| 8501 | CKNS | CRUISE, KEN & SON TRUCKING COMPANY | | | SCAC3 |
| 8502 | CKNS | COOKE TRANSPORTATION SERVICES LLC | | | SCAC4 |
| 8503 | CKNT | CLARKSON, T AND M TRANSPORTATION | | | SCAC3 |
| 8504 | CKNT | CURTIS, KEN TRUCKING | | | SCAC4 |
| 8505 | CKNU | KNAUF GIPS KG | | | SCAC4 |
| 8506 | CKNV | COCKSWAIN NAVIGATION CO LTD | | | SCAC3 |
| 8507 | CKNV | CUSTOM KITCHEN SERVICES | | | SCAC4 |
| 8508 | CKNW | CLARKDON WHOLESALERS INC | | | SCAC3 |
| 8509 | CKOA | CASINO KOA | | | SCAC3 |
| 8510 | CKOC | CLARK OIL COMPANY INC | | | SCAC4 |
| 8511 | CKOF | COOK OILFIELD SERVICES INC | | | SCAC3 |
| 8512 | CKOK | COOK TRANSPORTATION INC | | | SCAC4 |
| 8513 | CKOM | CEKOM CORPORATION | | | SCAC3 |
| 8514 | CKON | CLARKSON INDUSTRIAL CONTRACTORS | | | SCAC3 |
| 8515 | CKOR | CALKO TRANSPORT CO | | | SCAC3 |
| 8516 | CKOR | CALKO TRANSPORT COMPANY INC | | | SCAC4 |
| 8517 | CKOS | COOKS SERVICES INC | | | SCAC4 |
| 8518 | CKOT | COMPLETE TRUCK LINES LLC | | | SCAC4 |
| 8519 | CKOX | The Carson Carbon Co. | 7/1930-7/1932 | | NAKINA |
| 8520 | CKOX | CARSON CARBON CO. | | | PWRC |
| 8521 | CKOY | CORKLE OIL COMPANY LLC | | | SCAC4 |
| 8522 | CKP | Colorado, Kansas and Pacific Ry. Co. | 7/2000-7/2005 | | NAKINA |
| 8523 | CKP | Colorado, Kansas and Pacific Ry. Co. | Jul-00 | | NRHS |
| 8524 | CKP | COLORADO KANSAS & PACIFIC RAILWAY CO. | | | PWRC |
| 8525 | CKP | Colorado Kansas and Pacific Railway | | | RSRV |
| 8526 | CKPA | C K SERVICES INC | | | SCAC3 |
| 8527 | CKPC | CLARK TRANSPORTATION CORP | | | SCAC3 |
| 8528 | CKPD | CHICKS PRODUCE INC | | | SCAC3 |
| 8529 | CKPH | COOK, PHIL TRUCKING | | | SCAC3 |
| 8530 | CKPI | CLARKS PLANTFOOD INC | | | SCAC3 |
| 8531 | CKPN | CLARK TRANSPORTATION | | | SCAC3 |
| 8532 | CKPO | CLARK TRANSPORTATION | | | SCAC3 |
| 8533 | CKPP | C & K PETROLEUM PRODUCTS INC | | | SCAC4 |
| 8534 | CKPQ | CLARK TRANSPORTATION INC | | | SCAC3 |
| 8535 | CKPQ | CLARK TRANSPORTATION INC | | | SCAC4 |
| 8536 | CKPR | CENTRAL OKLAHOMA PRODUCE SERVICE | | | SCAC3 |
| 8537 | CKPS | CAMTRAK TRANSPORTATION SERVICES LTD | | | SCAC3 |
| 8538 | CKPT | CLARK TRANSPORTATION SERVICES INC | | | SCAC3 |
| 8539 | CKQA | COOKE AQUACULTURE INC | | | SCAC4 |
| 8540 | CKQC | CLARKE QUEBEC INC | | | SCAC4 |
| 8541 | CKQK | CPTR EXPRESS | | | SCAC4 |
| 8542 | CKQP | C & K TRUCKING EQUIPMENT INC | | | SCAC3 |
| 8543 | CKQT | CLARK TRANSPORTATION INC | | | SCAC3 |
| 8544 | CKQT | C & K TRANS INC | | | SCAC4 |
| 8545 | CKR | Crown Air Systems | Callsign: Crown Air, | USA | AVCODES |
| 8546 | CKR | Coker Aviation | Callsign: Coker, | USA | AVCODES |
| 8547 | CKR | Crown Air Systems | | | ICAO1 |
| 8548 | CKRA | CLARK, RAY TRUCKING | | | SCAC3 |
| 8549 | CKRA | CLARK, RAY TRUCKING INC | | | SCAC4 |
| 8550 | CKRB | CRACKER BARRELL STORES | | | SCAC4 |
| 8551 | CKRC | COOK, R L CO | | | SCAC3 |
| 8552 | CKRC | CLARK TRUCKING | | | SCAC4 |
| 8553 | CKRD | CRONK, RODNEY J TRUCKING INC | | | SCAC3 |
| 8554 | CKRE | CROOK, RICHARD E | | | SCAC3 |
| 8555 | CKRG | CHEEK TRUCKING | | | SCAC3 |
| 8556 | CKRG | CROOKE TRUCKING | | | SCAC4 |
| 8557 | CKRH | CLARK, RONALD H INC | | | SCAC3 |
