Let's start with some basic physics of the spin:
http://oea.larc.nasa.gov/PAIS/Concep...echnology.html from NASA
http://www.ozaeros.com/spin/ostivxx.html from Ozaeros
Then some data - not easy to find actual data online for the effect of power so let's start with power off. One of the classic NASA reports for indicating which aeroplanes are best to stay away from is TP 1009.
http://ntrs.nasa.gov/archive/nasa/ca...1977026167.pdf There are other reports showing the effect of aileron on recovery.
From memory, Birhle did some powered model tests in the early '80's but reports are not available electronically.
http://www.bihrle.com/site/bibliography.html Pitching moments are a lot more complex than a simple thrust or drag multiplied by a moment arm. First of all, there is the effect of the slipstream on flow at the tail. Secondary effects through gyroscopic moments effect spin rate and sideslip which further change the pitching moment per
http://www.ozaeros.com/spin/Spinfig4.jpg Interesting video of NASA's test of the Grumman Trainer showing attempts to recover from a flat spin.
http://www.allaboutguppys.com/spin/spin.mpg Finally, some training videos including the flat spin in an Extra 300.
http://www.fcitraining.com/video.htm Back to the question:
What actions would you take to attempt a recovery from a flat spin.
My answer is qualified by a few assumptions - you're endorsed on spins, in an airplane approved for intentional spinning and loaded within limits. Follow the method in the POH for the type. If that doesn't work its most likely that you messed up so check everything, go back and try again. That requires explanation, better done face to face which is where greeners and 7gcbc came in.