A B757 FLT CREW FLYING THE KENNEDY 9 DEP DEVIATED FROM THE PUBLISHED TRACK.

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I WAS PF. I LOADED THE FMS AS PER FLT PLAN FROM JFK. WE WERE GIVEN THE JFK RWY 9 DEP WITH THE BREEZY POINT CLB FOR EVENTUAL RADAR VECTORS FOR RBV (ROBBINSVILLE) VOR. I LOADED THE FMS FOR THE JFK RWY 9 TO CRI. THEN I LOADED THE CRI 223 DEG RADIAL TO 50 DME WITH A RTE DISCONTINUITY; THEN RBV AND FLT PLAN RTE. CAPT DOUBLE CHKED THE FMS. SOMETIME BEFORE DEP/PUSHBACK WE WERE DISTR WITH AN UNRULY PAX. WE OFFLOADED THE PAX; PUSHBACK; TAXI AND GOT IN A LONG LINEUP OF DEPS. EVENTUALLY WE TOOK OFF FROM RWY 31R. MADE THE L TURN DIRECT CRI INSIDE THE CRI 039 DEG RADIAL. I WAS HAND FLYING WITH THE MODE CTL PANEL IN LNAV MODE. I FOLLOWED THE FLT DIRECTOR AND OVER OR JUST PAST CRI DEP CTL TOLD US TO TURN L AND INTERCEPT THE CRI 223 DEG RADIAL. HE GAVE US A HDG OF 190 DEGS. SOMEHOW OR SOMEWHERE ALONG THE LINE THE CRI 223 DEG RADIAL AND RTE DISCONTINUITY WAS REMOVED/DROPPED OUT OF THE FMC AND WE WERE GOING DIRECT FROM CRI TO RBV; ABOUT A 240-245 DEG HDG. WE CORRECTED L TO 190 DEGS AS PER ATC INSTRUCTIONS; MANUALLY INTERCEPTED THE CRI 223 DEG RADIAL AND SHORTLY THEREAFTER WERE GIVEN DIRECT RBV. I BELIEVE WE OVERFLEW THE CRI 223 DEG RADIAL BY 1/2 TO 1 MI BEFORE TURNING BACK TO 190 DEGS TO REINTERCEPT THE CRI 223 DEG RADIAL. I TRULY DO NOT KNOW IF THIS WAS CAUSED BY FAULTY FMC LOADING OR A WRONG BUTTON PUSH EITHER BEFORE PUSHBACK OR ON TAXI-OUT WITH NUMEROUS DISTRS; OR A WRONG BUTTON PUSH ON DEP; OR AN FMS/FMC ANOMALY. NEXT TIME AND IN ALL FUTURE DEPS I WILL DOUBLE AND TRIPLE CHK FMC LOADING AND BACKUP RADIALS MANUALLY.