What was found
INVESTIGATED PILOT REPORT OF LT FUEL BOOST PUMP INDICATION. FOUND LT FUEL BOOST PUMP INOPERATIVE. INSTALLED BOOST PUMP WAS O/H 2/04/2011. REPLACED LT BOOST PUMP WITH AN O/H, PN 2C40-2, BOOST PUMP AS ORIGINALLY INSTALLED, OPS CKS OK. PUMP FAILURE MODE UNKNOWN, RECOMMEND INVESTIGATION AT TEAR-DOWN BY O/H FACILITY. PN 2070C.11 BOOST PUMPS WERE REPLACED BY OTHER PN 2C40-2 BOOST PUMPS YEARS PREVIOUSLY AT MFG AND RETROFITTED TO EARLIER ACFT SB 28-88 AND MODIFICATION 253256A. THE ACFT PARTS DISTRIBUTION DIVISION SHOW PN 2070C.11 PUMPS AS INTERCHANGEABLE WITH 2C40-2 BOOST PUMPS.