...and he replied that the Rolls Royce Dart engines operated more efficiently at higher speeds and the longer the aircraft stayed on the runway the more efficient the Dart would be if there was an engine failure.
Hmmm, never knew
that and I've got plenty of Dart flying in the past...I must pay attention more in ground school.
OTOH, with the FAA, there was no specific Vr with either the F.27 (Fokker) or the F-27/FH227 (Fairchild)...only V1 and V2.
And rotation was at V2, not before, just as on four engine piston transports certificaed under CAR4b...and the F.27 (etc) was a -4b airplane.