I have read that VR can be as high 150kts, with the days conditions as seen on tv ( dont know the performance of the a/c) V1 I guess, wouldnt be greatly less.I'm wondering could anyone say how much Rudder input would be needed for directional control with a failure after V1 on the MD82?
It takes whatever it takes, not to be flippant. Rudder would depend on thrust and whether the crew was using MAX thrust or a reduced or FLEX thrust. And also at what speed the failure occurs as the rudder becomes more effective at higher speeds.
You put in enough rudder to keep the plane going straight. One point no one has mentioned with the possibility of the airplane getting airborne is a failure at V2. From my time instructing in the simulator, V2 cuts were much uglier and more difficult than the V1 cuts.
With a V1 cut, you still have a tri-cycle but with a V2 cut, there is a tendency among some pilots to use a fair amount of aileron and then they begin a rudder dance of putting in inputs and taking them out. And the nose is in the air and if the crew over-rotates, it only compounds the problem for handling.