| 1 | OAR | Grupo One Air Aviacion, S.L. | Callsign: Boss Air, | E | AVCODES |
| 2 | OAR | Old Augusta R.R. Co. | added 7/1983; 1/1994-7/2005; eliminated 7/2006 | | NAKINA |
| 3 | OAR | Old Augusta R.R. LLC | added 7/2006 | | NAKINA |
| 4 | OAR | Old Augusta R.R. Co. | 1/94-7/2000 | | NRHS |
| 5 | OAR | OLD AUGUSTA RAILROAD COMPANY | | | PWRC |
| 6 | OAR | Old Augusta Railroad | | | RSRV |
| 7 | OAR | OLD AUGUSTA RAILROAD LLC | | | SCAC4 |
| 8 | OARD | ORCHARD PARK GROWERS LTD | | | SCAC4 |
| 9 | OARK | OLD ARK TRUCKING LLC | | | SCAC4 |
