AF447 was not spinning however. It was just pretty well stalled, with plenty of power from the engines throughout, and the pilots never realised it. The 3rd guy may have done, maybe, with the altimeters unwinding at a rate of about 1000ft every 6 seconds, but he was asleep because of a “heavy previous night” with his girlfriend, and didn’t arrive on the scene till too late.
One can’t simplify AF447… it was a complicated combination of factors. But it certainly wasn’t spinning, and the stall warner was AFAIK working “as designed”.
Both wings are stalled in a developed spin, one more deeply stalled than the other, with Angle of Attack of 25 degrees to 40 degrees plus (typical critical alpha being around 15 to 18 degrees).
In a flick roll one wing only is stalled.
RobertL18C wrote:
Both wings are stalled in a developed spin
I am not so sure? One wing for sure is stalled.
Peter wrote:
The 3rd guy may have done, maybe, with the altimeters unwinding at a rate of about 1000ft every 6 seconds, but he was asleep because of a “heavy previous night” with his girlfriend, and didn’t arrive on the scene till too late.
The “3rd guy” was the captain. You make it sound like it was a breach of procedure or poor airmanship that he was away from the flight deck. Of course not. The reason there are three (sometimes four) pilots on long distance flights is exactly that they take turns with the pilots not in the cockpit having rest periods. The accident investigation report says nothing about the captain being asleep, but even if he was it would have been perfectly legitimate – perhaps even desireable. In fact the report states that from the CVR “No signs of drowsiness or sleepiness are noticeable”.
Also, he didn’t arrive “too late”. When he entered the flight deck the aircraft was still at FL350. It had taken him no more than 52 seconds to get to the flight deck after being called.
I recommend reading the report.
Airborne_Again wrote:
The accident investigation report says nothing about the captain being asleep, but even if he was it would have been perfectly legitimate – perhaps even desireable. In fact the report states that from the CVR “No signs of drowsiness or sleepiness are noticeable”.Also, he didn’t arrive “too late”. When he entered the flight deck the aircraft was still at FL350. It had taken him no more than 52 seconds to get to the flight deck after being called.
Perhaps. But I recall the discussions over at PPrune, where several pilots who fly this route regularly commented that they found it odd that the captain was not on the flight deck during the ITCZ transition. IIRC most (all?) other airliners plying the same route that night diverted, e.g. LH by some 100 miles, if memory serves. A captain’s job is to proactively avert situations like that.
172driver wrote:
Perhaps. But I recall the discussions over at PPrune, where several pilots who fly this route regularly commented that they found it odd that the captain was not on the flight deck during the ITCZ transition. IIRC most (all?) other airliners plying the same route that night diverted, e.g. LH by some 100 miles, if memory serves. A captain’s job is to proactively avert situations like that.
This point is extensively discussed in the accident report! (Please read the report.) The report includes some indirect criticism of how the captain handled the ITCZ crossing, but it also notes (I quote):
The choice of in-flight rest time made by the Captain of flight AF 447 is however understandable considering the following:
The time period for in-flight rest chosen was that commonly used by most of the other Captains in the airline
Yeah… that makes it OK 
Air France did a few other interesting things, evidently, like poor pilot training at, presumably, their elite national academy. I know one can be accused of armchair criticism but to sit there for a few mins with all the altimeters running anticlockwise at some RPM… including the little standby one? I guess a GA pilot flying steam gauges finds it hard to understand how this can happen; hard to grasp the extent to which airline flying the Airbus can be little more than operating a video game for 5000hrs. But these pilots really had no idea of aircraft systems. If you are puzzled about WTF is it doing, go back to basics and look at the standby instruments. The Airbus has these too. Then, assuming you actually ever went to a school where you learnt about pitot, altimetry, etc, you might know that the 15 degree UP pitch is gyro derived and thus probably real, in the face of unreliable airspeed.
A number of holes in the cheese did line up to make it happen but most of them were due to inept pilots.
Peter wrote:
…most of them were due to inept pilots.
No doubt about that, but that doesn’t mean that every single decision taken by the pilots during the flight was wrong.
Reality is seldom black and white. Not in the case of AF447 either.
One of the most important items to learn with respect to icing in IMC, is the behaviour of altimeter, vario and airspeed indicator in case the pitot tube, the static port or both are freezing shut. Even more so during descend or climb
Peter wrote:
Then, assuming you actually ever went to a school where you learnt about pitot, altimetry, etc, you might know that the 15 degree UP pitch is gyro derived and thus probably real, in the face of unreliable airspeed.
On the other hand, if the crew thought they were in a strong downdraft/microburst situation, I believe that since the Delta Tri-Star went in at Dallas, the normal procedure is to pitch for takeoff and apply TOGA power. 15 degrees up pitch is, IIRC, pretty normal initial climb pitch for a jet airliner. Under normal conditions (in other words, when you’re NOT stalled!) pitch + power = performance so they could be forgiven for thinking in the absence of reliable airspeed and in turbulence that would mask the aerodynamic warnings of a stall, they were set up to climb out of trouble.
