What was found
GROUND PERSONNEL NOTED FUEL TYPE VAPORS TRAILING BEHIND TAXIING BEECH TRAVEL AIR. ACFT RETURNED TO AIRPORT. INVESTIGATION REVEALED VAPOR WAS, IN FACT, BURNING OIL FROM CHAFED THROUGH OIL LINES FROM COOLER. LINE WAS CHAFED AND BURNED THROUGH BY UNSHIELDED EXHAUST. REPLACED OIL LINE WITH LONGER HOSE AND ADDED AN ADEL CLAMP, ROUTING HOSE FURTHER DOWN IN COWL. A NEW OIL HOSE HAD BEEN INSTALLED ONLY 10 HOURS PREVIOUSLY.