MD11 CREW HAD A FALSE CAPTURE OF THE LOC ON RWY 7R AT VHHH.

Narrative

THE ACFT WAS CONFIGURED WITH FLAPS 28 DEGS; GEAR UP; SLOWING TO 160 KTS AND LEVEL AT 1700 FT MSL WITH AUTOPLT ENGAGED ON APCH TO THE HONG KONG INTL RWY 7R. WE WERE GIVEN A HEADING OF 040 DEGS TO INTERCEPT THE LOC; CLRED ILS RWY 7R APCH VHHH. I; FO; ARMED APCH/LAND. CAPT (PNF) CALLED OUT 'LOC ALIVE' AND 'LOC CAPTURE' AS THE ACFT BEGAN A TURN TOWARDS THE 073 DEGS INBOUND COURSE. SUDDENLY THE ACFT TURNED L AWAY FROM THE LOC AND TOWARDS THE APCH CORRIDOR OF PARALLEL RWY 7L; AN ACTIVE RWY. I DISCONNECTED THE AUTOPLT AND TURNED BACK TOWARD COURSE. ATC SAID WE'D GONE THROUGH THE LOC AND TO TURN BACK R TO A HEADING OF 110 DEGS TO RE-INTERCEPT THE LOC. THEY THEN ASKED IF WE WERE ESTABLISHED. WE REPLIED YES. I HAND FLEW THE APCH. THE FLT DIRECTOR WAS DIVERGENT WITH THE ILS SO WE USED RAW DATA. NO TFC WAS NOTED ON APCH TO PARALLEL RWY 7L. NO FAULTS WERE NOTED. PERHAPS AN ERRANT GND SIGNAL CAUSED ACFT TO DEVIATE. RAPID REACTION FROM PF KEPT ACFT FROM STRAYING FAR FROM COURSE. A FLT SAFETY RPT WAS ALSO FILED WITH THE COMPANY.