Which statement describes the HLZ marking criterion for day vs night?

• A. Daytime uses Air panels or smoke; Nighttime uses Inverted Y (chem lights)
• B. Daytime uses Inverted Y (chem lights); Nighttime uses Air panels or smoke
• C. Daytime uses Air panels or smoke; Nighttime uses Flares
• D. Daytime uses Air panels or smoke; Nighttime uses Flags and flares

Answer: (A)

Helicopter Landing Zone markings are chosen to be highly visible to pilots in the current light conditions, so the marker system changes with day or night. In daylight, bright, large markers like air panels or colored smoke provide a clear, high-contrast indication of the LZ and its boundaries, making the touchdown area easy to spot from altitude and across terrain.

At night, those daylight markers wouldn’t stand out as well, so a different system is used: chem lights arranged in an inverted Y pattern. The glow from the chem lights is easily seen in darkness, and the inverted Y shape gives pilots a quick, recognizable cue to identify the LZ location and the intended approach path. This combination—air panels or smoke by day, inverted Y chem lights by night—best matches how HLZ marking is designed to function across varying lighting conditions.

Other schemes (like using flags or flares at night, or switching the day markers to the inverted Y) don’t align with practical visibility and standard practice for HLZ marking.