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.
V2
Take-off Safety Speed
V2 is the take-off safety speed - the minimum speed that must be maintained after a critical engine failure at V1 in order to ensure the aircraft meets the required obstacle clearance gradient and climb performance during the initial departure phase. V2 is the target speed for the initial climb segment after lift-off and is maintained until the aircraft reaches acceleration altitude, at which point thrust is reduced and the aircraft accelerates to flap retraction speeds. It represents the speed at which the aircraft is aerodynamically safe to climb, even with one engine inoperative.
V2 must be at least 1.2 times the stall speed in the take-off configuration (VS1G) and at least 10% above the minimum control speed in the air (VMCA). It is calculated for each departure along with V1 and VR based on TOW, configuration, and environmental conditions. On modern aircraft, V2 is displayed on the PFD speed tape as a magenta target bug (Airbus) or a reference speed marker (Boeing), and the autothrust and flight director will manage thrust and pitch to maintain V2 in the event of an engine failure during the take-off phase. In normal (all-engines) operations, the aircraft will typically accelerate through V2 quickly during the initial climb and proceed directly to flap retraction.