BNR  Binary Words 
BO  Body Odour 
BO  Blocking Oscillator 
BOH  Brake-Off Weight 
BOT  Bottom 
BOT  Begin of Tape 
BP  Bottom Plug 
BPTU  Brake Pedal Transmitter Unit 
BR  Brown 
BRC  Brace 
BRD  Braid 
BRDG  Bridge 
BRG  Bearing 
BRK  Brake 
BRKNG  Braking 
BRKR  Breaker 
BRKS  Brakes 
BRKT  Bracket 
BRT  Bright, Brightness 
BSCS  Braking and Steering Control System 
BSCU  Braking and Steering Control Unit 
BSHG  Bushing 
BSU  Beam Steering Unit 
BT  Bus Tie 
BTA  Bogie Trim Actuator 
BTC  Bus Tie Contactor 
BTCM  Brake Temperature Compensation Module 
BTL  Bottle 
BTMS  Brake Temperature Monitoring System 
BTMU  Brake Temperature Monitoring Unit 
BTN  Button 
BTR  Bus Tie Relay 
BTS  Base Transceiver Station 
BTS  Brake Temperature Sensor 
BTU  British Thermal Unit 
BU  Battery Unit 
BUS  Busbar 
BWS  Body Wheel Steering 
BYDU  Back-Up Yaw Damper Unit 
BYP  Bypass 
B/B  Back-Beam 
B/C  Business Class 
B/D  Bottom of Descent 
C  Celsius, Centigrade 
C  Cyan 
C  Close 
C  Clear 
c  Equal Margin 
C  Cold (Electric Point) 
C  Comparator 
C  Convertible 
C-MOS  Complementary Metal Oxyde Semiconductor 
C of A  Certificate of Airworthiness 
CA  Constituent Assembly 
CA  Cable Assembly 

CA  Cable 
CAA  Civil Aviation Authority 
CAATS  Computer Assisted Aircraft Trouble Shooting 
CAB  Cabin 
CAB PRESS  Cabin Pressurization 
CAD  Computer Aided Design 
CADB  Component for Attestation Data Base 
CADETS  Computer Assisted Documentation Education Tutorial System 
CAG  Circulation Aérienne Générale 
CAGE  Commercial And Government Entity 
CAI  Combustion Area Inspection 
CAL  Calibration, Calibrated 
CALC  Cargo Acceptance and Load Control 
CAM  Computer Aided Manufacturing 
CAM  Cabin Assignment Module