ACR LGT SPD DEV EXCEEDED 250 KTS BELOW 10000 FT WITH AN ACI OBSERVING.

Narrative

DURING OUR INITIAL APCH I HAD PLANNED ON A VISUAL APCH TO RWY 1; WHICH WAS THE RWY ATIS SAID WAS IN USE. AFTER REVIEWING MY APCH CHARTS I HAD DETERMINED THAT I WOULD REMAIN AT AN ALT HIGHER THAN WHAT WE NORMALLY WOULD BE FOR RWY 25 AND CIRCLE TO THE L. WE WERE CLRED TO DSND TO 11000 FT AND THEN 10000 FT. AFTER BEING LEVEL AT 10000 FT FOR ABOUT 3 MINS; WE WERE CLRED FOR A VISUAL APCH TO RWY 25. THIS CAUGHT ME TOTALLY UNPREPARED. WE TUNED IN RWY 25 ILS AND REALIZED I WAS WELL ABOVE THE GS AT 300 KTS. I EXTENDED THE SPOILERS AND BEGAN DSNDING WHEN SUDDENLY I REALIZED I WAS AT 9300 FT; AND NOT 10300 FT. FOR SOME REASON I THOUGHT I WAS AT 11000 FT INSTEAD OF 10000 FT. I IMMEDIATELY REDUCED MY SPD TO 250 KTS; THEN CAME TO THE BIG RUSH TO LOWER THE GEAR AND REDUCE SPD TO ALLOW ME TO EXTEND THE FLAPS TO 30 DEGS; THE FINAL FLAP SETTING. WITH THE PWR AT IDLE; I INTERCEPTED THE GS AT 1100 FT AGL; THEN ADDED THRUST AND STABILIZED THE APCH AT 1000 FT; THE MIN ALT REQUIRED BY COMPANY POLICY TO HAVE THE ACFT STABILIZED. THROUGHOUT ALL THIS; AN ACR OPS INSPECTOR WAS OBSERVING FROM THE JUMP SEAT. I SHOULD HAVE PLANNED FOR A POSSIBLE VISUAL APCH TO RWY 25; STRAIGHT IN; AND REDUCED MY SPD ACCORDINGLY. I COULD NOT BE FLEXIBLE ENOUGH BECAUSE OF INADEQUATE PREPLANNING. ANOTHER FACTOR WAS EVEN THOUGH I OBSERVED 10000 FT ON THE ALTIMETER; I WAS THINKING 11000 FT. THE ACR INSPECTOR OBVIOUSLY WAS A DISTR ALSO. I GUESS I HAD BECOME COMPLACENT WITHOUT REALIZING THIS. IN THE FUTURE I WILL DEFINITELY BE MORE ALERT OR SITUATIONALLY AWARE.