When is a serviceable landing light required on an aircraft?

A serviceable landing light is required on an aircraft when carrying passengers at night due to safety considerations. The purpose of the landing light is to enhance visibility of the aircraft during landing and taxiing procedures in low-light conditions, thereby increasing the safety for both the passengers and the crew. Operating at night inherently poses more risks because of reduced visibility, which makes the presence of a functioning landing light essential for safe operations. It aids in illuminating the runway environment and ensures that the aircraft is visible to others, contributing to overall flight safety.

This requirement is particularly reinforced for passenger operations, where the safety and comfort of individuals is paramount. In contrast, other scenarios, such as flying over cities, during daylight, or for training flights, do not have the same stringent requirement for a landing light.