| 1 | TRP | Maryland State Police | Callsign: Trooper, | USA | AVCODES |
| 2 | TRP | Maryland State Police | | | ICAO1 |
| 3 | TRPC | TRANSPORTES CONTRERAS | | | SCAC4 |
| 4 | TRPE | TRANSPORTES AZTECA INTERNATIONAL IN | | | SCAC4 |
| 5 | TRPG | TRIPLE G CARRIERS | | | SCAC4 |
| 6 | TRPI | TRANSPORTES DE LOS RIOS RUBIO | | | SCAC4 |
| 7 | TRPJ | TRIPLE J TRANSPORT INC | | | SCAC4 |
| 8 | TRPK | TRAPKO ENTERPRISES INC | | | SCAC4 |
| 9 | TRPL | TRIPLE R PRODUCE INC | | | SCAC4 |
| 10 | TRPN | TRIMPE, BOB TRUCKING, LLC | | | SCAC4 |
| 11 | TRPQ | TRANSPORT P G R INC | | | SCAC4 |
| 12 | TRPS | TRANSPORT SERVICES INTERNATIONAL | | | SCAC4 |
| 13 | TRPT | TRIPLE TRANSPORT INC | | | SCAC4 |
| 14 | TRPU | TROPICAL TRAILER LEASING LLC | | USA | BIC |
| 15 | TRPU | Tropical Trailer Leasing | | | RSRV |
| 16 | TRPU | PACIFIC INTERNATIONA LINES (PTE) LT | | | SCAC4 |
| 17 | TRPV | TRANSPORTATION PROVIDER SERVICES IN | | | SCAC4 |
| 18 | TRPW | TRANS PLUS | | | SCAC4 |
| 19 | TRPX | Tropigas Inc. of Florida | added 1/1966; 10/1966-1/1980; eliminated 1/1989 | | NAKINA |
| 20 | TRPX | Petrolane Gas Service Ltd. Partnership | 1/1994; eliminated 10/1995 | | NAKINA |
| 21 | TRPX | AmeriGas Propane, L.P. | added 10/1995; eliminated 4/1998; 7/2000-7/2005 (not listed) | | NAKINA |
| 22 | TRPX | Tropigas Inc. of Florida | added 1/66; 10/66-1/80; eliminated 1/89 | | NRHS |
| 23 | TRPX | Petrolane Gas Service Ltd. Partnership | 1/94; eliminated 10/95 | | NRHS |
| 24 | TRPX | AmeriGas Propane, L.P. | added 10/95; eliminated 4/98; 7/2000 | | NRHS |
| 25 | TRPX | *TROLLEY PLAZA | | | PWRC |
| 26 | TRPX | +AMERIGAS PROPANE L.P. [(PGRX) PETROLANE GAS SERVICE LTD.; TROPIGAS INC. OF FLORIDA] | | | PWRC |
| 27 | TRPX | Tropigas of Florida | | | RSRV |
| 28 | TRPX | PETROLANE GAS SERVICE LIMITED PARTN | | | SCAC4 |
