What was found
IN CRUSE, FL 340, UNABLE REQUIRED NAV IAW RNP WARNING ILLUMINATED. ANP EXCEEDED RNP. COMPLETED QRH PROCEDURE. FMC SWITCH BUT IN LEFT. THE RIGHT FMC SHOWED THE ANP EXCEEDED THE RNP. ACFT GROUNDED. COULD NOT DUPLICATE. RT & LT FMC LOGGED ON RELATED FLT LEG RT FMC ADIRS-LT & RT INTERMITTENT PITCH ANGLE RATE FAULT. ACCOMP FIM 34-61/801 FMC BITE, CK NORMAL. ALSO, PERFORMED ADIRS BITE REF FIM34-21/801, CURRENT STATUS CK NORMAL, AND NO FAULTS LOGGED. NO HISTORY 30 DAYS.