| R | Red |
| ...R | Right (preceded by runway designation number to identify a parallel runway) |
| R... | Restricted area (followed by identification) |
| RA | Rain |
| RAC | Rules of the air and air traffic services |
| RADV | Minimum radar vectoring altitude chart |
| RAG | Ragged |
| RAG | Runway arresting gear |
| RAI | Runway alignment indicator |
| RAIM | Receiver autonomous integrity monitoring |
| RB | Rescue boat |
| RCA | Reach cruising altitude |
| RCC | Rescue co−ordination centre |
| RCF | Radiocommunication failure (message typ designator) |
| RCH | Reach or reaching |
| RCL | Runway centre line |
| RCLL | Runway centre line light(s) |
| RCLR | Recleared |
| RDH | Reference datum height |
| RDL | Radial |
| RDO | Radio |
| RDP | Radar data processing |
| RE... | Recent (used to qualify weather phenomena e.g.recent rain = RERA) |
| REC | Receive or receiver |
| REDL | Runway edge light(s) |
| REG | Registration |
| RENL | Runway end light(s) |
| REP | Report or reporting or reporting point |
| REQ | Request or requested |
| RERTE | Re−route |
| RG | Range (lights) |
| RHC | Right−hand circuit |
| RIF | Reclearance in flight |
| RL | Report leaving |
| RLA | Relay to |
| RLLS | Runway lead−in lighting system |
| RMAC | Radar minimum altitude chart |
| RMK | Remark |
| RNAV | Area navigation (to be pronounced "AR−NAV") |
| RNG | Radio range |
| RNP | Required navigation performance |
| ROC | Rate of climb |
| ROD | Rate of descent |
| ROFOR | Route forecast (in meteorological code) |
| RPL | Repetitive flight plan |
| RPLC | Replace or replaced |
| RPS | Radar position symbol |
| RQMNTS | Requirements |
| RQP | Request flight plan (message type designator) |
| RQS | Request supplementary flight plan (message type designator) |
| RR | Report reaching |
| RRA | Delayed meteorological message (or RRB, RRC ... etc., in sequence) (message type designator) |
| RSC | Rescue sub−centre |
| RSCD | Runway surface condition |
| RSP | Responder beacon |
| RSR | En−route surveillance radar |
| RTD | Delayed (used to indicate delayed meteorological message |
| RTE | Route |
| RTF | Radiotelephone |
| RTG | Radiotelehgraph |
| RTHL | Runway threshold light(s) |
| RTN | Return or returned or returning |
| RTODAH | Rejected take−off distance available, helicopter |
| RTS | Return to service |
| RTT | Radioteletypewriter |
| RTZL | Runway touchdown zone light(s) |
| RUS | Russian language |
| RUT | Standard regional route transmitting frequencies |
| RV | Rescue vessel |
| RVR | Runway visual range |
| RVSM | Reduced vertical separation minimum (300 m (1000 ft)) between FL 290 and FL 410 |
| RWY | Runway |
© 2012-21 Kristina Novotna