(b)
Except when one switch is used for the lights of a multiple light installation at one location, there must be a separate switch for each light.

(c)
There mustbe a means toindicate to thepilots when thelandinglights are extended.

FAR 25.1385 : Position light system installation.

(a)
General. Each part of each position light system must meet the applicable require-ments of this section and each system as a whole must meet the requirements of Secs. 25.1387 through 25.1397.

(b)
Forwardpositionlights.Forwardpositionlights must consist of a red and agreenlight spaced laterally as far apart as practicable and installed forward on the airplane so that, with the airplane in the normal .ying position, the red light is on the left side, and the green light is on the right side. Each light must be approved.

(c)
[Rear position light.The rearpositionlight mustbe a whitelightmounted asfar aft as practicable on the tail or on each wing tip, and must be approved.]

(d)
Light covers and color .lters. Each light cover and color .lter must be at least .ame resistant and may not change color or shape or lose any appreciable light transmission during normal use.

(e)
[[Deleted.]]

Amdt. 25-38, E.. 2/1/77
′
Elodie Roux. Septembre 2003
Subpart F : Equipment
FAR 25.1387 : Position light system dihedral angles.
(a)
[Except asprovidedinparagraph(e)of this section, eachforward and rearposition light must, as installed, show unbroken light within the dihedral angles described in this section.]

(b)
Dihedral angleL(left)isformedby twointersecting verticalplanes,the .rstparallel to the longitudinal axis of the airplane, and the other at 110 degrees to the left of the .rst, as viewed when looking forward along the longitudinal axis.

(c)
DihedralangleR(right)isformedbytwointersecting verticalplanes,the .rstparallel to the longitudinal axis of the airplane, and the other at 110 degrees to the right of the .rst, as viewed when looking forward along the longitudinal axis.

(d)
Dihedral angleA(aft) isformedby twointersecting verticalplanes making angles of 70 degrees to the right and to the left, respectively, to a vertical plane passing through the longitudinal axis, as viewed when looking aft along the longitudinal axis.

(e)
[Ifthe rearpositionlight,whenmounted asfaraft aspracticableinaccordancewith Sec. 25.1385(c), cannot show unbroken light within dihedral angle A (as de.ned in paragraph (d) of this section), a solid angle or angles of obstructed visibility totaling not more than 0.04 steradians is allowable within that dihedral angle, if such solid angleis within a conewhoseapexisatthe rearpositionlightand whose elements make an angle of 30'with a verticallinepassing through the rearposition light.]

Amdt. 25-30, E.. 11/5/71
FAR 25.1389 : Position light distribution and intensities.
(a)
General. The intensities prescribed in this section must be provided by new equip-ment withlight coversand color .ltersinplace.Intensitiesmustbedetermined with the light source operating at a steady value equal to the average luminous output of the source at the normal operating voltage of the airplane.Thelightdistribution andintensity of eachpositionlight must meet the requirements ofparagraph(b) of this section.

(b)
Forward and rear position lights. The light distribution and intensities of forward and rear position lights must be expressed in terms of minimum intensities in the horizontal plane, minimum intensities in any vertical plane, and maximum intensities in overlapping beams, within dihedral angles L, R, and A, and must meet the following requirements :

(1)
Intensities in the horizontal plane. Each intensity in the horizontalplane(the plane containingthelongitudinal axis of the airplane andperpendicular to the plane of symmetry of the airplane) must equal or exceed the values in Sec. 25.1391.
　
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本文鏈接地址：FAA規章 美國聯邦航空規章 Federal Aviation Regulations 4(25)