V1, Vr and V2 speed of aircraft.

           V1, Vr and V2 speed of aircraft.

 In aviation, V-speeds are standard terms used to define air speeds important or useful to the operation of all aircraft. These speeds are derived from data obtained by aircraft designers and manufacturers during flight testing for aircraft .
        
      The speed will vary among aircraft types and varies according to factors such as aircraft weight, runway length, wing flap setting, engine thrust used and runway surface contamination, thus it must be determined by the pilot before takeoff.
  




 So what really V1 , Vr and V2 speeds are . Let us discuss it below: 

V1 Speed 

V1 is the decision speed (sometimes referred to as critical engine speed or critical engine failure speed) by which any decision to reject a takeoff must be made. Above V1, the takeoff must be continued unless there is reason to believe that the aircraft will not fly. An engine failure identified not later than V1 should always result in a rejected takeoff. If it has to be aborted for some reason, it can only be if the speed aircraft less then V1.

Vr Speed

Vr is defined as the speed at which the rotation of the

aircraft should be initiated to takeoff attitude . It is the speed at which the pilot gives input to aircraft control .to be able to fly after the aircraft leaves the runway. Attention must be given to Vr when the aircraft landing nose leaves the runway

V2 Speed

V2 is the speed at which the aircraft may safely be climbed with one engine inoperative. This speed is nicknamed a “take-off safety speed”; it is the speed an aircraft with one engine inoperative must be able to attain in order to leave the runway and get 35 feet off the ground at the end of the runway, maintaining a 200 ft/min climb thereafter.

This is the lowest speed at which the aircraft complies with the handling criteria associated with a climb after a take-off, followed by the failure of an engine.