Narrative:

As our flight taxied to runway 30L, the tower advised us that if we would take a right taxiway departure, that we would be able to get right out ahead of the traffic ahead. I accepted and told the first officer to verify from our data that we could legally takeoff from right. While he was doing that, I continued taxiing the aircraft and turned at what I thought was right. Tower informed me that I had turned at Q and that there was 9100' available. From prior takeoffs at this weight I was confident that we were within limits, so I accepted the takeoff from Q. As I was taking the runway the first officer came back and said we were ok from right. I asked for the rest of the takeoff checklist and we accomplished it. At this time the first officer believed we had taken the runway at right taxiway. The takeoff was uneventful, with a takeoff roll of about 5000'. After we got up to cruise, I asked him to refigure the takeoff weight from Q taxiway. He came up with a figure which put us over our allowable takeoff weight. The amount was not significant and could have been justified by the winds but we don't normally use headwinds in our takeoff computations. At that time I told him about accepting takeoff at Q taxiway. As is to be expected, he was quite upset at having been left out of the decision loop. The worst danger here was not the overweight takeoff, but the fact that I had cut my crew out of the decision circuit. The actual amount of overweight if all allowances were taken was insignificant if not nonexistent. I see many ways this could have been done differently: don't let the pressure to move the airplane cause a hasty decision, don't use experience in lieu of hard numbers when they are available, (if I turned at the wrong taxiway) get clearance to the right intersection even if it means losing a takeoff slt, and finally and by far the most important lesson, don't cut the other crew members out of the loop. If I had mentioned at which intersection we were at, I'm sure that the first officer would have objected strenuously to our proceeding. That objection would have given me pause to reconsider my plan and I would no doubt have opted for an right taxiway takeoff.

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Original NASA ASRS Text

Title: ACR MLG MADE AN INTERSECTION TKOF AT GROSS WEIGHT OVER MAXIMUM ALLOWABLE FOR RWY LENGTH REMAINING.

Narrative: AS OUR FLT TAXIED TO RWY 30L, THE TWR ADVISED US THAT IF WE WOULD TAKE A R TXWY DEP, THAT WE WOULD BE ABLE TO GET RIGHT OUT AHEAD OF THE TFC AHEAD. I ACCEPTED AND TOLD THE F/O TO VERIFY FROM OUR DATA THAT WE COULD LEGALLY TKOF FROM R. WHILE HE WAS DOING THAT, I CONTINUED TAXIING THE ACFT AND TURNED AT WHAT I THOUGHT WAS R. TWR INFORMED ME THAT I HAD TURNED AT Q AND THAT THERE WAS 9100' AVAILABLE. FROM PRIOR TKOFS AT THIS WT I WAS CONFIDENT THAT WE WERE WITHIN LIMITS, SO I ACCEPTED THE TKOF FROM Q. AS I WAS TAKING THE RWY THE F/O CAME BACK AND SAID WE WERE OK FROM R. I ASKED FOR THE REST OF THE TKOF CHKLIST AND WE ACCOMPLISHED IT. AT THIS TIME THE F/O BELIEVED WE HAD TAKEN THE RWY AT R TXWY. THE TKOF WAS UNEVENTFUL, WITH A TKOF ROLL OF ABOUT 5000'. AFTER WE GOT UP TO CRUISE, I ASKED HIM TO REFIGURE THE TKOF WT FROM Q TXWY. HE CAME UP WITH A FIGURE WHICH PUT US OVER OUR ALLOWABLE TKOF WT. THE AMOUNT WAS NOT SIGNIFICANT AND COULD HAVE BEEN JUSTIFIED BY THE WINDS BUT WE DON'T NORMALLY USE HEADWINDS IN OUR TKOF COMPUTATIONS. AT THAT TIME I TOLD HIM ABOUT ACCEPTING TKOF AT Q TXWY. AS IS TO BE EXPECTED, HE WAS QUITE UPSET AT HAVING BEEN LEFT OUT OF THE DECISION LOOP. THE WORST DANGER HERE WAS NOT THE OVERWEIGHT TKOF, BUT THE FACT THAT I HAD CUT MY CREW OUT OF THE DECISION CIRCUIT. THE ACTUAL AMOUNT OF OVERWT IF ALL ALLOWANCES WERE TAKEN WAS INSIGNIFICANT IF NOT NONEXISTENT. I SEE MANY WAYS THIS COULD HAVE BEEN DONE DIFFERENTLY: DON'T LET THE PRESSURE TO MOVE THE AIRPLANE CAUSE A HASTY DECISION, DON'T USE EXPERIENCE IN LIEU OF HARD NUMBERS WHEN THEY ARE AVAILABLE, (IF I TURNED AT THE WRONG TXWY) GET CLRNC TO THE RIGHT INTXN EVEN IF IT MEANS LOSING A TKOF SLT, AND FINALLY AND BY FAR THE MOST IMPORTANT LESSON, DON'T CUT THE OTHER CREW MEMBERS OUT OF THE LOOP. IF I HAD MENTIONED AT WHICH INTXN WE WERE AT, I'M SURE THAT THE F/O WOULD HAVE OBJECTED STRENUOUSLY TO OUR PROCEEDING. THAT OBJECTION WOULD HAVE GIVEN ME PAUSE TO RECONSIDER MY PLAN AND I WOULD NO DOUBT HAVE OPTED FOR AN R TXWY TKOF.

Data retrieved from NASA's ASRS site as of August 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.