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BEA Recommendations - AF447  
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 5
Posted (2 years 3 months 3 weeks 6 days 9 hours ago) and read 15687 times:

Consequently, the BEA recommends (beginning on page 205):

€€1. that EASA review the content of check and training programmes and
make mandatory, in particular, the setting up of specific and regular
exercises dedicated to manual aircraft handling of approach to stall and
stall recovery, including at high altitude.

2. that EASA and the FAA evaluate the relevance of requiring the presence
of an angle of attack indicator directly accessible to pilots on board
aeroplanes.

I know many on this board have not agreed in the past when these exact ideas were brought up. In particular, I think there is a lack of understanding about high altitude flying. The change in critical AoA (low speed) with altitude, for instance, small as it is (only a few degrees on most planes), is not widely known. Debate about that fact by pilots and engineers is the canary in the coal mine, IMHO.

The AoA indicator is an idea that the military has implemented since the 1950s, especially the US NAVY, after which they saw the stall accident rate fall in half. While some airlines do have the AoA indicator, I think that most do not. Certainly most civilian pilots are not trained on AoA. Out of curiosity, did any of the AF447 pilots have military flying experience?

In these recommendations, BEA departs from the philosophy of only relying on stall avoidance training for pilots. Rather, recommending training in actual stall recovery, especially at altitude. I totally agree with the BEAs recommendations and commend them on a job very well done.

[Edited 2012-07-05 11:36:51]

[Edited 2012-07-05 11:43:17]

382 replies: All unread, showing first 25:
 
User currently offlinezeke From Hong Kong, joined Dec 2006, 9178 posts, RR: 76
Reply 1, posted (2 years 3 months 3 weeks 6 days 6 hours ago) and read 15610 times:

Quoting tommytoyz (Thread starter):
In particular, I think there is a lack of understanding about high altitude flying.

Like to explain how you arrived at this opinion ? What is the basis for you saying this ?

It would not be an informed opinion which any pilot of a jet transport would not agree with.

Quoting tommytoyz (Thread starter):
In these recommendations, BEA departs from the philosophy of only relying on stall avoidance training for pilots. Rather, recommending training in actual stall recovery, especially at altitude. I totally agree with the BEAs recommendations and commend them on a job very well done.

Not being rude, by going by your profile, I do not think you would be able to understand the report in its entirety, the target audience of the report is not the general public. I also do not think you know much about airline initial and recurrent pilot training and checking. I therefore find it difficult then for you to have an informed opinion either way.

It is a pitty when reports like AF447 and you get people coming out from all areas making fantastic observations, many are made by people who have no qualification or experience to base informed opinions with.

It is a thick document, I am yet to learn anything from it.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently onlineStarlionblue From Greenland, joined Feb 2004, 17075 posts, RR: 66
Reply 2, posted (2 years 3 months 3 weeks 6 days 4 hours ago) and read 15568 times:

Quoting zeke (Reply 1):
Quoting tommytoyz (Thread starter):
In particular, I think there is a lack of understanding about high altitude flying.

Like to explain how you arrived at this opinion ? What is the basis for you saying this ?

It would not be an informed opinion which any pilot of a jet transport would not agree with.

Quite. You hardly have to scratch the surface of the swept wing, high altitude, high speed jet literature without reading plenty about high altitude flying and its effects.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 3, posted (2 years 3 months 3 weeks 6 days 3 hours ago) and read 15537 times:

Quoting tommytoyz (Thread starter):
The change in critical AoA (low speed) with altitude, for instance, small as it is (only a few degrees on most planes), is not widely known.

It's actually a change with Mach, not a change with altitude. The practical impact is the same for most conditions (higher Mach when you're flying high altitude) due to the temperature changes but, crucially, not the same for lower speed maneuvers like a high altitude stall.

This is part of the challenge of pilot training; do you want to go way down into the weeds of very specific and relatively esoteric aerodynamic phenomenon, or do you want to stick with simple, practical rules that can be trained and remembered and not get you in trouble even when it all hits the fan?

Tom.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 5
Reply 4, posted (2 years 3 months 3 weeks 6 days 3 hours ago) and read 15536 times:

Quoting zeke (Reply 1):
It would not be an informed opinion which any pilot of a jet transport would not agree with.

I guess you don't count BEA as credible, which is OK. It's OK to be at odds with what the BEA. But ask yourself - Do you think there is a specific reason they are making these recommendations? Once you read the report you'll see why they made them. Perhaps you don't give any credibility to the BEA. That's the only way to square what you say.

Quoting Starlionblue (Reply 2):
Quite. You hardly have to scratch the surface of the swept wing, high altitude, high speed jet literature without reading plenty about high altitude flying and its effects.

That's not enough. One AF captain here on A.Net said he knew about high altitude because of pamphlets in training. BEA agrees. Why else would they make the recommendations to train more, differently and expressly including high altitude recovery? Unless you give the BEA no credibility, then fine.

Quoting zeke (Reply 1):
Not being rude, by going by your profile, I do not think you would be able to understand the report in its entirety,

We are talking facts. However, it's good that you say it is your belief, because that's all it is.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 5
Reply 5, posted (2 years 3 months 3 weeks 6 days 3 hours ago) and read 15525 times:

Quoting zeke (Reply 1):
It would not be an informed opinion which any pilot of a jet transport would not agree with.

Unless you exclude those at the BEA and Sullenbrger and my sister who is an ex USAF pilot. Zeke, you only represent yourself and your own opinions.

Training also needs improvement. "Currently, to my knowledge, air transport pilots practice approaches to stalls,
never actually stalling the aircraft.
(discussing training)
- "Sully" Sullenberger

I suggest we discuss the facts in the report and the recommendations contained therein. You can agree or disagree, but don't shoot the messenger.


User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 5
Reply 6, posted (2 years 3 months 3 weeks 6 days 2 hours ago) and read 15519 times:

Quoting tdscanuck (Reply 3):
This is part of the challenge of pilot training; do you want to go way down into the weeds of very specific and relatively esoteric aerodynamic phenomenon, or do you want to stick with simple, practical rules that can be trained and remembered and not get you in trouble even when it all hits the fan?

It's not a hard concept to understand and helps explain a lot of things that change with altitude. For all practical purposes it doesn't really matter if this is known or not. But it shows training has been simplified in certain areas.

I would argue that if the pendulum swings too far in the direction of dumbing everything down and oversimplifying things, for fear of confusing pilots, then that can be dangerous too. I have had two discussion with experienced pilots on this and they have little good to say about how new pilots are trained today.

I don't think the pilots of AF447 were incompetent or dumb. They responded in a manner that their training compelled them to respond. It is certainly not trained or written anywhere to do what they did. However, the totality of their training, resulted in them responding the way they did and were never able to figure it out.


User currently offlinezeke From Hong Kong, joined Dec 2006, 9178 posts, RR: 76
Reply 7, posted (2 years 3 months 3 weeks 6 days 1 hour ago) and read 15478 times:

Quoting tommytoyz (Reply 4):
But ask yourself - Do you think there is a specific reason they are making these recommendations?

The two points that you posted in the OP are asking the regulators review and evaluate, they do not require any changes to be made.

Where I work, we do approach to the stall, and stall training, also LOFT style simulator sessions are required under the LOSA system, which we are a member of. We also receive false stall warning training, which is actually more relevant to this incident.

Quoting tommytoyz (Reply 4):
We are talking facts. However, it's good that you say it is your belief, because that's all it is.

I asked a very simple question, what is the basis for your opinions ? i.e. what is your technical competency ? are you rated on the A330 ? are you in an airline check and training system ? are you a pilot ? are you an aeronautical engineer ? do you work for a regulator ?

The report is not designed for the general public to understand, it is written with an assumed level of knowledge by the target audience. The regulators will read the report with their technical competency, they will then evaluate the contents, and compare it to the existing design and operating regulations. They may decide that no changes are required.

Quoting tommytoyz (Reply 5):
Unless you exclude those at the BEA and Sullenbrger and my sister who is an ex USAF pilot. Zeke, you only represent yourself and your own opinions.

I am A330 rated, an airline pilot, and design engineer. I think that makes my opinion more relevant in looking at the report contents than just someone off the street, or paraphrasing other people and taking their opinions out of context. Sullenberger is correct, regular line pilots do not take the real airliners up and actually stall the aircraft, we do in the simulator, both false stall warnings, and stall recoveries. We have all stalled real aircraft before, during training.

Quoting tommytoyz (Reply 5):

I suggest we discuss the facts in the report and the recommendations contained therein. You can agree or disagree, but don't shoot the messenger.

I do not mind discussing the facts, if they are the actual ones in the report.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently onlineStarlionblue From Greenland, joined Feb 2004, 17075 posts, RR: 66
Reply 8, posted (2 years 3 months 3 weeks 6 days 1 hour ago) and read 15475 times:

Tommytoyz, let's keep it friendly please. We can have a discussion but please try to keep it factual, without posturing or rudeness. If you disagree, just say so and say why. Saying things like "Unless you give the BEA no credibility, then fine." is not very helpful.

Quoting tommytoyz (Reply 4):
Quoting Starlionblue (Reply 2):
Quite. You hardly have to scratch the surface of the swept wing, high altitude, high speed jet literature without reading plenty about high altitude flying and its effects.

That's not enough. One AF captain here on A.Net said he knew about high altitude because of pamphlets in training. BEA agrees. Why else would they make the recommendations to train more, differently and expressly including high altitude recovery? Unless you give the BEA no credibility, then fine.

Of course the literature is not enough. You also have to have training. But I would think most airliner pilots have more knowledge than just pamphlets. Pick up any well-known text like "Handling the Big Jets" and effects of high speed and high altitude with swept wing aircraft are discussed in great detail.

And in any case: Even if the pilots had had no idea, there are defined standard procedures to be followed in case of invalid speed indication. Set known pitch and power and so forth. The AF447 pilots did not follow these procedures.

As Tom says:

Quoting tdscanuck (Reply 3):
This is part of the challenge of pilot training; do you want to go way down into the weeds of very specific and relatively esoteric aerodynamic phenomenon, or do you want to stick with simple, practical rules that can be trained and remembered and not get you in trouble even when it all hits the fan?

***

Quoting tommytoyz (Thread starter):
The change in critical AoA (low speed) with altitude, for instance, small as it is (only a few degrees on most planes), is not widely known.

Correct me if I'm wrong but don't wings stall at the same AoA regardless of speed? Last place I read this was "Pilot's Handbook of Aeronautical Knowledge", an FAA publication. Would be happy to learn more about the subject.

[Edited 2012-07-05 20:09:03]


"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 9, posted (2 years 3 months 3 weeks 6 days 1 hour ago) and read 15473 times:

I expect that an AOA indicator will become standard on newly delivered transport catagory aircraft within the next couple years.

It doesn't matter that it very likely would have had no impact upon this accident.

It will be a CYA item by the manufacturers and the airlines.

I find the discussion about developing better flight simulator fidelity so that training can encompass recovery from actual stalls interesting. Also, that such development and training was part of the NTSB recommendations after the Colgan Air Dash-8 crash.

The very depressing thing in the report for me (besides the obvious lack of comprehension by the crew) was how many of the crews in similar UAS incidents did not recognize them as UAS, and did not apply the correct checklist procedure.


User currently onlineStarlionblue From Greenland, joined Feb 2004, 17075 posts, RR: 66
Reply 10, posted (2 years 3 months 3 weeks 6 days 1 hour ago) and read 15470 times:

Quoting rfields5421 (Reply 9):
The very depressing thing in the report for me (besides the obvious lack of comprehension by the crew) was how many of the crews in similar UAS incidents did not recognize them as UAS, and did not apply the correct checklist procedure.

Note, the following is my layman's understanding:
Following such procedures (known pitch and power) would do no harm even if the plane is flying fine and and allow the pilots time to troubleshoot the issue in a stable situation as opposed to a potentially rapidly deteriorating one.

Even if they didn't believe they had unreliable airspeed, it shouldn't matter. You only have the instruments and if you discount them you're in a world of trouble.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 11, posted (2 years 3 months 3 weeks 6 days ago) and read 15467 times:

Also from a laymans perspective (since I've never flown anything above a small GA plane, and current medical keeps me for doing that without a safety pilot)

From June 3, 2009 we were discussing UAS on these thread from the ACARS messages. After the first interim report, we were discussing UAS procedures being properly applied by about three dozen crews. Now the details of those few incidents with enough information show those crews also failed to properly apply UAS checklists.

Yes, proper pitch and power would likely have made this a non-event.

I did find in the BEA report something which we already knew from Mandala499's theory - that the PF may have been chasing 12 degrees pitch up - the correct pitch power for a low altitude UAS.

If the PNF had run the checklist - the proper pitch/ power would have been identified.


User currently offlinezeke From Hong Kong, joined Dec 2006, 9178 posts, RR: 76
Reply 12, posted (2 years 3 months 3 weeks 5 days 23 hours ago) and read 15433 times:

Quoting rfields5421 (Reply 9):
I expect that an AOA indicator will become standard on newly delivered transport catagory aircraft within the next couple years.

I know of no airliner that actually displays AoA, all that I am aware of have a vane that goes via a computer to give a calibrated value. Their usefulness outside their tested range is not known.

A better solution would be for a laser based system which needs no mechanical part to move, or free vents to operate.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 5
Reply 13, posted (2 years 3 months 3 weeks 5 days 21 hours ago) and read 15393 times:

Quoting zeke (Reply 7):
We also receive false stall warning training, which is actually more relevant to this incident.

I disagree, the AF447 crew did not receive any false stall warnings. Why then, do you think false stall warnings are relevant to AF447? The report does not mention that as a factor as far as I know.

Quoting zeke (Reply 7):
Sullenberger is correct,

Yes, he is correct that training is deficient, and I agree with that. That was his entire point and where you are at odds with Sully there and it refutes your entire "no airline pilot would agree"...

Quoting Starlionblue (Reply 8):
Correct me if I'm wrong but don't wings stall at the same AoA regardless of speed?

Speed yes, but not at different altitudes on the low end of the speed spectrum (watch many here jump on this) everything else being equal. There are two types of stalls, if you will. High speed, and low speed. The high speed stall is Mach dependent, the low speed is not. Talking strictly about the low speed stall and the critical AoA there, the critical AoA varies slightly with altitude approaching the low speed spectrum. Most people erroneously think low speed critical AoA remains constant at all altitudes, and it is often taught that way, as it varies little, but it does vary.


Quoting rfields5421 (Reply 9):
I expect that an AOA indicator will become standard on newly delivered transport catagory aircraft within the next couple years.

This is a suggestion I have been making for quite some time now. The military has show their usefulness and the improved safety after implementing them. Almost all military fixed wing aircraft display it. I concur with the BEA report and I think they are starting to think along the same lines and learning teh same lessons the military learned a long time ago. Does anyone know if any Af447 pilots had military pilot training?

Quoting zeke (Reply 12):
I know of no airliner that actually displays AoA, all that I am aware of have a vane that goes via a computer to give a calibrated value

That's plenty good enough. The calibrated values are pretty right on as measured in testing, representing the wing AoA well enough to full fill it's purpose. I have never heard anyone saying it's not good enough. Matter of fact the entire Airbus FBW system uses these calibrated AoA values, including the AoA values we know of that AF447 experienced.

Quoting zeke (Reply 7):
Where I work, we do approach to the stall, and stall training,

Does that mean you actually train in stall recovery, post stall, in the SIM - at high altitudes over 20,000 feet? Yes? What type of simulators do you use?

Quoting zeke (Reply 7):
what is your technical competency ? are you rated on the A330 ? are you in an airline check and training system ? are you a pilot ? are you an aeronautical engineer ? do you work for a regulator ?
Quoting zeke (Reply 7):
I am A330 rated, an airline pilot, and design engineer. I think that makes my opinion more relevant in looking at the report contents than just someone off the street,

So what is your opinion about the two recommendations?

[Edited 2012-07-05 23:39:50]

User currently offlineairtechy From United States of America, joined Dec 2006, 506 posts, RR: 0
Reply 14, posted (2 years 3 months 3 weeks 5 days 21 hours ago) and read 15379 times:

Quoting tommytoyz (Reply 13):
If the pilots had all gotten up and left the cockpit unattended for 5 minutes, autopilot off and all - they would all probably still be alive today, IMHO.

Actually, one minute would have been enough.

Quoting zeke (Reply 7):
Where I work, we do approach to the stall, and stall training, also LOFT style simulator sessions are required under the LOSA system, which we are a member of. We also receive false stall warning training, which is actually more relevant to this incident.

With all due respect, I don't think you work for Air France so the training you receive has no bearing on the training, or the lack thereof, that the pilots at Air France receive.

Quoting zeke (Reply 7):
I asked a very simple question, what is the basis for your opinions ? i.e. what is your technical competency ? are you rated on the A330 ? are you in an airline check and training system ? are you a pilot ? are you an aeronautical engineer ? do you work for a regulator ?

That is a very condescending attitude. Some of us have experience beyond what might be indicating by posting on this forum. Although I am three of the "are you's" that you posted, the lack of the other three should not prevent me or others from offering ideas or opinions especially with the detailed background and analysis provided by this report.

Jim


User currently offlineautothrust From Switzerland, joined Jun 2006, 1596 posts, RR: 9
Reply 15, posted (2 years 3 months 3 weeks 5 days 19 hours ago) and read 15327 times:

Quoting zeke (Reply 12):
A better solution would be for a laser based system which needs no mechanical part to move, or free vents to operate

Can you please explain me how exactly such a system would work? Just curious.



“Faliure is not an option.”
User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 16, posted (2 years 3 months 3 weeks 5 days 14 hours ago) and read 15243 times:

Quoting tommytoyz (Reply 13):
Does anyone know if any Af447 pilots had military pilot training?

The summary of the career progression of the three pilots does not indicate any military experience.

The captain - PPL in 74, FA with Air France from 76 to 82 - and completed his CP, IFR, CFI and ATP during that period. Started his professional flying career Inter Avia Service company in 83, got on with Air Inter 88, Air Inter and Air France merged in 97

The PNF Co-Pilot - PPL in 92, apparently was on the Air France training program, but delayed by the early 90s economic downturn, started Air France type rating in mid-1998 and began flying as an A320 co-pilot that fall.

The PF Co-Pilot - PPL in 2000, trained by AF in 2003, A320 in 2004

Quoting airtechy (Reply 14):
Quoting tommytoyz (Reply 13):If the pilots had all gotten up and left the cockpit unattended for 5 minutes, autopilot off and all - they would all probably still be alive today, IMHO.

Actually, one minute would have been enough.

I disagree with both timelines.

Unless you mean the crew should have not touched the controls when the AP disconnected.

Just before the one minute mark after A/P disconnect - the aircraft was stalled. And fully stalled past the point it could fly itself out.

Even during the inital disconnect and during the first minute - the aircraft wanted to roll right. Leaving his hands off the controls would likely have allowed the aircraft to roll sufficiently right to become unable to fly.


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 17, posted (2 years 3 months 3 weeks 5 days 12 hours ago) and read 15186 times:

Quoting Starlionblue (Reply 8):
Correct me if I'm wrong but don't wings stall at the same AoA regardless of speed? Last place I read this was "Pilot's Handbook of Aeronautical Knowledge", an FAA publication.

There is some Mach dependance (modern airfoils have a shockwave on the upper aft surface, this shock can trigger seperation). At low speeds, despite Tommytoyz insistance, there's no altitude variation (we have a longstanding disagreement on this point that's not going to get resolved here). Unless you get Mach (or, equivalently, Reynolds number) effects into play, stall AoA is constant.

Quoting Starlionblue (Reply 10):
Following such procedures (known pitch and power) would do no harm even if the plane is flying fine and and allow the pilots time to troubleshoot the issue in a stable situation as opposed to a potentially rapidly deteriorating one.

