Or a huge rudder FFF. I believe the seminole Vmca is lower than Vs although its been 2 years since i flew it.
As FFF says it is the speed after which the rudder dosn't have enough humf for you to keep the plane under control with one engine out and the other on full power.
The only reason why I remember this is because my CAAFU had me sweating asking questions on the twin commit height.
Apparently on bigger twins your approach speed can be less than Vmca. So if a engine goes on the approach you need enough height to be able to reconfigure, accelerate (by dipping the nose) the plane to past Vmca while slowly applying power until you have full power past Vmca heading for blue line and the climb. So if your engine goes below that height you are commited to land because the machine can't perform the go around.
It was all a bit hazy though because your IR GFT isn't the best place to remember the examiners pet subject.
Alex, Keith and those types does this sound about right?
MJ