(e)
[Ifthe rearpositionlight,whenmounted asfaraft aspracticableinaccordancewith Sec. 27.1385(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. 27-7, E.. 11/5/71
FAR 27.1389 : 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 thelight source operating at a steady value equal to the averageluminous output of the source at the normal operating voltage of the rotorcraft. The light distribution 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 containing the longitudinal axis of the rotorcraft and perpendicular to the plane of symmetry of the rotorcraft) must equal or exceed the values in Sec. 27.1391.
(2)
Intensitiesin any verticalplane.Eachintensityin any verticalplane(theplane perpendicular to the horizontal plane) must equal or exceed the appropriate value in Sec. 27.1393, where I is the minimum intensity prescribed in Sec. 27.1391forthe corresponding anglesinthehorizontalplane.
(3)
Intensities in overlaps between adjacent signals. No intensity in any overlap between adjacent signals may exceed the values in Sec. 27.1395, except that higherintensitiesin overlaps maybe used with mainbeamintensities substan-tially greater than the minima speci.ed in Secs. 27.1391 and 27.1393, if the overlap intensities in relation to the main beam intensities do not adversely a.ect signal clarity.Whenthepeakintensity of theforwardpositionlightsis greater than 100candles, the maximum overlapintensities between them may exceed the valuesinSec.27.1395if the overlapintensityinAreaAis not more than 10 percent of peak position light intensity and the overlap intensity in Area B is not more than 2.5 percent of peak position light intensity.
FAR 27.1391 : Minimum intensities in the horizontal plane of forward and rear position lights
Each position light intensity must equal or exceed the applicable values in the follo-wing table :
Dihedral angle (light included) Angle from right or left of longitudinal axis, measu-red from dead ahead '' Intensity (candles)
L and R (forward red and green). 0to 1010'to 20' 20'to 110' '' 40 30 5
A (rear white) 110to 180 20
FAR 27.1393 : Minimum intensities in any vertical plane of forward and rear position lights
Each position light intensity must equal or exceed the applicable values in the follo-wing table :
′
Elodie Roux. Septembre 2003
Subpart F–Equipment
Angle above or below the horizontal plane : ' Intensity
0'' 1.00 I.
0to 5'' 0.90 I.
5to 10'' 0.80 I.
10to 15'' 0.70 I.
15to 20'' 0.50 I.
20to 30'' 0.30 I.
30to 40'' 0.10 I.
40to 90 0.05 I.
FAR 27.1395 : Maximum intensities in over lapping beams of forward and rear position lights
No position light intensity may exceed the applicable values in the following table, except as provided in Sec. 27.1389(b)(3).
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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(127)
