Section 29.1389

14 CFR Ch. I (1-1-19 Edition)

spaschal on DSK3GDR082PROD with CFR

(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 degrees to the right of the first, as viewed
when looking forward along the longitudinal 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 longitudinal axis, as viewed when looking
aft along the longitudinal axis.
(e) If the rear position light, when
mounted as far aft as practicable in accordance with Section 29.1385(c), cannot show
unbroken light within dihedral angle A
(as defined 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 angle
is within a cone whose apex is at the
rear position light and whose elements
make an angle of 30Section with a vertical
line passing through the rear position
light.

(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 Section 29.1391.
(2) Intensities in any vertical plane.
Each intensity in any vertical plane
(the plane perpendicular to the horizontal plane) must equal or exceed the
appropriate value in Section 29.1393 where I is
the minimum intensity prescribed in
Section 29.1391 for the corresponding angles in
the horizontal plane.
(3) Intensities in overlaps between adjacent signals. No intensity in any overlap between adjacent signals may exceed the values in Section 29.1395, except that
higher intensities in overlaps may be
used with the use of main beam intensities substantially greater than the
minima specified in SectionSection 29.1391 and
29.1393 if the overlap intensities in relation to the main beam intensities do
not adversely affect signal clarity.

(49 U.S.C. 1655(c))

Section 29.1391 Minimum intensities in the
horizontal plane of forward and
rear position lights.

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

Each position light intensity must
equal or exceed the applicable values in
the following table:

Section 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 determined 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
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 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 horizontal plane

Dihedral angle (light included)

L and R (forward red
and green).
A (rear white) ..............

Angle from right or left
of longitudinal axis,
measured from dead
ahead
0Section to 10Section .....................
10Section to 20Section ...................
20Section to 110Section .................
110Section to 180Section ...............

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Section 29.1393 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 following table:
Angle above or below the horizontal plane
0Section .........................................................................
0Section to 5Section ................................................................
5Section to 10Section ..............................................................
10Section to 15Section ............................................................
15Section to 20Section ............................................................
20Section to 30Section ............................................................
30Section to 40Section ............................................................
40Section to 90Section ............................................................

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Intensity, I
1.00
.90
.80
.70
.50
.30
.10
.05