15.—(1) If any light required to be displayed by SERA.3215 fails during flight at night and cannot be immediately repaired or replaced, the aircraft must land as soon as it can safely do so, unless authorised by the appropriate air traffic control unit to continue its flight.
(2) An aircraft may continue to fly during the day in the event of a failure of an anti-collision light provided the light is repaired at the earliest practicable opportunity.