V1, V2, and VR Speeds Explained

V1 Speed: Takeoff Decision Point

V1, known as the takeoff decision speed, is the maximum speed during the takeoff roll at which a pilot must decide to abort or continue the takeoff following an engine failure. Below V1, a rejected takeoff is possible within the available runway. At or above V1, the aircraft must continue the takeoff, as there may not be enough runway left to stop safely. V1 is always equal to or less than VR and is never less than VMCG (minimum control speed on the ground).

VR Speed: Rotation Speed

VR is the rotation speed—the point at which the pilot initiates nose-up pitch to achieve lift-off. It is calculated to ensure that, even with an engine failure at V1, the aircraft can become airborne and clear obstacles. VR must be high enough to guarantee safe lift-off but not so high as to unnecessarily lengthen the takeoff roll.

V2 Speed: Takeoff Safety Speed

V2 is the takeoff safety speed, the minimum speed that must be achieved at screen height (35 ft for Class A aircraft, 50 ft for Class B) after liftoff with one engine inoperative. It ensures adequate climb performance and controllability. V2 is maintained until reaching a safe altitude for configuration changes (such as flap retraction). The minimum value for V2 (V2MIN) is determined by several regulatory criteria, including multiples of stall speed and minimum control speed (VMC).

Key Differences and Sequence

• V1 comes first: the go/no-go decision point.
• VR follows: the speed to begin rotation.
• V2 is achieved after liftoff: the speed to maintain for safe climb with one engine out.

Why These Speeds Matter

Correct use of V1, VR, and V2 ensures that the aircraft can either stop safely or continue the takeoff and climb out safely, even in the event of an engine failure. Misunderstanding these speeds or their sequence can compromise safety and regulatory compliance.

Practical Example

If an engine fails at or after V1 but before VR, the takeoff must be continued, and V2 must be maintained after liftoff for safe climb performance.