What was found
CREW ABORTED FLIGHT DUE TO SMELL COMING FROM AIR CONDITIONING VENTS. NO CAUTION/WARNING MESSAGES GIVEN. FOUND COMPRESSOR BELT TWISTED AND BURNED. HAVE HAD ONE OTHER OCCURRENCE A COUPLE OF DAYS PRIOR OF CREW DESCRIBING A "BURNING SMELL" FROM AIR CONDITIONING SYSTEM WITH NO FINDINGS OR DISCREPANCIES GIVEN. BELT WAS REPLACED A MONTH EARLIER DUE TO TEARING. WITH THE COLLECTIVE DISCREPANCIES GIVEN OVER TIME, DETERMINED CLUTCH MAY BE SLIPPING.