A B727 ON APCH AT 6000 FT AND CLRED TO 5000 FT DSNDED TO 4600 FT DUE TO FAILURE TO FULLY RETRACT THE EXTENDED SPD BRAKES.

Narrative

DURING APCH TO ATL RWY 26R; ON VECTORS TO INTERCEPT LOC; DSNDING TO 5000 FT MSL. AUTOPLT WAS ENGAGED; ALT CAPTURE WAS ARMED. SPD WAS 250 KIAS. PASSING 6500 FT; ATC SLOWED US TO 180 KIAS. I DEPLOYED THE SPD BRAKE IN DSCNT AND DECREASED THE PITCH TO SLOW. RATE OF DSCNT WAS DECREASED FROM ABOUT 1500 FPM TO APPROX 900-1000 FPM. AS THE ACFT APCHED APPROX 5200 FT; THE GREEN ALT CAPTURE LIGHT ILLUMINATED. FO STATED THAT 'WE'RE NOT GOING TO LEVEL AT 5000 FT.' THE AIRSPD HAD DECREASED TO 205 KIAS AND I STARTED TO LOWER THE SPD BRAKE SO I COULD DEPLOY THE FLAPS; WHEN THE COPLT; AT 5100 FT; SAID THAT WE WERE NOT GOING TO LEVEL AT 5000 FT MSL. I TOOK MY HAND FROM THE SPD BRAKE AND DISCONNECTED THE AUTOPLT; INCREASED PITCH AND ADDED GAR PWR -- ALL SIMULTANEOUSLY. THE ACFT CONTINUED TO DSND TO 4600 FT AS IF NO INPUT HAD BEEN APPLIED. I NOTICED IN MY HURRY TO BREAK THE DSCNT THAT I HAD NOT FULLY RETRACTED THE SPD BRAKE. I THEN LOWERED THE SPD BRAKE HANDLE AND THE ACFT BEGAN TO RESPOND. WE RECOVERED THE ALT AND TURNED BACK TO INTERCEPT THE LOC.