What was found
APPROX 2 HR 20 MIN INTO FLT CABIN STARTED FILLING WITH SMOKE IN VICINITY OF ROW 11. FAINT BURNING SMELL IN C/P / FOLLOWED BY F.O. AIRSPEED INDICATING RED WARNING LTS IAS DISAGREED, ONCE BEG AN DESCENT SMOKE BEGAN TO DISSIPATE IN CABIN AND A/C IND RETURNED TO NORMAL HAD FLT CREW FILLOUT FORM 46.6020 SMOKE IN PLANE AND FAXED TO MC. INSPECTED A/C PER MM 05-51-58-910-80-1C1 AND GMM 07-62-58 COULD NOT DUPLICATE SMOKE. REPLACED RT FCC PER MM 34-12-01 AND RT AIR DATE PER MM 34-12-01 401. PERFORMED TEST 30, TEST PASS A/C REMAINS CAT 111A AND ANN IN C/P READS SAME. REF LP 4270957 MORE ROTABLE PARTS CHANGE WAS INDICATED - TT # 1434761 SN OFF 03024 TT # 1444315 SN OFF 05058 COMPUTER, FLIGHT OFF 99-2211-9-0001 3024 ON 99-2211-9-0001 8571 COMPUTER, AIR D OFF 19-3412-9-0003 5058 ON 19-3412-9-0003 5776.