibration and unusual noise actually being what he "expected" in a high speed situation.

No pilot actually commented on the "noise", and perhaps this created a common acceptance of "over speed". The don't use the spoilers pronouncement could fall into this "thinking".

[RR_NDB]

Hi,

After worsening conditions: WX then ice crystals, obsolete AS sensors failing simultaneously, "law change", non trained (to this situation) PF applying large SS inputs at high FL, etc. one may ask:

The lack of reliable info during so many time together with non reliable SW and other factors (noise, alarms, etc.) are to promote, GRACEFUL DEGRADATION of the "effective aircraft" (System+PF) or are a recipe for ACCELERATED DEGRADATION? Stressing HF, etc. Actually their fate was sealed VERY FAST.

It seems like exactly when they needed most reliable resources,( e.g. good man-machine interface to allow them to do just the very basic: aviate.) their inputs (mainly the input to PF) were sub standard (lacking, intermittent and perhaps, misleading). This probably will be understood by summer.

PS

mm43:

his "inputs" rejected the visual evidence in favour of the cockpit vibration and unusual noise actually being what he "expected" in a high speed situation.

(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7087098)
We have to check carefully the timing.

The attitudes of PM and later CPT are coherent with "lack of enough info.". Like being unable to do any better, despite some moments briefly raising some "not so strong questioning". Seeming (with available info. we have) more doubts than what would be required to act with confidence. :{

[PJ2]

Hello Machinbird;

Re your post #869

"Is it proven that the Quick Access Recorder data cannot be resurrected from its time in the depths? I don't remember the answer anymore."

The QAR box etc is located on the main radio rack known as "800VU". It was brought to the surface. There is no information directly stating that the QAR has been found or what condition it may be in. It was stated that the two FMGC memory modules would be examined, (to my recollection the first time that was done was the AA965 at Bogota).

Though not crash-protected, the QAR on this aircraft is almost certainly solid state (vice optical etc) as well and if it survived the initial impact and subsequent water pressure it could be readable.

It's my experience that data frames for QARs is generally far more detailed and sometimes has higher sampling frequencies for some parameters. Let's hope all this comes to pass.

HN39;

Re, " I must admit that my understanding of FD commands is very limited, and I'm just assuming it 'mirrors' the commands that would have been given by an active autopilot."

Yes, that's the way the FDs work - they display the orders that the AFS is issuing, either to the AP or to the pilot flying.

[RR_NDB]

Hi,

mm43,

No pilot actually commented on the "noise", and perhaps this created a common acceptance of "over speed". The don't use the spoilers pronouncement could fall into this "thinking". (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-44.html#post7087098)

Is it possible (after stall) their thinking was just of being flying at high speed (and high ROD) just requiring to reduce (the speed) with NU? The inputs they received during the descent could "match" this modeling? Or this is too simple to be considered? (below a K.I.S.S. "safe" threshold). As we understand it seems they never acknowledged a stall. So...

:confused: Is it possible?

PS

Like as if the plane "entered" an state they never realized as something plausible. And without enough confidence in the available (considered not reliable, stable and erratic) resources to ascertain "what was happening"

PS2

Again, this is a risky exercise without more factual info. I know.

[Lyman]

This wreck started with duff speeds, and continued with duff speeds, and duff speeds killed them.

They HAD "crazy speed". The problem is that too much of it was vertical. No STALL recovery was discussed or attempted. It is as you say, and clear as day, they thought they had an overspeed, and whether they sussed their PITCH accurately or NOT, they all signed on to pull, after much apparent confusion.

Too much has been made of how "simple" the soluton was. It was NOT. What does a heavy sound like at 15k fpm descent with an AoA in the roof?

Spinkleman, hear this: I have NOT accused BEA of manipulation of data. What they have done is release too little, and set the stage for a miscarriage of the TRUTH. "OFFENDER"? How so? I counsel doubt, and scepticism, which to me is far short of purposely slandering dead pilots. Make a list of what is MISSING in sounds, conversation,and discussion. Then drive your truck through it.

Assess the state of UAS, STALL training, and high altitude upset recovery. Read Post #66. Ignore what I say, consider only what is missing from a fair stage.

We'll have to see. Patience, there is no other way.

[alanp]

Lyman, you were claiming at one point that obviously the VS had fallen off, because Europeans don't understand glue (so far as I understood it).

I understand,and appreciate, your desire to get to the root cause of this crash. It happened in flight school :- when the PF wasn't told to go away.

[Organfreak]

I don´t know, whether you consider that as an authorative source.

'FAA seeks to raise Airline Pilot Standards'


Hi F4 and JCJeant,
I stand corrected, in French no less. (Wish I could understand WTH they're talking about!) Reading all of the threads, I mistakenly got the impression that most here feel that the stall could have been corrected, mostly from earlier posts. I confused that issue with a separate one: the stall should not have happened in the first place.

I hate to add more useless noise to the discussion by posting this, on the other hand, I feel it is important to acknowledge my mistakes. I only like to appear arrogant if I actually know what I'm talking about! (Happens occasionally.)

Carry on gentlemen. :ouch:

[Machinbird]

Quote:
Originally Posted by Machinbird
FD data became available just in time to be suspect as a cause for the second pull up

What are your reasons for suspecting that the FD causes the second pull upJust that Airbus/EASA were concerned enough about that configuration to publish an AD about it. AD No.: 2010-0271
http://ad.easa.europa.eu/blob/easa_ad_2010_0271.pdf/AD_2010-0271_1

[Clandestino]

Is it possible? For at least 15th time on AF447 related threads: yes, it is not just possible, it happened before. There was at least one other crew mistaking stall buffet for overmach:

ASN summary of Northwest Orient B727 N274US accident near Stony Point on DEC 01 1974 (http://aviation-safety.net/database/record.php?id=19741201-1) with link to NTSB report included.

It happened in flight school :- when the PF wasn't told to go away. Could be, but so far I see no proof to it as: a) three preliminary reports are quite elaborate on the technical matters while being pretty thin on HF side b) being competent pilot does not come granted after the training obstacle course has been negotiated. It is matter of keeping oneself fit to fly; there was many a pilot with five-digits total times who perished after making a beginner's mistake c) there's the additional issue of CM1 not recognizing that pulling 15° ANU at typical cruise level is very bad idea or what is the significance of computer shouting "STALL STALL STALL". It's all very well discussing cockpit authority gradient but we are looking at failure of CM1 to realize the gravity of the situation and that CM2 actions will turn out to be lethal pretty soon. Idea of having two pilots is the same one behind having doubled or tripled ADC, IRUs and NAVs - CRM and MCC does not mean we use each other as a crutch but rather that as long as both pilots independently arrive to same conclusion where the aeroplane is, where it is going and where it should be going there's good chance they're correct.

I mistakenly got the impression that most here feel that the stall could have been corrected, mostly from earlier posts. I confused that issue with a separate one: the stall should not have happened in the first place.Second notion is totally correct, first notion is correct up to the certain point in time which cannot be precisely determined as no other A330 has ever ventured into AoA achieved by AF447. Given the pitch-down of the A330 when the sticks were released, chances are aeroplane could be recovered successfully until there was no sufficient altitude available to recover from dive. While it is certain that A330 can be recovered from stall if recovery is initiated as soon as practicable after G-break, we don't know what was the latest time/level at which recovery from extreme AoA had to be initiated. It could be FL300 or FL200 or even FL100, perhaps there will be enough data for aerodynamists to say their verdict, perhaps we'll never know.

[RR_NDB]

Hi,

Clandestino:


There was at least one other crew mistaking stall buffet for overmach:
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-45.html#post7088304)
Indeed there are similarities on this ferry flight with AF447 case. I commented this in an earlier post, IIRC on UAS and Pitot generating false (misleading) inputs to the crew.

Their (heater off) Pitot's "failure mechanism" generated false (increasing) speed misleading the crew during the climb.

I will locate my post and will be back with a comment on what i see common between both cases.

Anyway in both cases the stall buffet probably played an important role in their thinking, i agree with you. A dangerous one (the role).

