What was found
FMC WAS NOT PROVIDING GOOD NAV ORIENTATION IMMEDIATELY AFTER T/O. ALL DATA WAS OFF BY APPROX 300 MILES. UPON LANDING AT SNN POS SHOWED AIRCRAFT AT GATE IN HAM. RESET AND BITE CHECK OF BOTH FMCS, NO TROUBLE. CHECKED NAV DATA BASE FOR FMC, DATABASE CORRECT. CHECKED SENSORS AND READOUT ON FMC, CDU ALL OK. CHECKED ADCS, NO FAULT FOUND. REALIGNED IRU. NO FURTHER TROUBLE. FOUND A/C TO BE IN CORRECT WORKING ORDER.