The performance requirements that the transport category aircraft must meet are:
- Takeoff speeds
- Takeoff runway required
- Takeoff climb required
- Obstacle clearance requirements
- Landing speeds
- Landing runway required
- Landing climb required
Listed below are the speeds that affect the transport category aircraft’s takeoff performance. The flight crew must be thoroughly familiar with each of these speeds and how they are used in takeoff planning.
- VS—stalling speed or the minimum steady flight speed at which the aircraft is controllable.
- VMCG—minimum control speed on the ground, with one engine inoperative, (critical engine on two-engine airplanes) takeoff power on other engine(s), using aerodynamic controls only for directional control (must be less than V1).
- VMCA—minimum control speed in the air, with one engine inoperative, (critical engine on two-engine aircraft) operating engine(s) at takeoff power, maximum of 5° bank into the good engine(s).
- V1—critical engine failure speed or decision speed. Engine failure below this speed shall result in an aborted takeoff; above this speed the takeoff run should be continued.
- VR—speed at which the rotation of the aircraft is initiated to takeoff attitude. The speed cannot be less than V1 or less than 1.05 times VMC. With an engine failure, it must also allow for the acceleration to V2 at the 35-foot height at the end of the runway.
- VLOF—lift-off speed. The speed at which the aircraft first becomes airborne.
- V2—the takeoff safety speed which must be attained at the 35-foot height at the end of the required runway distance. This is essentially the best one-engine operative angle of climb speed for the aircraft and should be held until clearing obstacles after takeoff, or until at least 400 feet above the ground.
- VFS—final segment climb speed, which is based upon one-engine inooerative climb, clean configuration, and mximum continuos power setting.
All of the V speeds should be considered during every takeoff. The V1, VR, V2, and VFS speeds should be visibly posted in the flightdeck for reference during the takeoff.
Takeoff speeds vary with aircraft weight. Before takeoff speeds can be computed, the pilot must first determine the maximum allowable takeoff weight. The three items that can limit takeoff weight are runway requirements, takeoff climb requirements, and obstacle clearance requirements.