Correct.

Quoting zeke (Reply 12):
I know of no airliner that actually displays AoA, all that I am aware of have a vane that goes via a computer to give a calibrated value.

It's an option on all current Boeings; relatively few airlines take the option.

Quoting rfields5421 (Reply 16):
Just before the one minute mark after A/P disconnect - the aircraft was stalled. And fully stalled past the point it could fly itself out.

Stalled past the point of recover is a deep stall; AF447 was never in a deep stall. They had nose-down pitch authority the entire time. They could have flown out of it at any time as long as they had enough altitude.

Quoting rfields5421 (Reply 16):
Even during the inital disconnect and during the first minute - the aircraft wanted to roll right. Leaving his hands off the controls would likely have allowed the aircraft to roll sufficiently right to become unable to fly.

There's no such thing as a roll attitude at which you can't fly. Although highly not recommended, modern airliners are perfectly capable of rolling and recovering.

Tom.


User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 18, posted (2 years 3 months 3 weeks 5 days 11 hours ago) and read 15183 times:

Quoting tdscanuck (Reply 17):
They could have flown out of it at any time as long as they had enough altitude.

The report list 31,500 feet as unrecoverable except by a crew trained for that specific flight event and expecting to execute the maneuvers. The aircraft was passing through 31,500 feet a little before the 1 minute mark.

There must be some simulator exercises or math or other data to support their conclusion - I only reported their conclusion.

[Edited 2012-07-06 09:19:29]

User currently offlinecanoecarrier From United States of America, joined Feb 2004, 2842 posts, RR: 12
Reply 19, posted (2 years 3 months 3 weeks 5 days 11 hours ago) and read 15156 times:

Quoting tdscanuck (Reply 17):

There's no such thing as a roll attitude at which you can't fly. Although highly not recommended, modern airliners are perfectly capable of rolling and recovering.

Haven't we discussed that a rather significant roll would have been the only way to recover from the stall once the plane passed through 31,500'? I thought at some point just pointing the nose down would not have allowed the plane to recover. Although, I may be remembering a pre-Interim Report discussion where we hypothesized they could have entered a deep stall.

Quoting Starlionblue (Reply 8):
And in any case: Even if the pilots had had no idea, there are defined standard procedures to be followed in case of invalid speed indication. Set known pitch and power and so forth. The AF447 pilots did not follow these procedures.

Sort of. As Fields mentions it is possible they were using the values for the wrong phase of flight.

Quoting rfields5421 (Reply 11):
I did find in the BEA report something which we already knew from Mandala499's theory - that the PF may have been chasing 12 degrees pitch up - the correct pitch power for a low altitude UAS.

Right. The report discusses:

"the flight director displays could have prompted him to command a positive pitch angle, of about 12.5°. This value appears in the stall warning procedure for the take-off phase. It is possible that, even though he did not call it out, the PF had recalled this memorised value and then had clung to this reference without remembering that it was intended for a different flight phase. The conjunction of this remembered value and the flight director displays may have constituted one of the few (and maybe even the only) points of consistency in his general incomprehension of the situation"

[Edited 2012-07-06 09:40:36]


The beatings will continue until morale improves
User currently offlinetommytoyz From Tonga, joined Jan 2007, 1353 posts, RR: 5
Reply 20, posted (2 years 3 months 3 weeks 5 days 11 hours ago) and read 15157 times:

Quoting rfields5421 (Reply 16):
Just before the one minute mark after A/P disconnect - the aircraft was stalled. And fully stalled past the point it could fly itself out.

Even during the inital disconnect and during the first minute - the aircraft wanted to roll right. Leaving his hands off the controls would likely have allowed the aircraft to roll sufficiently right to become unable to fly.

That is actually one recovery technique from a stall. The 727, while in flight testing, it was decided to stall it. Well, it is a T-Tail and it can get into a deep stall, like most T-Tails. That is the horizontal stabilizer is in th wake of the main wing and is ineffective and normal revocery is impossible. The Boeng test pilot, anticipating this might happen from previous Bac-111 and DC-9 crashes due to this, was able to recover from the deep stall, by rolling steeply and letting the nose fall out.

I don't think the A330 would have stalled if left to fly without anyone touching the controls and left to it's inherent aerodynamic stability, despite turbulence. Might have been a wild ride at worst, but that's about it.

Quoting tdscanuck (Reply 17):
It's an option on all current Boeings; relatively few airlines take the option.

The same for A330s, though not on AF A330s.

[Edited 2012-07-06 09:52:09]

User currently offlineairtechy From United States of America, joined Dec 2006, 506 posts, RR: 0
Reply 21, posted (2 years 3 months 3 weeks 5 days 9 hours ago) and read 15106 times:

Actually, as we have discussed before, they would have been better off if the auto-thrust part of the autopilot had disconnected but the pitch and roll part had remained active. In a minute or so the correct airspeed would have been restored by the heaters and the auto-thrust would have/could have re-engaged.

As Tom has pointed out, this would have worked in this case but maybe not others.

I believe the auto-trim cranked in max up trim due to limits being removed in the ALT 2 LAW mode which, even with full down stick command, would have taken a while to crank out. Still they should have had enough altitude to recover.

Although it's obvious the pilots screwed up royally here, I think the report was light on criticism of Airbus regards the way information was being displayed to the pilots, the audible alarms adding to the confusion, the way the airplane handles in alternate law modes, and other things.

We have not had a high profile accident involving a large Boeing aircraft, thank goodness, so we don't have the type detailed analysis that this report provides us about the way the Airbus works. Who knows, Boeings may have similar issues.

Jim


User currently offlinecanoecarrier From United States of America, joined Feb 2004, 2842 posts, RR: 12
Reply 22, posted (2 years 3 months 3 weeks 5 days 8 hours ago) and read 15072 times:

If the purpose of this thread is to discuss the Final Report..which I'm not exactly sure it is, I'd add that the BEA did have some interesting observations about search and rescue as well as ATC in these remote areas of the world.

Particularly, the recommendation that a permanent and reliable link be made to between the aircraft and the ground in all areas where HF remains the only means of communication. And, that the SAR organizations in both Brazil and France could have operated more efficiently. Leading to a recommendation that coordination plans be made in the event something like this occurs again.

I'm not sure either recommendation would have made any difference here. It's unlikely that even with a permanent air to ground voice communication system that the pilots would have called out their position. Certainly the only thing that may have been improved with better coordination is that the crash site might have been not taken 3 tries to find if SAR aircraft were on scene earlier.

They do recommend the mandatory utilization of ADS-C in these areas. I thought Tom mentioned that all new aircraft are being fitted with this technology?



The beatings will continue until morale improves
User currently offlinerfields5421 From United States of America, joined Jul 2007, 7607 posts, RR: 32
Reply 23, posted (2 years 3 months 3 weeks 5 days 8 hours ago) and read 15062 times:

Quoting airtechy (Reply 21):
I think the report was light on criticism of Airbus regards the way information was being displayed to the pilots, the audible alarms adding to the confusion, the way the airplane handles in alternate law modes, and other things.

I find the report to be a strong negative of the way all aircraft manufacturers do such things - the presentation of data, the heavy reliance on audible alarms when they are known to be less effective than visual alarms, etc.

While the report does not specifically mention Boeing aircraft - being outside the scope of the report - the implication is clear that Boeing, Bombardier, Embraer, etc - all provide sub-optimal information to pilots when things go to heck.

I find the report to says there are serious problems in the entire current systems. This accident should not have been possible in these modern aircraft.

Quoting canoecarrier (Reply 22):
I'm not sure either recommendation would have made any difference here.

The SAR recommendations would not have done anything for this crew/ passengers. However, if the crew at taken actions sufficent to make this a survivable crash - in my opinion - the SAR system would have failed to get to the survivors in time to rescue them.

Reading the chronology of the confusion, lack of understanding of areas of responsiblity, not even having the correct phone numbers to talk to other centers watching the area - scary stuff if you could end up in a raft waiting for rescue.

BEA is recommending some fundamental changes in the way airlines do business, the way authorities do business, etc.


User currently offlinecanoecarrier From United States of America, joined Feb 2004, 2842 posts, RR: 12
Reply 24, posted (2 years 3 months 3 weeks 5 days 7 hours ago) and read 15047 times:

Quoting rfields5421 (Reply 23):
While the report does not specifically mention Boeing aircraft - being outside the scope of the report - the implication is clear that Boeing, Bombardier, Embraer, etc - all provide sub-optimal information to pilots when things go to heck.

BEA has put together a number of working groups on other systems (e.g., transmission of DFDR/DCVR data, locator beacons) that are not aircraft manufacturer specific. Therefore, there is the likelihood that some of the information gleaned from the development of this report may later be shared with other aviation regulatory bodies that could contribute to an overall improvement in flight safety regardless of the manufacturer (e.g., CRM).

Quoting rfields5421 (Reply 23):
I find the report to says there are serious problems in the entire current systems. This accident should not have been possible in these modern aircraft.

It's interesting that the report does mention that the PF may have embraced the common belief that this (modern) airplane could not stall.



