Скачать или смотреть what is V1 ? An important note about V1 that all pilots should know. (decision / go and stop speed )

what is V1 ?

V1 is the Decision speed (sometimes referred to as critical engine speed or critical engine failure speed) by which any decision to reject a takeoff must had been made. At and above V1, the takeoff must be continued unless there is reason to believe that the aircraft will not fly. An engine failure identified not later than V1 should always result in a rejected takeoff.

If the decision is made to reject, the aircraft can be brought to a stop within the Accelerate Stop Distance Available (ASDA). If the decision is made to continue the takeoff, either in a non engine failure case which occurs prior to V1 or in an engine failure case which occurs at or after V1, the aircraft can get airborne and achieve or exceed the appropriate screen height within the Takeoff Distance Available (TODA). If a reject is initiated at a speed above V1, a runway excursion is probable.

Stopping the aircraft within the confines of the runway or safely continuing the takeoff is predicated on an appropriate and timely stop/go decision and the corresponding appropriate and timely actions. The V1 call should be made such that the call is complete just as the speed is achieved. If a reject decision is taken, it is critical that stopping action is initiated within two seconds and that full stopping device capability is utilised. If the takeoff is continued, the yaw due to engine failure must be corrected, the aircraft rotation must occur at Vr and the appropriate climb speed must be maintained to guarantee that the screen height will be achieved.
V1 is the speed by which time the decision to continue flight if an engine fails has been made. It can be said that V1 is the "commit to fly" speed. V2 is the speed at which the airplane will climb in the event of an engine failure. It is known as the takeoff safety speed.
V1 is defined as the speed beyond which the take-off should no longer be aborted. Meaning that in case you experience any trouble with your plane before reaching V1 you would immediately abort your take-off and would apply all the necessary means to bring the aircraft to a halt. If pilots experience any serious aircraft malfunction after V1, otherwise they have to continue the take-off, a take-off board will lead to a runway overrun and could severely damage the plane.
Vr or Rotate is defined as the speed at which the pilot begins to apply control inputs to make the aircraft nose to pitch up, after which it leaves the ground. The easiest way to memorize the rotate speed is the point where the nose leaves the ground and vortexes are created at the wing tips which rotate behind the aircraft. Moreover, the point where the main gear leaves the ground is the point where the aircraft has reached the Vlof – lift off speed.
V2 is the speed at which the aircraft may safely be climbed with one engine inoperative. This speed is nicknamed a “take-off safety speed”; it is the speed an aircraft with one engine inoperative must be able to attain in order to leave the runway and get 35 feet off the ground at the end of the runway, maintaining a 200 ft/min climb thereafter. This is the lowest speed at which the aircraft complies with the handling criteria associated with a climb after a take-off, followed by the failure of an engine.

V
— From the French word vitesse, meaning “speed.”

V1
— Maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speedbrakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the surface within the takeoff distance.

V2
— Takeoff safety speed for jets, turboprops or transport-category aircraft. Best climb gradient speed (i.e., best altitude increase per mile with the most critical engine inop). Twin-engine aircraft with an engine inop are guaranteed a 2.4 percent climb gradient (24 feet up per 1,000 feet forward). Minimum speed to be maintained to at least 400 feet agl.

V2MIN
— Minimum takeoff safety speed. Usually 1.2 times the stall speed in takeoff configuration.
VA
— Design maneuvering speed. The highest safe airspeed for abrupt control deflection or for operation in turbulence or severe gusts. It does not allow for multiple large control inputs. If only one speed is published it is usually determined at max landing weight. This speed decreases as weight decreases.
VA at less than max landing weight: VA2 equals VA multiplied by current weight divided by max landing weight.

VABE
— Maximum speed for airbrake extension.

VABO
— Maximum speed for airbrake operation.
VAC
— Missed-approach climb speed for flap configuration with critical engine inop (2.1 percent climb gradient).

VAP
— Approach target speed. VREF plus configuration (flaps/slats setting) and wind factor.
Typically add (to VREF) half the headwind component plus all the gust factor