TM 1-1510-218-10 B-5 AM Amplitude Modulation ANG Army National Guard ANN Annunciator ANT Antenna AP, A/P Autopilot APRCH, APR Approach ARINC Aeronautical Radio, Inc. ARP Airport Reference Point ARTCC Air Route Traffic Control Center AS, A/S Airspeed ATC Air Traffic Control AUTO Automatic AUX Auxiliary AVGAS Aviation Gasoline AWOS Automatic Weather Observing Station BARO Barometric BAT, BATT Battery BC Back Course, Bus Controller BCN Beacon BFO Beat Frequency Oscillator BIT Built-In Test BL Bleed BOS Beginning Of Stack BOT Bottom BRG Bearing BRT Bright BTPS Body    Temperature    And    Pressure Saturated BU Backup, Battery Unit CAP Capture CDI Course Deviation Indicator CDU Control-Display Unit CH, CHAN Channel CHG Charge CL, CKLST Checklist CLE Clear Entry CLIMB GAD Current Aircraft Climb Performance CLR Clear CMPST Composite COMM Communications COMSEC Communications Secure COND Conditioning COPLT Copilot CR Cursor Return CRS Course CRUISE ALT Cruise Altitude CTAF Common Traffic Advisory Frequency CVR Cockpit Voice Recorder CW Continuous Wave CWS Control Wheel Steering CYCL Cycle DB Database DC Direct Current DECR Decrease DEF Default DEG Degrees DEL Delete DEN Density DET Detector DG Directional Gyro DH Decision Height DIAG Diagnostic DIF Difference DIR Direct DIS Distance DISC Disconnect DISP Display DME Distance Measuring Equipment DN Down DR Dear Reckoning DTRK, DTK Desired Track E East EADI Electronic Attitude Director Indicator