The beatings will continue until morale improves
25 tommytoyz : That was the intent. Especially the two recommendations I copied from the report. I would like to explore further, First: Why, as the report says (pa
26 airtechy : Which would indicate that the pilot either through lack of training or confusion did not understand how the various "LAWS" affected the control of th
27 canoecarrier : The report says there was a lack of training. And confusion. It doesn't say that had anything to do with which "LAW" the plane was in. edit: I think
28 Starlionblue : Well... That would mean the aircraft would have to have the means to recover by itself. And that means taking away those means from the pilots (since
29 rfields5421 : I'm not saying pilots should not have the ability to turn off protections, or that aircraft should not drop protections when the data sources necessa
30 Starlionblue : I don't think the aircraft was unclear. It told them speed data was invalid and the pilots confirmed it on the CVR recording. It told them the autopi
31 SLCPilot : While this post is a little late, I think some the original concerns about the nature of the OPs post are unfounded. To me, tommytoyz sounds like a sc
32 OldAeroGuy : All stalls are Mach related. You need to correct the stall AoA (and stall CL) for Mach effects across the flight envelope. Below 0.7M or so, the corr
33 tommytoyz : An AoA indicator would have shown the trajectory of their AoA and that their inputs were making the AoA worse, not better, even with inaccuracies due
34 Mir : They absolutely did, right after the problems started occurring. You can't fly a groundspeed, which is what GPS gives you - the difference between th
35 rfields5421 : Actually no - pilots don't know the winds aloft. They know what is predicted and over the period of a half-hour or so, can calculate the average wind
36 Post contains links zeke : What confirms the difference between a real stall warning and a false warning ? A bit like having a barometer at home indicating 28.5" and saying it
37 canoecarrier : Great post Zeke. What if the video only focused on the cockpit instruments and didn't show the pilots themselves? I'd have to go back to some of the t
38 Mir : It would defeat the point of the video. You might as well just record what the avionics computers are putting up onto the screens (which should be do
39 airtechy : I understand that, but evidently the transfer function of the control loop is different....higher gain in ALT B and DIRECT LAW vs NORMAL LAW. This co
40 zeke : I say again, they are controlled the same way, regardless of the law. With direct you have the addition of manual pitch trim. None of the laws requir
41 Post contains images airtechy : So are you saying that the response of the airplane is identical with regards to sidestick movement in any of the LAWS as long as we don't exceed wha
42 Post contains links zeke : Flying 101 is the operation and effects of controls. The control input response is not identical with variation of speed or flight control system/law
43 Starlionblue : Yepp. There was a checklist that would have made the whole problem go away. Actually what I like about the reporting is that even the tabloids I have
44 rfields5421 : From reading the latest report I can see three reasons the PF may have felt he had to do something immediately. 1) His preoccupation with getting abo
45 Post contains images Pihero : The case of the "not -executed unreliablre airspeed check-list " was bound to come up again... ... and again I will fight it. Let's look at what happe
46 Starlionblue : Fair point. However if the instruments screw up that badly don't we need to ground all 330/340s today? I think you answered your own question. How wo
47 rfields5421 : On my phone headed to Akansas now. Can't quote Re instruments / DFDR - BEA has recommend a change in recorder standards to require recording all instr
48 Post contains links canoecarrier : Airbus and BEA already defined that in their technical documents related to AF 447. They developed equations that defined what an "unsafe event" was,
49 tdscanuck : It went to max uptrim because the average command from the PF was a sustained nose-up. In FBW pitch laws, the elevators do the fast responses and the
50 airtechy : Tom, Do you know the record data rate for the DFDR. I ask that because I don't think you need to dump the entire recorded contents of the recorder....
51 airtechy : Is there a published standard for the performance and certification of FD's? I would assume that would have to come out of an international committee
52 Pihero : ...but it is basically wrong for all occurrences past 02;10;21sec Z, after which the FD engagement requirements change from the initial ALT CRZ ( i.e
53 Mir : Immediately after the airspeed indications went awry, they got a stall warning. That's an indication of a false warning, driven by incorrect air data
54 tdscanuck : It depends on the parameter. Fast one are, I believe, 8 Hz. Slower ones can have any integer multiple up to about 0.25 Hz. The trick is that you need
55 Post contains images airtechy : I probably didn't state that correctly. What i was asking would probably be better stated as what is the total saved byte count per second considerin
56 autothrust : Thank's for the explanation. Didn't know that about the helicopters. It would really make sense to change to a sensor which is not prone to icing, or
57 Pihero : The point is that the FD takes as init ref the values of heading and vertical speed that are present when it re-engages. All that happened earlier is
58 autothrust : Thanks, then what would a longer battery life be of use if you have to be exactly right above the beacons to hear them? I thought it was a loud signa
59 Starlionblue : Sure. But that seems like rather tricky engineering. And by tricky I mean expensive. In the end, even these recorders were found after an extremely r
60 airmagnac : It seems that the battery technology exists to length the emission life of the beacons at very little cost, so if it can be done, you might as well j
61 Post contains links zeke : That is not correct, the aircraft presents basic HDG and V/S mode when the FD comes back on, this is confirmed by the FMA with HDG and V/S +/- a valu
62 Post contains links tommytoyz : - That's it? - Anything is possible, but the entire A330 FBW AoA protections are derived from these vanes. Works perfectly fine. The AoA limits can b
63 tdscanuck : It's on the order of a few MB per second. The issue there is that you now make the CVR/FDR way harder to find, in general. Finding wreckage is relati
64 zeke : Incorrect Every flight at high flight levels near rec max in turbulence, every flight when the wing is contaminated, this is industry wide. Which is
65 tommytoyz : Your answer does not respond to my question about the aspect of power application. This was what I asked: - See? I did not ask about the aspect of Ao
66 Post contains images Pihero : Except that at every re-engagement occurrence, here the VS data seemed to have been coherent with the aircraft situation. as I wrote :
67 tdscanuck : But I think the results will be the same in either case; when you're on a precomputed path and you're below path the FD will command up (the situatio
68 Mir : Most professionals also know that there is not a hard relationship between how close you are to the critical AoA and when the stall warning sounds, a
69 tommytoyz : Tom, this is a good point. But Zeke, specifically mentioned light planes, which have little wing geometry changes due to LF changes. Even if they did
70 airmagnac : A warning is created by comparing the threshold value and a measured value. In this case, the threshold value is the critical AOA, which varies with
71 Mir : Amazingly enough, they do. -Mir
72 tommytoyz : Yes, thanks for pointing out the distinction between airliners and light aircraft. The stall warning threshold does not change by any perceptible amo
73 tommytoyz : Can you give me an example or two of which light aircraft has a stall warning system that varies the AoA trigger according to changes in LF (wing cha
74 Mir : First of all, changes in wing geometry aren't the same as changes in load factor. But, the Cessna 172 and 152 have stall warning devices that are aff
75 tdscanuck : On a light plane you're unlikely to get significant wing geometry change with load factor, but that's not the only thing going on. Light airplanes te
76 tommytoyz : Yes. But this is different from saying that the warning trigger point for the simple stall warning devices move around depending on LF, which is what
77 Tupolev160 : I think it is loud and clear now: Bonin is resposonsible for this crash by acting in the worst way he possibly could. These are the results of over-au
78 Mir : They have flaps, don't they? If those aren't geometry changes, I don't know what are. -Mir
79 tommytoyz : Simply changing LF only, as Zeke said, will not change the trigger point for the warning on light aircraft. You are talking about comparing one confi
80 Mir : You claimed that stall warning systems do not compensate for wing geometry changes. That's not correct. If you're talking about load factor, that's a
81 tommytoyz : Staying in context, nobody here said anything about comparing the warning trigger moving on light aircraft because of different wing configurations,
82 Mir : If you read Tdscanuck's Reply 75, you'll see that it can. Stall warning systems are aerodynamic, and thus are affected by airflow around their locati
83 bond007 : I think the accuracy of that statement might depend on whether you are at 30,000ft .... or 500ft! Jimbo
84 tommytoyz : An indicator shows the trend, like a speedometer on your car. If it errs slightly on the side of caution when the speed indicators are out, it's no b
85 Mir : Being led into doing a stall recovery procedure at 500 feet when you don't need to is a biggie. You can get unnecessarily close to the ground very ea
86 tdscanuck : That's not exactly what zeke said: He said that the stall warning can go off in a steep turn (high load factor) despite not being stalled (tacit assu
87 Starlionblue : Couldn't have said it better... tommytoyz, you need to realize that airliners are not fighter jets and cannot be flown as such.
88 Post contains links and images zeke : I have responded appropriately numerous times. No stall recovery procedure on any aircraft asked for the immediate application of thrust, never has.
89 bond007 : My point exactly! When I'm on short final, the last thing I want is a false stall warning, and you say .... May want to rethink that statement. Jimbo
90 tommytoyz : So do high altitude planes such as the U2 and others, like high altitude drones, which rely heavily on AoA at high altitude and on other phases of fl
91 Post contains links canoecarrier : Fairchild already sells them. http://www.fairchild-controls.com/wp...oads/2011/10/FC-VFDRS-brochure.pdf I think you're right. As you said, this was a
92 Mir : Airliners don't spend 90% of their time with 10kts between high and low speed buffet. If you're going to have them in the airplane anyway, you might
93 tommytoyz : Can you please elaborate? Are you saying the PFD is displaying the AoA? Or just using the speed as a reference and displaying that? What happens to t
94 Mir : The low speed cue is not fixed - it moves as appropriate for the current flight conditions (bank angle, weight, configuration, load factor, etc.). An
95 tommytoyz : AoA was never compromised throughout flight AF447 that night, even though speed went out - AoA sensors, their inputs and values performed exactly as
96 Mir : I didn't see anything in the report to that effect. The initial (and brief) stall warnings make me think that the AoA vanes were also compromised and
97 Starlionblue : You are now comparing U2 and drones to airliners. The laws of physics do not change, granted, but planforms and missions certainly do. It's not the s
