US Patent 10362657 Exterior aircraft light unit and aircraft comprising the same

An exterior aircraft light unit includes a support plate, an LED, mounted to the support plate, a near end of life detector for sensing a light output level of the LED, the near end of life detector being mounted to the support plate, and a transparent optical element for shaping an output light intensity distribution of the exterior aircraft light unit, wherein the transparent optical element jointly encases the LED and the near end of life detector, with light from the LED reaching the near end of life detector through the transparent optical element.