TKOF ABORTED WHEN FO'S SLIDING WINDOW OPENS PRIOR TO 80 KTS. ACFT CONFIGN PROB.

Narrative

WHEN WE ARRIVED AT THE ACFT BOTH COCKPIT WINDOWS WERE OPEN. THE CAPT CRANKED HIS SHUT AND LATCHED IT; AND I CRANKED MINE SHUT AND LATCHED IT. THE REMAINDER OF PREFLT AND TAXI OUT WERE UNEVENTFUL. THEN ON TKOF ROLL; WITH FULL PWR ON THE ACFT; MY WINDOW POPPED OPEN. THROTTLES WERE RETARDED AT 80 KTS AND AUTOMATIC BRAKING AND SPD BRAKES ENGAGED. WE EXITED THE RWY (25R) AT T36 UNEVENTFULLY. NO ASSISTANCE WAS REQUIRED. ONCE CLR OF THE RWY; FURTHER EXAMINATION OF MY WINDOW REVEALED THAT THOUGH THE HANDLE WAS FULL FORWARD AND THE 'CLOSED' SIGN WAS SHOWING (THE PROPER CHKS HAD BEEN DONE) THE ACTUATION BAR IN THE LOWER R SIDE OF THE WINDOW WAS NEVER OVER CTR; IN THE 90 DEG POS. SO I CRANKED THE WINDOW FULL AFT THEN FULL FORWARD ONCE AGAIN AND THIS TIME NOT ONLY WAS THE HANDLE FULL FORWARD AND SIGN SHOWING 'CLOSED;' BUT THE ACTUATION ROD WAS OVER CTR; IN THE 90 DEG POS. WE WERE CONFIDENT THAT THIS HAD REMEDIED THE SIT. SO WE ELECTED TO GET BACK IN LINE FOR TKOF. THE LINE WAS LONG ENOUGH TO ALLOW FOR 14 MINS OF BRAKE COOLING. WE TOOK OFF (UNEVENTFULLY) AND DELAYED GEAR RETRACTION UNTIL 10000 FT MSL FOR FURTHER PRECAUTIONARY BRAKE COOLING. THE REMAINDER OF THE FLT AND SUBSEQUENT LNDG WERE UNEVENTFUL. THE CAPT SUBMITTED A CREW IRREGULAR OPS RPT; BUT I CANNOT RECALL; AT THIS POINT; WHETHER OR NOT WE MADE A LOGBOOK ENTRY OF THE EVENT.