Primary Flight Computers (PFC)
NOTE
This is a stub page. Full system description pending ingest of FCOM Chapter 4.
Overview
The B777 uses three Primary Flight Computers (PFC L, PFC C, PFC R) as part of its fly-by-wire flight control system. The PFCs process pilot inputs and air data to command flight control actuators.
Key Facts
- Three PFCs provide triple redundancy
- Normal mode: full envelope protection and augmented stability
- Secondary mode: reduced protection (loss of some PFCs)
- Direct mode: basic control, no envelope protection (all PFCs failed)
- PFC DISC/AUTO switch used to reset PFCs after dual engine failure relight