Well since you've made your mind up there's no need to bother us all again, is there?:ok:

I once experienced the most dissorienting situation in a Lear Jet when my handflying FO was descending at high altitude and while balancing fuel looked up at the instruments while in the clouds and saw my attitude indicator go through 30 degrees bank and increasing towards redline on airspeed. I felt level as obviously did the FO so it took every bit of discipline to take control and level the three attitude indicators to level flight. I was actually flying sitting leaned over in my seat because I didn't feel level. Experience got us through it, JFK JR didn't fare as well with vertigo. I don't think this would have happened with the captain in his seat even though he was rightfully taking his scheduled rest. I wonder how many hours each of the FO's had of actually flying an airliner without an autopilot in the clouds? My guess is 10 to 30 hrs. Airlines don't want you to handfly any more at a lot of places.

Having suffered disorientation, just the once, all I can say to anyone who underestimates it's ability to totally deceive you in the most subtle of manners is..

...wake up quick!

No pun intended.

Something I read: pilots when they become disoriented tend to pull UP. Perhaps this is what we are dealing with here

I don't think pilots pull up when they get disoriented unless they are very knew at flying. I saw a Bonanza take off from Burbank, lose an engine, pull up and turn right into a cross control stall that caused them to spin in killing 4 people. More experienced pilots wouldn't have done that. Hopefully some day they will give us some meaningful information of what led up to this accident. So far they haven't told us much of anything even though they have all of the data. We have a lot of experts expounding on their theories with no data however. BOAC, I'm not saying you.

When the PF started to apply nose down control in the well developed stall, I wouldn't be surprised if the Captain, who by then had plopped himself into a jump seat, started to float out of the seat and vetoed further tests of that solution. After all, with the engines at idle, someone was probably figuring they might have contributed to the aircraft's pesky ~16 degree nose up attitude.

As long as the aircraft was in a stall, it was not flying, and was not under control so CFIT is, in my considered opinion, an overly broad brush for this situation. This is not even remotely like flying into a mountain on approach.

The aircraft was taken outside of its normal flight envelope during cruise. The crew was unable to accomplish the recovery into a normal flight envelope (which was apparently possible given the correct understanding of the situation). Part of the accident investigation will have to focus on why the crew did not achieve correct situational awareness.

Do you think that not having an AOA gage might have been a factor?
It boggles my mind that there are AOA sensors on the aircraft but no real cockpit display.

Yeah, I know, you never flew with it before, so why do you need one now?:ugh::mad::mad::mad:

Since improper flying technique can get an aircraft into stall, a pilot is trained for and is expected to recover from such condition, promptly and efficiently.
An aircraft with handling qualities which make it unlikely to recover a stall isn't suitable for passenger transport.
A stall as encountered by AF447 is a stable flight condition outside its authorised operating envelope, perfectly recoverable in airworthy passenger transports, and far from the second stage of PSG (post stall gyrations) and later, third, stabilized spin. Both later conditions may be unrecoverable in certain types and conditions.
I have flown with and without AOA indicators. They don't replace airmanship and flying skills.

AOA indicator
 

Computers and all other stuff built in to modern FBW aircraft don´t either, but they are deemed necessary anyway. Because they help and assist to implement airamship and flying skills, as an AOA indicator would do as well.

Otherwise we could argue about what is really necessary besides airmanship and flying skills:
A cup of coffee: When the coffee leaves the cup, you are flying upside down.
And a cigar: When it is finished, it´s time to land.

Part of the AF447 crew problem that night must have been stall recognition. The flying qualities in the stall were too much like normal flight. Should that be a certification issue?

What about the "stall stall stall" warning you say? Unfortunately that occurred in a context where its validity was called into question. That is why AOA indicators could have helped.

Did you use your AOA as you flew, or did you consider it redundant?
When the airspeed packs up and anytime you are flying slowly, it can tell you quite a lot about your aircraft's performance potential.

Were your airmanship and flying skills as good at 0200 in the morning as they were at 1000 in the morning? If you had been in one of the front office seats in AF447 when the airspeed went South, are you certain it would have been a non-event for you?

