<Li> Boats classed as "small" are not compelled to carry navigation lights and may make use of a handheld torch . </Li> <P> Aircraft external lights are any light fitted to the exterior of an aircraft . They are usually used to increase visibility to others, and to signal actions such as entering an active runway or starting up an engine . Historically, incandescent bulbs have been used to provide light, however recently Light - emitting diodes have been used . </P> <P> Aircraft navigation lights are placed in a way similar to that of marine vessels, with a red navigation light located on the left wingtip leading edge and a green light on the right wingtip leading edge . A white navigation light is as far aft as possible on the tail or each wing tip . High - intensity strobe lights are located on the aircraft to aid in collision avoidance . Anti-collision lights are flashing lights on the top and bottom of the fuselage, wingtips and tail tip . Their purpose is to alert others when something is happening that ground crew and other aircraft need to be aware of, such as running engines or entering active runways . </P> <P> In civil aviation, pilots must keep navigation lights on from sunset to sunrise . High - intensity white strobe lights are part of the anti-collision light system, as well as the red rotating beacon . </P>

What side of a powered aircraft has green navigation lights