(b)
Theincrementalhorizontaltailloadsdue to maneuvering andgusts must be reacted by the angular inertia of the airplane in a rational or conservative manner.

(c)
[Mutual in.uence of the aerodynamic surfaces must be taken into account when determining .ight loads.]

Amdt. 23-42, E.. 02/04/91
FAR 23.333 : Flight envelope.
(a) General. Compliance with the strength requirements of this subpart must be shown at any combination of airspeed and load factor on and within the boundaries of a .ight envelope(similartothe oneinparagraph(d) of this section) that represents theenvelopeof the .ightloading conditionsspeci.edby themaneuvering andgust criteria ofparagraphs(b) and(c) of this section respectively.
′
Elodie Roux. Septembre 2003
Subpart C : Structure
(b)
Maneuvering envelope.Except wherelimitedby maximum(static) lift coe.cients, the airplane is assumed to be subjected to symmetrical maneuvers resulting in the following limit load factors :

(1)
The positive maneuvering load factor speci.ed in Sec. 23.337 at speeds up to VD ;

(2)
The negative maneuvering load factor speci.ed in Sec. 23.337 at VC ; and

(3)
Factorsvaryinglinearly with speedfromthespeci.ed valueat VC to 0.0 at VD forthenormal[and commutercategory,] and -1.0 at VD for the acrobatic and utility categories.

(c)
Gust envelope.

(1)
The airplane is assumed to be subjected to symmetrical vertical gusts in le-vel .ight. The resulting limit load factors must correspond to the conditions determined as follows :

(i)
Positive(up) and negative(down) gusts of50f.p.s. at VC must be consi-dered at altitudes between sea level and 20,000 feet. The gust velocity maybe reducedlinearlyfrom50f.p.s. at20,000feetto25f.p.s. at50,000 feet.

(ii)
Positive and negativegusts of25f.p.s. at VD must be considered at alti-tudesbetween sealevel and20,000feet.Thegust velocity maybe reduced linearly from 25 f.p.s. at 20,000 feet to 12.5 f.p.s. at 50,000 feet.

(iii) [In addition,for commuter categoryairplanes,positive(up) and negative (down)rough air gusts of 66 f.p.s. at VB must be considered at altitudes between sea level and 20,000 feet. The gust velocity may be reduced li-nearly from 66 f.p.s. at 20,000 feet to 38 f.p.s. at 50,000 feet.]

(2)
The following assumptions must be made :

(i) The shape of the gust is–
Ude 2πs
U =1.cos
2 25 Cˉ
where– 
s :Distance penetrated into gust ˉC :Mean geometric chord of wing Ude :Derived gust velocity referred to in subparagraph (1) of this section. (ii) Gust load factors vary linearly with speed between VC and VD. (d) [Flight envelope].  (ft.); (ft.); 
Amdt. 23-34, E.. 02/17/87 
FAR 23.335 : Design airspeeds. 
Except as provided in paragraph (a)(4) of this section, the selected design airspeeds are equivalent airspeeds (EAS). (a) Design cruising speed, VC. For VC, the following apply : (1) [WhereW S菩= wingloading at the design maximum takeo. weight, VC (in knots) may not be less than– 

Load factor n

C AD +Maneuver
-Maneuver G F acrobatic)
Limit maneuver envelopes
Limit gust envelope
Limit combined envelope
Fig. 30.1 – Note : Point G need not be investigated when the supplementary condition speci.ed in Sec. 23.369 is investigated.
W
(i) 33 (for normal, utility, andcommuter category airplanes); and
S
W
(ii) 36 (for acrobatic categoryairplanes).]
S
(2) For values of W more than 20, the multiplying factors may be decreased li-
S
nearly with W to a value of 28.6 where W =100.
SS
(3)
VC need not be more than 0.9 VH at sea level.

(4)
At altitudes where an MD is established, a cruising speed MC limited by compressibility may be selected.
　
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本文鏈接地址：FAA規(guī)章 美國聯(lián)邦航空規(guī)章 Federal Aviation Regulations 1(143)