In AF447 what is impressive is how (and why) they failed to even understand (timely) they simply (after stall) were not flying. Just performing a "free fall" trajectory (at near terminal speed).

The role of the man machine interface "performed similarly" to the (much simpler) one of the 727: Not helpful.

Will think and compare HF aspects in both before continuing.

[Lyman]

Hiya RR NDB

I do not know if this is pertinent, but on 330, Stall buffet is encountered after the STALL WARNING, so buffet should not be confused with high Mach.

(In ALT and DIRECT LAW, obviously).

ciao paisan

[HazelNuts39]

It could be FL300 or FL200 or even FL100Once the airplane was deeply into the stall, I think a distinction has to be be made between whether the airplane was physically able to recover, and what psychologically the pilots could reasonably be expected to accomplish.

As I gather with my scanty understanding of the French language, AB Chief Test Pilot J. Rosay states in the video (post #863) that the airplane's physical capabilities at extreme AoA have not been determined in flight test and thus will remain somewhat speculative.

Apart from the question whether the simulator reflects the real airplane, the psychological aspect is amply illustrated in "post #66" of the other thread:
Recovery at high altitudes require significant nose low pitch, to be held for a very uncomfortably long time, and you have to accept a VERY high rate of descent (15,000fpm or higher).
For example, around 02:13:20 the airplane descended through FL120 with pitch attitude +10° and FPA -40°, i.e. AoA= +50° (assuming still air). To unstall and stop the stall warning, the airplane would need to be pitched down until the AoA was less than approximately 10°. Even if the airplane would respond to forward sidestick by pitching down, the lift and drag forces and hence FPA and airspeed would not change significantly until the airplane was unstalled, i.o.w. the airplane would have to pitch down to an attitude of -40 +10 = -30° to stop the stall warning. That attitude would then have to be maintained for some time until the airspeed had increased enough to permit a pull-up from the dive.

[jcjeant]

Hi,

Nothing to do with AF447 A330 but this recovery of the Tarom A310 show how the pilot go in a steep dive to recovery ....
Footage of Tarom A310 diving Paris Orly 1994 (Imagini cu un Tarom A310 in picaj, Paris Orly 1994) - YouTube

[Machinbird]

The diagram is from NASA TM X- 73,229 which is about recovering hang gliders from dives, but has broader implications as well as a fair bit of aviation history behind it.
http://home.comcast.net/%7Eshademaker/PHUGOID-CURVES.jpg
Do you see a connection with the TAROM Airbus over Paris, the Interflug A310 on approach to Moscow, and for that matter what the AF447 crew would have faced in recovering their aircraft to level flight if the trim did not run down quickly enough?
Just trading potential and kinetic energy.

[RR_NDB]

Hi,

Machinbird:

...what the AF447 crew would have faced in recovering their aircraft to level flight... (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-45.html#post7088589)

Tarom Airbus A310-325 24 SEP 1994 (http://aviation-safety.net/database/record.php?id=19940924-1)

Interflug Airbus A310-304 11 FEB 1991 (http://aviation-safety.net/database/record.php?id=19910211-0)

Feedback systems in action. And for Ho you need 3Ho

Question: What about air density change effect during the descent? Seems to me makes easier the recovery. Dampens, provides more lift, ground effect :}
(it comes to my mind Ekranoplan. You mentioned Interflug :E :)

[HazelNuts39]

Machinbird,

Thanks for an interesting reference (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770017109_1977017109.pdf).

[Lonewolf_50]

Originally Posted by Machinbird The man's scan was obviously broken at that point. He was not monitoring pitch! If I may ask as a non-pilot: If you're struggling with roll control and your scan has narrowed to the ADI, is it plausible that you miss pitch altogether?
Most likely not, but you may not focus on it as much, depending on a lot of things. It also depends on what scan you are using. While I cannot fathom a scan that does not depend upon primary reference to the Attitude Indicator (Artificial horizon) that takes a primary reference pitch and roll, and then crosschecks from there), even that scan basis, if rusty from disuse, can break down under stress.

Is it possible that he was aware of increasing pitch attitude, but didn't care because 15° was his target all along?

While I would hope not, it seems that IF he was paying attention to his pitch, THEN he had a target pitch in mind. 12 def? 15 deg? 10 deg? Hard to say. As was discussed some threads ago, an element of the scan breakdown may have been him used to "flying the bird" (FPV). If the bird wasn't behaving as usual, or had dropped out, etc, then getting his scan into operation using the pitch/roll, cross check all else, might have taken him a few cycles to realize needed doing. If he ever did.
Perhaps he only reluctantly and half-heartedly gave in to the PNF's urging "You're climbing, go down" until at 02:10:49 he changed his mind and went for 15° instead. Was there perhaps a similar mental process taking place at 02:11:32 when he admitted "I don't have control of the airplane anymore now (...) at all" and, after the PNF had taken control, abruptly took the controls back?
What he was seeing didn't match what he expected, that much seems to be true.

Nerves of steel? Ice water in the veins. I doubt it. "We are going to crash, this cannot be..." "Four spades? Double". Eh?
Heh, that made me laugh. :ok:
Retired F4 Thanks for this:
As for the AF447 accident: I am an instructor on the A320 and we are now doing high altitude stall demonstrations during recurrent training. When given similar circumstances as the AF447 guys, less than half of the pilots can successfully recover even when they know it is coming. It is not because the pilots do not know how to recover from a stall, it is because pilots at all levels have not been trained in the dynamics of high altitude stalls. High altitude stalls are very different animals. Recovery at high altitudes require significant nose low pitch, to be held for a very uncomfortably long time, and you have to accept a VERY high rate of descent (15,000fpm or higher).
AFTER that you have to have a very slow pitch up because a secondary is very easy to occur. Historically when training stalls pilots are taught to lower the nose to the horizon and add full power and to minimize altitude loss. You cannot recover from a high altitude stall using that procedure. If you read what happened, and know how to correctly recover from a high altitude stall, it becomes clear that the AF447 guys were caught off guard because the aircraft did not recover in a way they were accustomed to when training lower altitude stalls. I have a lot more sympathy for the actions of the AF447 guys having trained and demonstrated high altitude stalls in Airbus FBW aircraft.
Flying in a flight regime they weren't trained for. That has killed more than a few ... :(
alanp: I understand,and appreciate, your desire to get to the root cause of this crash. It happened in flight school :- when the PF wasn't told to go away.

Maybe, but I think it's fair to say that the training and qualification system at AF seems to have some play in this accident.

1. How well equipped was this crew for the UAS drill? CVR seems to show that the response didn't quite fit what was in the book at the time. Training issue?

2. How well grooved was the instrument scan of either pilot?

3. CRM question: how does the LH seat pilot's scan, or lack thereof, and his attempts to get RH seat pilot back into the game reflect on the currency and training at AF?

4. As asked with some frequency before, how much time hand flying at 37K did any of the AF pilots have?

[jcjeant]

Hi,

4. As asked with some frequency before, how much time hand flying at 37K did any of the AF pilots have?
I think we could very quickly have a simple answer to this question if some Air France pilots (who certainly read this forum) would dare answer ...

[chris weston]

All,

I have read all and I mean all the pages and grow dizzy with the content but, with no great confidence, do I recall correctly reference at some point by someone no doubt better informed than me, to AF SOPs (et al) specifically forbidding hand flying up there without a d*** good reason?

[jcjeant]

Hi,

specifically forbidding hand flying up there without a d*** good reason? Why this interdiction ?? .. it's so dangerous .. ? .. so .. this can explain why AF447 had some ... troubles .....

[Machinbird]

Why this interdiction ?? .. it's so dangerous .. ? .. so .. this can explain why AF447 had some ... troubles .....You just have to be smooooooth to fly in cruise at altitude. Actually no big deal once you relax. Unfortunately, AF447's PF was anything but relaxed or smooth. The unexpected cavalry charge set his heart racing and it appears he never did begin to fly cooly and deliberately. He continued to beat snakes with the stick all the way down.:rolleyes:

Unless you are in RVSM airspace, pilots should be grabbing a few minutes of stick time just to keep the feel of the aircraft. What kind of back up system can you be if you don't actually fly?

