← All explained questions · Supplemental · II — Preflight Procedures
Aircraft anti-collision lights (typically red BEACON and/or white STROBES) must be operating
Choices
only at night.
Required during day too.
✓ anytime the engine is running, day OR night, unless the PIC determines they should be turned off in the interest of safety.correct
e.g., distracting other pilots in formation, blinding ground crew during taxi). Per 14 CFR 91.209(b) — anti-collision lights operate anytime the engine is running, day or night, EXCEPT when the PIC determines safety considerations require otherwise (formation, ground crew, etc.). Position lights are required from sunset to sunrise (91.209(a)). Strobes can blind other pilots in cloud, so frequently turned off in IMC.
only above 10,000 ft.
Required at all altitudes.
only when in IFR conditions.
Required in VFR too.
Why
e.g., distracting other pilots in formation, blinding ground crew during taxi). Per 14 CFR 91.209(b) — anti-collision lights operate anytime the engine is running, day or night, EXCEPT when the PIC determines safety considerations require otherwise (formation, ground crew, etc.). Position lights are required from sunset to sunrise (91.209(a)). Strobes can blind other pilots in cloud, so frequently turned off in IMC.
FAA source: 14 CFR §91.209(b), aircraft lightsbrowse the reference library →
Original study question written for this course — representative of FAA knowledge-test topics, not an actual current FAA exam question.