ORIGINAL: Globemaster3c17
Wait, you had a 172 trimmed for 90Kts. and extended 10* of flaps and it pitched up 35* and stalled? Um, the 172 has a trim change with change in flaps, but I've never experienced anywhere even in the ballpark of 35*, and I've dang sure never had one stall from flap extension, same goes for any of the 8 or so other planes I've flown. My students fail to apply a little forward pressure when they extend flaps all the time, and the plane doesn't even pitch up to the normal climb attitude. I think something was majorly off with your experiment there, but I'm going to try those things out to get my own comparison there.
The amount of pitch up surprised me a little too, as I had never not applied any pitch correction before. I would have guessed on the order of 20 degrees or so. Your mileage may vary, as the CG position may affect how much it pitches up. Remember, I took my hand off the yoke entirely until after the stall recovery. Pitch went off the scale - I had to extrapolate the last 10 degrees. Not that this should make any difference, but it is a CAP 172 with 180 hp. Also, keep in mind that the power and trim were set to maintain altitude at 90 knots - about 2150 RPM - which is more power than normal for 10 degrees flap extension, and a little lower than normal speed. Ususally the RPM is down around 1900 - 1700 before flaps are lowered, at least the way I fly and was taught. The amount of power applied will have a profound effect on the amount of pitch up with flaps. I'm sure you have done trim stall demos.
BTW, I'm a 4600+ hour ATP with CFI/II/MEI and I have flown more than two dozen types and you might want to replicate an experiment
before you say something's wrong with it. The amount of pressure it takes to keep the nose down is not great, but in my experiment, NO pitch correction whatsoever did indeed result in a 35 degree pitchup. I did use the rudder to keep heading. If I had not used rudder, the nose would have gone left, the wings would have banked, and the pitchup would not have been quite as great. Oh yes, I was solo, took off with full fuel, with 30 lbs in the back seat, and another 30 lbs in the baggage area.
I am interested to read your results.
<edit: changed "last 5 degrees" to "last 10 degrees". Measurement is unchanged.>