Sim time twice a year? Give me a break. Flying is one of those skills that needs more frequent refreshing. Sims are close, but not quite the real deal. On an 8 hour+ cruise, the extra fuel used because you are hand flying for 5 minutes can probably be measured easily with a cup, that is, if you are smooth:).

[Lyman]

Machinbird

Yes, and no. My neighbor flew the baby bus for ---Lines for many years. He was out of NORMAL LAW, exactly: not once. I am not sure what manual stick (NORMAL) accomplishes up high. The sim cannot duplicate what these three inherited. I could argue that it is a negative, perhaps imparting a false security when LAW degrades for real (which is hardly ever).

BEA say the a/c rolled right to 8 degrees, they do not mention trend, and therefore people assume it stopped at 8 degrees, right? The a/c started a rapid and cyclic ROLL that you have eloquently described, and hand flying in NORMAL LAW is nothing like it. It is NORMAL Law itself that wants mayonnaise, and AL that wants smoothe; so practicing mayo up high is exactly wrong, and could be the source of the entire problem? DIRECT ROLL with mayonnaise is poison.

There is one salient point that is my take away, that BEA mentions very directly.

Pilots of this aircraft MUST have an AoA reference, PERIOD.

cheers sailor.

[Machinbird]

BEA say the a/c rolled right to 8 degrees, they do not mention trend, and therefore people assume it stopped at 8 degrees, right? Speaking for myself, I don't believe it stopped there by itself, but as a result of PF's control (over reaction) input. There really is nothing to stop a roll rate in Alt 2 except a bit of opposite turbulence, a bit of counter control input from aileron or rudder, or the aircraft's natural stability once it begins to slip a bit.

If PF had been accustomed to flying smoothly at altitude in normal law, he would have just had to fly even a little smoother than usual in Alt 2. As it was, he was completely clueless in that environment.

PJ2 describes the proper effort as little more than a light squeeze on the stick if I remember correctly, although he also indicates that the aircraft is a bit goosey in roll in Alt 2 (my words, not his). I expect he will jump in if I have misinterpreted his intent.:}

Anyone who thinks an airliner needs an AOA gage is not going to get an argument from me. It is an excellent performance indicator. Just don't hide it away in some corner of the panel. It belongs right in front. You want it where you can incorporate it into your scan easily should a problem arise.

[PJ2]

Machinbird;

re, "PJ2 describes the proper effort as little more than a light squeeze on the stick if I remember correctly, although he also indicates that the aircraft is a bit goosey in roll in Alt 2 (my words, not his)."

That's just how I described it: light squeeze, if anything at all, and that's how the sim performed. Taking one's hand off the stick would have been by far the best decision and then gently correct the right roll with one small motion. Tough to do? You betcha. This is just hindsight.

Really, this initial roll and the few back-and-forths were entirely a non-event...in the sim one rolled back and forth a bit just like we see in the data, primarily because it is sensitive, but as Owain Glyndwr has stated and I completely agree based upon experience with hand-flying the airplane at cruise altitudes (in Normal Law), the PF learned quickly and got this bit of roll under control quite nicely.

The rolling response of the airplane is all but inconsequential to any of this including the initial, instant pitch-up. This pitch-up was instant, steady (uncorrected, unchallenged) and held for a relatively long time. It went from what may have been perceived as the "correct" response (to the UAS) to an urgent pull-up to arrest either the descent, or what may have been later assessed as an overspeed, (I think that notion is difficult to support). The lateral stick forces which produce the minor rolling we see in the data (+/- 8deg) are tiny but the half-pull (10deg NU IIRC) to produce such pitch-up requires a much stronger force - I don't think it is a result of 'being distracted'.

The eight degrees is nothing to be concerned over, nor are the back-and-forths; such minor gyrations don't lead to a complete loss of control, and he got it under control. Now, over thirty-five degrees bank at that point would be something to comment upon.

I've never understood the fascination with this initial roll and subsequent minor PIO. There's just nothing in it - it's what the airplane would do with just a bit of lateral stick and he very quickly got it right. But it doesn't stall the airplane.

While it has generally been agreed that the sim cannot - does not reproduce aircraft behaviour at and post stall, nor does it behave wildly and unexpectedly in the stall and subsequent descent if one keeps the stick back. The stall is however quite recoverable, taking about 20,000ft or so. The positive lift from the THS even at 13deg NU and the elevators 30deg UP has been acknowledged as contributing to a ND tendency which, if full ND stick is applied AND HELD, with pitch at 15-18deg ND until the airplane is clearly flying again, (rapid increase in CAS, disappearance of buffet, increasing wind noise), the stall is exited before FL200. That's the sim, (Level D). I am not an engineer but my pilot instincts tell me that below FL200, opportunity for a successful recovery rapidly reduces, mitigated only by the thicker air. It would take very aggressive action on the controls to do so and we're just not trained to do that. That means the guy at the controls at that very late point in the event would be of a mindset that recognizes only one way out with seconds to decide..., "15deg nose down, 15,000ft away from earth doing 18,000fpm down is my only chance" and that capacity to think and do that is, I expect, rare.

After all situational awareness was lost and reassessing what had occurred just prior to the apogee, (meaning, why the airplane couldn't be in a high-speed condition given its initial pitch up after stable flight), the loss of energy & post-stall entry became extremely difficult to assess and respond to. there just isn't the instrumentation to tell you that and I firmly believe that an AoA indicator would not have saved this flight at that point. It may have up to the apogee but the psychology of perception/assessment/agreement rapidly changed after the descent began.

The recurring stall warning was a sad happening in an extremely complex and impossible-to-assess set of circumstances but that occurred very late into the descent, (about FL200 to 180) where recovery was rapidly becoming impossible even with extremely aggressive actions.

[A33Zab]

The video highlights a new addition to the airline's flight-analysis protocol, which Air France implemented in 1974 and today analyzes operational data from the carrier's 1,500 daily flights.
Each flight records some 100 different data points, including altitude, speed and trajectory. The new feature is expected to reduce the time necessary to identify and address areas of operational safety concern.
Air France employees, called gatekeepers (http://corporate.airfrance.com/en/press/news/article/item/everyones-role-in-the-flight-safety-chain-flight-analysis/), will provide pilots with faster access to flight-analysis data.
"With the gatekeepers," explains Gilles Laurent, vice president of Air France's flight safety division, in the same video, "we can question the crew about contextual elements just a few days later and not a few weeks later."
Gatekeepers' duties range from simple discussions with pilots about safety concerns to recommendations of extra flight training where warranted.
While pilots normally cringe at the idea of flight-data gathering, fearing possible disciplinary actions, this new Air France safety protocol was established with the full agreement of the SNPL, the French arm of the Air Line Pilots Association.
Data gathered in the program will also be reviewed on a bi-monthly basis by an Air France committee with a mandate to suggest improvements to operational procedures, equipment, infrastructure, crew training and aircraft maintenance programs.
While Air France's overall safety record is quite good, the airline has suffered two high-profile fatal crashes in the past 12 years: the Concorde crash in Paris in 2000 and the 2009 loss of an Airbus A330 in the South Atlantic.

Source: AINSAFETY (http://www.ainonline.com/)

[RR_NDB]

Hi,

PJ2:

...out with seconds to decide...

...psychology of perception/assessment/agreement rapidly changed after the descent began.
(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7090591)

HF, as the "key" to/of/from, this accident.

PS

Excellent post :ok:

PS2

On how a inadequate behavior may led to "non manageable" situations:

and it appears he never did begin to fly cooly and deliberately. He continued to beat snakes with the stick all the way down. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-45.html#post7090385)

[RR_NDB]

Hi,

A33Zab,

Excellent approach: (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7091009)

Air France employees, called gatekeepers (http://corporate.airfrance.com/en/press/news/article/item/everyones-role-in-the-flight-safety-chain-flight-analysis/), will provide pilots with faster access to flight-analysis data.


"Air France is the first airline to have implemented a prevention system based on the analysis of recorded flight data." :=

This was published in carrier corporate site. And it sounds like a phrase generated by marketing personnel perhaps without enough info. on what was done also by other carriers many decades ago. And applied by competitors with similar objectives.

