I wish I could go do a few practice runs in the D9 right now and help but I'm on the road and not going to be in the game for a few months. I can't really give any specific advice because I'll probably give you incorrect information. So all I can say is throttle work is the most important factor, being able to adjust the throttle based on your speed as you get your nose up to the point of the maneuver. Then being able to maintain the correct speed as you attempt to flip your plane over as efficiently as you can. It's all based on feel, how much aileron,elevator, rudder to give. I can't give you specific input values right now because I can't fly and I can't do any test runs.