From section 3-4-2 of the VC10 Flying Manual 3. ERRONEOUS INSTRUMENT INDICATIONS When questionable information is indicated on instruments dependent on the pitot/static system, suspect icing or contamination in the system and FLY ATTITUDE whilst assessing the situation. It couldn't be clearer really. I concur with the report's findings so far. vololiberista

So? The Airbus Flight Crew Training Manual also deals with this "PART 3: FLYING WITHOUT ANY SPEED REFERENCEWhen the trouble shooting procedure did not permit to identify at least one correct indication, this part of the procedure gives pitch/thrust reference to fly the aircraft safely, in all flight phases, down to landing. ..."

Except in the case of AAF447, which is exactly why perhaps an independent A0A gauge with an audible alarm could have been of help. Quite, but perhaps AAF447 would not have reached deep stall, and perhaps could have even recovered.

The stall warning sounded on AF447 so what benefit would an extra AoA alarm have offered in those circumstances? The real unanswered question is why did the aircraft enter a deep stall? Until that's known there's little point in speculating how it could have been avoided.

Well for a start the THS was stuck at full nose up, when in alternate law you lose autotrim. The flightcrew never used manual pitch trim and no amount of forward sidestick would have got the nose down far enough to get the aircraft flying again.

Morn'n, This was the best post on the crash I've seen... It was posted over at AOPA...

June 6, 2011 ( FYI)I would like to offer my comments and perspective with regard to the Air France Flight 447 accident:I have been a A-330 captain since 2003 and have over 4500 hours in the aircraft. While many A-320 pilots undoubtedly have more series time, I believe this probably makes me one of the most experienced A330 pilots in the world.When asked how I like the aircraft, I tell people that there is likely no easier airplane to take over an ocean, and that the systems design and presentation is superb.That said, the automation is more complex and less intuitive than necessary, and the pilot-aircraft interface is unlike that of a conventional aircraft. Most important with regard to this accident is the fly-by-wire sidestick control.The sidestick itself has a very limited range of motion, making inadvertent over-control very easy. Of even greater significance, the stick itself provides no "feel" feedback to the pilot. That is, unlike a conventional aircraft, the pilot does not get a sense through pressure of how much input is being sent to the control surfaces.The most important advice I give to pilots new to the Airbus is to treat the aircraft not as an airplane, but as a video game. If you wait for the sidestick to tell you what you are doing, you will never get an answer.Taking into consideration that Air France 447 was at FL 350 (where the safe speed envelope is relatively narrow), that they were in the weather at night with no visible horizon, and that they were likely experiencing at least moderate turbulence, it does not surprise me in the least that the pilots lost control of the aircraft shortly after the autopilot and autothrust disconnected.Let's keep in mind that these are not ideal conditions for maintaining controlled flight manually, especially when faced with a sudden onslaught of warning messages, loss of autofllght, confusing airspeed indications, and reversion to "alternate law" flight control, in which certain flight envelope protections are lost.A very bad Airbus design feature is thrust levers that do not move while in autothrust. They are instead set in a detent which would equal climb trust in manual mode. If the pilots did not reset the thrust levers to equal the last cruise power setting, they likely eventually ended up in climb power, making it difficult to reset the proper cruise power setting and adding to what was likely already a great deal of confusion.But the real problem probably occurred immediately after the pilot flying grabbed the sidestick and took over manually. Unfortunately, airline pilots rarely practice hand-flying at high altitude, and almost never do so without autothrust engaged. As a result, we forget that the aircraft is very sensitive to control inputs at high altitude, and overcontrol is the usual result. Because the Airbus sidestick provides no feedback "feel" to the pilot, this problem is dramatically compounded in this aircraft.I believe the Air France pilot grabbed the sidestick, made an immediate input (because as pilots, that's what we tend to do), and quickly became quite confused as to what the aircraft was truly doing. This confusion likely was exacerbated by fixating on airspeed indications that made no sense while trying to find a power setting with no airspeed guidance.When transitioning from autopilot to manual control at altitude in the Airbus, the most important thing to do at first is nothing. Don't move a thing, and then when you do, gently take hold of the sidestick and make very small inputs, concentrating on the flight director (which, in altitude hold, should still have been providing good guidance).Of course, this is much easier said than done with bells and whistles going off all over the place, moderate turbulence and a bunch of thunderstorms in the area. As I said before, treat it like a video game.So why did the Air France pilot find himself at the limits of sidestick travel, and then just stay there, maintaining a control input that simply could not logically be correct? When things go really bad and we are under intense pressure, it is human nature to revert to what we know from previous experience. Remember, the Airbus flies like no other aircraft in that the sidestick provides no feedback to the pilot. It is a video game, not an airplane.I believe the Air France pilot unintentionally fell back on all of his previous flying experience, in which aircraft controls "talkedF" to him when he moved them. Distracted by many confusing inputs, he instinctively expected to be able to control the aircraft by "feel" while dividing his attention to address other matters.I've seen it happen in the simulator, and in an Airbus this is a sure way to lose control of the aircraft and is possibly the most dangerous aspect of Airbus design philosophy.One last note: Airbus pilots often claim that the aircraft "can not be stalled." When the flight controls are in "normal law" this is a reasonably true statement. However, in "alternate law," as was the case here, stall protection can be lost. If we ever practiced this in the simulator, I don't remember it.Lest anyone think I am blaming the Air France pilots for this accident, let me be clear. Despite all of my experience in the aircraft, I am not the least bit certain that I would have been able to maintain control under the same circumstances.I do feel certain that were you to spring this scenario on pilots in a simulator without warning less than half of them would have a successful outcome.Safely flying the 320, 330 and 340-series Airbus requires something of a non-pilot mindset.Name Withheld

