THE FLC OF A B737-800 MISPROGRAMS THEIR FMS WITH THE ACFT TAKING A SUDDEN TURN OVER THE VOR TO THE NW INSTEAD OF FOLLOWING THE 176 DEG RADIAL OF THE VOR AT CRI; NY.

Narrative

DEPARTED JFK FROM RWY 31L. CLRNC (PDC) WAS KENNEDY 9; CANARSIE CLB. RTE OF FLT WAS THEN COATE; J136... AFTER TKOF AND INITIAL CONTACT WITH DEP WE WERE CLRED TO 17000 FT. THE CAPT WAS FLYING WITH THE AUTOPLT ENGAGED AND LNAV/VNAV ENGAGED. AS WE APCHED CANARSIE (CRI) THE ACFT BEGAN A R HARD TURN TO THE NW INSTEAD OF A L TURN ON THE CRI 176 DEG RADIAL AS PER THE CANARSIE CLB. AS SOON AS WE BEGAN THE TURN ATC ASSIGNED US A L TURN TO THE S AND REASSIGNED US TO CLB TO 11000 FT. ATC ASKED 'WHERE WERE YOU GOING?' THE CAPT HAD MODIFIED THE KENNEDY 9 DEP; CANARSIE CLB IN THE FMS; TO PROCEED DIRECT TO COATE AFTER CRI WHICH RESULTED IN A TURN IN THE WRONG DIRECTION. CONTRIBUTING FACTORS: BOTH CREW MEMBERS HAD VERY LITTLE EXPERIENCE IN JFK. FO CHKED RTE OF FLT PRIOR TO CAPT MODIFYING DATA; BUT NOT AFTER THE CAPT MODIFIED THE DEP. PROB WAS DISCOVERED: AFTER ATC VECTORED US TO THE S; FO WAS AWARE/REALIZED THAT A DEV HAD OCCURRED. CAPT DID NOT UNDERSTAND UNTIL THE FO EXPLAINED THE DEP TO HIM. CORRECTIVE ACTION: VECTORS BY ATC. HUMAN PERFORMANCE CONSIDERATIONS: EXCESSIVE OR BLIND RELIANCE ON FMC (LNAV). CREW DID NOT BRIEF THE CANARSIE CLB SEGMENT OF DEP. IT WAS NOT ADEQUATELY UNDERSTOOD WHILE IT WAS BEING LOADED/MODIFIED. IMPROVE CREW COORD OF NAV DATA LOADING AND XCHKING EACH OTHER. GARBAGE IN; GARBAGE OUT!