Something learned? (http://corporate.airfrance.com/en/press/news/article/item/everyones-role-in-the-flight-safety-chain-flight-analysis/)

A33Zab, :) Good question. :)

PS

Thanks PJ2 for "limiting the time" duration of the incorrect info. in my post.

[PJ2]

RR_NDB;

Re, "Air France is the first airline to have implemented a prevention system based on the analysis of recorded flight data."

No, it isn't. Their statement on the page to which the link is provided is incorrect and misleading and is spin. BOAC/BA was doing flight data analysis in the late fifites and pioneered the entire field and remains a leader today. BA today has the most enlightened and advanced FDM Program in the industry. I know some of the people involved in their work and we took many lessons from them and from QANTAS when developing our own program in 2000.

Many airlines are doing FDM/FDA/FOQA especially in the United States where FOQA is regulated and privacy of data supported in law.

It seems they are implementing one of the most important learning processes which is using pilot gatekeepers to contact crews to learn more about the circumstances of the events being seen. As may be imagined, such processes require a mature, trusting relationship which guarantees that recorded flight data will not be used against individual pilots for disciplinary or legal proceedings. Except for Asia, these enlightened approaches seem to be the norm in FDM Programs.

Management never does this work and do not have access to actual data due to conflicting priorites and trust, again except at BA where, I understand, FDM data is even shared with the regulator, (de-identified).

Perhaps BOAC or another PPRuNer can tell us more, but I wouldn't consider an implementation date of 1974 "late".

PJ2

[jcjeant]

Hi,

PJ2
The recurring stall warning was a sad happening in an extremely complex and impossible-to-assess set of circumstances but that occurred very late into the descent, (about FL200 to 180) where recovery was rapidly becoming impossible even with extremely aggressive actions.
Indeed ... and is to remember that in all the cases of a Airbus stall identified (Toulouse-Perpignan and AF447) the result was a crash ...
Coincidences ?

[Lyman]

RE: "Gatekeepers".

Don't go looking for applause for doing what you should have been doing all along....

It makes one look foolish.

[RR_NDB]

Hi,

Bear:

Don't go looking for applause for doing what you should have been doing all along.... (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7091572)

Let's hope the results of the program to be much better than the way they are doing the marketing of this "basic feedback tool" as PJ2 mentioned being used since long time ago.

It makes one look foolish.

Or much worse.

[Organfreak]

Lyman and RR,
I don't give a fig if they're "looking for applause." If it serves to improve flying skills and safety for the public (as I have no doubt it will) then it is a Good Thing. Let's not condemn, out of cynicism, what looks like a good effort.
:=

Back to flying my armchair.

[Lyman]

Howdy.

Safety is like humility. If you splash it about, you don't have it. Real time monitoring of a/c is done extensively, and doesn't need a Jeanne come lately to validate it.

Clueless.

[RR_NDB]

Hi,

PJ2:

FDM is a large and fascinating field of aviation safety work. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7091414)

And the issue (Quality) is Rich! Addressing what is most important to "accomplish the mission". In "search of Excellence" as i understand it.

I personally had a great opportunity in my career to understand the importance of this (type of) feedback. May represent the "differential" of a good Company.

As relevant and "capable to correct" as any well designed feedback. In this case with hierarchy to almost everything in the carrier ops.

[RR_NDB]

Hi,

Bear,

Safety is like humility. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7091634)

:ok:

An intrinsic value.. That acts silently.

Organfreak, my position was clear:

Let's hope the results of the program to be much better than the way they are doing the marketing of this "basic feedback tool" ...

[Lyman]

One can but hope. Fecklessness and chauvinism can be dropped as a weight at any time, is there the will?

[RR_NDB]

Hi,

Bear,

is there the will?

This is the most important question.

Intrinsically connected to A33Zab one:

Something learned?

The title of his post (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7091009)

[Organfreak]

Safety is like humility. If you splash it about, you don't have it. Real time monitoring of a/c is done extensively, and doesn't need a Jeanne come lately to validate it.

Clueless.

@Lyman:

Who is clueless? Was that aimed at me? We disagree; does that make me clueless?

Safety is not at all like humility. So what if real-time monitoring of a/c is done extensively? What really matters is what is done with that info.

[Lyman]

Organfreak. Forgive me, of course I did not mean that for you. For Air France.

"We are missing an a/c....", "Fortes Turbulences.." "Wait, no, Lightning, yep lightning..." "No, it was the Radars, the poor pilots were not lucky..." "They flew into a Storm, right, it was the Storm..." "Whatever, Non?......" "Pitots?" "Certainement, the Pitots..." "Oh, we were to have replaced the Pitots?" "Then certainly not the pitots, it was Airbus..."

et plus la meme chose.

Air France is so used to hiding, they have forgotten how to "get in front".

Hence, clueless.

I value your postings, and would never insult. You are well informed, and articulate. Again, please excuse.

[Organfreak]

Lyman,
Ah, I took it too personally. Thanks for clearing that up. I don't disagree.

Zut alores!

[RR_NDB]

Hi,

Looking to what A33Zab post (#904) (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7091009) i think this is a potentially powerful "mechanism" being introduced by the carrier.

If well applied with absolutely essential aspects mentioned by PJ2 like:

As may be imagined, such processes require a mature, trusting relationship which guarantees that recorded flight data will not be used against individual pilots for disciplinary or legal proceedings. Except for Asia, these enlightened approaches seem to be the norm in FDM Programs.

Management never does this work and do not have access to actual data due to conflicting priorites and trust, again except at BA where, I understand, FDM data is even shared with the regulator, (de-identified).

(http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-46.html#post7091414)

It could represent a "very good answer" to the question put in the title of A33Zab post.

In my opinion this came in time to show AF probably learned important lessons and seems committed to a "process of change".

PS

The concept using "pilot gatekeepers" is new?

PS2

PJ2:

Perhaps BOAC or another PPRuNer can tell us more, but I wouldn't consider an implementation date of 1974 "late".

Sure, is not.

[PJ2]

Hi RR_NDB;

None of this is "new". Flight data analysis and monitoring has been around for fifty to sixty years at BOAC/BA. The rest of the industry began getting on board in the '70's. Some just don't get it and don't implement it for some strange reason but in this day and age of cheap equipment, massive processing and storage capacity and the ability to "know" vice "not know" and the notion of the accountable executive, there simply is no excuse for a major carrier to resist or ignore such programs. But believe me, it happens and all kinds of excuses are given. It is complex, takes a very long time to design, create and implement and for those who like to think that their operation is "pretty good" it is an unwelcome and difficult wake-up call to accept. No carrier is immune and no management has the right to think that they don't have such events occurring on a regular basis.

Air France was a very early entrant and user of FDM and they run a good program from the information and presentations I have seen them create.

The notion of the "gatekeeper" is equally not new. The data process tells us "what", but not "why" something out of the ordinary occurred on a particular flight.

FDM data is trended, graphed and presented to Flight Ops managements, (de-identified) and other stakeholders including the pilots' association.

Gatekeeper contact, once established and trusted, is an extremely valuable process which puts pilot association member, the pilot(s) and the data together in a confidential private process of discussion. Such discussions may be straightforward or may be quite detailed depending upon the event. In almost all initial contacts the captain is contacted first. Very often the response is relief and a willingness to be a partner in finding out what occurred and trying to improve those areas which were felt to be contributing factors.

It may be appreciated that this is no ordinary conversation. It requires great comprehension on the part of the pilot association FDM representative and also requires great confidence in such a system by those so contacted, and it further challenges the Operations people to trust that such a process is being done and is providing through appropriate channels the necessary and timely feedback to address problems where they may have emerged in the data. This involves the training/checking process as well as the SOP and policy documents.

FDM people also keep an eye on the industry. Sometimes an occurrence is not monitored such as "split thrust levers at landing", (a result of the TAM accident), and a new FDM "event" is created; all of a sudden an airline learns something new about its operation where it was "blind" before.

For those who want to know more about this safety tool, try CAP 739 (http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&id=1002), FAA FOQA (http://atcvantage.com/docs/FAA_AC_120-82.pdf), and the Flight Safety Foundation for starters.

