CAPT OF CANADAIR; CL65; DSNDED BELOW VECTORING ALT PRIOR TO BEING ESTABLISHED ON FINAL APCH.

Narrative

ATC WAS ISSUING VECTORS AS WE APCHED MYR FROM THE NNW. WE CALLED THE ARPT IN SIGHT; AND ATC TOLD US TO MAINTAIN 1600 FT UNTIL ESTABLISHED ON A STRAIGHT-IN FINAL; CLRED VISUAL APCH RWY 35. WE DISCUSSED THE 1600 FT LIMITATION AND 1600 FT WAS SET/CONFIRMED IN THE ALT PRESELECTOR/ALERTER. ON MID-FIELD L DOWNWIND AT 1600 FT WITH THE CAPT HAND-FLYING; TWR CLRED US TO LAND RWY 35 AND REPEATED THE INSTRUCTION TO MAINTAIN 1600 FT UNTIL ON FINAL TO AVOID BANNER TOW ACFT ALONG THE COASTLINE. WE ACKNOWLEDGED THE CLRNC AND 1600 FT INSTRUCTION. OUR LNDG WT REQUIRED USE OF THE 46000 LB V-SPD/MANEUVERING SPD CARD POSITIONED ON THE ACFT COCKPIT CTR PEDESTAL. THE MINIMUM MANEUVERING SPD FOR OUR FLAPS 30 DEG CONFIGN/WT WAS 161 KIAS. ANY TURNS AT LESS THAN 161 KTS ARE RESTR TO 15 DEG BANK ANGLE. PRIOR TO THE CAPT BEGINNING HIS DOWNWIND-TO-BASE TURN; I NOTIFIED HIM THAT OUR MINIMUM SPD WAS 161 KTS (OUR IAS WAS 150 KTS). NO CORRECTION WAS MADE. THE CAPT THEN ENTERED A FULL 30 DEG BANK L TURN AT 145 KIAS AND BEGAN TO DSND FROM 1600 FT WHILE ON BASE. THE ALT ALERTER SOUNDED AS WE WENT 200 FT LOW BUT NO CORRECTION WAS MADE. I TOLD THE CAPT WE WERE 300 FT LOW BUT AGAIN NO CORRECTION WAS MADE AND DSCNT CONTINUED UNTIL WE ROLLED OUT ON FINAL AT 800 FT MSL. ATC MADE NO COMPLAINTS.