What was found
BROWN SMOKE AND BURNING ODOR FROM COCKPIT AIR VENTS, TEMP IN CABIN INCREASED TO 110 DEGREES. ACCOMPLISHED TSM`S 055000810831A AND 240000810823. DEBRIEFED FLT CREW. COCKPIT TEMP REACH 135 DEGREES. ON ARRIVAL THE NR 1 PACK OVERHEAT. TROUBLESHOT AND REPEATED PACK 1 OVERHEAT, DUCT TEMP CLIMBED TO 115 BEFORE SHUTDOWN. ALL OTHER SYSTEMS OK. NO ELECTRICAL PROBLEMS NOTED. R & R PACK 1 AIR CYCLE MACHINE IAW AMM 21-52-21. SYSTEM LEAK AND OP CHECKS GOOD.