SAE ARP 4087C
This SAE Aerospace Recommended Practice (ARP) is intended to cover the external lights on fixed wing aircraft for illuminating the wing leading edge and engine nacelles and the upper surfaces of the wing. The addition of ice detection system should be implemented when the areas to inspect are not visable from the aircraft cockpit. It is not intended that this Recommended Practice require the use of any particular light source such as Halogen, LED or other specific design of lamp.The purpose of this document is to set forth basic considerations and criteria which should be observed when designing wing inspection lights for all aircraft.