Section 121.177 - Airplanes: Reciprocating engine-powered: Takeoff limitations(a) No person operating a reciprocating engine powered airplane may takeoff that airplane unless it is possible- (1) To stop the airplane safely on the runway, as shown by the accelerate stop distance data, at any time during takeoff until reaching critical-engine failure speed;(2) If the critical engine fails at any time after the airplane reaches critical-engine failure speed V1, to continue the takeoff and reach a height of 50 feet, as indicated by the takeoff path data, before passing over the end of the runway; and(3) To clear all obstacles either by at least 50 feet vertically (as shown by the takeoff path data) or 200 feet horizontally within the airport boundaries and 300 feet horizontally beyond the boundaries, without banking before reaching a height of 50 feet (as shown by the takeoff path data) and thereafter without banking more than 15 degrees.(b) In applying this section, corrections must be made for the effective runway gradient. To allow for wind effect, takeoff data based on still air may be corrected by taking into account not more than 50 percent of any reported headwind component and not less than 150 percent of any reported tailwind component.(c) This section does not apply to large nontransport category airplanes operated under § 121.173(c) .Doc. No. 6258, 29 FR 19198, Dec. 31, 1964, as amended by Amdt. 121-159, 45 FR 41593, June 19, 1980; Amdt. 121-251, 60 FR 65928, Dec. 20, 1995