(2) V1, in terms of calibrated airspeed, is selected by the applicant; however, V1may not be less than VEFplus the speed gained with critical engine inoperative during the time interval between the instant at which the critical engine is failed, and the instant at which the pilot recognizes and reacts to the engine failure, as indicated by the pilot's initiation of the first action (e.g., applying brakes, reducing thrust, deploying speed brakes) to stop the airplane during accelerate-stop tests.
(1) 1.13 V
(i) Two-engine and three-engine turbopropeller and reciprocating engine powered airplanes; and
(ii) Turbojet powered airplanes without provisions for obtaining a significant reduction in the one-engine-inoperative power-on stall speed;
(2) 1.08 V
(i) Turbopropeller and reciprocating engine powered airplanes with more than three engines; and
(ii) Turbojet powered airplanes with provisions for obtaining a significant reduction in the one-engine-inoperative power-on stall speed; and
(3) 1.10 times V
(3) A speed that provides the maneuvering capability specified in §25.143(h).
(i) V 1;
(ii) 105 percent of V
(iii) The speed (determined in accordance with §25.111(c)(2)) that allows reaching V 2before reaching a height of 35 feet above the takeoff surface; or
(iv) A speed that, if the airplane is rotated at its maximum practicable rate, will result in a V
(2) For any given set of conditions (such as weight, configuration, and temperature), a single value of V
(3) It must be shown that the one-engine-inoperative takeoff distance, using a rotation speed of 5 knots less than V
(4) Reasonably expected variations in service from the established takeoff procedures for the operation of the airplane (such as over-rotation of the airplane and out-of-trim conditions) may not result in unsafe flight characteristics or in marked increases in the scheduled takeoff distances established in accordance with §25.113(a).
(g) V FTO, in terms of calibrated airspeed, must be selected by the applicant to provide at least the gradient of climb required by §25.121(c), but may not be less than—
(1) 1.18 V
(2) A speed that provides the maneuvering capability specified in §25.143(h).
(h) In determining the takeoff speeds V1, VR, and V2for flight in icing conditions, the values of VMCG, VMC, and VMUdetermined for non-icing conditions may be used.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25–38, 41 FR 55466, Dec. 20, 1976; Amdt. 25–42, 43 FR 2320, Jan. 16, 1978; Amdt. 25–92, 63 FR 8318, Feb. 18, 1998; Amdt. 25–94, 63 FR 8848, Feb. 23, 1998; Amdt. 25–108, 67 FR 70826, Nov. 26, 2002; Amdt. 25–121, 72 FR 44665, Aug. 8, 2007]