14 CFR 27.1387 - Position light system dihedral angles.

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There are 4 Updates appearing in the Federal Register for 14 CFR Part 27. View below or at eCFR (GPOAccess)
§ 27.1387 Position light system dihedral 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 dihedral 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 degrees to the left of the first, as viewed when looking forward along the longitudinal 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 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 § 25.1385(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 30° with a vertical line passing through the rear position light.

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-7, 36 FR 21278, Nov. 5, 1971]

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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 27 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
The section you are viewing is cited by the following CFR sections.

Title 14 published on 2015-11-17.

The following are only the Rules published in the Federal Register after the published date of Title 14.

For a complete list of all Rules, Proposed Rules, and Notices view the Rulemaking tab.

  • 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