What was found
FLT 4772 - DURING CRUISE FROM MOB-DFW, AT APPROXIMATELY 31,000 FT, A STRONG FUEL ODOR OCCURRED IN THE COCKPIT. THE CREW INITIATED DESCENT OT 24,000 FEET AND SELECTED THE LEFT PACK OFF WHICH ELIMINATED THE FUEL ODOR. THE AIRCRAFT LANDED SAFELY IN DFW. MAINTENANCE REMOVED AND REPLACED AN O-RING AT THE FUEL FLOW ELBOW ON THE AUXILIARY POWER UNIT. OPERATIONAL AND LEAK CHECKS GOOD. AIRCRAFT OK FOR SERVICE. (M)