V1 : The highest speed , during takeoff , at which the flight crew has a choice between continuing the t/o or stopping the aircraft .
VR : The speed at which the pilot rotates in order to reach V2 at an altitude of 35' at the latest after an eng failure.
V2 : Takeoff safety speed that the aircraft attains at the latest at an altitude of 35' with one eng failed and maintains during the second segment of the t/o.
[This message has been edited by Royan (edited 01 December 2000).]