ACR MLG ALT DEV OVERSHOT XING RESTRICTION NOT MET.

Narrative

WE WERE ON A CIVET 2 ARR TO LAX; AND CLRED TO INTERCEPT 24R ILS; MAINTAIN 10000 FT. BY THE TIME WE WERE CLRED THE 24R ILS APCH; WE HAD GONE SLIGHTLY ABOVE THE GS. AFTER CLRNC FOR THE APCH; I ENGAGED THE APCH MODE OF THE AUTOPLT. EVEN THOUGH WE WERE SLIGHTLY ABOVE THE GS; THE AUTOPLT CAPTURED THE GS AND DSNDED TO GET ON THE GS. WHAT A DSCNT! THE ACFT PITCHED OVER AN EXCESSIVE AMOUNT AND DOVE FOR THE GS; THE AIRSPD INCREASED TO ABOVE 250 KTS (285) WHILE I FRANTICALLY TRIED TO PUT THE AUTOPLT ON VERT SPD OR ALT HOLD AND EXTENDED THE SPD BRAKES. WHEN I REALIZED THAT I COULD NOT DEPROGRAM THE AUTOPLT FROM THE APCH MODE; I DISCONNECTED THE AUTOPLT AND LEVELED THE AIRPLANE. HOWEVER; BY THIS TIME; WE HAD DSNDED TO 7500 FT BEFORE WE GOT TO DENAY AS THE AUTOPLT HAD OVERCOMPENSATED AND HAD GONE BELOW THE GS. THE FO TOLD ME THAT THE ONLY WAY TO GET OUT OF THE APCH MODE IS TO DISCONNECT THE AUTOPLT AND TURN OFF THE FLT DIRECTORS. I AM FAIRLY NEW IN THE AIRPLANE; HAD NEVER BEEN TOLD THIS BEFORE; AND HAD NEVER FLOWN AN AIRPLANE WITH AN AUTOPLT WHICH COULD NOT BE DEPROGRAMMED ONCE ENGAGED ON A PARTICULAR MODE. I CONSIDER THIS A LESS THAN DESIRABLE DESIGN FEATURE AND I WISH SOMEONE HAD TOLD ME THIS EARLIER.