When preparing for a night flight, what should an sUAS pilot be aware of after assembling and conducting a preflight of an aircraft while using a bright flashlight or work light?

Why: This is a published FAA UAG sample knowledge-test question. Its correct answer is that dark adaptation takes approximately 30 minutes, matching the Pilot's Handbook of Aeronautical Knowledge: "the rods can take approximately 30 minutes to fully adapt to darkness. A bright light, however, can completely destroy night adaptation," forcing the process to repeat.

• Dark-adapted eyes are not immune to bright light — a single bright light exposure, like a work light during preflight, can destroy night adaptation already built up.
• The handbook does not single out LED flashlights as protecting night vision; any bright white light, regardless of bulb type, can disrupt dark adaptation. Dim red lighting, not LED specifically, is the usual night-vision-preserving choice.