MLG BIZJET CREW WAS ISSUED A LOW ALT ALERT BY THE N90 APCH CTLR AFTER THE CREW HAD CREW COORD PROBS. THE GS ALARM INDICATED A FAULTY GS; REQUIRING A LOC (GS OUT) APCH. THE CAPT TOLD THE FO TO DSND EARLY TO 1500 FT.

Narrative

IFR/HIGH ALT FLT HOU-TEB. LAST SECOND HOLDING PATTERN PHL APCH CTL AIRSPACE. L HOLD; RADAR VECTOR BY NEW YORK TRACON TO TEB. NIGHT/IFR. CLRED ILS RWY 6 (200 FT; 1/2 SM MINIMUMS). ON INTERCEPT; APCH CTLR ADVISED TO EXPECT TO HOLD; LOCATION UNMENTIONED; GS ALARM AT TEB. PNF (ME) LOOKED UP LOC MINIMUMS; THEN TOOK RADAR VECTOR OFF LOC; THEN TURNED BACK TOWARD CTRLINE AND RECLRED LOC APCH. DURING THIS PERIOD; PF (CAPT) DECIDED TO USE THE R SIDE FMS (MINE) WHICH I WAS USING FOR ORIENTATION AND LOCATION; WITHOUT TELLING ME. WHILE I WAS MONITORING THE APCH; I TOLD THE PF TO GO TO 1500 FT MSL AFTER PASSING A CERTAIN INTXN. I RESET THE ALT ALERTER FROM 2000 FT TO 1500 FT; AND WHEN I GOT MY NAV SYS RESET BACK TO WHERE I HAD HAD IT SET TO BEGIN THE APCH; WE WERE ALREADY AT 1500 FT. APCH CTL CALLED A LOW LEVEL ALERT AND DIRECTED US BACK TO 2000 FT. THE REST OF THE LOC APCH WAS CONDUCTED TO PUBLISHED MINIMUMS AND THE LNDG COMPLETED. LOSS OF COCKPIT COMS AND ORIENTATION BY THE PF; LED TO WHAT AT ANOTHER TIME OR LOCATION; COULD HAVE BEEN DISASTROUS. THIS TIME THE FAMOUS TETERBORO TWRS WEREN'T UNDER US -- WE WERE LUCKY!