TM 1-1510-224-10 ADC Air data computer ADF Automatic direction finder ADI Attitude director indicator AFC Automatic frequency control AFCS Automatic flight control sys- tem A/G Air to ground AGC Automatic gain control AGL Above ground level AI Airborne interceptor AJ Anti-jam ALM Almanac ALSE Aviation life support equip- ment ALT Altitude AM Amplitude modulation ANT Antenna AP, A/P Autopilot APPR Approach ARINC Aeronautical radio, inc. AS, A/S Airspeed ASE Aircraft survivability equip- ment ASET Aircraft survivability equip- ment training ATC Air traffic control ATT Attitude AUX Auxiliary AVGAS Aviation gasoline AVUM Aviation unit maintenance AZ Azimuth BARO Barometric BAT Battery BC Back course BCD Binary coded decimal BFO Beat frequency oscillator BIT Built-in test BOT Bottom BRG Bearing BU Back-up, battery unit CAP Capture CDI Course deviation indicator CDS Control-display system CDU Control-display unit CH Channel CHAALS Coherent high-accuracy air- borne location system CIPH Cipher CKLST Checklist CKW Cryptokey weekly CLR Clear CMD Command COMM Communications COMSEC Communications security CONFIG Configuration CN Carrier to noise CPU Central processing unit CRS Course CV Crypto variable CW Continuous wave C/W Caution/warning CWA Caution, warning, and advi- sory DA Drift angle DASR Direct air to satellite relay D/A Digital to analog DC Direct current B-5