BOAC, yes, we sort of went through this before, but in that iteration degradation of attitude reference was written out ... and this may be another misunderstanding on my part that, sorry to wander off the reservation. L@zerdog's pointing to something amiss at the :12 minute point with that system might or might not be of significance. Even if degraded.
I may not be using the best terms. By partial panel I refer to flying on instruments without reference to the primary attitude reference instrument. (Nose and wing). You use cross check (heading, air speed, ascent/descent) to infer actual aircraft attitude and use performance to determine how to make corrections based on second order input to set an estimated attitude that yields the airspeed, turn or non turn, and speed that you desire to maintain, rather than the usual set your attitude and adjust performance based around that primary reference. It isn't just "turn needle and ball" reference.
Regarding stand by attitude reference, roger. That was explained before, and I think snowfalcon2 said better what I was trying to get at.
Your scenario then seems to suggest initially an in-flight attitude upset beyond the gyro's limits, which then caused a "tumbling gyro" malfunction.
Yes, which may not be a possible failure mode, as you (IIRC it was you) suggested previously. The standby attitude reference system would have limits as well, would it not?
Assuming that the attitude reference system, primary or back up, remains reliable enough to refer to and keep in one's scan, one is still likely dealing with an
on instrument scan upset/dynamic upset/unusual attitude recovery problem in turbulent air, possibly in violently turbulent air, so l@zerdog's second question remains a valid pilot concern.
Not sure how many "spins under the bag" (instrument training hood, if you like) you got to do, or how common it is any more in any sort of pilot training. The first time I did it, full panel, was an eye opener. It's a skill that a bit of practice improves immensely. (The first few times I tried it partial panel (gyro failed) it was a double handful. Took quite a few tries to get it right.)
If full panel recovery, versus prevention, it isn't trained for, how well prepared is any crew to deal with it when facing the situation, with a full instrument panel?
