Narrative:

We were given clearance to taxi to runway 14R for takeoff. The runway was notamed shortened due to construction at the approach end. Published length with shortening was 8330 ft available. We had temporary data for the shortened runway. Neither of us had been at this airport since construction began. We taxied northwest until the barrier at taxiway K to turn onto the runway. We were 'cleared into position and hold' at that point. I assumed our temporary data was from that taxiway K. The first officer made the same assumption. The takeoff was uneventful with a normal takeoff run. The first officer began to look at the book (performance) again on climb out and noticed a note at the page bottom explaining that the computed data required a back taxi to a temporary blast fence. This made the runway approximately 800 ft longer than we had actually used. The first officer had neglected to read the note at the bottom of the temporary data page and I didn't ask him if the data was computed from taxiway K. The displaced threshold is also located just northwest of the taxiway K/runway intersection. All of this, plus the fact that we were not cleared to 'back taxi' on to hold, contributed to the false assumption that we were beginning the takeoff from the correct point. (We had approximately 7100 ft of runway available for our actual takeoff, which is not that abnormal for our operation). I have learned to always ask the first officer (or check myself) that our performance data is computed based on the proper intersection or shortened temporary site and not assume that we are at the proper position.

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Original NASA ASRS Text

Title: FLC OF AN MLG FAILED TO TKOF FROM ALL OF THE AVAILABLE RWY REQUIRED BY THE ACFT'S TKOF PERFORMANCE DATA. THE RWY HAD BEEN SHORTENED DUE TO CONSTRUCTION, BUT BACK TAXI WAS NOT DONE TO USE THE TOTAL SHORTENED RWY LENGTH.

Narrative: WE WERE GIVEN CLRNC TO TAXI TO RWY 14R FOR TKOF. THE RWY WAS NOTAMED SHORTENED DUE TO CONSTRUCTION AT THE APCH END. PUBLISHED LENGTH WITH SHORTENING WAS 8330 FT AVAILABLE. WE HAD TEMPORARY DATA FOR THE SHORTENED RWY. NEITHER OF US HAD BEEN AT THIS ARPT SINCE CONSTRUCTION BEGAN. WE TAXIED NW UNTIL THE BARRIER AT TXWY K TO TURN ONTO THE RWY. WE WERE 'CLRED INTO POS AND HOLD' AT THAT POINT. I ASSUMED OUR TEMPORARY DATA WAS FROM THAT TXWY K. THE FO MADE THE SAME ASSUMPTION. THE TKOF WAS UNEVENTFUL WITH A NORMAL TKOF RUN. THE FO BEGAN TO LOOK AT THE BOOK (PERFORMANCE) AGAIN ON CLBOUT AND NOTICED A NOTE AT THE PAGE BOTTOM EXPLAINING THAT THE COMPUTED DATA REQUIRED A BACK TAXI TO A TEMPORARY BLAST FENCE. THIS MADE THE RWY APPROX 800 FT LONGER THAN WE HAD ACTUALLY USED. THE FO HAD NEGLECTED TO READ THE NOTE AT THE BOTTOM OF THE TEMPORARY DATA PAGE AND I DIDN'T ASK HIM IF THE DATA WAS COMPUTED FROM TXWY K. THE DISPLACED THRESHOLD IS ALSO LOCATED JUST NW OF THE TXWY K/RWY INTXN. ALL OF THIS, PLUS THE FACT THAT WE WERE NOT CLRED TO 'BACK TAXI' ON TO HOLD, CONTRIBUTED TO THE FALSE ASSUMPTION THAT WE WERE BEGINNING THE TKOF FROM THE CORRECT POINT. (WE HAD APPROX 7100 FT OF RWY AVAILABLE FOR OUR ACTUAL TKOF, WHICH IS NOT THAT ABNORMAL FOR OUR OP). I HAVE LEARNED TO ALWAYS ASK THE FO (OR CHK MYSELF) THAT OUR PERFORMANCE DATA IS COMPUTED BASED ON THE PROPER INTXN OR SHORTENED TEMPORARY SITE AND NOT ASSUME THAT WE ARE AT THE PROPER POS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.