C550 ACFT ON DSCNT OVERSHOT ALT WHEN PAX ASKED QUESTION OF PF; CAPT. ALT ALERT BROUGHT FLC'S ATTN TO ALT AND ACFT WAS CLBED BACK TO ASSIGNED.

Narrative

KNOXVILLE APCH CTL GAVE US A DSCNT TO 7000 FT FOR OUR LNDG AT TYS RWY 23R. I WAS USING THE AUTOPLT AND MY COPLT SET 7000 FT IN THE ALT SELECTOR. I PRESSED THE ARM BUTTON ON THE AUTOPLT TO DSND TO 7000 FT MSL. OUR DSCNT WAS AT ABOUT 2000 FPM. AT 8000 FT I ROLLED THE PITCH UP TO ABOUT 1500 FPM. AT APPROX 7300 FT AS I WAS BRINGING THE PITCH UP AND DECREASING OUR RATE OF DSCNT; ONE OF OUR PAX CAME FORWARD AND ASKED IF WE HAD ARRANGED A TAXI FOR THEIR ARR. WHEN HE DISTRACTED US THE AUTOPLT WAS CAPTURING AND I ROLLED THE PITCH WHEEL UP SOME MORE DISABLING THE ALT SELECT ON THE AUTOPLT. THE ALT SELECT SOUNDED AURALLY AND VISUALLY AT 6500 FT MSL; WHERE I BEGAN A CLB BACK UP TO 7000 FT. THEN SOON AFTER APCH SAID HE SHOWED US AT 6500 FT AND TO MAINTAIN 7000 FT; WHICH WE SOON DID. CONTRIBUTING FACTORS INCLUDE THE FLC'S FAILURE TO CALL ALT INCREMENTS AND 7000 FT MSL. ALSO; DISRUPTION BY PAX WHEN THE 'FASTEN SEAT BELTS' SIGN WAS ON AND COMING FORWARD TO THE FLC. AFTER LNDG I CALLED THE CTLING FACILITY TO APOLOGIZE AND MAKE SURE WE DID NOT CREATE A CONFLICT WITH ANOTHER ACFT.