What is a common failure mode for runway edge lights?

• A. Burned-out lamps, damaged fixtures, or failed power supply/ballasts.
• B. Misalignment of light fixtures.
• C. Excessive glare from nearby reflectors.
• D. Too many birds perching on fixtures.

Answer: (A)

Runway edge lights fail most often due to electrical and hardware issues within the lighting system. Lamps burn out when their filaments or LEDs reach end of life, fixtures can be damaged by weather, corrosion, or impact, and the power supply or ballast can fail, causing lights to go out or operate inconsistently. These are the kinds of problems that maintenance routinely monitors, tests, and replaces to keep the runway edge lighting reliable.

Misalignment of fixtures is typically a setup or maintenance alignment issue rather than a true failure mode of the lighting system itself. Excessive glare from nearby reflectors is an optical or design concern, not a direct failure of the lights. Birds perching on fixtures can cause nuisance or damage, but it’s not the common, underlying failure mechanism for the edge lighting system.