| Abbreviation | Definition |
|---|---|
| RA | Radar Altimeter (R/A preferred) |
| Ra | Radium |
| RA | Range Area |
| RA | Right Aft |
| RA | Right Ascension |
| RAAB | Remote Amplifier and Adaption Box |
| RAAB | Remote Application and Advisory Box |
| RAAD | Roll Attitude Anomaly Detection |
| RAAM | Roll Attitude Acquisition Mode |
| RAB | Risk Assessment Board |
| RAC | Reliability Action Center |
| RAC | Risk Assessment Code |
| RACS | Remote Automatic Calibration System |
| RACS | Rotation Axis Coordinate System |
| RACU | Remote Acquisition and Command Unit |
| RAD | Radar |
| RAD | Radiation Assessment Detector |
| RAD | Radiation Dosage |
| RAD | Radiator |
| RAD | Radius |