(i)
The airplane structure must be designed for a vertical load of 1.33 times the vertical static reaction at eachjackingpoint acting singly andin com-bination with a horizontal load of 0.33 times the vertical static reaction applied in any direction.
(ii)
Thejackingpads andlocal structuremustbedesignedfor averticalload of2.0 times the vertical static reaction at eachjackingpoint, acting singly andin combinationwith ahorizontalload of0.33 timesthe vertical static reaction applied in any direction.
(c)
Tie-down.If tie-downpointsareprovided,the maintie-downpointsandlocal struc-ture must withstand the limit loads resulting from a 65-knot horizontal wind from any direction.]
Amdt. 25-81, E.. 5/31/94
46.7 Water Loads
FAR 25.521 : General.
(a)
Seaplanes mustbedesignedfor the waterloadsdevelopedduringtakeo. andlanding, with the seaplane in any attitude likely to occur in normal operation, and at the appropriate forward and sinking velocities under the most severe sea conditions likely to be encountered.
(b)
Unless a more rational analysis of the water loads is made, or the standards in ANC-3 are used, Secs. 25.523 through 25.537 apply.
(c)
The requirements of this section and Secs. 25.523 through 25.537 apply also to am-phibians.
′
Elodie Roux. Septembre 2003
Subpart C : Structure
FAR 25.523 : Design weights and center of gravity positions.
(a)
Design weights. The water load requirements must be met at each operating weight up tothedesignlanding weight exceptthat,forthetakeo. conditionprescribedin Sec.25.531,[thedesign watertakeo. weight(the maximum weightfor watertaxi and takeo. run)] must be used.
(b)
Center ofgravitypositions. The critical centers ofgravity within thelimitsfor which certi.cation is requested must be considered to reach maximum design loads for eachpart of the seaplane structure.
Amdt. 25-23, E.. 5/8/70
FAR 25.525 : Application of loads.
(a)
Unless otherwise prescribed, the seaplane as a whole is assumed to be subjected to the loads corresponding to the load factors speci.ed in Sec. 25.527.
(b)
In applying the loads resulting from the load factors prescribed in Sec. 25.527, the loads may be distributed over the hull or main .oat bottom (in order to avoid excessive local shear loads and bending moments at the location of water load application) using pressures not less than those prescribed in Sec. 25.533(c).
(c)
Fortwin .oatseaplanes, each.oat mustbetreated asanequivalenthull ona .ctitious seaplane with a weight equal to one-half the weight of the twin .oat seaplane.
(d)
Except in the takeo. condition of Sec. 25.531, the aerodynamic lift on the seaplane during the impact is assumed to be 2/3 of the weight of the seaplane.
FAR 25.527 : Hull and main .oat load factors.
(a)
Water reaction load factors nW must be computed in the following manner :
(1) For the step landing case
2
C1 VS0
nW =
2313
(tanβ)
W
(2) For the bow and stern landing cases
2
C1 VS0 K1
nW =
2313 23
(1+r2)
x
(tanβ)
W
(b) The following values are used :
(1)
nW = water reactionloadfactor(thatis, the water reactiondividedby seaplane weight).
(2)
C1 = empirical seaplane operationsfactor equalto0.012(except that thisfactor may not be less than that necessary to obtain the minimum value of step load factor of 2.33).
(3)
VS0 =seaplanestalling speed[(inknots)] with.apsextendedintheappropriate landing position and with no slipstream e.ect.
(4)
β= angle of dead rise at the longitudinal station at which the load factor is being determined, in accordance with .gure 1 of Appendix B.
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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 3(62)
