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Morning civil twilight period under part 107

Remote Pilot (Part 107) practice question 18 of 19 on Operations / Emergency Procedures. ACS element UA.V.C.K7 · difficulty: recall. Want to answer it in a timed quiz? Use the Remote Pilot (Part 107) practice mode.

Question bank updated 2026-09-22

QUESTIONUnder 14 CFR part 107, for operations conducted outside of Alaska, which period of time is morning civil twilight?

  1. ABegins 1 hour before official sunrise and ends 30 minutes later
  2. BBegins at official sunrise and ends 30 minutes after sunrise
  3. CBegins 30 minutes before official sunrise and ends at sunrise
Show the answer and explanation

Correct answer: C. Begins 30 minutes before official sunrise and ends at sunrise

  • A — incorrect The regulation uses 30 minutes before official sunrise, not 1 hour, and the period runs until sunrise itself.
  • B — incorrect This reverses the morning period; the 30-minute span that follows the event applies to official sunset under § 107.29(c)(2).
  • C — correct § 107.29(c)(1) defines this period, except for Alaska, as beginning 30 minutes before official sunrise and ending at official sunrise.

BACKGROUND

Small unmanned aircraft system (sUAS) operations conducted during periods of low light carry added collision risk, so 14 CFR part 107 attaches a lighting requirement to them. Section 107.29(b) states that no person may operate a small unmanned aircraft system during periods of civil twilight unless the aircraft has lighted anti-collision lighting visible for at least 3 statute miles with a flash rate sufficient to avoid a collision. Section 107.29(c) then defines civil twilight for this purpose. Outside Alaska, the morning period begins 30 minutes before official sunrise and ends at official sunrise, and the evening period begins at official sunset and ends 30 minutes after official sunset. In Alaska, civil twilight is instead the period defined in the Air Almanac.

STUDY TIP

Memorize the two 30-minute windows in § 107.29(c) as bracketing sunrise and sunset from the outside, and remember that Alaska uses the Air Almanac definition instead of a fixed 30 minutes.

KEY POINTS

  • Outside Alaska, morning civil twilight runs from 30 minutes before official sunrise until official sunrise.
  • Evening civil twilight runs from official sunset until 30 minutes after official sunset.
  • Anti-collision lighting visible for at least 3 statute miles is required during civil twilight.

SOURCES

  • 14 CFR 107.29(c)(1)
  • 14 CFR 107.29(b)
  • 14 CFR 107.29(c)(2)
  • 14 CFR 107.29(c)(3)
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MORE ON OPERATIONS / EMERGENCY PROCEDURES

SkyDrill is not affiliated with the FAA. This is an original practice item based on 14 CFR part 107, 14 CFR part 89, and the FAA Remote Pilot – Small UAS Study Guide (FAA-G-8082-22). Regulations and handbooks are revised; confirm details against the current edition.