Originally Posted by 320Driver
Is the "big brake" explanation really the issue or was there a worry of the effects of a tailstrike on the composite structure?
I don't think drag of the tail skid is the issue, nor is "worry of the effects of a tail strike". The test is successful if the geometry-limited attitude is attained at or before lift-off. To avoid tailstrike and over-rotation one normally wants to have the tail on the runway well before reaching Vmu, but that requires sufficient elevator effectiveness at airspeeds well below Vmu.
On some airplane types, the minimum speed at which the nosewheel can be lifted off the runway determines Vmu, rather than the maximum body angle.
regards,
HN39