Originally Posted by
H Peacock
V2 is the nominated speed to fly once airborne but still with any take-off flap in the event of an engine failure. It's effectively your best climb-angle speed and used until you reach your acceleration altitude.
V2 is the speed that you will reach (all engines operating) at the screen height of 50' (old types) or 35' (newer types). It is also the speed at which: " A sufficient margin of control exists for the average pilot with the a/c in the T/O configuration (ie flap) to maintain directional control whilst achieving the maximum climb angle following failure of the most critical engine."