AF 447 Thread No. 7

[PJ2]

Machinbird;

In re the sim exercise, power was at various settings (though never TOGA). Also, there were variations in altitude needed for recovery. In one exercise we "did nothing" and the aircraft happily remained in stable flight at FL350 as power remained in "TOGA LOCK" (last setting before disconnect) and the pitch at 2.5deg, approximately.

I suspect some tests of hand-flying the A330 in Alternate Law would be part of the investigation to see how sensitive the aircraft is, to further understand the initial actions on the stick of the PF.

As I've mentioned a number of times throughout these threads and because not all here seem to comprehend, the air is much thinner at cruise altitudes and so with something the mass of an airliner one must be gentle with the controls and make tiny stick adjustments in manual flight. This fact was first stated in Davies' book, "Handling the Big Jets", in 1967 - 1970.

gums, you're right about the sim not really being able to teach this kind of thing - you can't feel "the mush"...the slight delay in responsiveness in both changes in attitude and flight path even though the subtle indications may be accurately simulated. These kinds of things need to be taught in the airplane at cruise altitude. The airplane hand-flies very well in cruise in Normal Law but I haven't flown it in Alternate Law so can't comment on that. Alt Law is supposed to be wysiwyg. I've hand-flown other transports at cruise which don't have C* Laws or the "add-on's" which provide the usual protections we see in these aircraft, (the B777 has some protections built in and I suspect the B787 has more), and they're sensitive so it is important to know how the A332 responds when hand-flown at altitude in Alternate Law. I suspect with gentle handling it responds as any other similar type, (but "gentle handling" it appears, is not always natural and must be taught)

I stress too, that, in accordance with most air regulations (I have cited the CARS here in the past but the JARS I suspect are similar), the simulator is only used to teach the approach to the stall and not stall recovery. The full stall is never taught and is not required to be taught, for a number of important reasons, (this has been extensively discussed in other AF 447 threads.)

In the approach to the stall, the SOP is to apply TOGA power, lower the nose and minimize altitude loss. This still applies! The standard response to a full stall is to first get out of the stall and that means reducing the AoA to below the wing's stall AoA, then recovering by (gently!) controlling the loss of altitude and re-applying thrust as needed.

For some here who still don't appear to comprehend these things and who won't and can't support their recent statements that recovery from a full stall in transport category aircraft from cruise altitude, (as occurred here), takes "3500ft" or "7400ft", unloading the wing to reduce the AoA to below the stall AoA takes an enormous amount of altitude, and, while stalled, the altitude loss is extremely high, again as seen in the data.