812 

14 CFR Ch. I (1–1–14 Edition) 

§ 29.1385 

(1) No objectionable glare is visible 

to the pilot; 

(2) The pilot is not adversely affected 

by halation; and 

(3) It provides enough light for night 

operation, including hovering and land-
ing. 

(c) At least one separate switch must 

be provided, as applicable— 

(1) For each separately installed 

landing light; and 

(2) For each group of landing lights 

installed at a common location. 

§ 29.1385

Position light system installa-

tion. 

(a) 

General.  Each part of each posi-

tion light system must meet the appli-
cable requirements of this section and 
each system as a whole must meet the 
requirements of §§ 29.1387 through 
29.1397. 

(b) 

Forward position lights. Forward 

position lights must consist of a red 
and a green light spaced laterally as 
far apart as practicable and installed 
forward on the rotorcraft so that, with 
the rotorcraft in the normal flying po-
sition, 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 rear posi-

tion light must be a white light mount-
ed as far aft as practicable, and must 
be approved. 

(d) 

Circuit.  The two forward position 

lights and the rear position light must 
make a single circuit. 

(e) 

Light covers and color filters. Each 

light cover or color filter must be at 
least flame resistant and may not 
change color or shape or lose any ap-
preciable light transmission during 
normal use. 

§ 29.1387

Position light system dihe-

dral angles. 

(a) Except as provided in paragraph 

(e) of this section, each forward and 
rear position light must, as installed, 
show unbroken light within the dihe-
dral angles described in this section. 

(b) Dihedral angle 

L  (left) is formed 

by two intersecting vertical planes, the 
first parallel to the longitudinal axis of 
the rotorcraft, and the other at 110 de-
grees to the left of the first, as viewed 
when looking forward along the longi-
tudinal axis. 

(c) Dihedral angle 

R (right) is formed 

by two intersecting vertical planes, the 
first parallel to the longitudinal axis of 
the rotorcraft, and the other at 110 de-
grees to the right of the first, as viewed 
when looking forward along the longi-
tudinal axis. 

(d) Dihedral angle 

A  (aft) is formed 

by two intersecting vertical planes 
making angles of 70 degrees to the 
right and to the left, respectively, to a 
vertical plane passing through the lon-
gitudinal axis, as viewed when looking 
aft along the longitudinal axis. 

(e) If the rear position light, when 

mounted as far aft as practicable in ac-
cordance with § 29.1385(c), cannot show 
unbroken light within dihedral angle A 
(as defined in paragraph (d) of this sec-
tion), a solid angle or angles of ob-
structed visibility totaling not more 
than 0.04 steradians is allowable within 
that dihedral angle, if such solid angle 
is within a cone whose apex is at the 
rear position light and whose elements 
make an angle of 30

° 

with a vertical 

line passing through the rear position 
light. 

(49 U.S.C. 1655(c)) 

[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as 
amended by Amdt. 29–9, 36 FR 21279, Nov. 5, 
1971] 

§ 29.1389

Position light distribution 

and intensities. 

(a) 

General. The intensities prescribed 

in this section must be provided by new 
equipment with light covers and color 
filters in place. Intensities must be de-
termined with the light source oper-
ating at a steady value equal to the av-
erage luminous output of the source at 
the normal operating voltage of the 
rotorcraft. The light distribution and 
intensity of each position light must 
meet the requirements of paragraph (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 min-
imum intensities in the horizontal 
plane, minimum intensities in any 
vertical plane, and maximum inten-
sities in overlapping beams, within di-
hedral angles, 

L, R, and  A,  and must 

meet the following requirements: 

(1) 

Intensities in the horizontal plane. 

Each intensity in the horizontal plane 

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