Sec. 25.161 - Trim.
(a) General. Each airplane must meet the trim requirements of this section 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 V
(c) Longitudinal trim. The airplane must maintain longitudinal trim during --
(1) A climb with maximum continuous
power at a speed not more than 1.4 V
(2) A glide with power off at a speed
not more than 1.3 V
(3) Level flight at any speed from 1.3
(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 V
(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 maintain trim in rectilinear flight --
(1) At the climb speed, configuration, and power required by §25.123(a) for the purpose of establishing the rate of climb;
(2) With the most unfavorable center of gravity position; and
(3) At the weight at which the
two-engine-inoperative climb is equal to at least 0.013 V
[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. 1-49, 67 FR 70827, Nov. 26, 2002]