Narrative:

We were on a scheduled flight from oak to lax. Lax was doing flow control and we had a wheels up time of XX23 local. We were cleared 'on to hold' for runway 29 with another aircraft on what I guess to be about a 4 NM final. The time was XX20. Next the tower controller asked us if we would turn off our transponder during takeoff and then switch it back on as we were handed off to departure control. The reason for this, as the controller explained to us, was that the transponder is what triggers the flow control time into lax and since we were a couple mins early, it would make it closer to on time if we waited until he handed us off to departure. With an aircraft on short final and the fact that we were already late due to our aircraft getting into the gate late it sounded like a great idea to us. We turned off our transponder, took off, turned on the transponder as we were handed off to departure, and continued on to lax. At the time, it sounded like a great idea, but looking back, I'm not sure it was the smartest thing to do. Had we said no, the controller would have had two options: send the aircraft around that was on short final or let us takeoff anyways with an early wheels up time. I realize the controller was only trying to help us out and keep aircraft flowing as quick as possible, but there may have been a better way to do it.

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Original NASA ASRS Text

Title: IN ORDER TO PROVIDE A MORE ACCURATE FLOW TIME FOR ATC, TWR REQUESTED FLC TO TURN OFF XPONDER UNTIL AFTER TKOF.

Narrative: WE WERE ON A SCHEDULED FLT FROM OAK TO LAX. LAX WAS DOING FLOW CTL AND WE HAD A WHEELS UP TIME OF XX23 LCL. WE WERE CLRED 'ON TO HOLD' FOR RWY 29 WITH ANOTHER ACFT ON WHAT I GUESS TO BE ABOUT A 4 NM FINAL. THE TIME WAS XX20. NEXT THE TWR CTLR ASKED US IF WE WOULD TURN OFF OUR XPONDER DURING TKOF AND THEN SWITCH IT BACK ON AS WE WERE HANDED OFF TO DEP CTL. THE REASON FOR THIS, AS THE CTLR EXPLAINED TO US, WAS THAT THE XPONDER IS WHAT TRIGGERS THE FLOW CTL TIME INTO LAX AND SINCE WE WERE A COUPLE MINS EARLY, IT WOULD MAKE IT CLOSER TO ON TIME IF WE WAITED UNTIL HE HANDED US OFF TO DEP. WITH AN ACFT ON SHORT FINAL AND THE FACT THAT WE WERE ALREADY LATE DUE TO OUR ACFT GETTING INTO THE GATE LATE IT SOUNDED LIKE A GREAT IDEA TO US. WE TURNED OFF OUR XPONDER, TOOK OFF, TURNED ON THE XPONDER AS WE WERE HANDED OFF TO DEP, AND CONTINUED ON TO LAX. AT THE TIME, IT SOUNDED LIKE A GREAT IDEA, BUT LOOKING BACK, I'M NOT SURE IT WAS THE SMARTEST THING TO DO. HAD WE SAID NO, THE CTLR WOULD HAVE HAD TWO OPTIONS: SEND THE ACFT AROUND THAT WAS ON SHORT FINAL OR LET US TKOF ANYWAYS WITH AN EARLY WHEELS UP TIME. I REALIZE THE CTLR WAS ONLY TRYING TO HELP US OUT AND KEEP ACFT FLOWING AS QUICK AS POSSIBLE, BUT THERE MAY HAVE BEEN A BETTER WAY TO DO IT.

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.