What are key performance speeds used for takeoff on a 787?

What are key performance speeds used for takeoff on a 787?

• A. V-speeds such as V1, VR, and V2, determined from the weight and conditions.
• B. Only V1 is used.
• C. V1 and V2 are fixed values independent of weight.
• D. V1 is the only speed required for takeoff.

Answer: (A)

Takeoff performance is driven by three key speeds—V1, VR, and V2—that are computed from the airplane’s weight and current conditions. V1 is the decision speed: if an issue occurs before V1, the takeoff can be aborted safely; after V1, the takeoff must continue. VR is the rotation speed at which the nose is pitched up to liftoff, and V2 is the takeoff safety speed, the minimum speed for a safe climb with one engine inoperative and with adequate stall margin. On a 787 these speeds aren’t fixed; the flight management system and performance data calculate them from weight, flap setting, runway conditions, temperature, altitude, wind, and any contamination. That’s why the best answer is that the key takeoff speeds are V1, VR, and V2 determined from weight and conditions.

Takeoff performance is driven by three key speeds—V1, VR, and V2—that are computed from the airplane’s weight and current conditions. V1 is the decision speed: if an issue occurs before V1, the takeoff can be aborted safely; after V1, the takeoff must continue. VR is the rotation speed at which the nose is pitched up to liftoff, and V2 is the takeoff safety speed, the minimum speed for a safe climb with one engine inoperative and with adequate stall margin. On a 787 these speeds aren’t fixed; the flight management system and performance data calculate them from weight, flap setting, runway conditions, temperature, altitude, wind, and any contamination. That’s why the best answer is that the key takeoff speeds are V1, VR, and V2 determined from weight and conditions.