[Code of Federal Regulations]

[Title 14, Volume 1]

[Revised as of January 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 14CFR25.121]



[Page 355-356]

 

                     TITLE 14--AERONAUTICS AND SPACE

 

CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION

 

PART 25_AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES--Table 

of Contents

 

                            Subpart B_Flight

 

Sec. 25.121  Climb: One-engine-inoperative.



    (a) Takeoff; landing gear extended. In the critical takeoff 

configuration existing along the flight path (between the points at 

which the airplane reaches VLOF and at which the landing gear is fully 

retracted) and in the configuration used in Sec. 25.111 but without 

ground effect, the steady gradient of climb must be positive for two-

engine airplanes, and not less than 0.3 percent for three-engine 

airplanes or 0.5 percent for four-engine airplanes, at VLOF and with--

    (1) The critical engine inoperative and the remaining engines at the 

power



[[Page 356]]



or thrust available when retraction of the landing gear is begun in 

accordance with Sec. 25.111 unless there is a more critical power 

operating condition existing later along the flight path but before the 

point at which the landing gear is fully retracted; and

    (2) The weight equal to the weight existing when retraction of the 

landing gear is begun, determined under Sec. 25.111.

    (b) Takeoff; landing gear retracted. In the takeoff configuration 

existing at the point of the flight path at which the landing gear is 

fully retracted, and in the configuration used in Sec. 25.111 but 

without ground effect, the steady gradient of climb may not be less than 

2.4 percent for two-engine airplanes, 2.7 percent for three-engine 

airplanes, and 3.0 percent for four-engine airplanes, at V2 

and with--

    (1) The critical engine inoperative, the remaining engines at the 

takeoff power or thrust available at the time the landing gear is fully 

retracted, determined under Sec. 25.111, unless there is a more 

critical power operating condition existing later along the flight path 

but before the point where the airplane reaches a height of 400 feet 

above the takeoff surface; and

    (2) The weight equal to the weight existing when the airplane's 

landing gear is fully retracted, determined under Sec. 25.111.

    (c) Final takeoff. In the en route configuration at the end of the 

takeoff path determined in accordance with Sec. 25.111, the steady 

gradient of climb may not be less than 1.2 percent for two-engine 

airplanes, 1.5 percent for three-engine airplanes and 1.7 percent for 

four-engine airplanes, at VFTO and with

    (1) The critical engine inoperative and the remaining engines at the 

available maximum continuous power or thrust; and

    (2) The weight equal to the weight existing at the end of the 

takeoff path, determined under Sec. 25.111.

    (d) Approach. In a configuration corresponding to the normal all-

engines-operating procedure in which VSR for this configuration does not 

exceed 110 percent of the VSR for the related all-engines-operating 

landing configuration, the steady gradient of climb may not be less than 

2.1 percent for two-engine airplanes, 2.4 percent for three-engine 

airplanes, and 2.7 percent for four engine airplanes, with

    (1) The critical engine inoperative, the remaining engines at the 

go-around power or thrust setting;

    (2) The maximum landing weight;

    (3) A climb speed established in connection with normal landing 

procedures, but not more than 1.4 VSR; and

    (4) Landing gear retracted.



[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-84, 

60 FR 30749, June 9, 1995; Amdt. 25-108, 67 FR 70826, Nov. 26, 2002]