[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR25.161]

[Page 363-364]
 
                     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.  25.161  Trim.

    (a) General. Each airplane must meet the trim requirements of this 
section

[[Page 364]]

after being trimmed, and without further pressure upon, or movement of, 
either the primary controls or their corresponding trim controls by the 
pilot or the automatic pilot.
    (b) Lateral and directional trim. The airplane must maintain lateral 
and directional trim with the most adverse lateral displacement of the 
center of gravity within the relevant operating limitations, during 
normally expected conditions of operation (including operation at any 
speed from 1.3 VSR1 to VMO/MMO).
    (c) Longitudinal trim. The airplane must maintain longitudinal trim 
during--
    (1) A climb with maximum continuous power at a speed not more than 
1.3 VSR1, with the landing gear retracted, and the flaps (i) 
retracted and (ii) in the takeoff position;
    (2) Either a glide with power off at a speed not more than 1.3 
VSR1, or an approach within the normal range of approach 
speeds appropriate to the weight and configuration with power settings 
corresponding to a 3 degree glidepath, whichever is the most severe, 
with the landing gear extended, the wing flaps (i) retracted and (ii) 
extended, and with the most unfavorable combination of center of gravity 
position and weight approved for landing; and
    (3) Level flight at any speed from 1.3 VSR1, to VMO/MMO, 
with the landing gear and flaps retracted, and from 1.3 VSR1 
to VLE with the landing gear extended.
    (d) Longitudinal, directional, and lateral trim. The airplane must 
maintain longitudinal, directional, and lateral trim (and for the 
lateral trim, the angle of bank may not exceed five degrees) at 1.3 
VSR1 during climbing flight with--
    (1) The critical engine inoperative;
    (2) The remaining engines at maximum continuous power; and
    (3) The landing gear and flaps retracted.
    (e) Airplanes with four or more engines. Each airplane with four or 
more engines must also maintain trim in rectilinear flight with the most 
unfavorable center of gravity and at the climb speed, configuration, and 
power required by Sec.  25.123(a) for the purpose of establishing the en 
route flight paths with two engines inoperative.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-23, 
35 FR 5671, Apr. 8, 1970; Amdt. 25-38, 41 FR 55466, Dec. 20, 1976; Amdt. 
25-108, 67 FR 70827, Nov. 26, 2002; Amdt. 25-115, 69 FR 40527, July 2, 
2004]

                                Stability