98 tdscanuck : An airliner stall warning system includes speed, load factor, configuration, and AoA. It's not just AoA. They do. That's what a pitch limit indicator
99 Post contains links and images Starlionblue : Let's illustrate what Tom and Mir are on about: EDIT: I don't know how Airbus does it, but I guess in Normal Law there is no need for a PLI as the air
100 tommytoyz : - Indeed and excellent article, and I quote from it: The U.S. National Transportation Safety Board (NTSB) has recommended visual indication of AOA in
101 tdscanuck : Nobody's resistant to presenting the information. PLI is standard on Boeing aircraft now, exactly as the NTSB wanted. People are resisting adding *an
102 Post contains images Mir : There are little indicators on the PFD that will show where the limits are (i.e. where the FBW will intervene). They're not big, but they're there. T
103 Starlionblue : Thx for infor Mir. So basically the same kind of presentation. And again no need for explicit AoA apparently as that information is presented as per
104 Post contains links Mir : Here's a video to illustrate it better: http://www.youtube.com/watch?v=ECV3IBkzZLc Starting off, you can see the two little green tick marks on each
105 zeke : I feel the same way, I think they were overwhelmed with what they had. I would have liked a bit more emphasis on making sure the air data remains val
106 canoecarrier : You bring up good points. The report seems to say that the problem went away on any aircraft that had the original Thales probes replaced with the C1
107 tommytoyz : PLI is basically an AoA indicator by another name. It's good that it's finally standard on Boeing planes. However, I still think a stand alone back u
108 tdscanuck : Sort of. It conveys all the information that an AoA indicator does, plus more. Hence the puzzlement on the insistence that an AoA indicator is needed
109 Post contains links tommytoyz : Then why has the BEA and NTSB made the recommendation to display AoA since well after PFDs? I am confused here. By displaying AoA and the limits and
110 canoecarrier : What about the stall that this aircraft was in was sudden and violent? If I recall correctly, there is no simulator that can reproduce airplane chara
111 Starlionblue : If the PLI is wrong, an AoA indicator would be wrong. They're driven by the same data. I'm guessing the rule is that if data is obviously wrong or mi
112 tdscanuck : Because there are several thousand non-PFD airplanes out there. Whenever one of them crashes because the crew didn't have a PLI-type indicator, the N
113 tommytoyz : The BEA, in the AF447 report, must think it is relevant, as they have have made that recommendation regarding an AoA indicator. Why would they do tha
114 Post contains links zeke : They made numerous recommendations, none should be read in isolation, in particular the 4.1.2 Certification recommendation with the one you keep harp
115 Starlionblue : The crucial facts of this accident IMHO. Aircraft lost speeds. PF pitched up. Eventually, the stall warning blared at them for almost a minute. The s
116 flipdewaf : Another display reduces information? As far as I can tell AoA needs airspeed data to display/work correctly so if pilots can't rely on airspeed then
117 David L : That might be fine for keeping the aircraft flying but suppose the pitots become blocked permanently? What would it be like to fly the rest of the cr
118 Kaiarahi : Because that's what investigators do. For example, AF358 (YYZ, 2005) touched down in an unstabilized approach wayyyy down a contaminated runway in a
119 Post contains images tom355uk : That's a pretty reflexive and broad statement to make. You still need a functioning attitude and altitude indication as a minimum - even then you hav
120 Mir : It's true that stalls in simulators appear to be smooth and controlled, but that's because of the way they're conducted. The way we train for stalls
121 canoecarrier : I agree. Its unfortunate that BEA took the time to send out the press release and gather a number of professionals in this field but didn't release m
122 Mir : Even if they do, remember that the military is a very insular organization with its own well-established culture, so they may well have insisted on a
123 Post contains links tommytoyz : The stats favor AoA indicators if this is your metric. Many more people have died due to exceeding critical AoA, than due to AoA system failures. The
124 tdscanuck : No. It's completely possible to exceed pitch, yaw, roll, and speed limits with AoA in the green. The PLI already shows this difference. You get nothi
125 tommytoyz : Safe speed limits and safe pitch can be controlled with AoA - easily - even easier than with only speeds, some Navy pilots say. "Exceeding" roll and
126 tom355uk : I wonder how it actually stands up when you consider how many of these incidences you speak of incorporated no stall warning (imminent AoA exceedance
127 tommytoyz : I never said ignore everything and fly by AoA alone. What I said was: If altitude and attitude are deemed fine - then use it. But one thing to always
128 Mir : You're saying that you can determine what speed you're flying at and what your pitch is by comparing where your nose is pointed to where the airplane
129 tdscanuck : No, they can't. You seem to think AoA and speed are coupled; that's only true *at constant load factor in straight flight*. In other words, the compl
130 Mir : And, it should be added, they're not the only ones to have done so. -Mir
131 tommytoyz : Ok, let me take a lug of coffee. We will never agree on this. But certain things need to be set straight: I know they don't depend on each other. And
132 tommytoyz : Stable enough. As you said, the ae not unstable. Bottom line is AoA is helpful, especially in critical situations. Otherwise Boeing would not have PL
133 Starlionblue : I don't see your point. It is perfectly possible to have the same AoA at widely differing pitch angles. If the PLI on the attitude indicator doesn't
134 canoecarrier : As others have asked you, what would another instrument, who's output was already available to these pilots on that night in the form of a PLI, have
135 Post contains links and images zeke : Produce the stats. No, the military do not teach that AoA is a primary instrument, they teach just like in the civil world attitude and thrust as the
136 tommytoyz : Not permanently. Besides, all you have to do if you are in a dive and can't notice it, is look at your VS or altimeter to know to level out by increa
137 Starlionblue : tommytoyz, I still fail to comprehend why you think a dedicated AoA indicator would have saved AF447. What would a dedicated AoA indicator have given
138 tdscanuck : No, you can't, without at least one other piece of data...load factor. If I give you a time history of just AoA you can't get any pitch data out of t
139 Post contains images Mir : No you can't, because AoA neither knows nor cares about the horizon. You'd have to use other instruments in conjunction in order to get a meaningful
140 Post contains links zeke : That is exactly what the regulator will be doing when they evaluate the recommendations, they have a long history of unlikely scenarios that have hap
141 Starlionblue : Quite. Remember that this was the proverbial dark and stormy night. Many many pilots have been disoriented is such situations. They might well not kn
142 tommytoyz : That is not true Tom. You can not get from a horizontal to a nose down dive of 170 degrees without changing AoA from the 1g horizontal AoA. Even if y
143 David L : Exactly, so "staying in the green on AoA" does not mean that "automatically, all the others are in the green also". Flying pitch and power seems a lo
144 Starlionblue : That wasn't what Tom said. He said the AoA can be the same in both those situations. Quite. In instrument flight without visual references, as this m
145 Kaiarahi : That's exactly what the AF447 crew did. That's as simplistic as maintaining that a separate instrument replicating what's already on the PFD would re
146 Mir : Yes, it is possible. We're trained not to put a lot of credence in those, for good reason - they can be seriously misleading. It knew what the report
147 tdscanuck : Yes, you can. To do the entire maneuver at constant AoA would require some very careful flying but it's certainly possible (you need to modulate spee
148 tommytoyz : Agreed. That's why I disagreed with Tom when he mentioned LF and also because you can not control nor monitor AoA via LF. I didn't read anything in t
149 tommytoyz : My point was exactly as stated. It can not remain constant. It must change. As you mentioned - it must modulate to get there. Any pilot using AoA wou
150 Post contains images flyingturtle : These sentences just jumped at my eyes. How many people are dying is a questionable metric. You would also have to ask how many people survive both t
151 David L : I don't think anyone suggested that at all, only that keeping the AoA "in the green" won't prevent such departures from happening without you knowing
152 tommytoyz : My main point in that statement was not to recommend to throw everything out, but to illustrate how powerful controlling AoA is. If the rudder and ai
153 tdscanuck : No, it mustn't. To pitch over the load factor has to change. That's not the same as an AoA change because AoA is coupled to load factor through speed
154 Mir : Strangely enough, I didn't read much about the AoA values in the report at all, at least those developed by the vanes. There was some data on IRS-gen
155 Kaiarahi : I can't believe you said this - or maybe I can; it just destroyed your last shred of credibility. Buttocks are the primary cause of death in IFR flig
156 Starlionblue : I concur. Seat of the pants in IFR is a bad bad bad idea because, to paraphrase Obi-Wan Kenobi: "Your senses can deceive you. Don't trust them." Now
157 AirlineCritic : Now that you mention it, that was indeed something that was missing. I remember that when reading one of the earlier reports, I badly wanted to under
158 Post contains images mandala499 : Go and read the FDR plots in the report. It's there, and the discrepancies are there (eg: stuck AoA). Actually, in this case BEA recommends "that EAS
159 tommytoyz : Please reread my entire sentence in that post. I never made such a statement. I never suggested for anyone to fly by the seat of their pants or anyth
160 flipdewaf : Then you should go and read what a phugoid is go and read up then come back. Yes, permenantly (well as long as it takes to ruin your day). Unlikely?
161 zeke : I see you have declined my invitation to clarify the use of AoA in the event of unreliable speed on military aircraft. For giggles today I looked at
162 tommytoyz : really? What do you know that the BEA does not? (page 198) The aeroplane’s angle of attack is not directly displayed to the pilots. I am tired of f
163 Post contains links and images zeke : That does not say it is not available, it says it was not directly displayed, which is true as they had HDG/V/S selected. All the pilots have to sele
164 Post contains images Kaiarahi : Do you read what you write? You're utterly and blatantly misquoting Zeke. What he said was: We've been down this road with you in at least two other
165 Starlionblue : Well said Kaiahari. I may not have credentials with regards to piloting or aircraft engineering. Certainly my knowledge has come about from self-stud
166 Post contains images mandala499 : You wrote: Sorry, that, in my books is asking for trusting the buttocks in IFR... Spin it anyway you like, I'm not the only one who thinks you're adv
167 Pihero : What is -interestingly - funny is that the whole thread passes over one glaring point : Our performance data are based on equivalent airspeeds, taken
