A FALCON 2000 DEVIATED FROM CLRED RTE WHEN THE CREW LOADED THEIR PLANNED RTE IN THE FMC INSTEAD OF THE CLRED RTE.

Narrative

AFTER HAVING REACHED A CRUISE ALT OF FL290; ATC INQUIRED AS TO WHY WE WERE S OF OUR CLRED COURSE. I READ THE CTLR OUR CLRNC WHICH HE REPLIED WAS SLIGHTLY DIFFERENT THAN WHAT WAS ON HIS STRIP. HE TURNED US DIRECT TO A FIX AND THEN SAID THAT WE WERE STARTING TO MINGLE WITH LGA ARRS WHICH MADE IT DIFFICULT TO GET US DOWN ON THE BOUNO3 ARR INTO HPN. I STATED THAT THIS HAS HAPPENED BEFORE WITH THIS VERY RTE ALTHOUGH IT WAS A FEW YRS AGO. I WAS ACTING AS THE SIC AND I RECALL THE CAPT LOADING THE FLT PLAN FROM THE RELEASE AND I DO NOT THINK I VERIFIED THE FMS RTE FROM THE CLRNC I RECEIVED. I KNOW THAT OFTEN; ESPECIALLY IN THE NE CORRIDOR; YOUR FILED RTE IS NOT WHAT YOU ARE CLRED TO. AS I RECALL; THE FILED RTE AND THE ONE RECEIVED WERE THE SAME. IT MAY HAVE BEEN THAT THESE RTES LOOKED THE SAME (THEY WERE VERY CLOSE; INDEED) BUT THE DIFFERENCE WAS ENOUGH TO BE NOTICED. HOW THE CLRNC WE HAD AS OPPOSED TO THE ATC ONE WERE DIFFERENT I DO NOT KNOW. IN THE FUTURE I WILL NOT ALLOW THE FMS TO BE LOADED UNTIL AFTER THE CLRNC IS RECEIVED. IN THIS MANNER THERE WILL BE NO REASON TO BE OFF COURSE.