14 CFR 23.1389 - Position light distribution and intensities.

§ 23.1389 Position light distribution and intensities.

(a)General. The intensities prescribed in this section must be provided by new equipment with each light cover and color filter 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 airplane. The light distribution and intensity of each position light must meet the requirements of paragraph (b) of this section.

(b)Position lights. The light distribution and intensities of 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 (the plane containing the longitudinal axis of the airplane and perpendicular to the plane of symmetry of the airplane) must equal or exceed the values in § 23.1391.

(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 § 23.1393, where I is the minimum intensity prescribed in § 23.1391 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 § 23.1395, except that higher intensities in overlaps may be used with main beam intensities substantially greater than the minima specified in §§ 23.1391 and 23.1393, if the overlap intensities in relation to the main beam intensities do not adversely affect signal clarity. When the peak intensity of the left and right position lights is more than 100 candles, the maximum overlap intensities between them may exceed the values in § 23.1395 if the overlap intensity in Area A is 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.

(c)Rear position light installation. A single rear position light may be installed in a position displaced laterally from the plane of symmetry of an airplane if -

(1) The axis of the maximum cone of illumination is parallel to the flight path in level flight; and

(2) There is no obstruction aft of the light and between planes 70 degrees to the right and left of the axis of maximum illumination.

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as amended by Amdt. 23-43, 58 FR 18977, Apr. 9, 1993]

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United States Code

Title 14 published on 2015-11-17

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 14 CFR Part 23 after this date.

  • 2017-02-08; vol. 82 # 25 - Wednesday, February 8, 2017
    1. 82 FR 9677 - Revisions to Operational Requirements for the Use of Enhanced Flight Vision Systems (EFVS) and to Pilot Compartment View Requirements for Vision Systems
      GPO FDSys XML | Text
      DEPARTMENT OF TRANSPORTATION, Federal Aviation Administration
      Final rule; delay of effective date.
      The effective date of the rule amending 14 CFR parts 1, 23, 25, 27, 29, 61, 91, 121, 125, and 135 published at 81 FR 90126, December 13, 2016, is delayed until March 21, 2017, except for the amendments to §§ 61.66 (amendatory instruction no. 15), 91.175 (amendatory instruction no. 18), 91.1039 (amendatory instruction no. 23), 121.651 (amendatory instruction no. 27), 125.325 (amendatory instruction no. 33), 125.381 (amendatory instruction no. 35), and 135.225 (amendatory instruction no. 38), which are effective March 13, 2018.
      14 CFR Parts 1, 23, 25, 27, 29, 61, 91, 121, 125, and 135
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