Definition
Battery-powered or otherwise self-contained lighting equipment used aboard an aircraft as a backup source of illumination when the primary electrical lighting system has failed or is unavailable. Examples include flashlights, chemical light sticks, and portable battery-operated lamps carried for use in the cabin, cockpit, or cargo area during emergencies.
Plain English
Backup lights, like flashlights or glow sticks, kept on board so the crew and passengers can still see if the aircraft's normal lights stop working.
Context Anchor
Seen in airport operations, night flying, emergency airport use, and discussions of temporary or substitute runway lighting.
Derivation
Alternative comes from a Latin root meaning “the other of two choices.” In this term, it points to lighting used as another choice when the normal lights are unavailable or unsuitable.
Why Pilots Care
They allow modern, energy-efficient, and longer-lasting lighting while maintaining compliance with airworthiness standards.
Intuition Check
Do not read “alternative” as meaning optional decoration. Here it means a substitute lighting method used to help pilots operate safely when the normal lighting is not available or sufficient.
Example Sentence 1
Before the night flight, the captain checked that the alternative lighting devices in the cockpit were stowed and working.
Example Sentence 2
Pilots must verify that any alternative lighting devices installed on the aircraft are listed in the approved equipment list.