What was found
ENROUTE, (3-20-04, 11:38 PM) THE PILOT NOTED A MAIN ROTOR TRANSMISSION CHIP LIGHT. A PRECAUTIONARY LANDING WAS PERFORMED. UPON INSPECTION OF THE MAGNETIC PLUGS (UPPER AND LOWER) NO METAL WAS FOUND. A LIGHT COAT OF VERY FINE BLACK PARTICLES THAT LOOKED LIKE DUST WAS REMOVED FROM THE CHIP PLUGS. A109E MAINTENANCE MANUAL CHAPTER 63 PAGE 63-5 TABLE 63-1. CORRECTIVE ACTION FOR METAL PARTICLES CONTAMINATION STATES FUZZ, FINE HAIR LIKE PARTICLES, (NORMAL WEAR) AND IN THE CORRECTIVE ACTION COLUMN IT SAYS: BOTH MAGNETIC PLUGS WERE CLEANED AND THE AIRCRAFT WAS RETURNED TO SERVICE.