| 1 | HRT | Transporte Aereo Rioplatense | Callsign: Rioplatense, | RA | AVCODES |
| 2 | HRT | Chartright Air Inc. | Callsign: Chartright, | CDN | AVCODES |
| 3 | HRT | Chartright Air | | | ICAO1 |
| 4 | HRT | Hartwell R.R. Co. | added 4/1991; 1/1994; eliminated 7/1997; 7/2000-7/2005 | | NAKINA |
| 5 | HRT | Hartwell Ry. Co. | 1/1975-1/1980; added 4/1981; eliminated 4/1988; eliminated 4/1991 | | NAKINA |
| 6 | HRT | Hartwell Ry. Co. | 1/75-1/80; added 4/81; eliminated 4/88; eliminated 4/91 | | NRHS |
| 7 | HRT | Hartwell R.R. Co. | added 4/91; 1/94; eliminated 7/97; 7/2000 | | NRHS |
| 8 | HRT | HARTWELL RAILROAD COMPANY | | | PWRC |
| 9 | HRT | Hartwell Railroad | | | RSRV |
| 10 | HRT | HARTWELL RAILROAD COMPANY | | | SCAC4 |
| 11 | HRT | Hartwell Railroad Company | | USA | TRAFFIC |
| 12 | HRTA | Helsinki Regional Transport Authority | Real: HSL | FIN | TRAFFIC |
| 13 | HRTC | HERTCO KITCHENS | | | SCAC4 |
| 14 | HRTD | HARTT TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 15 | HRTE | HARTLEY TRANSPORTATION LLC | | | SCAC4 |
| 16 | HRTG | HERITAGE TRANSPORT | | | SCAC4 |
| 17 | HRTI | HOOSIER RAPID TRANSPORT INC | | | SCAC4 |
| 18 | HRTL | H & R TRANSFER LLC | | | SCAC4 |
| 19 | HRTM | HARTMANN OIL COMPANY | | | SCAC4 |
| 20 | HRTS | HAR RAI TRANSPORT LTD | | | SCAC4 |
| 21 | HRTT | HORSFALL, R TRUCKING | | | SCAC4 |
| 22 | HRTV | HIGH ROLLERS TRUCKING INC | | | SCAC4 |
| 23 | HRTZ | HERTZ, KARL B TRANSPORTATION | | | SCAC4 |
