All Q400 take-offs have to be brakes-off, rolling start." No explanation is given as to why, do any Q400 drivers know why this is the case?
Not sure if this is the same reason for the Q4, but take a look at this quote re the Learjet 60XR:
Rolling take offs are standard in the Lear 60XR. It never makes a standing start take off, applying power with the brakes set as you might do in a lesser jet, because it has so much thrust the wheels would simply be dragged, locked, along the surface, flatting, and possibly bursting the tyres.
KING LEAR - Flying the The LearJet 60XR