| R | Radial; Right; Red |
| R (+ number) | Red or Romeo :airway designator) |
| R (+ number) | Restricted Area |
| R | Radar |
| RA | Radio Altimeter |
| RAC | Rules of the Air and Air Traffic Services (ICAO) |
| RAD | Radar |
| RAD | Radius |
| RAI | Runway Alignment Indicator |
| RAIL | Runway Alignment Indicator Lights |
| RAPCON | Radar Approach, Control Centre |
| RAR | Radar Arrival Route |
| RATCF | Radar Air Traffic Control Facility (USN) |
| RCA | Reach Cruising Altitude |
| RCAG | Remote Communications Air Ground |
| RCC | Rescue Co-ordination Centre |
| RCF | Radio-communication failure (message type designator) |
| RCL | Runway Centre Line |
| RCLL | Runway Centre Line Lights |
| RCLM | Runway Centre Line Markings |
| RCO | Remote Communications Outlet |
| RCVS | Receives |
| RDH | Reference Datum Height (Synonymous of TCH) |
| RDO | Radio |
| RDR | Radar Departure Route |
| REC | Receiver/receiving/received |
| REDL | Runway edge light(s) |
| REF | Reference |
| REG | Registration |
| REGL | Regular |
| REIL | Runway End Identification Light |
| REP | Report |
| REP | Reporting Point |
| REP | Ramp Entrance Point |
| REQ | Request/require |
| RESP | Respective |
| RESTR | Restricted |
| RF | Radio Facility |
| RFC | Radio Facility Chart |
| REFL / RFLC | Refuelling |
| REV | Revision/revised |
| RG | Range (lights) |
| RH | Right Hand |
| RIF | Reclearance in Flight |
| RL | Rhumb Line |
| RL | Runway (edge) Lights |
| RLCE | Request Level Change En route |
| RLLS | Runway lead-in lighting system |
| RMI | Radio Magnetic Indicator |
| RMK | Remark |
| RNAV | Area Navigation |
| RNG | Radio Range (LF or MF aural 4-course range) |
| RNP | Required Navigation Performance |
| RNPC | Required Navigation Performance Capability |
| ROC | Rate of Climb |
| ROD | Rate of Descent |
| ROS | Route Oriented Scheme |
| RP | Reporting Point |
| RPL | Repetitive Flight Plan |
| RPLC | Replace or replaced |
| RPM | Revolutions per Minute |
| RPT | Repeat |
| RRZ | Radar Regulation Zone |
| RSC | Runway Surface Condition |
| RSP | Responder Beacon |
| RSR | En route Surveillance Radar |
| RT | Right Turn/Turn Right |
| R/T | Radiotelephone(y) |
| FITE | Route |
| RTF | Radiotelephony |
| RTG | Radiotelegraphy |
| RTR | Remote Transmitter/Receiver |
| RTS | Return to Service |
| RVR | Runway Visual Range |
| RVR End | Runway Visual Range End |
| RVR MID | Runway Visual Range Mid-point |
| RVR TDZ | Runway Visual Range Touch Down Zone |
| RVSM | Reduced Vertical Separation Minima |
| RVV | Runway Visibility Value |
| RWY | Runway |