[Machinbird]

The eight degrees is nothing to be concerned over, nor are the back-and-forths; such minor gyrations don't lead to a complete loss of control, and he got it under control. Now, over thirty-five degrees bank at that point would be something to comment upon.

I've never understood the fascination with this initial roll and subsequent minor PIO. There's just nothing in it - it's what the airplane would do with just a bit of lateral stick and he very quickly got it right. But it doesn't stall the airplane.

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

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

I am not an engineer but my pilot instincts tell me that below FL200, opportunity for a successful recovery rapidly reduces, mitigated only by the thicker air. It would take very aggressive action on the controls to do so and we're just not trained to do that. That means the guy at the controls at that very late point in the event would be of a mindset that recognizes only one way out with seconds to decide..., "15deg nose down, 15,000ft away from earth doing 18,000fpm down is my only chance" and that capacity to think and do that is, I expect, rare.This second sentence is very concerning to me. From observing the posts of others, I know that stuffing the nose down is avoided like the plague in airline flying-and for good reason when you have people in the back of your aircraft.

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

[roulishollandais]

In a ballistic trajectory, your aircraft will not stall. This is the core idea behind many tactical maneuvers. In airline use, you would not have to fully adopt a zero g ballistic flight to recover from a potential low speed excursion. 1/10th g is sufficient to keep most things stuck to the floor and still provide almost all the benefit of zero g.

Hi Maching Bird,

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

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

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

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

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

[mm43]

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

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

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

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

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

[jcjeant]

Hi,

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

[RR_NDB]

Hi,

What kind of "inputs" they received?

PS

We have all, related to their "outputs".

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

PS2

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

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

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

PS3

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

[Lyman]

Human Factors

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

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

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

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

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

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

regards

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

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

[Machinbird]

Why they discuss (all 3 pilots) all the way down about keep the wings level and the speed.. but not about all the blue they must certainly seen on the instrument ? Simple answer to this question. When the bank became excessive, the sensation of down became well off to the side. If the Captain was standing between the seats, holding on to head rests, he would have trouble remaining there. The wing was no longer carrying much of the aircraft's weight. The missing lift was replaced by the drag of the fuselage so that the aircraft was at a relatively stable speed (but velocity vector pointed very down).
To summarize, it was as if the fuselage had rolled partially onto its side while on the ground. Hard to maneuver inside like that. That was having an immediate effect on everyone's ability to function.

[RR_NDB]

Hi,

Some days ago Clandestino (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-45.html#post7088304) mentioned similarities (buffet misleading) between both cases.

Yes, there are many similarities:

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

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

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

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

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

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

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

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

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

A recipe for serious HF issues.

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

PS

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

[Lyman]

Machinbird

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

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

[jcjeant]

Hi,


Why they discuss (all 3 pilots) all the way down about keep the wings level and the speed.. but not about all the blue they must certainly seen on the instrument ?

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

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

[Lyman]

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

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

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

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

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

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

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

[roulishollandais]

Vario, short for variometer, is usually used in English AFAIK only in gliding terminology. Our glider varios are sensitive to small changes in vertical velocity. The equivalent instrument in powered aircraft, from small single engine to airliners, is usually called a VSI (again, AFAIK) – Vertical Speed Indicator.

I suspect the same term for both is used in France – vario. If my surmise is correct, we have a translation from French to English of “vario” to “vario”, whereas it would be more usual to translate vario as VSI.

Hope that helps. If I have it wrong, and English usage in airliners is to call it a vario after all, I shall stand corrected (and have learnt something!).


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

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

[Machinbird]

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

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

[RR_NDB]

Hi,

Machinbird:

...but the management of priorities.

If PF was not using his shoulder harness

and if he was not properly seated, he would be almost unable to function

Makes a lot of sense.

[RR_NDB]

Hi,

Machinbird:

For a tactical experienced pilot, there is a concept called unloading the wing. If you establish a ballistic trajectory with your aircraft, you do not require lift and this allows your aircraft to accelerate much more quickly than it would while maintaining high AOA. In a ballistic trajectory, your aircraft will not stall. This is the core idea behind many tactical maneuvers. In airline use, you would not have to fully adopt a zero g ballistic flight to recover from a potential low speed excursion. 1/10th g is sufficient to keep most things stuck to the floor and still provide almost all the benefit of zero g. Unloading is a concept that every jet pilot should have in their back pocket through practical (airborne) flying experience. (You cannot do it in a Sim). A pilot who understands the concept won't have difficulty getting the nose down to get flying... (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-47.html#post7092469)

Supposing the limitations are disabled: The only limitations are likely those built into your flight control system.

Questions:

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

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

[Machinbird]

Supposing the limitations are disabled: Quote:
The only limitations are likely those built into your flight control system.
Questions:

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

2) This stall recovery technique should be incorporated in (SIM) pilots training?RR_NDB, unloading the wing is used to prevent entering a stall, even when the aircraft is well below its normal level flight stall speed.

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

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

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

[Lyman]

Mach

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

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


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

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

I suppose it is an aerodynamic exercise, help?

[RR_NDB]

Hi,

Machinbird:

unloading the wing is used to prevent entering a stall, even when the aircraft is well below its normal level flight stall speed. (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-47.html#post7097358)



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

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

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

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

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

Obs. The sooner AOA is reduced to un-stalled ranges, the lower the likelihood of entering a spin.


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

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

[RR_NDB]

Hi,

Bear:

On the face of it, it appears at least that they may have considered the STALL was not real?

Disturbing to imagine (a training could do) this.

May match elements we have so far.

(*) trajectory with HEAVY LOADED WINGS :E

[Machinbird]

3) In this case at what safe minimum FL the maneuver (by the same trained pilot) should be initiated (at what FL) to present reasonable chances to recover in time. (before SL http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif)In the AF447 case, they could have recovered if they had initiated somewhere around 10,000 feet, maybe even less, but there would be no room for secondary stalls. It would have to be done perfectly, and if you don't have Normal law, then you need an AOA indicator to do the recovery perfectly. Your flight control system can screw you up if it trims the THS too slowly.

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

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

[OK465]

MACH:

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

:)

[boofhead]

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

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

What has/is being done to prevent a reoccurrence?

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

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

[Machinbird]

....and pulling those numbers out of your glass.
Well of course I am! ;)Are there any more reliable numbers in FCOM?

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

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

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

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

[HazelNuts39]

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

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

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

[Lyman]

boofhead

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

Just a thought.

[Machinbird]

And Presto! we have some numbers and they show that, "If you do not mess it up you would do surprisingly well."Thank you HazelNuts:ok:.

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

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

Just remember that HN39's chart has the following initial condition: The maneuver assumes constant total energy (thrust = drag), and begins after the airplane has been pitched down to unstall. We still have to consider how much altitude might be lost in pitching the aircraft down.

[HazelNuts39]

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

[OK465]

We still have to consider how much altitude might be lost in pitching the aircraft down.

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

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

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

[Machinbird]

We still have to consider how much altitude might be lost in pitching the aircraft down. The recordings stopped at 2 h 14 min 28 . The last recorded values were a vertical speed of -10,912 ft/min, a ground speed of 107 kt, pitch attitude of 16.2 degrees nose-up, roll angle of 5.3 degrees left and a magnetic heading of 270 degrees.
My experience in the A-4 Skyhawk which had a similar THS configuration to the A330, and the results of the Perpignan A320 accident lead me to believe that the THS trim is going to pace the recovery.

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

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

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

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

[Lyman]

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

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

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

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

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

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

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

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

[boofhead]

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


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

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

Aviation can be very humbling.

