| 1 | CKR | Crown Air Systems | Callsign: Crown Air, | USA | AVCODES |
| 2 | CKR | Coker Aviation | Callsign: Coker, | USA | AVCODES |
| 3 | CKR | Crown Air Systems | | | ICAO1 |
| 4 | CKRA | CLARK, RAY TRUCKING | | | SCAC3 |
| 5 | CKRA | CLARK, RAY TRUCKING INC | | | SCAC4 |
| 6 | CKRB | CRACKER BARRELL STORES | | | SCAC4 |
| 7 | CKRC | COOK, R L CO | | | SCAC3 |
| 8 | CKRC | CLARK TRUCKING | | | SCAC4 |
| 9 | CKRD | CRONK, RODNEY J TRUCKING INC | | | SCAC3 |
| 10 | CKRE | CROOK, RICHARD E | | | SCAC3 |
| 11 | CKRG | CHEEK TRUCKING | | | SCAC3 |
| 12 | CKRG | CROOKE TRUCKING | | | SCAC4 |
| 13 | CKRH | CLARK, RONALD H INC | | | SCAC3 |
| 14 | CKRI | COOK, RICH INC | | | SCAC3 |
| 15 | CKRJ | C K R B INC | | | SCAC4 |
| 16 | CKRL | C K R TRANSPORT LTD | | | SCAC3 |
| 17 | CKRM | COOK, ROGER L TRUCKING INC | | | SCAC3 |
| 18 | CKRN | CHECKER LIMOUSINE SERVICE | | | SCAC3 |
| 19 | CKRO | CRACKER STATE OIL CO INC | | | SCAC3 |
| 20 | CKRP | CHEROKEE TRANSPORT | | | SCAC3 |
| 21 | CKRQ | CLARK, ROBERT W | | | SCAC3 |
| 22 | CKRR | CLARKS TRUCKING SERVICES | | | SCAC3 |
| 23 | CKRS | CHECKERS TRANSPORT INC | | | SCAC3 |
| 24 | CKRS | CROSS TRANSPORT INC | | | SCAC4 |
| 25 | CKRT | CLARKE ROAD TRANSPORT INC | | | SCAC4 |
| 26 | CKRV | CLACKAMAS RIVER TOWING & AUTO WRECK | | | SCAC3 |
| 27 | CKRW | Central Kansas Ry., Inc. | added 10/1993 | | NAKINA |
| 28 | CKRW | Central Kansas Ry., Inc. | added 10/93 | | NRHS |
| 29 | CKRW | CENTRAL KANSAS RWY., INC. | | | PWRC |
| 30 | CKRW | COKER, RAY WRECKER SERVICE | | | SCAC3 |
| 31 | CKRX | Canadian Kodiak Refineries Ltd. | added 7/1960; 4/1961; eliminated 10/1963 | | NAKINA |
| 32 | CKRX | Chickasaw Refining Co. | 8/1920 | | NAKINA |
| 33 | CKRX | Shippers Car Line Corp. | 7/1930 | | NAKINA |
| 34 | CKRX | Canadian Kodiak Refineries Ltd. | added 7/60; 4/61 | | NRHS |
| 35 | CKRX | *CHICKASAW REFINING CO. | | | PWRC |
| 36 | CKRX | *SHIPPERS CAR LINE CORP. | | | PWRC |
| 37 | CKRX | *CANADIAN KODIAK REFINERIES LTD. | | | PWRC |
| 38 | CKRY | Kansas & Oklahoma R.R., Inc. | added 10/2001; 7/2005 | | NAKINA |
| 39 | CKRY | Central Kansas Ry., Inc. | added 4/1993; 1/1994-7/2000; eliminated 10/2001 | | NAKINA |
| 40 | CKRY | Central Kansas Ry., Inc. | added 4/93; 1/94-7/2000 | | NRHS |
| 41 | CKRY | KANSAS & OKLAHOMA RAILROAD [CENTRAL KANSAS RAILWAY, INC.] | | | PWRC |
| 42 | CKRY | Central Kansas Railway (Kansas and Oklahoma Railroad) | | | RSRV |
| 43 | CKRY | Central Kansas Ry., Inc. | | USA | TRAFFIC |