If the stall warning operates off aoa sensors, and you are in the mode not to believe the warning, why would you believe the aoa readout ? Can see it could potentially help, especially in recovery with uas, but otherwise what evidence is there that it would have helped the SA here ?

Harryman
Excellent point, Harryman, IMO. My guess is that it's almost impossible for the programmers (however talented) to 'reproduce' stalls in a simulator; and equally impossible for the trainers (and the accountants) ever to let novice pilots actually stall real airliners worth hundreds of millions of dollars as part of their training..........

Any of us who have learned to fly anything have learned to 'deal with' stalls. But only in basic training (in my case in the odd Cessna and Blanek or T21 gliders). AND with the benefit of good visibility and instruments that were all working.

I doubt (well, just about KNOW) that any such practice would have been unlikely to have been of much help to the unfortunate guys flying AF447; in icing conditions, with at least periodically-malfunctioning instruments, zero visibility, and severe turbulence. AND with pre-programmed 'systems' interfering as well, though some at least of them will have been 'signing off' and 'leaving it to you' in the middle of things, and just sending you a useless 'encoded' message that the PNF just had to waste time reading and cancelling........

So I'm reasonably sure in my own mind what the accumulating 'problem(s)' that caused the accident were.

But I have no idea at ALL as to what the manufacturers AND the airlines can DO about it. And, seems to me, THEY likely won't have much idea either, up to the present time........

RWA and all the other boys and girls here - I'm sorry to bang on about this, but please stop MAKING THINGS UP! - NB NOT 'Severe Turbulence':mad: Please try to stick to the given facts - it only confuses the thread. Soon it becomes 'fact' eg - "why did they fly straight into a CB?".

Well, let us see how this could be laid out in the cockpit.

First you have Port side AOA going to LHS AOA indicator, then Stbd side AOA going to RHS AOA indicator. The indication should be on the PFD if possible, and should NOT be numeric, but instead should be a simulated analog needle or tape display.

Then if you hear the stall warning, you can see the indicator bouncing in the stall zone and check with the other side for the same indications. Hopefully it is designed so as to get your attention, such as a pulsing red color when your AOA is excessive. Since it is moving you know it isn't stuck. Then all you have to do is believe it. Apply nose down stick and observe AOA decrease. Keep AOA in a safe range. Apply power as necessary. You sure as heck know you aren't approaching Vmo.

If you slap the equipment in a cockpit and don't train people in its use, then it is a waste. I'm sure a creative sim instructor can figure out some excellent training exercises to help bring AOA into your scan.

Of course, Concorde had an AoA and 'G' indicator...

http://www.concordesst.com/inside/co...ictures/c1.jpg

To what extent it was included in the normal T scan is another question.....

Not being argumentative, but this is not quite correct.

Flight test data from stall testing, to the extent it was conducted, is incorporated in advanced Full Flight Simulators. These flight tests are obviously structured for some measure of safety, so that beyond a certain point where data collection is out-weighed by risk, any additional data used in simulation is predicted data from other sources.

Beyond the stall boundary there is still a certain amount of training value where simulator characteristics and response to pilot inputs is valid. The problem is you cannot necessarily tell where flight test data transitions to predicted or extrapolated data during a more extended encounter. And truthfully this has not been given any priority in regulatory evaluation requirements of individual simulators. You don't "down" a sim for something for which you have no experience or guidance for subjective evaluation or a flight validated QTG for an automated evaluation.

The big jets are stalled and recovered so as to produce stall warning system functionality and tolerances and recommended avoidance and recovery procedures and technique. Simulations don't discount this.

As has been stated previously, however, improper pilot inputs to any simulation can also take you out of the realm of what was tested and into "new territory".

The advantage of simulation, of course, is that pilots can make improper inputs and get negative feedback safely. There is currently a lot of effort being directed at substantially improving jet transport stall simulations and incorporation into operator training.

If the AoA is being monitored by the 'system' why not include it as part of any related 'aural'.

