A/EPCU -- Auxiliary/external Power Control Unit
ADC  -- Air Data Computer
ADF -- Automatic Direction Finder
ADS -- Air Data System  
AFCS  -- Automatic Flight Control System
AFIS  -- Airborne Flight Information System
AGL  -- Above Ground Level
AIM -- Align-In-Motion
AOA  -- Angle Of Attack
AP -- Autopilot
APU  -- Auxiliary Power Unit
ASCB -- Aircraft Standard Communications Bus
A/T -- Autothrottle
ATC -- Air Traffic Control
BC -- Back Course
BIT -- Built In Test
CAS -- Crew Alerting System or Calibrated Airspeed
BRNAV -- Basic RNAV
CB  -- Circuit Breaker
CCD -- Cursor Control Device
CDI -- Course Deviation Indicator
CIS -- Commonwealth Of Independent States
CLB -- Climb
CMC -- Central Maintenance Computer
CMF -- Communications Management Function
CMS  -- Configuration Management System
CPU  -- Central Processor Unit
CVR  -- Cockpit Voice Recorder