(1)
The system must withstandloads resulting fromthelimitpilotforcesprescri-bed in Sec. 27.397.
(2)
Notwithstandingparagraph(b)(3) of this section, whenpower-operated actua-tor controlsorpowerboost controlsareused,the system must also withstand the loads resulting from the force output of each normally energized power device, including any single power boost or actuator system failure.
(3)
If the systemdesign orthe normal operating loads are such that apart of the system cannot reactto thelimitpilotforcesprescribedinSec.27.397,thatpart of the system must be designed to withstand the maximum loads that can be obtained in normal operation. The minimum design loads must, in any case, provide a rugged system for service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction loads. In the absence of rational analysis, the design loads resulting from 0.60 of the speci.ed limit pilot forces are acceptable minimum design loads.
(4)
If operationalloads may be exceeded throughjamming,groundgusts, control inertia, or friction, the system must withstand the limit pilot forces speci.ed in Sec. 27.397, without yielding.]
Amdt. 27-26, E.. 4/5/90
FAR 27.397 : Limit pilot forces and torques
(a)
Except as provided in paragraph (b) of this section, the limit pilot forces are as follows :
(1)
Forfoot controls,130pounds.
(2)
For stick controls,100poundsfore and aft, and67poundslaterally.
(b)
For .ap, tab, stabilizer, rotor brake, and landing gear operating controls, the follo-wing apply(R=radiusininches) :
(1+R)
(1) Crank,wheel,andlevel controls, 50pounds,butnotlessthan50pounds
3
nor more than 100 pounds for hand operated controls or 130 pounds for foot operated controls, applied at any angle within20degrees oftheplane of motion of the control.
(2) Twist controls,[80Rinch-pounds.]
Amdt. 27-40, E.. 5/9/2001
FAR 27.399 : Dual control system
Eachdualprimary.ightcontrol systemmustbedesigned towithstand theloadsthat result when pilot forces of 0.75 times those obtained under Sec. 27.395 are applied–
(a)
In opposition; and
(b)
In the same direction.
FAR27.401 :[Removed.]
[Removed.] Amdt. 27-27, E.. 10/22/90
FAR27.403 :[Removed.]
[Removed.] Amdt. 27-27, E.. 10/22/90
′
Elodie Roux. Septembre 2003
Subpart C : Strength Requirements
FAR 27.411 : Ground clearance : tail rotor guard
(a)
Itmustbeimpossiblefor the tail rotorto contact thelanding surfaceduring a normal landing.
(b)
If a tail rotor guard is required to show compliance with paragraph (a) of this section–
(1)
Suitable design loads must be established for the guard; and
(2)
The guard and its supporting structure must be designed to withstand those loads.
FAR27.413 :[Removed.]
[Removed.] Amdt. 27-27, E.. 10/22/90
FAR 27.427 : Unsymmetrical loads
(a)
Horizontal tail surfaces and their supporting structure must be designed for unsym-metrical loads arising from yawing and rotor wake e.ects in combination with the prescribed .ight conditions.
(b)
To meetthedesign criteria ofparagraph(a) ofthis section,inthe absence of more rational data, both of the following must be met :
(1)
[One hundred percent of the maximum loading from the symmetrical .ight conditionsin actsonthe surfaceon onesideof theplaneof symmetry,and no loading acts on the other side.
(2)
Fifty percent of the maximum loading from the symmetrical .ight conditions in acts on the surface on each side of the plane of symmetry but in opposite directions.]
(c)
For empennage arrangements where the horizontal tail surfaces are supported by the vertical tail surfaces, the vertical tail surfaces and supporting structure must be designed for the combined vertical and horizontal surface loads resulting from each prescribed .ight condition, considered separately. The .ight conditions must be selected so the maximum design loads are obtained on each surface. In the absence of more rational data, the unsymmetrical horizontal tail surface loading distributions described in this section must be assumed.
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 4(76)