[Lyman]

boofhead

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

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

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

Thanks

[Machinbird]

Aviation can be very humbling. Ain't that the truth!
Just for purposes of convenient reference, I am going to bring Hazelnut's Phugoid chart over to discuss how to possibly improve the results. To improve the results, we have to play with the assumptions.
Now lets look at piece of a Wikki article on BFM. The whole article can be found here: Basic fighter maneuvers - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Basic_fighter_maneuvers)
Both turn rate, (degrees per second), and turn radius, (diameter of the turn), increase with speed, until the "corner speed" is reached. At this point, the growing turn radius begins to decrease the turn rate, so the aircraft will reach its best turn performance at its particular corner speed. The corner speed of an aircraft is the minimum speed at which it can sustain the maximum g-force load, and varies with its structural design, weight, and thrust capabilities.[10] It often falls in the area of 250 to 400 knots.[9]http://i.imgur.com/QRe1H.gif?1
One of the key assumptions in the chart is constant TE=total energy. Suppose we begin accelerating the engines from idle at T=0. (You probably will want to have the engines near idle to break the stall and negate the pitch up moment they would otherwise create.) By T=6 and later, you can begin to strongly increase CAS (Brownish line) and this will increase G available (Lift/Weight-The blue line). In the chart example. AOA is limited (somehow) to 7 degrees by the pilot. Using these conditions, we hit maximum structural g of 2.5 at the bottom of the pullout (321 knots). 321 knots is therefore our cornering speed.

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

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

An even better trajectory would be achieved if the pilot managed to stay on the threshold of stall warning:
Initial normal acceleration 0.73 g, and level off at FL 69, M.47, 276 kCAS, AoA 8.5°, and az=2,05 g.
Using these parameters, we do not get into g limiting at all, so we are probably still leaving the thrust card on the table. (But you will still need some thrust to counteract induced drag and meet the TE=Constant condition).

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

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

[OK465]

It will "BFM" better with the slats out.

[Lyman]

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

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

[roulishollandais]

In the AF447 case, they could have recovered if they had initiated somewhere around 10,000 feet, maybe even less,


the only aircraft I flew in my short, undistinguished AF career was a jet that I intentionally spun on a regular basis. I flew others with the militia and was very cognizant of the handling quirks of the 100, 105, F-4 & F-16. However, the A-7 I also departed on a regular basis, thanks to training initially provided by the USN. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif

The one thing I remember learning from the AF was to keep my hair neatly trimmed. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/badteeth.gif)


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

[OK465]

RH:

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

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

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

:)

[roulishollandais]

informal personal inputs, which may or may not be ultimately of any value.

http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif

OK465, I bet !! :):)

dutchroll

[HazelNuts39]

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

[A33Zab]

There are hints that Bonin did deploy slats, and Flaps.


Where are those 'HINTS'?

[Machinbird]

Hmmm, key assumption?? The "on the threshold of stall warning" trajectory with specific excess thrust (T-D)/W = 0.15 results in level off after 15 s (was 18s) at FL76, Mach 0.51, 295 kCAS, az=2,24 g. An A330 is not a fighter.
No, it most certainly is not a fighter. But we have gained ~2000 feet in pull out altitude from the initial cut at at the pull out. We haven't even hit the cornering speed. To avoid secondary stalls, we are likely to have to give some of that hard earned altitude back.

If fighter maneuvering theory helps, we should understand the theory. Far better to pull out at +100 feet than -100 feet. When your life is on the line, you may have to walk a delicate line between not making a fatal maneuvering error (secondary stall) and achieving maximum performance. All this while your heart is beating 10 miles per minute. Give yourself as much leeway as possible. In Alternate law, you govern the AOA. Don't mess it up!

It will "BFM" better with the slats out.
Yep, but it will roll on you if you tear one off. Best bet is to leave them in. The fewer things you have to do during the critical pullout, and the fewer risks you have to take, the better.




http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/statusicon/user_offline.gif http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/buttons/report.gif (http://www.pprune.org/report.php?p=7100578) http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/buttons/reply_small.gif (http://www.pprune.org/newreply.php?do=newreply&p=7100578&noquote=1)

[NeoFit]

Hi

Interim #3, page 94

02:12:04 - 02:12:07 The airbrakes are controlled and deployed

02:12:07 PNF (left seat) said "No above all, don't extend"

[A33Zab]

Hi
Interim #3, page 94
02:12:04 - 02:12:07 The airbrakes are controlled and deployed
02:12:07 PNF (left seat) said "No above all, don't extend"


Don't extend........The airbrakes (A.K.A. Flight spoiler or Speedbrake)
This is clearly visible in the FDR spoilertraces @ 02:12:04 - 02:12:07.

Another hint/clue.........

[Lyman]

A33Zab

Better than that. In BEA IR #3, there is a picture of a recovered Flap rail that was EXTENDED. The "Extended" was in their caption, it is not my conjecture.

Hypothetically, since S/F trace is U/A, it cannot be ruled out that that is exactly how the Rudder was reinvigorated after RTLU instant at a/p loss.

A hint? RIGHT ROLL, the bias is apparent from the outset, and cannot be explained. He had extended the brakes, and stowed them, and the evidence is unclear that all were successfully stowed at deselect.

For that matter, it is not impossible that one or more spoilers was lost in the air.

Find the pic, and see what you think. F1 is possible, eithwr as a STALL recovery memory item, or as a desperate attempt to gain control, or lose a/s or Level out, or......

Lyman

[canyonlight]

Anybody know when the final report from BEA will be issued?

[Machinbird]

Find the pic, and see what you think. F1 is possible, eithwr as a STALL recovery memory item, or as a desperate attempt to gain control, or lose a/s or Level out, or......Lyman, on a scan through BEA interim report 3, I found no such picture-but I admit to being occasionally unobservant.:O There was a picture of a flap track in an earlier report, but that showed the trailing edge flaps to be retracted.

There was a tabulation of the final readings and configuration including this bit:
Last values recorded on the FDR....
Configuration CleanWhen aircraft get crumpled, the forces are very high, and adjacent parts bang together. This generally leaves copious marks of where components were located at the moment of impact. BEA would have known from the recovered wreckage almost immediately if a flap or slat was extended. It would have been published in IR3.

[Machinbird]

Anybody know when the final report from BEA will be issued?Nothing new on the BEA site. Publication of the report is planned for the first half of 2012.

[Lyman]

Mach, hi. I looked again, dismayed, at IR #3 , and struck out also. It was group of three flap tracks, two retracted, and the third extended. Color pix, where?

BEA would not caption extended without an extension actual, so I think not wreck scramble. It is around. I swear it was #3. I'll find it.

[Organfreak]

Nothing new on the BEA site. Publication of the report is planned for the first half of 2012.

I had read July, as per BEA, but can't remember exactly where I saw that. Let's see, April, May, June...............zzzzzzzzzzzzzzzzzzzzzz

[jcjeant]

Hi,

Better than that. In BEA IR #3, there is a picture of a recovered Flap rail that was EXTENDED. The "Extended" was in their caption, it is not my conjecture.Confused ?
In the BEA report N°2 (english) it's indeed a photo ... page 21

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

and this caption:
From these observations it can be seen that the general direction of the loads
that caused these deformations is bottom-upwards.
Several parts of the flap extension mechanism fairing were found. There were
marks on two of them (positioned at the level of flap track No. 3), made by the
flap extension track on impact. Analysis of these marks (morphological and
dimensional examinations) and comparison with an identical aircraft made
it possible to determine that the flaps were in the “retracted” position at the
time of impact with the water (measurement of the distance between the
track and the lower surface of the flap, position of the carriage on the track).

[AlphaZuluRomeo]

(...)I cannot state honestly what possessed the designers of Bus products to hide the SS one from the other.
Are you sure they are "hidden"?
AFAIK, the position of the other sidestick is less obvious than the position of the yoke (particularly with conjugued yokes), but not impossible to assess, as you seem to think it is.

[A33Zab]

Better than that. In BEA IR #3, there is a picture of a recovered Flap rail that
was EXTENDED. The "Extended" was in their caption, it is not my conjecture.

Thx, jcjeant for explaining this misleading picture.

Hypothetically, since S/F trace is U/A, it cannot be ruled out that that is
exactly how the Rudder was reinvigorated after RTLU instant at a/p loss.


Well, NO....IF S/F where selected (in flight S/F lever #1, slats only! are extended to 16°) the RTLU traces would have shown +/- 31° to allow max. rudder deflection of 35° within 10s.
There is no sign of such RTLU movement so we can conclude FLAPS were FULL retracted and slats (only IF selected) never reached the 16° position.

