The speed above which an aircraft can fly safely with a given load and configuration. The most important safety speed is the takeoff safety speed (V2)—the speed at which an aircraft after takeoff can safely climb away in the event one engine fails. This is the minimum control speed with an added safety cushion to account for the following factors that could apply if an engine fails during or immediately after takeoff: (i) The element of surprise and the reaction time; (ii) the failure of the critical engine (i.e., the port engine); (iii) the landing gear is down, the flaps are in the takeoff position, and the propeller is windmilling; and (iv) the pilot is of average strength and ability. The airplane should reach V2; at the screen after engine failure at V1 and climb up to 400 ft (120 m) without the speed falling below V2. The wings should be level, the angle of bank should not exceed 5°, and the engine should be at the takeoff rating.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved