AN A320 CREW; ON ARR TO JFK; DEVIATED FROM PUBLISHED COURSE.

Narrative

WHEN USING THE AUTOPLT IN CONJUNCTION WITH THE FMGC AND NAV MODES IN THE A320; THERE ARE SOME SCENARIOS THAT MAY BE DIFFICULT FOR THE SYS TO NEGOTIATE. ONE SUCH SCENARIO IS THE KINGSTON 6 ARR TO JFK ARPT. WE OFTEN FLY THIS ARR FROM YODAA INTXN. THE AUTOPLT IS INCAPABLE OF PASSING DIRECTLY OVER THESE FIXES AND REMAINING WITHIN 4 NM OF COURSE/STATION/FIX. THIS IS RECOGNIZED BY HONEYWELL; AIRBUS; AND OUR COMPANY GIVEN THE PROGRAMMED ANGLE OF BANK/RATE OF TURN IN THE NAV MODE; THE ARR CANNOT BE NEGOTIATED AND REMAIN WITHIN BOUNDARIES. THIS PROB IS PARTICULAR TO THIS ARR DUE TO CHANGES IN COURSE IN EXCESS OF 60 DEGS. BECAUSE OF THIS PROB; I USE HDG MODE TO NEGOTIATE THESE TURNS. ON THIS OCCASION; WE WERE ASKED TO GO AS FAST AS POSSIBLE AND DID SO. AS WE NEARED LOLLY INTXN (WE HAD BEEN CLR DIRECT TO EARLIER); REDUCED THE RANGE ON MY NAV DISPLAY TO BE MORE ACCURATE IN MY TURN FROM/OVER LOLLY INTXN. IN DOING SO; I OBSCURED THE NEXT INTXN 'DOORE' FROM MY DISPLAY. I; THEREFORE; DID NOT TURN FAR ENOUGH TO THE SW AND ENDED UP E OF COURSE. I WAS ESSENTIALLY HDG TOWARD LENDY INTXN INSTEAD OF DOORE; LENDY BEING THE ONLY INTXN VISIBLE ON MY REDUCED RANGE NAV DISPLAY AS I ROUNDED THE CORNER.