COMMUTER FLT FAILS TO RETRACT FLAPS AFTER TKOF. FATIGUE.

Narrative

CHAIN OF EVENTS: THE LAST LEG OF AN 8 'LEG' DAY. RPT TIME WAS AT AA30 AM LCL TIME. BLOCK TIME WAS APPROX 6.3 HRS TOTAL; EVENT OCCURRED AT BC50. AFTER CLOSE TO 13 HRS ON DUTY WITH THE ONLY BREAK AT BTWN BA50 TO BC30 LCL TIME; I FELT VERY TIRED AND IT WAS DIFFICULT TO CONCENTRATE DURING THE LATER PART OF THIS LONG DAY. DURING THE TKOF ROLL FROM SEA THE CAPT (PF) NOTED THAT WE WEREN'T OBSERVING THE 'TORQUE BUGS' ON OUR EICAS SCREEN TO SET TKOF PWR. THIS DISTRACTED ME. SO WHEN HE CALLED LATER FOR FLAPS UP CLB PWR; AFTER TKOF CHKLIST; I OMITTED THE FLAP RETRACTION FROM MY FLOW AND CONSEQUENTLY WE FLEW ALL THE WAY TO WENATCHEE (APPROX 20 MIN FLT) WITH THE FLAPS AT 12 DEGS FOR TKOF. WE ONLY NOTICED IT ON DSCNT. I CAN'T HONESTLY EVEN REMEMBER DOING THE CHKLIST AFTER TKOF. I BELIEVE THAT FATIGUE HAD A LARGE ROLE TO PLAY IN THE FAILURE OF THE CAPT AND I TO NOT NOTICE THE FLAPS REMAINING DOWN. WE WERE BOTH VERY TIRED AND WORN OUT FROM THE 7 PRIOR LEGS AND LONG DAY. OUR JUDGEMENT WAS IMPAIRED. 13 HRS OF DUTY IS VERY LONG NO MATTER WHAT TASK IS ACCOMPLISHED. BEING VERY TIRED; ONE MUST RELY ON SOP AND CHKLISTS. I WILL TRY TO BE MORE CAREFUL FROM NOW ON; BUT FATIGUE IS A DIFFICULT FACTOR FOR PLTS TO FIGHT OFF. THE AIRLINES (COMMUTERS ESPECIALLY) NEED TO QUIT ABUSING CREWS; FORCING THEM TO OPERATE IN THIS REALM OF CONSTANT FATIGUE AND FLT CYCLES. IT WAS ALMOST LIKE BEING ASLEEP WITH OUR EYES WIDE OPEN; SO LATE; SO DARK; SO TIRED.