| 1 | FDD | Feeder Airlines | | SUD | AVCODES |
| 2 | FDDI | FDD INC | | | SCAC3 |
| 3 | FDDI | FERIA DEL DISCO DE LOS MOCHIS S A D | | | SCAC4 |
| 4 | FDDJ | FLETES DE CIUDAD JUAREZ | | | SCAC4 |
| 5 | FDDK | FOUR-D (4-D) TRUCKING INC | | | SCAC4 |
| 6 | FDDM | Union Pacific R.R. Co. | added 10/1995; 7/2000-7/2005 | | NAKINA |
| 7 | FDDM | Chicago and North Western Ry. Co. | added 1/1995; eliminated 10/1995 | | NAKINA |
| 8 | FDDM | Chicago and North Western Transportation Co. | 1/1980-1/1994; eliminated 1/1995 | | NAKINA |
| 9 | FDDM | Chicago and North Western Transportation Co. (Fort Dodge, Des Moines & Southern Ry. Co.) | 1/1975 | | NAKINA |
| 10 | FDDM | Chicago and North Western Transportation Co. (Fort Dodge, Des Moines & Southern Ry. Co.)) | Jan-75 | | NRHS |
| 11 | FDDM | Chicago and North Western Transportation Co. | 1/80-1/94; eliminated 1/95 | | NRHS |
| 12 | FDDM | Chicago and North Western Ry. Co. | added 1/95; eliminated 10/95 | | NRHS |
| 13 | FDDM | Union Pacific R.R. Co. | added 10/95; 7/2000 | | NRHS |
| 14 | FDDM | UP [CHICAGO & NORTH WESTERN] [FORT DODGE, DES MOINES & SOUTHERN] | | | PWRC |
| 15 | FDDM | Fort Dodge, Des Moines and Southern Railway (Union Pacific Railroad) | | | RSRV |
| 16 | FDDM | FORT DODGE, DES MOINES & SOUTHERN R | | | SCAC3 |
| 17 | FDDM | Fort Dodge, Des Moines & Southern Ry. Co. | | USA | TRAFFIC |
| 18 | FDDMS | Fort Dodge, Des Moines & Southern | | USA | TRAFFIC |
| 19 | FDDN | FLOYD, DENNIS, TRUCKING COMPANY, INC | | | SCAC3 |
| 20 | FDDN | FLOYD, DENNIS TRUCKING COMPANY INC | | | SCAC4 |
| 21 | FDDQ | FORDS DELIVER SERVICE | | | SCAC3 |
| 22 | FDDU | SEATRADE CHARTERING N.V. | | NL | BIC |
