Definition
A set of fixed exterior position lights required on aircraft, consisting of a red light on the left wingtip, a green light on the right wingtip, and a white light on the tail. They show other pilots an aircraft's position and direction of travel, and are required to be on from sunset to sunrise.
Plain English
Coloured lights on the wings and tail that let other pilots see where your aircraft is and which way it is pointing in the dark.
Context Anchor
Seen on the exterior lighting checklist, including before engine start and during night or low-light operations.
Derivation
Navigation comes from older words connected with guiding or steering a ship. That helps here because these lights come from the same basic idea used in boats and airplanes: colored lights help others understand a vehicle’s direction in the dark.
Why Pilots Care
They are required by regulation for night operations and greatly reduce the risk of mid-air collision by showing other traffic your exact position and direction of flight.
Intuition Check
Navigation lights do not light up the path ahead like landing or taxi lights. They help other people see the airplane and tell which way it is facing or moving.
Example Sentence 1
Before taxiing at night, the pilot turned on the navigation lights and confirmed all three were working.
Example Sentence 2
From a distance the green light on the right wing told the approaching pilot that the aircraft was flying away from him.