I don't need to continuously monitor an AoA indication but ...

"Stall warning 10, Stall warning 20, Stall warning 30, Stall warning 40"

... would sure get my attention ...

and ...

"Stall warning 30, Stall warning 20, Stall warning 10"

... just might let me know that ND was having an effect.

When you're flying at Mach 0.6, and have lost your airspeeds, how do you know where your stall zone is on the AoA indicator?

If there is NO AOA indicator in the cockpit, it is NEVER available.

I drink gin and tonics in the back. Give it up boys, an aoa monitor would have made no difference here.

Trouble with forum
 

I am having trouble with progressing further than page 92 on this topic

Any hints or tips? sorry for the trouble

If you travel by air frequently, you may want to switch to something stronger.

Apparently applying nose down control with the side stick is about as effective as selecting page 94 of this thread. The thread defaults to 93. I guess the flight program defaults to stall.

AoA surely is valuable information, but if nose points 16 deg up and altitude is going down, one would assume figuring out that there's a !!!!!load of AoA doesn't really take a rocket scientist?

So maybe they didn't believe what any of their instruments were telling them - still they must have remembered climbing to FL350 - how can 16 deg NU attitude seem like a good idea up there unless you're trying to massively bleed off speed (then you're somewhat unlikely to select TOGA I guess?) or flying a Blackbird?

The more one thinks about it, the less sense it makes. :confused:

The more confused the crew, the more important it is that they have clear, unequivocal, easy to interpret information available. Their internal computers were no doubt overloaded trying to make sense of what they were seeing. They didn't figure it out in time.

Canyonlight
If you will observe, the next potential page is set up prior to the exhaustion of the current page. If you select the next page prematurely, it defaults to the current page.

Ecam alerts and warnings must have been a cacophony. The CVR audio must be interesting.

BOAC

With all (genuine) respect, BOAC, in my view the BEA's use of the word 'slightly' is valueless (like much of the rest of the document) since the BEA provides no information at all on how much turbulence was being experienced before the increase (whether 'slight' or not)?

That there WAS an increase is clearly shown by two paragraphs in the note:-

So the facts are that the flightcrew warned the cabin about likely additional turbulence, and then, two minutes later, diverted 12 degrees to the left of course and reduced speed.

Perhaps 'severe' was too strong a word; and I'll happily substitute 'significant' if you prefer it. But you'll know much better than I do that airline pilots hate diverting or reducing speed unless they have to, because it means delays.

So I hope that you'll agree that there's little doubt that turbulence was a factor in the early stages of the accident?

And moving on from there, one has to wonder why the BEA used the word 'slightly' at all, when it provides no evidence at all to back it up - and, I repeat, no information at all on what level of turbulence was occurring before said increase?

RWA - my position on the 'paucity' of information released by BEA is on record on the site. I agree we have only a 'subjective' assessment of turbulence, but it is pretty much standard practice that if moderate or worse is expected, the cabin will be told to secure carts etc and get the pax and then themselves seated and strapped. I cannot see AF being different there but with so many vital clues missing from the published CVR extracts we do not know. Of course turbulence was present, but the experts opinion is that it would have been 'average' ITCZ turbulence. From what little is published, it appears the pilots took the appropriate action initially - warn the crew, adjust route. Based on what little I see so far I do NOT consider turbulence to have been a contributory factor in the accident.

I am trying to stop the growing spread of the 'urban legend' that they "flew blindly and stupidly into the mother of all CBs". As long as that remains unproven (and unposted), I am happy. As I and others have said, there are significant and meaningful chunks of flight deck comment missing from the release for some reason which may well hold an explanation as to why they zoom climbed, for example, which precipitated the stall.

I have commented in Tech Log also on the Atlantic incident in 2001 where an A340 did a similar zoom - without crew input - and its speed reduced to a very low figure too. Way to go.

Edit to correct my error on Vls

Re unavailable pages, as posted by somebody else, when posts reach a number higher than ending in 00/20/40/60/80, a new page is generated. If Mods. delete some so the “latest” is now within the 00/20 etc. range, the new page number is visible but has no entries and it was said that we can’t get into it.

