TKOF ABORTED AFTER TKOF WARNING HORN ALERTS CREW.

Narrative

CLRED FOR TKOF RWY 27R PBI. I ADVANCED THE THROTTLES AND ENGAGED THE AUTOTHROTTLE AT 70 PERCENT N1. TKOF WARNING HORN SOUNDED AND THE CAPT IMMEDIATELY RECOGNIZED THAT THE TRIM SETTING WAS NOT IN THE TKOF RANGE. HE CALLED ABORT AND I RETARDED THE THROTTLES. THE CAPT TOOK CTL OF THE ACFT AND I ADVISED TWR THAT WE WERE CLRING THE RWY AND THAT WE WANTED TO TAXI BACK TO THE DEP END OF THE RWY. WE COMPLETED THE BEFORE TKOF CHKLIST AGAIN AND TOOK OFF AFTER SETTING THE CORRECT TRIM. THE TAXI CHKLIST HAD BEEN COMPLETED; HOWEVER; WE WERE INTERRUPTED WHEN WE HAD TO CHK DATA FOR OUR DEP RWY; AS IT WAS DIFFERENT FROM THE ONE LISTED ON OUR WT AND BAL. I HAD READ THE CHKLIST ITEM FOR 'STABILIZER TRIM' AND VERIFIED IT WITH THE PERCENT MAC; BUT FAILED TO SET THE TRIM WHEEL DUE TO OUR DISTR. THIS WAS A CASE OF READING THE CHKLIST BUT NOT COMPLETING THE CHKLIST ITEM. WITH THAT INTERRUPTION I SHOULD HAVE STARTED THE TAXI CHKLIST FROM THE BEGINNING. SUPPLEMENTAL INFO FROM ACN 205964: THE RWY WAS EXITED RATHER THAN CONTINUE THE TKOF BECAUSE SIGNIFICANT PAVEMENT WAS UTILIZED TO ANALYZE AND CORRECT THE CONFIGN PROBLEM. THIS EXPERIENCE IS ANOTHER REMINDER THAT COCKPIT ROUTINE; WHEN INTERRUPTED; IS HIGHLY SUSCEPTIBLE TO ERROR. WHEN INTERRUPTIONS OCCUR; LITTLE RED FLAGS SHOULD APPEAR IN OUR MINDS TO REMIND US TO 'WATCH OUT.'