168 tdscanuck : In straight & level cruise, pull back power slightly. AoA will increase to compensate if you stay straight and level. Then let a phugoid take hol
169 Kaiarahi : For what it's worth (there's not much in the report from the specialized Human Factors Working Group commissioned by BEA): 1. The vastly less experien
170 tommytoyz : Where do I begin Zeke? -AoA can not be properly controlled by looking at pitch or trajectory. These are not AoA indicators, as you seem to think. The
171 Aircellist : Let's see if I get this right: the angle of attack is the angle at which a body (airplane, wing...) meets, "attacks", the surrounding flow, isn't it?
172 flyingturtle : ...the AoA values were not directly available to the pilots, but they certainly were. What I believe Zeke is saying here is the stall warning can be
173 tdscanuck : It's geometry. Pitch angle minus flight path angle plus incidence angle = AoA. Since incidence angle is fixed for all time on any particular aircraft
174 Post contains links tommytoyz : I only give out my private info to people I trust. Besides, who is to verify anything anyone says about themselves? Anyone can say anything. I think
175 Starlionblue : So you are saying that at least 5 pilots from different airlines, at least 2 of whom fly Airbus, and a Boeing flight test engineer are all wrong? And
176 tommytoyz : You can have many different pitch angles with the same trajectory. That's not what I am talking about. Speak to crews who use them and are trained to
177 tommytoyz : We are I maintain the importance of AoA being displayed to pilots, at all times, especially in critical situations like airspeed malfunctions. There
178 tdscanuck : Yes. And the difference between your pitch and your trajectory is your AoA (counting the constant incidence angle offset). It's physically impossible
179 tommytoyz : Tom, may think it's OK to yank away perfectly valid and good AoA information from pilots, when speed data malfunctions above 60 knots. I don't. I mere
180 Starlionblue : Actually it could be simpler. Such a display needs to be certified. More importantly, it needs to be proven useful beyond current PLIs etc. It must a
181 Post contains images mandala499 : I'm not Zeke, but I suggest again, that we begin by you having a look at yourself in the mirror. Who's the idiot here? Pitch - Trajectory = Alpha...
182 zeke : No, they said, and you have already quoted this, "The aeroplane’s angle of attack is not directly displayed to the pilots." That is entirely correc
183 tommytoyz : Aibus V alpha max is not available when speed data malfunctions above 60 knots, despite available and valid AoA data being supplied. This I find a ba
184 flyingturtle : Hello tommytoyz, I know you want your privacy protected. But it would be a start to actually trust those magnificent men in their flying machines. I h
185 Post contains images flipdewaf : Yes, the information is speaking loud and clear. Your lack of information however is something different. Attitude - flight path vector = AoA, Altitu
186 zeke : How does the system know that the AoA is valid if the airspeed is invalid ? The USAF has lost a number of F-16s because the flight control system had
187 tdscanuck : I do not think, nor have I ever said, that you should take away valid and good AoA information from the pilots. I thing we may be disagreeing about w
188 Kaiarahi : I prefer the explanations of flight test engineers and experienced pilots. Has it escaped your attention that everyone on this thread except you does
189 Post contains links tommytoyz : It can be done, and it does address many of the problems mentioned, all at once: Here a Boeing article: AOA backup indication following pitot or stat
190 tdscanuck : Boeing implemented this as standard on the 787; it's the AOA SPD display. They did *not* put up an AoA value display. Airbus didn't "make it dependan
191 tommytoyz : If the reported speed is under 60 knots, it is deemed invalid. What if the actual speed is far higher than 60 knots? THe speed will still be deemed i
192 tommytoyz : The point is to have a not normalized AoA display as a back up. That way it is not tied into the speeds in any way and remains useful regardless. Is t
193 Starlionblue : Yes but what I believe Tom is saying is that if the speed is deemed invalid then you can't be sure of the data from the AoA sensor.
194 tommytoyz : A not normalized AoA indicator, one not tied to speeds in any way, is not as accurate, by any means. But you can still fly by it in a pinch, fairly e
195 mandala499 : And the question remains, there are 3 AOA vanes... which one to display? You want the AOA 1 on the left and AOA 2 on the right? and AoA 3 as a select
196 flipdewaf : Then the AoA would be correct, but the question remains how would you know you were higher than 60kts to validate the AoA? if there was a way to know
197 airmagnac : Yes it is, through the laws of physics. As long as you are displaying a value measured by a mechanical probe sticking out in the air flow, you will h
198 Post contains images flyingturtle : To solve this problem for once and for all: Just attach this red string at the side windows of the cockpit. I'm sure the airline's beancounters would
199 Kaiarahi : This thread is now reminding me of the Rocky Mountain goat .... Because it lives on the side of mountains, its left legs are shorter than its right le
200 tdscanuck : Yes, because the AoA vanes don't work (they provide incorrect data) when the airspeed is that low. How would you know that condition existed if the a
201 canoecarrier : It's unfortunate because there were other interesting recommendations and findings in the final report that were worth discussing outside of [Edited
202 tommytoyz : I guess the Boeing article has zero credibility here. Or the fact Boeing offers exactly such an AoA indicator as I am describing. I don't think it mat
203 mandala499 : You're not addressing the issue of source to display selection. Normalized or not, the AoA whatever you want to display, need a source. There are THR
204 Post contains images flyingturtle : I'll sign this. The recommendation to record the RH instruments is quite a no-brainer. Is there any upper limit on the FDR/CVR data storage capacity?
205 tommytoyz : - I addressed this already. In any case, you do realize, that those values occurred after they stalled, and after they reached an extremely high AoA,
206 Post contains images flyingturtle : See annex 2 to the final report, 2 hours 10 minutes 10 seconds. At this moment, they did not have an "extremely high AoA". But the AoA did already di
207 tommytoyz : They did not diverge at this point. All 3 remained almost in perfect harmony till after 2h 11minutes 30seconds for an incident that started at 2h 10m
208 Post contains images flyingturtle : Let the fun continue... David
209 Post contains images airtechy : Sorry, I'm still hung up on the need for the autopilot disconnect....and yes "autopilot" is probably not the correct Airbus term but please humor me!
210 Starlionblue : Probably. However with current storage technologies this is easily upgrade-able. No way storage capacity is a problem in this sort of application. Al
211 rfields5421 : There is also a need for reprogramming, and possibly new wiring in some existing aircraft. No insurmountable technical problems - just a bit of money
212 tdscanuck : It has plenty of credibility. Selectively quoting it to make a particular point while ignoring the portions of the same article that don't support th
213 tommytoyz : What should I have included? Was I misleading? If so, please include what I should have quoted. The entire link is available to you. What is it, that
214 flipdewaf : I think maybe rather than the word valid you use the word validated (Subtle but I think different) I think the point tom is making is that when the a
215 Post contains images flyingturtle : One problem is quite obvious. The pilots announce "airspeed alive" on the take-off roll. And you are technically stalling during some part of the tak
216 Post contains images tom355uk : So what if your 'magic bullet' Non-normalized backup AoA vane becomes iced by whatever conditions threw your valid airspeed out of the window? Now yo
217 Post contains images David L : Adding to the reasons given by Tdscanuck', there's also the fact that if the AP hangs on as long as possible after a partial failure then there's alw
218 zeke : Airbus has BUSS standard on the A380/A350, however that only works below FL250 due to mach effects. It is optional on other FBW aircraft. Very true,
219 tdscanuck : mandala499, Reply 203. Boeing states outright that their proposal won't always show the correct AoA. You stated the opposite. I consider that "materi
220 Kaiarahi : As someone who has misquoted/misrepresented very many of the posts on this thread, I think you should get on your knees and and proffer a thoroughly
221 Post contains images airmagnac : Your idea is to display non-normalised AOA to the pilots. It is an idea that has its merits as well as its drawbacks, as discussed in the Boeing artic
222 Post contains images David L : Actually, I think what Tommytoyz wants is this: Yes, I know.
223 tdscanuck : Yes. How they actually do that is a kind of black art from my point of view, but they do so some kind of continuous update/filter of inertial off GPS
224 tommytoyz : Of course you need a real airspeed over the fuselage for the vanes to work, I already mentioned this like 40 posts ago. Isn't that obvious? What is p
225 David L : But you've also been saying that as long as you have sufficient airspeed you know the AoA data is valid... which is not correct. You need to know tha
226 Post contains links Kaiarahi : No they weren't. There was an internal blockage. AoA 3 was valid. Fortunately, the BEA is a professional investigation organization and did not fixat
227 canoecarrier : That recommendation came from the "Flight Data Recovery Working Group Report". They looked into new flight recorder technology. Specifically: 1) Inst
228 tommytoyz : Not the same as saying you need speed data or need to know your speed. Once you take off, it's clear you have enough speed. It takes way longer than
229 tdscanuck : Pitch and power. Works all the time, is totally independent of all air data sensors and computers, is immune to all the pitfalls of even non-normaliz
230 Post contains images mandala499 : I think that's better discussed elsewhere without someone saying "pilots should be taught to fly by AoA" while also saying "I didn't say ignore speed
231 Post contains images David L : More relevantly, how long does it take for the airspeed to drop from being sufficient to make the AoA data useful to being insufficient? Whoops, I ov
232 tommytoyz : I never said that. Just one of the many things that have been falsely attributed to me in this thread. And the other two agreed, the AoA data supplie
233 canoecarrier : What you said was: Emphasis added. And everyone here is telling you that had they used the UAS procedure "Pitch and Power" they would likely still be
234 Starlionblue : Couldn't be simpler. And that should be the bottom line. But no doubt we'll continue for a while longer.
235 Jetlagged : Additional information they would have to interpret correctly. Pitch and power does not need interpretation. Non-normalised AOA could well give indic
236 tommytoyz : I never said use AoA in lieu of pitch and power or forget ditch pitch/power or anything even close to it. I have not criticized that technique in any
237 tdscanuck : In hindsight, given far more data than the airplane or crew had at the time, we know which were probably correct and which weren't. But, during the e
238 Post contains images flyingturtle : I've neglected that part of the report until now... I've some reading to do. A simple question to you, Tommytoyz: What is your goal? What are your in
239 Post contains images David L : No? So what did you mean here: It still looks as though you won't accept that raw AoA data does not always represent the actual "flyability" of the a