Look at the most recent post number. If lower than 00/20 etc., there is no accessible next page. If 00/20 etc., there may be another on the next page, or maybe not yet – just have to try it.

Hope that helps.

RetiredF4 wrote: Computers and all other stuff built in to modern FBW aircraft don´t either, but they are deemed necessary anyway. Because they help and assist to implement airamship and flying skills, as an AOA indicator would do as well.

Otherwise we could argue about what is really necessary besides airmanship and flying skills:
A cup of coffee: When the coffee leaves the cup, you are flying upside down.
And a cigar: When it is finished, it´s time to land.

AOA indicator necessity is a function of aircraft handling qualities and mission. It is neccessary in F4 where above 15 units AOA you start using pedals for lateral control, and approach using 19. Otherwise you may depart its operating envelope. In A4 you need it for carrier landings, but don't for airbase operations, although it could be more accurate than airpspeed for determination of climb airspeed, cruise airspeed, endurance airspeed etc...

If it were mandatory, it wouldn't be offered as option, e.g. most Boeing passenger transports. Like ashtrays.

BOAC, we do have the report of one 'expert' on conditions along the airway that night, someone who was actually there and not in some chair greatly separated by distance and time.

The original in French:
IB6024 was 12 minutes behind AF447 (before it deviated, and before AF447 looped in its heading).

For reasons known only to the BEA, the interactive track map that was subsequently released omitted both this flight and the Lufthansa 744 that was 20 minutes ahead, and which deviated to a lesser extent. (The LH track can be traced somewhat by the AMDAR record.)

I will leave it to native Francophones to correct, but I believe turbulence forte is usually translated as severe turbulence.

Macinbird wrote:
Incorrect statement, the aircraft was nose high, low airspeed far below minimum for the configuration, weight and airmass instability, sinking like a rock.

What about the "stall stall stall" warning you say? Unfortunately that occurred in a context where its validity was called into question. That is why AOA indicators could have helped.

Needs no complex evaluation to determine flight condition and corrective actions. AOA indicator would confirm it, and the stall warning is obvious.


Did you use your AOA as you flew, or did you consider it redundant?
When the airspeed packs up and anytime you are flying slowly, it can tell you quite a lot about your aircraft's performance potential.

Were your airmanship and flying skills as good at 0200 in the morning as they were at 1000 in the morning? If you had been in one of the front office seats in AF447 when the airspeed went South, are you certain it would have been a non-event for you?

I am not the typical airline type. As chief experimental pilot with decades experience, who determines the authorized flight envelope by flying out of it (for example, to determine VMO [maximum operating airspeed] we fly at 125% its value), and writes pilot manuals and procedures including stall recovery.

In my operational flying, I am better at 2 am, because I know the associated problems and make proper advance preparations. I never use any questionable chemical substance, not even anti-perspirants which poison your body with aluminum, but instead deodorants which lack it (most readers don't know that).

I agree with "BOAC", there WAS a turbulence increase but, since they only elected to reduce speed at 2h 08, the level of turbulence before that time must have been very benign ideed.
This is very close to the LH crew testimony :
Imho, all this means that those who chose to divert to the east of track had to deviate more, for a longer time and suffered more turbulence.

Read
 

Saturn V, #1868,

you are correct in your statement that the French words

"Ces conditions sont particulièrement fortes"

can be translated into the English words

"These conditions were particularly severe".

But where in this little piece of text do you see the word "turbulence"?

The typical ITCZ conditions that were particularly severe may mean that there were more CB's than usual, so a little more deviating action than usual could be necessary.