A hint? RIGHT ROLL, the bias is apparent from the outset, and cannot be
explained. He had extended the brakes, and stowed them, and the evidence is
unclear that all were successfully stowed at deselect.

For that matter,
it is not impossible that one or more spoilers was lost in the air.


No abnormalities at the spoiler traces before 02:13:40 (@ PRIM1/SEC1 selected OFF).
I admit these are servo positions only, but why should a panel separate if the lower gap is closed by the retracted! flaps.

[thermalsniffer]

Jcjeant, technically Lyman is correct, albeit not with respect to the ultimate question.

Your quoted language is from the text.

The actual caption to the picture in the English version of the report at your citation reads:

"Flap extension mechanism (or flap track) no. 3 in extended position."

[Hamburt Spinkleman]

Interim report no. 2 makes it quite clear that the two images of flap track no. 3, in both retracted and extended positions, are not of recovered wreckage but from an identical aircraft used to analyse marks left on recovered flap track fairing parts.

Another misrepresentation of items taken out of context.

[Clandestino]

Confused ?No, just spectacularly amused. How come we can have sensible and rather short discussion when African pilots flying Boeing get disoriented splash it in the Mediterranean while AF447 disaster brings out myriad of hypotheses that would be charitable to call unrealistic?

[Organfreak]

Well, in defense of all the speculators.....this crash seems to be much more complicated and mysterious than that straightforward cockup. And, of course, the 'extra' FBW dimensions of this airplane and situation add many layers to speculate about! :)

Besides (I would argue as devil's advocate), It's a very long wait for a resolution, over three years, and I think ppl are tempted to furnish their own "resolutions." Inquiring minds want to know, or else just make s*** up! :rolleyes:

This crash raises all sorts of questions and fears about the long-simmering Airbus control issues/debate, and gives the multitudes all kinds of fodder to discuss that. Stop me if I am making sense.

But yeah...."flaps"??? C'mon, get real! :hmm:

[Lyman]

Organfreak

A strong hint is furnished on the CVR, when PNF admonishes PF not to extend flaps. Later, there is an order to "Climb". One second later, we hear "NO, don't climb". "well, then, go down."

You question FLAPS? I wouldn't, but the man flying wanted to extend them, NO?

This is not speculation, this is an extension of CVR evidence. This kind of confusion develops on the Flight deck of a Legacy wide body in ETOPS?

This is not a third World cock up. This is a First World C/F. Boeing got nuthin to do with anything. This is NOT AB v. B. That is a sideshow.

cheers, bill

[Organfreak]

@ Lyman:
A strong hint is furnished on the CVR, when PNF admonishes PF not to extend flaps. Later, there is an order to "Climb". One second later, we hear "NO, don't climb". "well, then, go down."

You question FLAPS? I wouldn't, but the man flying wanted to extend them, NO?


Well OK, YES, but at impact? Evidence does not support. As to the cause of the crash, I highly doubt that flaps had much to do with the end result. Am I being difficult? Sure, that's my hobby! :8

This is not a third World cock up. This is a First World C/F. Boeing got nuthin to do with anything.

That's what I said, so I'm glad we agree on that much! But,

This is NOT AB v. B. That is a sideshow.

I don't agree. Numerous speculative (I admit) posts have convinced me that the design of this airplane may have contributed to the confusion, but, of course, not directly responsible for the accident. I think the arguments in favor of very obvious pulled-back yokes are very convincing. Hell, I don't fly, and even I would have intervened had I seen that! YMMV.

[Lyman]

AB/B

When a pilot types, he is assumed to know the a/c. Is AB different? Yep. In approved and certificated ways? Yep, no room to argue. One knows his machine, or he does not. If anyone is confused due prior Boeing time, or vice versa, get a different job. It is ironic that the focus of some criticism is the system that has made the BUS so safe. Who would think to make ALTERNATE LAW a focus, especially re: high altitude upset? As I said before, my neighbor flew the 320 for years, for a Legacy carrier. In his thousands of hours he was out of NORMAL LAW not once. Fair?

The reason there is yet such passion re: 447 is because of the sheer number of shortcomings, poor decisions, bad design, etc. that killed these folks. We get complacent, and complacency leads to more complacency, then we forget.......

add. The lady in the RHS in COLGAN didn't push the yoke forward, and she had more time than her Captain. Don't be so sure "I would have intervened..."

then it happens...... I for one believe the attention is justified, and we let this go at great peril to all of us who fly....

[Machinbird]

You question FLAPS? I wouldn't, but the man flying wanted to extend them, NO?Lyman, I hate to say this, but you are flaunting your confusion and lack of knowledge.
You are confusing speedbrakes and flaps. One goes up, one goes down on the A330.
Time for you to re-read FCOM flight controls again.

PM was telling PF not to extend the speed brakes and PF complied after briefly extending the speedbrakes. If all the emotional sparks had not been flying at that point, one of them might have realized, "Hey! We put out the boards and nothing happened. Maybe we are very slow."

[Lyman]

Mach.

Perhaps. However, and it may be merely linguistic, but FLAPS are extended, Spoilers are Deployed. The first bit of FLAP is an extension of the chord of the wing, and adds lift, further FLAP extension creates more drag than lift. Anything on top of the wing spoils lift, as you know.

Could be wrong, wouldn't be the first time.....

[Organfreak]

When a pilot types, he is assumed to know the a/c. Is AB different? Yep. In approved and certificated ways? Yep, no room to argue.

Sure, but here we had a "perfect storm" where the pilots were apparently not trained (properly). Then, and only then, did these design characteristics come into play. Surely that's a reasonable argument to have.

In the case of your A320 friend, I think that is exactly WHY there had been prior complacency about high-altitude training. It wasn't considered a likely issue, until now. Now there's a mad scramble to address this, and high time, too. What if he HAD found himself in a similar situation? Would he have survived? That can't be known, and I for one don't choose to gamble when the houses get tiny.

How'm I doin', guys? :hmm:

[Lyman]

Organfreak

John is reluctant to discuss 447. He does say the pilots were screwed from the outset, and for many reasons, not the least of which is lack of training, especially re: UAS and high altitude SOPS.

Mach. Who's to say PF did NOT conclude "Hmm.... Spoilers were no help, perhaps FLAP?" The word EXTEND suggests that, at least to me... If, as is possible, all three ended up being worried re: Ospeed, there were discussions re: FLAPS, and prolly GEAR.

In a descent as weird as this one, how is it all are so sure what happened?

Can there be another explanation except that they believed Overspeed?

Never gamble, Organfreak, and try always to keep the houses tiny. Big houses are a problem.

[Organfreak]

Lymanaroonie:
Mach. Who's to say PF did NOT conclude "Hmm.... Spoilers were no help, perhaps FLAP?"

Perhaps due to my lack of advanced technical knowledge, but I have never been able to get my mind around the idea that they thought they were in OS.
Why not? Because of the highly unusual deck angle. How in the world could anyone suspect OS when tipped back like that???????????????????????????? I ask you.

I rest my cases and will now quit while I'm behind.

[PJ2]

Machinbird;

This may help the discussion regarding flap position.

The first photograph is from IR2 (IIRC) but copied/rendered in B&W and rotated for easier comparison with the second image which is from the initial wreckage photographs, also copied, cropped and enhanced for clarity.

I think this is conclusive evidence that the flaps were in the up/retracted position. The rotating flap actuator faces forward (retracted) in the accident photograph but faces rearward (extended) in the IR photograph.

For further clarity, a flap-track schematic showing the rotator in both postions is provided below.

PJ2

http://www.smugmug.com/photos/i-xTPnhHP/0/XL/i-xTPnhHP-XL.jpg


http://batcave1.smugmug.com/photos/i-q9sgjB8/0/XL/i-q9sgjB8-XL.jpg



http://www.smugmug.com/photos/i-qT6X7Hh/0/XL/i-qT6X7Hh-XL.jpg

[Lyman]

Where in Heaven's name did you retrieve that accident image? That is one I saw that I believed to be in IR3. If not, it should have been.