Regards,Scott

...the stick itself provides no "feel" feedback to the pilot.

I understand that on all Airbus models models featuring fly-by-wire technology, moving the side stick controller by more than 5 degrees (equivalent to a force of 7.7 pounds) causes the autopilot to disconnect.

Scott this has been posted before, when I first read it I thought something was not right, there are too many mistakes for it to be written by a real a330 pilot, my old man also read it and spent over 5 years on the 330/340 he also said it sounds dodgy. And to top it off half of pprune laughed it out of the forum.He does make some good points, all of which are completely obvious to anyone with minor knowledge of the 330No disrespect to you, I'm not surprised this guy wanted to keep his name hidden.Regards

Oops - then - sorry guys...No worries... Regards,Scott

...The stall warning sounded on AF447 so what benefit would an extra AoA alarm have offered in those circumstances?

As I said, a separate backup system is useful when for whatever reason you don't trust your primary system.

Scott this has been posted before, when I first read it I thought something was not right, there are too many mistakes for it to be written by a real a330 pilot, my old man also read it and spent over 5 years on the 330/340 he also said it sounds dodgy. And to top it off half of pprune laughed it out of the forum. He does make some good points, all of which are completely obvious to anyone with minor knowledge of the 330 No disrespect to you, I'm not surprised this guy wanted to keep his name hidden. Regards

Can you elaborate on the weak points in that post? Far from a RW 'Bus driver were, so I'm most interested in what RW pilots have to say. As a simmer, I would add I don't like flying Airbus aircraft because the flight experience feels too much like, well, a video game! Cheers, - jahman.

As I said, a separate backup system is useful when for whatever reason you don't trust your primary system.

Would it really have helped to have both an Aoa and stall waring sounding at the same time/

Would it really have helped to have both an Aoa and stall waring sounding at the same time/

No, but a quick glance at a separate gauge driven by an independent AoA vane indicating an AoA in the "red zone" would. Cheers, - jahman.

Hi. It seems to me, reading the foregoing, that there may be some oversights in the design of the plane's overall control systems with regard to how people interface with machines, stemming in great part from the lack of force or position indication from the stick, and the effective failure of the stall indication due to 'invalid' AoA. I'm an armchair pilot in the real world & remember reading somewhere else some time ago that the A330 suffers a lack of, uh, tactile feedback. The side stick looks very like the £25 model I have in front of my monitor... Still 60° means the plane was close to going backwards and I wonder how easy it would be to drag it back out of that in no more than a couple of minutes. 10000 fpm is near enough 100 mph and it's a large lump of metal to turn around when it's travelling along the wrong axis. On the subject of how the plane got to that state in the first place, could the following, described in the BEA interim report (linked in a post above), have been to blame? • There was no explicit task-sharing between the two copilots • Even though they identified and announced the loss of the speed indications, neither of the two copilots called the procedure "Unreliable IAS" • The copilots had received no high altitude training for the "Unreliable IAS" procedure and manual aircraft handling D