240 Post contains links and images mandala499 : There is one family of airliners that DO NOT HAVE any AoA vanes... partly, because of these possible issues. But that's another story which I will el
241 Pihero : Sterling work, Mandala499 ! But remember : "nul n'est pire sourd que celui qui ne veut entendre !" I'm about finished with reading the report, compari
242 Jetlagged : There are references all over the place to pitch and power in relation to AF447, it's not just here on A.net. Every pilot is taught to fly pitch and
243 tommytoyz : It's interesting. You, Tom and some other here ask a millions questions, making it seem virtually impossible to do what I am suggesting. Yet you all
244 Jetlagged : It says it's useful, it doesn't say it is the solution to unreliable airspeed events. Tom has repeatedly pointed this out to you, and he works for Bo
245 tommytoyz : 1. Which is * exactly* what I have been saying. Probably 30 times. *Useful*, *helpful*. I never said "the solution" - to anything, nor anything even
246 tdscanuck : Nobody has said anything even resembling the idea that it's impossible. It's really easy to implement. It's also a bad idea...it's that latter part t
247 canoecarrier : Or, he could have the courage to contact people outside this forum, in the industry, like I'm sure many that have contributed have in their own field
248 airmagnac : This thread has actually been quite instructive and interesting thanks to the contributions of several very talented people here. But it is already n
249 tommytoyz : I have been 100% consistent. You kept asking how the back up indicator was able to determine the buffer to Critical AoA (or variations there on). I h
250 David L : No he didn't and neither did anyone else. I think a large part of the problem is that you're seeing shades of grey as either black or white. What has
251 Post contains images Mastropiero : Having read top to bottom both this thread and the Boeing article about the AoA indicator I think there are a couple of points that might need to be c
252 Post contains links and images mandala499 : Consistent? Really? I think you made the U-turn. The thing is there are problems in your previous assertions (to which you deny later on): No false a
253 tdscanuck : OldAeroGuy and I agree on the usefulness. Mandala499 cleared up the difference between what OldAeroGuy actually said what what you're implying he sai
254 Post contains links and images zeke : I did some more research, other aircraft military aircraft apart from the C-17 that do not have an AoA probe, let alone an indicator include the USN
255 tommytoyz : - Measuring AoA devices the aircraft uses. Basically similar to the stall warning system, but not connected to air speed data, as Tom continues to in
256 tommytoyz : KC-135. I included the pilot report on his experience in using it. Do you know how many versions of the C-130 there are and how many branches use it?
257 Post contains images David L : You also said... and... ... but say you've been 100% consistent. How are we supposed to know which of your views you are standing by and which you ar
258 Post contains images airtechy : I must be reading this wrong.....are you saying don't disconnect the autopilot? I proposed that a year ago! Jim
259 tdscanuck : 1) Without airspeed (and using current AoA vanes) you don't know if AoA is valid. You do not show invalid data to the flight crew. 2) Except in the a
260 Post contains links and images Pihero : like quite a few of us, Tom ! As I wasn't going to add more to the funniest argument on A.net - and I admired Tom and Gerry's and David's... et al's
261 flyingturtle : Excellent discovery you've made, Roland! Do we have a KC-135 pilot here? Could he tell us why the KC-135 have AoA indicators? My humble idea would be
262 tommytoyz : You can not know how right or wrong the AoA data is, from the speed data. You can not know how right or wrong the AoA data is, from the speed data. Y
263 tdscanuck : We have. Lots of them. If you don't believe those sources, or you think we're lying about what they said, say so, say why, and we can discuss that ra
264 Klaus : No, you have fundamental misunderstandings about how validity dependencies inherently work. The Perpignan crash was caused by another source of inval
265 zeke : I am suggesting that a modification could be made so that the autopilot could remain on to give the crew time to sort a solution out, or even for the
266 tommytoyz : Link please, as I have done various times to various sources and you have none. Thank you. - That's exactly my point. The accuracy, or even blockage,
267 tommytoyz : Not exactly. Trust the readout of the back up AoA, when speed data goes out, yes of course. Would you discard the altimeter data as well? Of course n
268 zeke : Lets have a look at the links you provided, reply 62 flight global and someones blog reply 109 bloomberg news article reply 123 pprune post reply 174
269 Post contains images David L : Hence the reason AoA data cannot be be relied on as a primary tool in UAS situations. You're the one promoting its use as a primary indicator of how
270 tommytoyz : Zeke, since you admitted you have no opinion of your own, what is the purpose of your posts? To antagonize? To put others down? To belittle others? I
271 Post contains links zeke : I have never said I have no opinion of my own. I have also said I think the regulators should evaluate the recommendations. The regulator are the one
272 Post contains images flyingturtle : ...we expect just a few lines telling us which AoA gauge to trust (as in the KC-135 pictures found by Pihero). As a hobby, I am a kind of mountain gu
273 Aircellist : Thanks to all. This thread is absolutely fascinating. It is in itself a study on human factors.
274 flipdewaf : Yes, the irony of the airfrance pilots seemingly ignoring data placed infront of them and this thread is not lost on me. Fred
275 tommytoyz : 1. Yes, the Boeing article specifically about AoA was linked to in post 99. The point is? It escapes me. 2. The Boeing articles you linked to - have
276 tdscanuck : Nobody has claimed a backup AoA gauge is useless. Several people have claimed, correctly, that it is not *always* useful and that, when it is useful,
277 tommytoyz : Nobody advocates using faulty AoA data. I certainly don't. In the case of Af447, the AoA data did remain valid up to a certain point. That point was
278 tommytoyz : That's fine. Some airlines insist on it and have it installed, so there are differing views on this. I can respect those opinions. Perhaps some posts
279 tdscanuck : As far as I know, neither Boeing nor Airbus offer a non-speed data backup currently. They offer display of the existing speed-corrected AoA, and the
280 Post contains images flyingturtle : Tommytoyz, I love it how you are stonewalling around your one and holy opinion. A case of UAS! The Super A330 Repairman to the rescue! With his black
281 tommytoyz : I don't understand why that is essential for all practical purposes. Could it not be possible, for example, to validate that there is sufficient airs
282 Starlionblue : Tom has explained it multiple times. In essence "valid" means the data can be proven correct. If you cannot prove it correct you don't display it. Th
283 tdscanuck : Because there is a very real (and proven in past accidents) danger that crew will use invalid data if it is presented to them. Since invalid data is
284 tommytoyz : "The red tick mark for stall warning may behave erratically in a pitot or static failure state, as may stick shaker, PLI, and speed tape amber and re
285 flyingturtle : When I woke up this morning, a wonderful idea crossed my mind... Tommytoyz, could you spare us some time and write your own UAS procedure, based on Ao
286 Post contains links and images flyingturtle : As has been previously answered... the aircraft only cares about airspeed, not ground speed. See the epic battles fought in the "plane on a conveyor
287 David L : The same could be said of their pitch attitude indication, which did not malfunction and was displayed the whole time, combined with the VS. Yet thei
288 tdscanuck : That's true if, and only if, you have enough airspeed to keep the vanes stable. AF447 didn't. The FDR readouts show this clearly. Tom.
289 Post contains links tommytoyz : By the way, that Boeing article I have been quoting from, is from the year 2000. I just came across this website. Here one of many many comments: Bria
290 Aircellist : Thanks for that one! I would use it as my signature, if only there was room for so many characters...
291 tom355uk : You did notice that all of those pilots were military trained - who you yourself said rely more on the AoA during flight. They probably only think it
292 tommytoyz : Steve Nicholson flew the A-6 Intruder in the Marine Corps and heavy jet transports for Northwest Airlines. "I have a personal story directly related t
293 tommytoyz : Let's imagine that the AF447 crew had reacted correctly and began flying pitch/power....but the speeds never came back. Flying for hours manually on p
294 Post contains images flyingturtle : There have been worse things than that. Like flying *manually* all the way over the pond when the A/P went the way of the dodo. This means a lower al
295 zeke : AF447 was a case of erroneous speed, that is the whole crux of the report. Exactly, they do not even mention AoA for erroneous speed, that is what th
296 rfields5421 : In a couple of the UAS incidents they were never able to get the aircraft back to Normal Law and did fly manually across the ocean to their destinati
297 tdscanuck : I was talking about the other displays (altitude, VSI, roll, heading, FPV, etc.) when I said "all else". If you're going pitch/power because of bad U
298 zeke : 100% correct. Even with an AoA indication, you are going to fly it like a C172,
299 Post contains links canoecarrier : If you're going to post that quote you should at least post the site you found it at: http://www.ballyshannon.com/aoavoices2.html
300 Post contains links and images mandala499 : Oops! Missed that out on the proof read after I got the pics of the gauges... Thanks! So, since you quoted that your viewpoint is based on all what y
301 tommytoyz : Regarding the AoA I have been talking about, you can either: Pretend American Airlines and other airlines have not installed it Pretend top Boeing eng
302 David L : OK, using the same tactic, you can either: Pretend American Airlines and other airlines recommend it as a primary reference in UAS situations Pretend
303 Starlionblue : You are (probably deliberately) ignoring the points made by the pilots and engineers on this thread. You are (probably deliberately) misinterpreting
304 Post contains images flipdewaf : That seems like you. Yes it is. An EAS/IAS And for the fact that AoA probe position is a function of both aircraft AoA and airspeed. We all seem to u
305 Pihero : to tommytoyz We're noticing that there are quite a few questions you never managed to answer. Amongst those, there is one asking you to propose your o
306 Post contains images flyingturtle : Hi rfields, ...but the airspeed indication came back in most instances? That was what I remember reading in the final report. That was the point I wan
307 tdscanuck : Nobody has pretended that, and you know that. Everyone acknowledges that some airlines have it, just as everyone acknowledges that *none* of them use
308 Post contains links and images zeke : It does not however form any pay or the unreliable airspeed checklist. And as far as I am aware, it is only installed on a subset of their fleet, it
309 rfields5421 : That was my understanding. Somewhere in the couple thousand pages of documentation I have on AF447 it said that while airspeed data became relaible,
