FLC COMMENCED TKOF GOT CONFIGN WARNING; ABORTED TKOF; SET FLAPS FOR TKOF; AND TAXIED BACK FOR UNEVENTFUL TKOF. THE FLAPS WERE OVERLOOKED ON THE BEFORE TKOF CHKLIST.

Narrative

THE ACFT WAS PUSHED FROM THE GATE ON TIME FOR A SCHEDULED DEP. A NORMAL START WAS ACCOMPLISHED ; AND AFTER START CHKS COMPLETED. TAXI CLRNC WAS OBTAINED BY THE FO AND THE TAXI WAS COMMENCED WITH NUMEROUS GND VEHICLES MOVING IN THE AREA. THIS GND VEHICLE SIT SOMEWHAT COMPOUNDED BY THE CLOSURE OF A LARGE PORTION OF THE RAMP AREA (S RAMP; N SIDE AT SEATAC) WHICH HAS BEEN AND IS PRESENTLY UNDER CONSTRUCTION. THE CONSTRUCTION BARRIERS SERVE TO 'FUNNEL' THE RAMP TFC ENHANCING THE HAZARD. I CAUTIOUSLY BEGAN A SLOW TAXI WITH THE ASSISTANCE OF THE FO CLRING ON THE R. AS WE DEPARTED THE CONGESTED AREA COMPANY CALLED WITH WT AND BAL CORRECTIONS. I ANNOUNCED THAT I WOULD MONITOR GND SO THE FO COULD GET THE CORRECTIONS. IT WAS AT THIS TIME THAT WE NEGLECTED TO DEPLOY THE FLAPS AS WE NORMALLY WOULD. WITH CORRECTIONS COMPLETED WE APCHED THE HOLD LINE AND SWITCHED TO TWR. WHEN CLRED TO TAKE THE ACTIVE WE COMPLETED THE BELOW THE LINE CHKS TO THE LIGHTS AND HELD FOR TKOF CLRNC. WHEN CLRED TO TKOF; WE COMPLETED THE CHKS WITH THE LIGHTS AND I BEGAN TO ADVANCE THE THRUST LEVERS. WE IMMEDIATELY RECEIVED A TKOF CONFIGN WARNING HORN AND CLOSED THE THRUST LEVERS. THE ACFT WAS AT APPROX 40 KTS. I RECOGNIZED THE PROB IMMEDIATELY; AND REQUESTED THE FO GET CLRNC TO CLR THE RWY AND REPOSITION FOR TKOF VIA THE TXWY. WE DEPLOYED THE FLAPS; COMPLETED ALL CHKS; AND NOTING MORE THAN ADEQUATE FUEL; REPOSITIONED FOR TKOF AND PROCEEDED AS NORMAL WITH AN UNEVENTFUL FLT. I DID HAVE THE FO CAUTION THE PAX CABIN OVER THE PA TO REMAIN SEATED AND WE WOULD BE UNDERWAY SHORTLY. CONGESTED RAMP TFC IN CONJUNCTION WITH UNTIMELY RADIO CALL FROM COMPANY (WHICH IN RETROSPECT WE SHOULD HAVE IGNORED) CONTRIBUTED TO THIS POTENTIALLY DANGEROUS SIT. I HAVE RESOLVED IN THE FUTURE TO DISREGARD ALL COMPANY RADIO TFC UNTIL THE BEFORE TKOF CHKS ARE COMPLETE TO THE LINE. SUPPLEMENTAL INFO FROM ACN 282717: I DON'T KNOW HOW WE MISSED SETTING THE FLAPS FOR TKOF BUT WE DID AND THE TKOF CONFIGN WARNING WORKED AS ADVERTISED. THE ONLY CAUSES FOR THIS OVERSIGHT I CAN THINK OF ARE: THE VERY SHORT TAXI TIME; THE FO WORKLOAD DURING THIS TIME; AND CREW FATIGUE DUE TO A PARTY TAKING PLACE AT THE POOL JUST OUTSIDE OUR ROOMS AND THE ROOM NEXT DOOR THE NIGHT BEFORE AT THE HOTEL WHERE WE REQUIRED OVERNIGHT. THIS WAS THE THIRD AND FINAL LEG OF THE LAST DAY OF A 4 DAY TRIP. SINCE THERE WAS NO REAL MECHANICAL PROB WE DIDN'T CONTACT OUR COMPANY -- AND THERE WAS NO SIGNIFICANT CHANGE WT AND BAL TO BE CONCERNED WITH EITHER.