(1)
0.75 times those obtained under Sec. 23.395; or
(2)
The minimum forces speci.ed in Sec. 23.397(b).
(b)
Each dual control system must be designed to withstand the force of the pilots applied together, in the same direction, using individual pilot forces not less than
0.75 times those obtained under Sec. 23.395.]
Amdt. 23-48, E.. 03/11/96
FAR 23.405 : Secondary control system.
Secondarycontrols, such as wheelbrakes, spoilers, and tab controls, mustbedesigned for the maximum forces that a pilot is likely to apply to those controls.
FAR 23.407 : Trim tab e.ects.
The e.ects of trim tabs on the control surface design conditions must be accounted for only where the surface loads are limited by maximum pilot e.ort. In these cases, the tabs are considered to be de.ected in the direction that would assist the pilot. These de.ections must correspond to the maximum degree of ”out of trim” expected at the speed for the condition under consideration.
FAR 23.409 : Tabs.
Control surface tabs must be designed for the most severe combination of airspeed and tab de.ection likely to be obtained within the .ight envelope for any usable loading condition.
FAR 23.415 : Ground gust conditions.
(a) The control system must be investigated as follows for control surface loads due to groundgusts andtaxiing downwind :
(1)
If an investigation of the control system for ground gust loads is not required by subparagraph(2) ofthisparagraph,butthe applicant electstodesign a part of the control system of these loads, these loads need only be carried from control surface horns through the nearest stops or gust locks and their supporting structures.
(2)
[If pilot forces less than the minimums speci.ed in Sec. 23.397(b)are used for design,the e.ects of surfaceloadsduetogroundgusts and taxiing downwind must be investigated for the entire control system according to the formula :
H = K cSq
where-
H :limit hinge moment c :mean chord of the control surface aft of the hinge line S :area of control surface aft of the hinge line q :dynamic pressure based on a design speed not . (ft.-lbs.); (ft.); (sq. ft.); (p.s.f.)
less than 14.6
WS
+ 14.6 (f.p.s.) where
WS
= wing loading at design maximum weight, except that the design speed need not exceed 88(f.p.s.);
K :limithinge momentfactorforgroundgustsde-rivedinparagraph(b) of this section.(For ai-lerons andelevators, apositive value of K indi-cates a moment tending to depress the surface and a negative value of K indicates a moment tending to raise the surface).]
(b) The limit hinge moment factor K forgroundgusts mustbederived asfollows:
′
Elodie Roux. Septembre 2003
Subpart C : Structure
Surface K Position of controls
(a)Aileron 0.75 Control column locked or lashed in mid-position.
(b)Aileron ±0.50 Ailerons at full throw; + moment on one aileron, -moment on the other.
(c)Elevator ±0.75 (c)Elevator full up (-).
(d)Elevator - (d)Elevator full down (+).
(e)Rudder ±0.75 (e)Rudder in neutral.
(f)Rudder - (f)Rudder at full throw.
