[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: 14CFR25.123]



[Page 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. 25.123  En route flight paths.



    (a) For the en route configuration, the flight paths prescribed in 

paragraphs (b) and (c) of this section must be determined at each 

weight, altitude, and ambient temperature, within the operating limits 

established for the airplane. The variation of weight along the flight 

path, accounting for the progressive consumption of fuel and oil by the 

operating engines, may be included in the computation. The flight paths 

must be determined at any selected speed, with--

    (1) The most unfavorable center of gravity;

    (2) The critical engines inoperative;

    (3) The remaining engines at the available maximum continuous power 

or thrust; and

    (4) The means for controlling the engine-cooling air supply in the 

position that provides adequate cooling in the hot-day condition.

    (b) The one-engine-inoperative net flight path data must represent 

the actual climb performance diminished by a gradient of climb of 1.1 

percent for two-engine airplanes, 1.4 percent for three-engine 

airplanes, and 1.6 percent for four-engine airplanes.

    (c) For three- or four-engine airplanes, the two-engine-inoperative 

net flight path data must represent the actual climb performance 

diminished by a gradient of climb of 0.3 percent for three-engine 

airplanes and 0.5 percent for four-engine airplanes.