This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
V1
Decision Speed
V1 is the take-off decision speed - the maximum speed at which a rejected take-off can be initiated and the aircraft can still stop within the remaining runway distance available. More precisely, V1 is defined as the speed at which the pilot must have made the decision to continue or reject the take-off following a critical engine failure or other malfunction. If an engine fails or another serious event occurs before V1, the crew should reject the take-off. If the same event occurs at or after V1, the take-off must be continued because there is insufficient runway remaining to stop safely.
V1 is calculated for each departure using the aircraft’s TOW, runway length, elevation, temperature, wind, runway condition, and the aircraft’s certified performance data. It is always equal to or greater than the minimum control speed on the ground (VMCG) and equal to or less than VR (rotation speed). The V1 callout is made by the Pilot Monitoring at the moment the indicated airspeed reaches the calculated value. Airlines train extensively for engine failures at and around V1 because it represents the most demanding certification scenario - a continued take-off on one engine from the most critical point possible.