OK465;
RE yr post #1341:
The diagram in post 1172 implicitly assumes still air and standard temperature. The effect of wind is not shown. There is a line drawn at the pitch angle of 16 degrees to illustrate that AoA=pitch + flight path gradient = 61 degrees. Agreed. The length of the line represents 86 knots, and I assume that 89 is a typo which doesn't bother me. My problem is that I don't understand the significance of that speed.
Originally Posted by Tailspin Turtle
...it is almost certain, not just a possibility, that the indicated airspeed was something different than the actual airspeed because of the angle of attack involved.
Agreed. More specifically, the pitot pressure is likely be less than the free stream total pressure at extreme angles of attack near the probe. Aggravating this is the static source, which will probably be exposed to a greater local pressure than the free stream static pressure at large angles of attack. These pressure errors combined are very likely to be the reason that the 'sensed' airspeed dropped below 60 kt, and then 30 kt, while a slight reduction in AoA was sufficient for the airspeed and AoA to become 'valid' again.