COMMUTER MAKES NDB APCH WITHOUT PROC TURN AS DEPICTED.

Narrative

FLT WAS CLRED DIRECT ANG NDB FROM ENRTE PHASE; ESTABLISHED ON B-520. WE WERE CLRED DOWN FROM FL170 TO 3000 FT. UPON REACHING 3000 FT; CAPT TURNED TO INTERCEPT THE FINAL APCH COURSE FOR THE NDB RWY 10 APCH. WE WERE NOT IN RADAR CONTACT AT THIS TIME. WHEN THE CAPT THOUGHT HE WAS WITHIN THE 10 MI RADIUS; WHICH CANNOT BE DETERMINED; HE PROCEEDED TO DSND TO 1500 FT. 1500 FT IS THE ALT WHICH YOU CAN DSND TO OUTBOUND ON THE PROC TURN. WHEN THE CAPT DETERMINED HE WAS CLOSE ENOUGH (APPROX 5 MI) HE DSNDED TO 800 FT MSL. HE WAS GOING TO HOLD THAT TILL XING ANG NDB THEN DSND TO THE MDA UNTIL THE MISSED APCH. I REMINDED THE CAPT THAT HE NEEDED TO EXECUTE THE FULL APCH (INCLUDING PROC TURN) IN ORDER TO ACCURATELY DETERMINE OUR LOCATION IN RELATION TO ANG NDB. HE ARGUED A LITTLE BUT SAID THIS IS THE WAY HE NORMALLY EXECUTES THE APCH. I DEEMED IT BETTER TO LET HIM FLY THE ACFT THAN TO TAKE OVER. UPON DISCUSSING THE APCH ON THE GND; HE TOTALLY BELIEVED HE WAS CORRECT IN WHAT HE WAS DOING. WX CONDITIONS: LIGHT RAIN; SCATTERED CLOUDS AT 800-1000 FT; NO TSTMS INDICATES ON RADAR. WE BROKE OUT AND HAD INTERMITTENT GND (ISLAND) CONTACT APPROX 3-4 MI OUT. RWY NOT IN SIGHT UNTIL 1 1/2 MI FINAL.