TAKEOFF SPEED V1/VR/V2

V1-1SEC : THE DECISION SPEED         

V1 is the speed, which is used as a reference, whether to reject or continue the takeoff. At this speed, the first braking action should be applied (in case of rejecting the takeoff). V1 speeds are selected based on the following:

a. If an engine failure is recognized before V1, the takeoff must be rejected. A stop can be made within the available accelerate-stop distance without the aid of reverse thrust, provided rejecting actions are initiated at or before V1

b. If an engine failure is recognized at or above V1, the takeoff must be continued. A height of 35ft (Screen height)* will be reached above the takeoff surface

c. When the required takeoff distance is equal to the required accelerate-stop distance, the takeoff is called a "balanced takeoff," and the selected V1 speed is called "balanced V1"

d. V1 must not be less than VMCG plus the speed gained between the instant at which the engine is failed and pilot recognizing and reacting to the engine failure, and not greater than VR and VMBE

(VMCG ≤ V1 ≤ VR & VMBE)

ROTATION SPEED (VR)        

The rotation speed is the speed at which the airplane is rotated for liftoff. The main determinant of this speed is for the aircraft to reach takeoff safety climb speed at the screen height.

VR may not be less than:

a. VR>V1

b. VR>1.05 VMCA

TAKEOFF CLIMB SPEED (V2)        

This speed (also called Takeoff Safety Speed) has to be reached at the screen height, and must be maintained for the entire climb, with takeoff flaps, in the event of an engine failure at or after V1. In an all-engine-takeoff, the takeoff climb is made with a higher speed (10 to 15 kts above V2, depending on the airplane type).

The lower limits of V2 are:

a. V2>1.2 VS (or 1.13 VS1G)

b. V2>1.1 VMCA