· A/P - autopilot
· AC - alternating current
· ACP - audio control panel
· ALT - alternate
· AMP - amplifier
· B - both
· BITE - built-in test equipment
· CDS - common display system
· DEU - display electronics unit
· DME - distance measuring equipment
· FDAU - flight data acquisition unit
· DU - display unit
· FT - functional test
· GND - ground
· Hz - hertz
· I/C - intercom
· ILS - instrument landing system
· IM - inner marker
· I/O - input/output
· LCD - liquid crystal display
· LED - light emitting diode
· LRU - line replaceable unit
· MAINT - maintenance
· MB - marker beacon
· MHz - mega hertz
· MM - middle marker
· NAV - navigation
· NC - not connected
· ND - navigation display
· NORM - normal
· NVM - non-volatile memory
· OM - outer marker
· PFD - primary flight display
· R - range
· REU - remote electronics unit
· RF - radio frequency
· R/T - receive/transmit
· RCVR - receiver
· STA - station
· TFR - transfer
· V - voice
· V - volt
· VHF - very high frequency
· VOR - vhf omnidirectional ranging