| 8558 | CKRI | COOK, RICH INC | | | SCAC3 |
| 8559 | CKRJ | C K R B INC | | | SCAC4 |
| 8560 | CKRL | C K R TRANSPORT LTD | | | SCAC3 |
| 8561 | CKRM | COOK, ROGER L TRUCKING INC | | | SCAC3 |
| 8562 | CKRN | CHECKER LIMOUSINE SERVICE | | | SCAC3 |
| 8563 | CKRO | CRACKER STATE OIL CO INC | | | SCAC3 |
| 8564 | CKRP | CHEROKEE TRANSPORT | | | SCAC3 |
| 8565 | CKRQ | CLARK, ROBERT W | | | SCAC3 |
| 8566 | CKRR | CLARKS TRUCKING SERVICES | | | SCAC3 |
| 8567 | CKRS | CHECKERS TRANSPORT INC | | | SCAC3 |
| 8568 | CKRS | CROSS TRANSPORT INC | | | SCAC4 |
| 8569 | CKRT | CLARKE ROAD TRANSPORT INC | | | SCAC4 |
| 8570 | CKRV | CLACKAMAS RIVER TOWING & AUTO WRECK | | | SCAC3 |
| 8571 | CKRW | Central Kansas Ry., Inc. | added 10/1993 | | NAKINA |
| 8572 | CKRW | Central Kansas Ry., Inc. | added 10/93 | | NRHS |
| 8573 | CKRW | CENTRAL KANSAS RWY., INC. | | | PWRC |
| 8574 | CKRW | COKER, RAY WRECKER SERVICE | | | SCAC3 |
| 8575 | CKRX | Canadian Kodiak Refineries Ltd. | added 7/1960; 4/1961; eliminated 10/1963 | | NAKINA |
| 8576 | CKRX | Chickasaw Refining Co. | 8/1920 | | NAKINA |
| 8577 | CKRX | Shippers Car Line Corp. | 7/1930 | | NAKINA |
| 8578 | CKRX | Canadian Kodiak Refineries Ltd. | added 7/60; 4/61 | | NRHS |
| 8579 | CKRX | *CHICKASAW REFINING CO. | | | PWRC |
| 8580 | CKRX | *SHIPPERS CAR LINE CORP. | | | PWRC |
| 8581 | CKRX | *CANADIAN KODIAK REFINERIES LTD. | | | PWRC |
| 8582 | CKRY | Kansas & Oklahoma R.R., Inc. | added 10/2001; 7/2005 | | NAKINA |
| 8583 | CKRY | Central Kansas Ry., Inc. | added 4/1993; 1/1994-7/2000; eliminated 10/2001 | | NAKINA |
| 8584 | CKRY | Central Kansas Ry., Inc. | added 4/93; 1/94-7/2000 | | NRHS |
| 8585 | CKRY | KANSAS & OKLAHOMA RAILROAD [CENTRAL KANSAS RAILWAY, INC.] | | | PWRC |
| 8586 | CKRY | Central Kansas Railway (Kansas and Oklahoma Railroad) | | | RSRV |
| 8587 | CKRY | Central Kansas Ry., Inc. | | USA | TRAFFIC |
| 8588 | CKS | Kalitta Air LLC | IATA: CB, Callsign: Connie, IATA designator changed to K4. Name changed from Kitty Hawk International, Inc. d/b/a American International Airways | USA | AVCODES |
| 8589 | CKS | American International Airways, Inc. | IATA: CB, Callsign: Connie, | USA | AVCODES |
| 8590 | CKS | Kitty Hawk International, Inc. | IATA: CB, Callsign: Connie, | USA | AVCODES |
| 8591 | CKS | Kitty Hawk International, Inc. d/b/a American International Airways | IATA: CB, Callsign: Connie, Name changed to Kalitta Air LLC | USA | AVCODES |
| 8592 | CKS | Kalitta Air LLC | IATA: K4, Callsign: Connie, IATA designator changed from CB*. Name changed from Kitty Hawk International, Inc. d/b/a American International Airways | USA | AVCODES |
| 8593 | CKS | Connie Kalitta Services, Inc. | Callsign: Connie, | USA | AVCODES |
| 8594 | CKS | Kalitta Air | IATA: K4 | | ICAO1 |
| 8595 | CKSB | C & K TRANSPORTATION | | | SCAC4 |
| 8596 | CKSC | CLACKAMAS SERVICE CORP | | | SCAC3 |
| 8597 | CKSC | CLIK-CLIK SYSTEMS INC | | | SCAC4 |
| 8598 | CKSD | CREEKSIDE CARRIERS | | | SCAC4 |
| 8599 | CKSE | CRACK-SEALING INC | | | SCAC4 |
| 8600 | CKSF | CK SHADOW ENTERPRISES LLC | | | SCAC4 |
