B737-200 FLC REJECTED TKOF AND RETURNED TO GATE AFTER 2 ATTEMPTS TO BRING UP ENG PWR PRODUCED TKOF CONFIGN WARNING HORN. PROB FOUND TO BE FO'S LAP BELT BUCKLE INADVERTENTLY CAUGHT AND PULLED ONE OR MORE CIRCUIT BREAKERS WHEN STRAPPING IN SEAT.

Narrative

AS PWR WAS ADVANCED FOR TKOF THE CONFIGN WARNING HORN SOUNDED AND THE TKOF REJECTED. FINDING ALL PARAMETERS NORMAL; THE SPD BRAKES; FLAPS; TRIM AND LEADING EDGE DEVICES WERE CYCLED TO ENSURE THAT SENSORS WERE POSITIVELY ENGAGED. ACFT WAS POSITIONED FOR TKOF AND AGAIN AS PWR WAS ADVANCED; THE HORN SOUNDED AGAIN. I NOTIFIED COMPANY OF OUR INTENTION TO RETURN TO THE GATE AND REQUESTED MAINT. ONCE AT THE GATE I OBSERVED THE 'LEADING EDGE DEVICE' CIRCUIT BREAKER WAS OUT. IN RETROSPECT; THE FO HAD STRAPPED IN A COUPLE OF TIMES BEFORE PUSHBACK AND THE STRAP OR BUCKLE HAD CAUGHT ON THE CIRCUIT BREAKER (LOCATED BEHIND THE FO'S SEAT HEADREST). WE CONFERRED WITH MAINT AND THEY CHKED ACFT HISTORY TO VERIFY NO CHRONIC PROB EXISTED. PERMISSION WAS GIVEN TO RESET THE CIRCUIT BREAKER AND PROCEED. SUBSEQUENT DEP AND FLT WAS OPS NORMAL. AN EVENT RPT WAS FILED TO THE CHIEF PLT'S OFFICE UPON RETURN TO BASE AT XA15 LCL. AN 'INFO-ONLY' WRITE-UP IN THE LOGBOOK WAS NOT ACCOMPLISHED IN LIEU OF THE EVENT RPT AND CONVERSATION WITH MAINT. THE PROB OF SHOULDER STRAPS CATCHING ON AND TRIPPING CIRCUIT BREAKERS IS COMMON ENOUGH THAT A BULLETIN WAS ISSUED IN THE PAST TO ADDRESS THE SIT. IN THE B737-200 IT CREATED A GEAR RETRACTION MALFUNCTION SINCE THOSE ARE THE CIRCUIT BREAKERS LOCATED IN THAT RELATIVE POS BEHIND THE FO. A GUARD OR STRAP STIFFENER COULD BE HELPFUL TO PRECLUDE THIS TYPE OF PROB. IN ADDITION TO THE COMPANY EVENT RPT; AND THE COORD WITH MAINT CTL; AN INFO-ONLY WRITE UP MAY HAVE BEEN USEFUL IN CASE A CHRONIC PROB WITH THE CONFIGN WARNING SYS COINCIDENTALLY BEGAN TO DEVELOP. A CONTRIBUTING FACTOR THAT LED TO THE ORIGINAL CORRECTIVE ATTEMPT IS THE FACT THE SENSORS AND SQUAT SWITCHES OFTEN OPERATE IN CLOSE TOLERANCES AND FALSE INDICATIONS ARE REMEDIED BY CYCLING THE SYS WHICH CAN ESTABLISH MORE POSITIVE CONTACT.