What was found
INCREDIBLY LOUD SQUEAL FROM FO SIDE WINDOW STARTED AT FL240 AND COC KPIT COMMS DIFFICULT WILL REQUIRE POSITIVE FIX. SEAL AND WINDOW SHOW IN STOCK SFO ITEM UNLOCKED FOR UPDATE F/O INDICATED THAT NOISE CAME FROM THE SLIDING WINDOW, UPPER AFT CORNER, AND DID NOT FEEL AIR ENTERING THE FLIGHTDECK. FOUND FO''S SLIDING WINDOW NOT LOCKED CLOSED. CLEANED SEAL AS A PRECAUTIONARY AND PRESSURIZED CABIN TO 4.5 PSI. NO LEAKS DETECTED AND FLIGHT DECK IS QUIET. CONCURRED WITH TOMC CONTROLLER EICHHORN AND TOMC SEN MGR MCNEELRY AS POSITIVE FIX. ADD EMP:U110100,U139376