Amdt. 25-108, E.. 12/26/2002
45.4 Trim
FAR 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 adverselateraldisplacement of the center ofgravity withinthe relevant operating limitations, during normally expected conditions of operation (includingoperation at any speedfrom[1.3VSR1]to VMO/MMO).
(c)
Longitudinal trim. The airplane must maintain longitudinal trim during–
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Elodie Roux. Septembre 2003
Subpart B : Flight
(1)
A climb with maximum continuouspowerat a speed not morethan[1.3VSR1] ,withthelandinggearretracted,andthe .aps(i) retracted and(ii) inthe takeo. position;
(2)
A glide with power o. at a speed not more than [1.3 VSR1] , with the lan-dinggearextended,thewing .aps(i) retractedand(ii) extended,themost unfavorable center of gravity position approved for landing with the maxi-mum landing weight, and with the most unfavorable center ofgravityposition approved for landing regardless of weight; and
(3)
Level .ight at any speed from [1.3 VSR1] to VMO/MMO , with the landing gear and .aps retracted, and from [1.3 VSR1] to VLE with the landing gear extended.
(d)
Longitudinal, directional, and lateral trim.The airplane must maintainlongitudinal, directional, andlateral trim(andforlateral trim, the angle ofbank may not exceed .vedegrees) at[1.3VSR1]during climbing .ight with–
(1)
The critical engine inoperative;
(2)
The remaining engines at maximum continuous power; and
(3)
The landing gear and .aps retracted.
(e)
Airplanes with four or more engines. Each airplane with four or more engines must maintain trim in rectilinear .ight–
(1)
At the climb speed, con.guration, and power required by Sec. 25.123(a) for thepurpose of establishing the rate of climb;
(2)
Withthe most unfavorable center ofgravityposition; and
(3)
At the weight at which the two-engine-inoperative climb is equal to at least [0.013VSRO2] at an altitude of 5,000 feet.
Amdt. 25-108, E.. 12/26/2002
45.5 Stability
FAR 25.171 : General.
The airplane must be longitudinally, directionally, and laterally stable in accordance withtheprovisionsofSecs.25.173through25.177.In addition, suitable stability[and controlfeel(static stability)]is requiredin any condition normally encounteredin service, if .ight tests show it is necessary for safe operation. Amdt. 25-7, E.. 11/14/65
FAR 25.173 : Static longitudinal stability.
[Under the conditions speci.ed in Sec. 25.175, the characteristics of the elevator controlforces(including friction) mustbe asfollow:
(a) Apullmustbe requiredto obtain and maintain speedsbelowthe speci.edtrim speed, and apush mustbe requiredto obtain and maintain speeds above the speci.ed trim speed.Thismustbeshownatany speed thatcanbe obtained exceptspeedshigher thanthelandinggearorwing .ap operatinglimitspeedsor VFC/MFC , whichever is appropriate, or lower than the minimum speed for steady unstalled .ight.
(b)
The airspeed must return to within 10 percent of the original trim speed for the climb, approach, andlanding conditions speci.edinSec.25.175(a),(c), and(d), and must return to within 7.5 percent of the original trim speed for the cruising conditionspeci.edinSec.25.175(b),whenthe controlforceisslowly releasedfrom any speed withinthe range speci.edinparagraph(a) of this section.
(c)
The average gradient of the stable slope of the stick force versus speed curve may not be less than 1 pound for each 6 knots.
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 3(36)
