What was found
DURING STRAIGHT & LEVEL FLIGHT, THE FLIGHT CREW HAD BOTH THE CABIN REAR NVG LIGHTS ON FOR ABOUT 30 MINUTES OF THE 40 MINUTE FLIGHT. AT 30 MINUTES THEY NOTICED SPARKS & A SMALL PUFF OF SMOKE COME OUT OF THE LIGHT SOCKET AREA. NOTICED SMOKE RESIDUE AROUND THE LIGHT SOCKETS PLASTIC SHROUD ENCASING. REMOVED UNIT & LOOKED INSIDE & SMALL TRACES OF SMOKE RESIDUE ON BACK OF LIGHT FIXTURE AREAS. COULD NOT FIND ANY INDICATION OF BURNING, PITTING OR ARCING OF THE WIRING OR FIXTURES. THE LIGHTS WERE OPERATIVE & DID NOT SMOKE WHEN I ARRIVED TO BEGIN MY INSPECTION.