Keep in mind this is someone claiming to be one of the most experienced A330 captains in the world.The A/THR will lock at it's last power setting if it experiences an inadvertent disconnect, no need to move the T/L unless needed, the PF or PNF can clearly look at the E/WD and match the doughnuts (markers on the N1 or EPR guage) they are free to move the levers to whatever power setting or back into a gate. Once A/THR is disconnected it works like any other aircraft but with the added markers for reference. How someone who is a senior captain on type claim an inadvertent disconnect will do what he says is beyond me. At the least he is getting confused with a manual A/THR disconnect, but even that is simple. Regarding the sidestick, while you don't get force back you can definitely tell how much force you are applying, even in direct law.Airbus even went as far as changing the force for inbound and outbound due to the human arm being stronger on inbound roll, besides the A3xx sidestick commands a load factor and roll rate.Regards

BEA released a very detailed 3rd Interim Report with diagrams of the latter part of the flight. It's in French although an English version will be available. The French report looks very comprehensive but my technical French is not up to interpreting it with any confides so I'll just wait. http://www.bea.aero/en/enquetes/flight.af.447/flight.af.447.php

I am waiting for the English version. No French whatsoever. Cheers, MAB

Keep in mind this is someone claiming to be one of the most experienced A330 captains in the world. The A/THR will lock at it's last power setting if it experiences an inadvertent disconnect, no need to move the T/L unless needed, the PF or PNF can clearly look at the E/WD and match the doughnuts (markers on the N1 or EPR guage) they are free to move the levers to whatever power setting or back into a gate. Once A/THR is disconnected it works like any other aircraft but with the added markers for reference. How someone who is a senior captain on type claim an inadvertent disconnect will do what he says is beyond me. At the least he is getting confused with a manual A/THR disconnect, but even that is simple. Regarding the sidestick, while you don't get force back you can definitely tell how much force you are applying, even in direct law. Airbus even went as far as changing the force for inbound and outbound due to the human arm being stronger on inbound roll, besides the A3xx sidestick commands a load factor and roll rate. Regards

Many thanks for posting, that's exactly the kind of inside info we can benefit from.

BEA released a very detailed 3rd Interim Report with diagrams of the latter part of the flight. It's in French although an English version will be available. The French report looks very comprehensive but my technical French is not up to interpreting it with any confides so I'll just wait. http://www.bea.aero/...ight.af.447.php

That's an amazingly detailed report:

1. On p. 31 three pages worth of aircraft variables and control inputs from the DFR. On p.43 there's a chart of what looks like horizontal stabilizer trim over time (simulated vs. actual), with the actual trace hitting what I presume whould be the nose-down stop several times (and staying there.)
2. On p. 46 there's a very detailed chart of displayed KIAS vs. time, Left vs. Right PFDs, and ADIRU selection.
3. On p. 47-48 there's an ECAM message timeline. (Trying to wrap their heads around these messages during turbulence in the middle of the night + inconsistent KIAS readings must have been quite something!)
4. On p.89 a most detailed timeline extracted from CVR and FDR (17 pages!).
5. On p. 109 the detaild aircraft variables timeline obtained from the FDR (8 pages.)

Can't wait for the english translation (where is alainneedle1 when we need him? ) since my french goes into deep stall when reading an aviation accident report. Cheers, - jahman.

Hi all ! Last week, I was talking about the confusing stall warning. It worked when the pilot was pushing the stick and reduced the angle of attack, it stopped working when the pilot was increasing the angle of attack.I didn't understand why the BEA didn't make any recommendation about this stall warning system last week:http://www.bea.aero/fr/enquetes/vol.af.447/reco29juillet2011.en.pdfIn fact, they did, but this recommendation was removed in the published document. Is it because France is a EADS/Airbus shareholder ?La Tribune published a very interesting note about this. You can read the Google translation here.