310 tdscanuck : Just to head off a potential confusion... Zeke and I are *not* disgreeing here. The AoA gauge that you can get as an option (what Zeke is talking abou
311 tommytoyz : Perhaps I was exaggerating a little. But as you can see from the completely one sided responses here, it certainly seems like it. And misinformation
312 flipdewaf : Don't take the actual values too seriously, it was just a 10 minute model to demonstrate the effect of dynamic pressure on the AoA probe. You should
313 tdscanuck : I agree that ignoring others' opinions is *a* possible reason for the observed behavior. However, it is not the only one. Further, I would argue, it'
314 Pihero : 1/- No need for any assumption : centered ball on the stby horizon, all engines running perfectly in synch, flaps and speedbrakes stored... Yes, that
315 tommytoyz : Nice job regardless. What it does show is that with testing, the errors can be known and probably compensated, for the vane installation locations ch
316 Post contains links and images flyingturtle : Ahhh, new stuff to answer. Which would defeat the purpose, because you want to rely on AoA in non-normal, aerobatic maneuvers. Yes. You can measure an
317 Post contains images flipdewaf : Yes but the speed has to be known to compensate for speed Fred
318 tommytoyz : Boeing and Airbus offer independent AoAs that do not require speed data to operate perfectly fine. Or are you denying this? In testing the local erro
319 tommytoyz : I don't either. Picture can not tell you that. They can't tell you many things. Good point. Though others think they are accurate enough for their ro
320 canoecarrier : So, to be clear, you agree that turbulence can effect the AoA vanes on a military aircraft? Rendering them in disagreement with each other.
321 tommytoyz : Not at all, as the AoA I am talking aboutand is installed - is also static port data independent, as well as pitot data independent. It would not hav
322 tdscanuck : No. His graph is showing the speed error that's independent of position. There is no position on the aircraft that will make the error shown in that
323 tommytoyz : You are denying reality: From the 737-300/400/500 Flight crew training manual, When abnormal airspeed is recognized....... ....... For airplanes equi
324 tommytoyz : PLI is not displayed without Speed Data.
325 Post contains images mandala499 : So in cruise and approach under unreliable airspeed, you're saying that we should fly with the AOA needle at the 3 o'clock position because Boeing sa
326 airtechy : Thanks for posting the FCOM bulletin in reply 308 Zeke....very interesting reading. Jim
327 David L : But you've omitted the rest of the Airspeed Unreliable section, which focuses on... flying pitch and power. The part about the AoA in no way suggests
328 flipdewaf : Managed to make a massless AoA probe? Or are they making new laws of physics? I don't believe this to be true if that's what you mean, I believe ther
329 flyingturtle : Let's see... ...yes, let's see. It says so in the 777 FCTM. The full quote is, however: "When the abnormal airspeed is recognized, immediately return
330 Post contains images David L : I think we need a definition of "operating just fine". If it means they'll "do something" then, yes, they will. If it means they'll show how flyable
331 flipdewaf : Are we stalled? no, technically not. Are we basically falling? Damn right! Fred
332 Pihero : why don't you just say that you just don't know anything about instrumentation, validation of presented data, ergonomics... etc... your answer amount
333 Klaus : No, they don't. Their accuracy in measuring local airflow at their installation position does indeed depend on airspeed. And from that local airflow
334 flyingturtle : On a more personal side, and offering some personal advice... I've had long talks with a friend of mine and one point was that she did not want to be
335 tdscanuck : Yes, it tells you what the angle of attack indicator displays *when the data is valid*. It says nothing about the low speed lockout...that's in the F
336 Post contains images mandala499 : Yeah, well, it was expected. Then we go to another problem if we even follow that! But, I'd rather wait for Tommytoyz to come up with an answer to: T
337 tommytoyz : Yes, and so what? What's the problem with that? Airspeed also fluctuates (when working) in turbulence. So what? No. The speed data independent AoA in
338 tdscanuck : You argued that stability of the vane was one of its advantages: There's no particular problem with the AoA gauge being wiggly. There's a problem wit
339 flyingturtle : I tried, but HAL 9000 didn't give me any answers. He said he could not do that. David
340 Post contains images David L : Did you read the responses? Where are they advised to use it over PLI? So is AoA data. There's functioning and there's "functioning". Yes, they "do s
341 tommytoyz : Being wiggly in turbulence does not exclude it from being stable and useful when others are useless. The red tick mark for stall warning may behave e
342 tdscanuck : Maybe we're attacking this all wrong. We all agree that the pilots need some way to maintain stable control in the event of UAS. We all agree that the
343 Post contains images mandala499 : Well, REALLY? Airspeed converts the pressures in the ADM to electronic data and sends it to the ADR. AOA vane position is detected by the resolver, w
344 tommytoyz : 1. Did I say to ignore the SOP for UAS or to ignore pitch/power in the statement above? 2. I mention clearly that other data is also displayed. 3. In
345 mandala499 : OK, you win... Since you're the smart guy here, and that the Boeing Flight Test Engineers, the A330 captain for over 10yrs, and a 320/330 TRI/TRE/Cap
346 tdscanuck : Pitch - FPV = AoA. Simple geometry. FPV is purely inertial; there is no barometric input. FPV worked fine. It comes from the IRU's only. Reply 109. Y
347 tommytoyz : They're complementary. The FCTM says to fly pitch/power AND use the AoA for planes that have them. They do not conflict, they augment each other. Thi
348 Pihero : I notice that, once again, you've quoted my post in a very suspect manner. The answer is above : I was asking you the question about the use of these
349 Post contains links and images mandala499 : Let me answer for Pihero... Here we go: OK... so, here's the question... HOW DO YOU FLY THE PITCH AND POWER, AND KEEP THE AOA NEEDLE ON THE 3 O'CLOCK
350 tom355uk : And that's Mandala499 for the game! So, let's all just agree that an additional, unfiltered speed independent AOA indicator would add absolutely nothi
351 tommytoyz : Neither you nor I know all the data pertaining to those pictures in the KC-135, nor, I assume, are you familiar with SOP for the KC-135. Nor do you k
352 David L : I think the point was clear, i.e. that it's not unusual for two AoA indicators to give different readings in the same situations. The photos were mea
353 Pihero : ... which you still haven't answered, squirming as usual into another tangent. Easy as pie ?I'd like to see you there. Mandala499 has trapped you ver
354 zeke : Simple answer. It is part of the air data system, and that air data system has been compromised. Whatever can compromised airspeed, static pressure,
355 Post contains images flyingturtle : Superb explanations, as always, Mandala449! Because I read the UAS part of the A330 QRH just yesterday I had a faint feeling what the problem is with
356 tommytoyz : FPV display uses altitude barometric data Tom. You can read this in many places. I can not discus anything if these are the types of misstatements tha
357 Post contains links tdscanuck : Pitch/power. That's why all the OEM's, all the airlines, and all the regulators have that in their UAS procedure. Not a single one has you fly AoA. T
358 Post contains links Klaus : Translation: You have realized that any injection of real-world context beyond single, carefully massaged snippets immediately obliterates your theor
359 buckfifty : I don't know where this 'many places' is, but FPV is always based on inertial data. The meaning 'Flight Path Vector' means that it is showing your ac
360 tdscanuck : I think tommytoyz is reading the Boeing FCTM descriptions of the FPV, which are very careful to distinguish FPV (a cue on the PFD and HUD) from FPA (
361 Post contains links and images flyingturtle : Even better, but a bit longer... http://www.youtube.com/watch?v=kQFKtI6gn9Y&t=1m12s David
362 tdscanuck : I dug into the AMM's a bit more to make sure I wasn't getting this wrong. The inertial system does, indeed take data from the air data system. That's
363 buckfifty : Our manuals tell us nothing, but your explanation does sound entirely logical.
364 Post contains links and images mandala499 : The one who is trying to reinvent the wheel is you sir. Please note at the FCTM 0.2.1 where it says clearly: And the FCOM consists of Vol 1, Vol 2, a
365 tommytoyz : - Thanks for that. So it stays silent on how and when to use AoA, even though it's there. Strange. Since it makes no mention one way or the other, do
366 tdscanuck : It's not silent, it's very explicit. You *don't* use it. Procedures are procedures...they "mention it" by explicitly not including it in the procedur
367 Post contains images David L : A draw it is, then. It stays silent on doing how to wear your tie in UAS situations, too, even though most airline pilots wear them. Ambiguous... or
368 Post contains images Klaus : Obviously.
369 Post contains links and images tommytoyz : Oh boy. BUSS = Back Up Speed Scale. Used even when there is a total air data failure. Please study the Airbus BUSS and you will see you are as wrong
370 Post contains images tom355uk : You clown. If you Actually had any idea about the documents you were quoting, rather than Googling and using the first result that comes to hand you
371 Post contains links and images zeke : We do not fly AoAs in airliners, so we do not need to "determine the accuracy of your AoA" for everyday use. No doubt as you would have read in that
372 tdscanuck : I defer to the Airbus experts on BUSS; I'm not as familiar there and may have the underpinnings of BUSS wrong. As for FPV, I went straight to the man
373 zeke : In Airbus terminology the symbol on the PFD known as the FPV or "the bird" indicates the track and flight path angle in relation to the ground (to se
374 tdscanuck : All of the following, as general statements, were wrong: I got yet more data and, much to my own surprise, although the FPV is always the vector in in
375 Post contains images mandala499 : Well, FCOM is higher than the FCTM, QRH is part of FCOM. As stated in FCTM, if it contradicts the FCOM, follow FCOM. The FCTM wording for the use of
376 tommytoyz : - Well said. Which ties into the changes in training content the BEA mentions. I suggest all pilots get thoroughly trained on it. That is probably th
377 Post contains images flyingturtle : Yes, AoA is weight- and air density dependent. That's one of the important things I've acknowledged when I played around with the F-18 flight sim on
378 Post contains images flyingturtle : To elaborate on my posting above... Imagine an aircraft in the wind tunnel: There, the aircraft model is mounted on that pylon you see in the picture.
379 tom355uk : FYI, the clown reference was referring to your inaccurate description and usage of BUSS, not your general approach. Like Mandala said, BUSS is only an
380 tommytoyz : You are comparing two different aerodynamic configurations with each other. Same as if you compared an airliner with flaps extended and one without f
381 tommytoyz : - The rub is your assumption, "With constant velocity". Yes with those assumptions, that would be correct. However, the target AoA does not keep you
382 Post contains links srbmod : This thread has gotten extremely long and much longer than the Moderators prefer threads to get, so a new thread has been started in which to continue
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