Narrative:

I had the autobrakes set at 2 for the planned arrival at runway 24R in lax. During approach; ATC changed our runway to runway 25L. I forgot that the autobrakes had been set at 2 and would slow the aircraft too much for an exit downfield. Upon landing at lax; I brought the thrust levers to idle while noticing the aircraft slowing more rapidly than desired. I quickly switched the autobrakes off and extended our landing roll as desired. Due to the strong headwind and light aircraft load; the plane slowed very rapidly. The first officer noticed I was not using the reversers as we slowed and made the call. I could not remember if I used reverse thrust at all; due to the distraction of turning the autobrake switch off. I was wrong to switch the autobrakes off. Company policy calls for us not to switch it off. I made a quick misjudgement and acted on it inappropriately. I should have lived with the decision to use the autobrakes even though we would have unnecessarily slowed too soon and exited upfield. There really isn't anything wrong with exiting early. I just had it in my head to exit later to decrease our taxi time to the gate. Stick with company SOP and not switch the autobrake off if previously selected for landing. Review the runway assignment and appropriate approach considerations when ATC changes the runway. This might have helped me catch the undesired autobrake setting. We do need some way to disarm the system when the autobrake would slow the aircraft in an undesirable way without causing a distraction from an important procedure such as using reverse thrust.

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Original NASA ASRS Text

Title: LATE RWY CHANGE AT LAX CONTRIBUTES TO B737-700 CAPTAIN'S DECISION TO MANUALLY DISENGAGE AUTOBRAKES CONTRARY TO ACR SOP.

Narrative: I HAD THE AUTOBRAKES SET AT 2 FOR THE PLANNED ARR AT RWY 24R IN LAX. DURING APCH; ATC CHANGED OUR RWY TO RWY 25L. I FORGOT THAT THE AUTOBRAKES HAD BEEN SET AT 2 AND WOULD SLOW THE ACFT TOO MUCH FOR AN EXIT DOWNFIELD. UPON LNDG AT LAX; I BROUGHT THE THRUST LEVERS TO IDLE WHILE NOTICING THE ACFT SLOWING MORE RAPIDLY THAN DESIRED. I QUICKLY SWITCHED THE AUTOBRAKES OFF AND EXTENDED OUR LNDG ROLL AS DESIRED. DUE TO THE STRONG HEADWIND AND LIGHT ACFT LOAD; THE PLANE SLOWED VERY RAPIDLY. THE FO NOTICED I WAS NOT USING THE REVERSERS AS WE SLOWED AND MADE THE CALL. I COULD NOT REMEMBER IF I USED REVERSE THRUST AT ALL; DUE TO THE DISTR OF TURNING THE AUTOBRAKE SWITCH OFF. I WAS WRONG TO SWITCH THE AUTOBRAKES OFF. COMPANY POLICY CALLS FOR US NOT TO SWITCH IT OFF. I MADE A QUICK MISJUDGEMENT AND ACTED ON IT INAPPROPRIATELY. I SHOULD HAVE LIVED WITH THE DECISION TO USE THE AUTOBRAKES EVEN THOUGH WE WOULD HAVE UNNECESSARILY SLOWED TOO SOON AND EXITED UPFIELD. THERE REALLY ISN'T ANYTHING WRONG WITH EXITING EARLY. I JUST HAD IT IN MY HEAD TO EXIT LATER TO DECREASE OUR TAXI TIME TO THE GATE. STICK WITH COMPANY SOP AND NOT SWITCH THE AUTOBRAKE OFF IF PREVIOUSLY SELECTED FOR LNDG. REVIEW THE RWY ASSIGNMENT AND APPROPRIATE APCH CONSIDERATIONS WHEN ATC CHANGES THE RWY. THIS MIGHT HAVE HELPED ME CATCH THE UNDESIRED AUTOBRAKE SETTING. WE DO NEED SOME WAY TO DISARM THE SYS WHEN THE AUTOBRAKE WOULD SLOW THE ACFT IN AN UNDESIRABLE WAY WITHOUT CAUSING A DISTR FROM AN IMPORTANT PROC SUCH AS USING REVERSE THRUST.

Data retrieved from NASA's ASRS site as of May 2009 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.