Originally Posted by
Free123
Flaps extended: angle of attack is reduced, which lowers lift and hence p-factor. Resulting in lower vmc
No, net lift is initially increased, and the pilot would typically lower AOA to compensate, resulting in the same net lift that existed initially. Not to be confused with the pitch trim change caused by flap extension.
The so called keel effect from flaps would be very small but real. As the plane starts to yaw the flaps on the good engine side would move forward, while the flaps on the bad side would move backwards. This would result in slightly more drag on the good side flaps due to higher airflow relative to the bad side flaps. I'd be surprised if it changed Vmc by more than one kt.