What was found
LHR - FLT 116 - EN ROUTE JFK/LHR DURING CRUISE, SLIGHT SMOKE NOTED IN B/C GALLEY WHEN WARMING CART AND OVEN TURNED ON. TURNED OFF B/C GALLEY WARMING CART AND OVEN AND AIRCRAFT PROCEEDED TO LHR, LANDING WITHOUT INCIDENT. WARMING CART REPLACED BY CATERING AND B/C GALLEY OVEN PLACARDED INOPERATIVE. SUBSEQUENTLY AT SFO/18, B/C GALLEY OVEN OPERATION CHECKED BY RUNNING AT 375 DEGREES FOR ONE HOUR WITH NO SMOKE NOTED. UNABLE TO DUPLICATE PROBLEM AND AIRCRAFT RETURNED TO SERVICE. (M)