Once again, as BOAC has stated many times now, it is not at all necessary to fly through the middle of a CB, in order to get the pitot icing problem. I have seen the TAT anomaly (TAT probe icing due to high ice crystal content) when flying through "light green" radar returns in the neighbourhood of CB's, in other words, while avoiding CB's. Turbulence then was only light, occasionally moderate, nothing out of the ordinary. Saint Elmo's and a sound like rain on the windscreen were also present.
Certainly it is problematic that on certain Airbus types the pitot heating can be overwhelmed by ice crystal icing, that's why a recommendation has been made to change the type of pitots, even before AF447 happened, but the outcome of the accident has much to do with basic pitch and power flying. Remember, four perfect attitude sources where always available, showing a very unusual 15 degrees nose up attitude at high altitude.

Saturn -it would help if you would lay your cards on the table with all this back and forth stuff - most indications we have so far.are that we have NO evidemce that the crew penetrated an active CB, either from a 'separated' armchair or anywhere. You obviously believe they did. Why not state so and declare your evidence please?

I think 'turbulence forte' was discussed extensively on thread 1. I believe it was said to be a non-'standard' grading and thus thought to be subjective. I also think the report was sent well before the LOC. Had it been 'severe' (in your words) the a/c would most probably have been forced to turn back or descend to avoid LOC at that point and/or structural damage and injury to crew and pax. Even your quote from your 'armchair expert' did not consider the weather conditions there to be exceptionally bad.

So - let's hear your facts?

Gerard C, of the three other flights on the track that BEA references, the LH reported moderate turbulence and deviated to the west, the IB chose to deviate 30NM to the east, and said conditions were severe. AF459 deviated 20 NM to the west, then chose to deviate 70-80 NM to the east of the track. (The summary of AF459 indicates they encountered unexpected turbulence at NATAL, and immediately began adjusting their radar, but there is no further mention of conditions they encountered, only what they saw on their radar.) So I don't know how you conclude that going in one direction off the track produced a smoother ride. (AF447 deviated slightly to the west.)

EMIT, as noted in the BEA's first interim report,
The narratives of the other flights as published by the BEA are incomplete, and the BEA has not yet provided any additional information. The BEA has also chosen to not release transcripts of the other flights' communications with ATLANTICO. Are there descriptions of conditions being encountered in their communications with ATLANTICO?

(The BEA summarizing seems to contain at least one error: the LH is said to be at FL 350; but the AMDAR trace says 325.)

I agree we have to await the full CVR transcript to see how situationally aware the flight crew was of the weather they were encountering. For example, did they adjust the mode and tilt of the radar, as AF459 did? If they had, and there was discussion of such on the CVR, would you think the BEA might have mentioned that in their most recent note?

BOAC, I don't believe they knowingly and purposefully flew into a meso-convective complex with cells that were overshooting to FL 520 or 560.

I do have questions, suspicions if you will, about how aware they were of the weather they were encountering. I do wonder whether and why their perceptions of the outside environment were so different from the flights following that they continued on, and the other flights chose to avoid. Clearly, the actions of the crew of AF459 following, with the same plane model, same radar, presumably the same AF training and procedures, on encountering the amas between ORARO and TASIL were dramatically different. How to explain or reconcile the actions of the two AF flight crews?

Just a point to consider, beyond agreeing with many that there is quite a bit of information lacking.

The conditions previous to upset are not as important (in terms of understanding pilot response) as conditions during the period 2:10 to 2:14.

As we all know, conditions change in the vicinity of big buildups. Sometimes those changes are significant. The crew expected some change in conditions before the course correction of 12 degrees. There is no guarantee that their correction was sufficient, though it may have been. It also could have been insufficient, with a result of flying into turbulence that they'd expected to avoid by the course change.

One useful piece of non-evidence that we can work with is lack of evidence of an action taken: absence of further warning to the CC to secure the cabin for turbulence.

I do not feel it reasonable to rule out the possibility that a change in condition was coincident to the other problems they encountered.

The well asked question is then: why no alert to the cabin crew? When things get rough, it is standard practice to have the CC secure the cabin.

Aviate, navigate, communicate is also standard. Crew got very focused on aviate, and were having sufficient trouble with aviate to summon the Captain. That is a possible accounting for the non-call to the CC to secure the cabin.

Admittedly, this doesn't give an answer, it just raises another question. So be it, only so much information to work with.