Part of my post in
the spin thread at the instructors' forum:
Extract from an article by Gene Beggs in Sport Aerobatics of October 1985:
"In my telephone conversation with Bill Kershner, he told me of a spin mode in his Cessna Aerobat from which he was unable to recover using my power-off, hands-off, opposite-rudder method of emergency spin recovery....…
If I placed the aircraft in a spin to the left with the power on as might happen with a student who did not correct for the “P” factor properly, and let it spin with the power on for two turns or more, and then cut the power off, released the yoke completely, and then applied full right rudder and held it, the aircraft would continue to spin and showed no sign of recovery evern after as many as 10 turns! I would then place the heel of my hand on the padded center portion of the yoke and briskly push it forward, and the aircraft would always recover promptly in one additional turn ....
I found that the Cessna 150 would spin very docile, as long as the ailerons were held neutral and the power completely off in either direction .. Trouble developed only in the spin to the left, either when the power was left on or when “in-spin” aileron was applied and the aircraft permitted to turn two turns or more ..."
tinpis - I'd use aileron there too.