Mechanically, I am more comfortable than aerodynamically, so I would ask for clarification, as the wreck image seems to show a fully extended flap actuator, not a retracted one. The dog is fully exposed aftward, whereas if stowed, it would be sheltered forward, and along the the top of the carriage. Also, I believe though the images and schematic are oriented correctly, they show opposite side wing attachment. Aren't the Rotators outboard?

Also, isn't the carriage extended aft first, before the rotator deflects the flap surface downward? So the actuator could be stowed, and the FLAP still extended FLAP1?

Thx, Captain.

[mm43]

It is rather obvious to me that the rotating actuator controls the fore and aft position of the carriage and hence the flap angle.

Thanks for the clear images PJ2

[Lyman]

Got it. I see. Are there two other images of the FLAP rails, one that is captioned "EXTENDED"? (From the wreck situs)?

[PJ2]

Cheers, mm43.

Lyman;

The original image was provided by the BEA just after the discovery of the wreckage. There were seven other images provided at the time. I don't think that there are/were other images of flap tracks from the wreckage site.

(Edit: I took a look at the two photos of the tracks in IR2, one showing the flap rotational actuator in the extended position and the lower image showing it in the retracted position. The track itself is very beefy, (about six feet long in total, IIRC) and hangs down a long way thus the need for the aerodynamic "canoes". The first photo in the above post was actually from the left wing, but in the rotation to conform to the photo of the wreckage, it appears to be "correctly" oriented. It makes no difference as longitudinal orientation is here unaffected by lateral orientation. This is Flap Track 2 from the R.Wing. Flap Track 1 is differently structured and mounted inboard of the gear near the fuselage/wing join).

PJ2



http://batcave1.smugmug.com/photos/i-h65dtfr/0/XL/i-h65dtfr-XL.jpg

[Lyman]

It is very kind of you to post that additional image, sir. Now I must locate the image with the "extended" caption.

In IR2, the canoes were used as a proxy to suss position at impact, that is why I had assumed the images I saw were from the IR3, the actual equiment is not likely to have remained floating.

Also from this image, I see no evidence that Gear was extended, There is no deflection evident other than mostly vertical whilst stowed.

Thank you again, Captain.

[Turbine D]

Lyman,

In the BEA IR#2, go to page 20. There you will see a photo of the flap extension #3 in the extended position.

Go to page 21. There you will see a flap extension #3 in the retracted position.

Both photos are from an identical A-330 aircraft, not AF447.

The photo of flap extension from the floor of the sea posted by PJ2 is from a series of photos taken by the BEA from the wreckage, but is not in BEA IR#3. Only 4 photos are shown in the report, an engine, a wing section, a fuselage section and the nose landing gear.

Now, if you go to PJ2's post containing the flap extension drawings, you will see how the mechanism works. As the flap actuator rotates clockwise, the flap is pushed rearward and is pulled downward by the carriage as it travels down the angled track. Conversely, when the actuator is rotated counterclockwise, the flap is pulled forward and is pushed upward as it moves up the angled track to its nesting position. IMO, the photo of AF447's flap is in the retracted position.

Hope this clears up your confusion. But Lyman, I have a question: Why is this flap or spoiler position important at all? This large swept wing jet was descending at a pitch up of 16.3º, an AoA of at least 35º or more and a vertical speed equal to the horizontal speed of ~124 miles per hour. So what exactly would flaps extended or spoiler extended do in this situation?

TD

[Clandestino]

Time for you to re-read FCOM flight controls again.Reading the FCOMs when one cannot tell the subtle difference between speedbrakes and flaps is total waste of time.

How in the world could anyone suspect OS when tipped back like that???????????????????????????? I ask you.

How in the world could anyone not abort the takeoff when it's obvious left ASI is not working then after liftoff couple autopilot and autothrottle to the single malfunctioning ASI and stall the airliner on initial climb?

How in the world could anyone hit the ground below airport elevation?

How in the world could anyone turn ninety degrees off required heading during night descent into long, narrow valley?

How in the world could anyone not understand that using the rudder to roll the airliner is reserved strictly for total loss of lateral control and not for wake encounter?

How in the world could anyone pull when faced with stall warning?

How in the world could anyone push the aeroplane into sea during go-around?

Simple.

All it takes to provoke the Grim reaper is to stop thinking and acting as a pilot.

[Lyman]

Hi TD

From the Captain's re-entry to the flight deck til impact, we are told there were no displays on the panel, for either pilot. That means all the flight data available had to be guesswork. The a/c meandered about a "g"of a fairly consistent "1", so deck angle, A/S, and control actuated excursions were all a matter of guess, and what we are shown to have been very little discussion amongst the three.

You claim a NU of 16.3? How luxurious! As I have said many times, that is from the DFDR, and the pilots were "out the LOOP". My picture of this flight Path from the outset of Manual Control is that the crew were outside looking in, they were victims of circumstances that prevented their recovery, having caused the Upset in the first place.

The captain had to have noticed the Deck angle, he was walking, not sitting. Whilst seated, at one g, and nothing visible outside, the a/c could have been inverted, for all the pilots could suss. One G is one G. The popular image of goofy pilots at war one with the others is a painstakingly created construct. Deployed Spoilers, (they were) Extended FLAP (we don't KNOW), and Throttle settings seem outrageous. We were not there.

Just as the G traces for PERPIGNAN have not been released, damning evidence of a/c behaviour wil not be seen, as BEA have morphed their mission statement into releasing "ONLY DATA THAT MAY SERVE TO PREVENT FUTURE ACCIDENT".

That's nice, but consider how much unilateral maneuvering that allows re: evidence and its disclosure. Uncommanded Climb? Let's say we knew PF, and he seemed a competent sort of pilot.

Instead of keeping an open mind, the masses have claimed he screwed the poodle from the git, pulling like a maniac, instead of doing what WE all knew was the "RIGHT" thing. His inability to understand (seemingly) what the PNF was saying was construed as incompetence, rather than a genuine take on a misbehaving a/c. He did not know he was climbing? More like he did not know WHY? Again, with the ergo, lack of proper belting, and the shaking deck, how was he to suss what his stick was doing, w/o a speed tape, a FD, etc? Now this too is damning, but also Human.

I don't know this, but neither do you. When I see all the data, to include all the discussion, (what else is there, that all three had?) I'll give it up.

[Lyman]

Clandestino. FLAPS are extended and then retracted. Also SLATS. Spoilers are DEPLOYED, then STOWED. Words have meaning.

[Hamburt Spinkleman]

"Facts are meaningless. You could use facts to prove anything that's even remotely true" seems to be the philosophy.

Word games or feigned ignorance does not alter the fact that no flaps were extended. Neither were slats.

[HazelNuts39]

Words have meaningNon surtout ne ne (les) sors pas

[Lyman]

Hamburt Spinkleman

"Word games or feigned ignorance does not alter the fact that no flaps were extended. Neither were slats."


Hmm......At Impact? You don't even know that for certain. Is that from chicken guts? Ouija? Not extended then retracted between LOC and Impact?

Who's making bold statements?

If such selections were made, it meant the pilots were desperate, and it is very important to paint them not as desperate, but stupid. Desperate draws attention to their lack of instrumentation, or displays, and that might be construed as a platform problem? Only stupid pilots get wet? Nothing re: Flaps slats or spoilers can be demonstrated conclusively, probably ever. That means certainly that not disclosing these things brings no harm. Only to the pilots, and once they are demonstrated to be fools, to the majority, we can move on?

[OK465]

Neither were slats.

"Aye, there's the rub."

[Lyman]

Slats retracted, sir. Well, that is... the servos are shut. One's missing, but who will know?

[Hamburt Spinkleman]

I have come to realize that is it pointless to use facts as they will just be ignored, twisted or otherwise mangled to suit whatever agenda it is you are pursuing.

Nevertheless, flaps were retracted at time of impact. That is know from impact marks on flap track fairing debris. That is a fact. Slats were retracted at time of impact. That is known from DFDR recorded data, as is the flap position. That is a fact.

Had flaps or slats been extended and then retracted in flight it would have been recorded on the DFDR and caused the RTLU to return to low-speed position. That did not happen. That is a fact.