14 C.F.R. § 25.107 Takeoff speeds.
Title 14 - Aeronautics and Space
(a) V1 must be established in relation to V (1) V (2) V1, in terms of calibrated airspeed, is selected by the applicant; however, V1 may not be less than VEF plus 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. (b) V (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 (c) V (1) V (2) V (3) A speed that provides the maneuvering capability specified in §25.143(g). (d) V (e) V (1) V (i) V1; (ii) 105 percent of V (iii) The speed (determined in accordance with §25.111(c)(2)) that allows reaching V2 before 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). (f) V (g) VFTO, 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(g). [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]
Title 14: Aeronautics and Space
PART 25—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
Subpart B—Flight
Performance
§ 25.107 Takeoff speeds.