| 4501 | HRSW | HERZOG, STEVEN W | | | SCAC4 |
| 4502 | HRSX | Harbor Rail Services of California, Inc. | 7/2005 (not listed) | | NAKINA |
| 4503 | HRSX | Heritage Ry. Service, Inc. | added 7/1986; eliminated 1/1990 | | NAKINA |
| 4504 | HRSX | Heritage Ry. Service, Inc. | added 7/86; eliminated 1/90 | | NRHS |
| 4505 | HRSX | *HAWAIIAN RAILWAY SOCIETY | | | PWRC |
| 4506 | HRSX | +HARBOR RAIL SERVICES OF CALIFORNIA [HERITAGE RAILWAY SERVICE INC.] | | | PWRC |
| 4507 | HRSX | Harbor Rail Services of California | | | RSRV |
| 4508 | HRSX | HARBOR SERVICES OF CALIFORNIA INC | | | SCAC4 |
| 4509 | HRT | Transporte Aereo Rioplatense | Callsign: Rioplatense, | RA | AVCODES |
| 4510 | HRT | Chartright Air Inc. | Callsign: Chartright, | CDN | AVCODES |
| 4511 | HRT | Chartright Air | | | ICAO1 |
| 4512 | HRT | Hartwell R.R. Co. | added 4/1991; 1/1994; eliminated 7/1997; 7/2000-7/2005 | | NAKINA |
| 4513 | HRT | Hartwell Ry. Co. | 1/1975-1/1980; added 4/1981; eliminated 4/1988; eliminated 4/1991 | | NAKINA |
| 4514 | HRT | Hartwell Ry. Co. | 1/75-1/80; added 4/81; eliminated 4/88; eliminated 4/91 | | NRHS |
| 4515 | HRT | Hartwell R.R. Co. | added 4/91; 1/94; eliminated 7/97; 7/2000 | | NRHS |
| 4516 | HRT | HARTWELL RAILROAD COMPANY | | | PWRC |
| 4517 | HRT | Hartwell Railroad | | | RSRV |
| 4518 | HRT | HARTWELL RAILROAD COMPANY | | | SCAC4 |
| 4519 | HRT | Hartwell Railroad Company | | USA | TRAFFIC |
| 4520 | HRTA | Helsinki Regional Transport Authority | Real: HSL | FIN | TRAFFIC |
| 4521 | HRTC | HERTCO KITCHENS | | | SCAC4 |
| 4522 | HRTD | HARTT TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 4523 | HRTE | HARTLEY TRANSPORTATION LLC | | | SCAC4 |
| 4524 | HRTG | HERITAGE TRANSPORT | | | SCAC4 |
| 4525 | HRTI | HOOSIER RAPID TRANSPORT INC | | | SCAC4 |
| 4526 | HRTL | H & R TRANSFER LLC | | | SCAC4 |
| 4527 | HRTM | HARTMANN OIL COMPANY | | | SCAC4 |
| 4528 | HRTS | HAR RAI TRANSPORT LTD | | | SCAC4 |
| 4529 | HRTT | HORSFALL, R TRUCKING | | | SCAC4 |
| 4530 | HRTV | HIGH ROLLERS TRUCKING INC | | | SCAC4 |
| 4531 | HRTZ | HERTZ, KARL B TRANSPORTATION | | | SCAC4 |
| 4532 | HRUK | HORN, S TRUCKING INC | | | SCAC4 |
| 4533 | HRV | Sahara Aero Service (SAS) | Callsign: Sahara-Service, Name changed to AirInter1 | TCH | AVCODES |
| 4534 | HRV | AirInter1 | Callsign: Sahara-Service, Name changed from Sahara Aero Service (SAS) | TCH | AVCODES |
| 4535 | HRVA | HOOSIER RV TRANSPORT INC | | | SCAC4 |
| 4536 | HRVE | HARVEY TRUCKING | | | SCAC4 |
| 4537 | HRVG | HARVEY, GEORGE | | | SCAC4 |
| 4538 | HRVK | HUDSON RIVER BULK INC | | | SCAC4 |
| 4539 | HRVN | HARVEST TRANS INC | | | SCAC4 |
| 4540 | HRVQ | HARVEY, HOMER L | | | SCAC1 |
| 4541 | HRVS | HARVESTER SHIPMNAGEMENT LTD | | | SCAC4 |
| 4542 | HRVT | HARVEY TRUCKING LLC | | | SCAC4 |
| 4543 | HRVY | HARVEY, KENNETH INC | | | SCAC4 |
| 4544 | HRWK | HOMRICH WRECKING INC | | | SCAC4 |
| 4545 | HRXD | HARTT TRANSPORTATION SYSTEMS INC (T | | | SCAC4 |
| 4546 | HRXI | HOME RUN TRANSPORT INC | | | SCAC4 |
| 4547 | HRXL | HARVEY EXPORTS LTD (DIV OF E L HARV | | | SCAC4 |
| 4548 | HRXP | HARE EXPRESS, INC | | | SCAC1 |
| 4549 | HRXQ | HARRIS MOTOR EXPRESS, INC | | | SCAC1 |
| 4550 | HRYE | HARRYS ENTERPRISES | | | SCAC4 |
| 4551 | HRYL | HURLEY, JOHN E TRUCKING INC | | | SCAC4 |
| 4552 | HRYM | HOLT, RAY M INC | | | SCAC4 |
| 4553 | HRYO | HENRY OIL COMPANY INC | | | SCAC4 |
| 4554 | HRYP | HERRAMIE | | | SCAC4 |
| 4555 | HRYR | HARRY'S TRANSPORT INC | | | SCAC4 |
| 4556 | HRYT | HARDY LEASING COMPANY LTD | | | SCAC4 |
| 4557 | HRZ | Croatian Air Force (Hrvatsko Ratno Zrakoplovstvo) | Callsign: Croatian Airforce, | HR | AVCODES |
| 4558 | HRZ | Croatian Air Force | | | ICAO1 |
| 4559 | HRZC | HORIZON LOGISTICS INC | | | SCAC4 |
| 4560 | HRZD | HORIZON LINES LLC | | | SCAC4 |
| 4561 | HRZE | HORIZON EXPRESS INC | | | SCAC4 |
| 4562 | HRZG | HERZOG TRUCKING COMPANY, INC | | | SCAC1 |
| 4563 | HRZG | HERZOG TRUCKING COMPANY INC | | | SCAC4 |
| 4564 | HRZI | HORIZON SHIP SUPPLY INC | | | SCAC4 |
| 4565 | HRZK | HORIZON LINES OF ALASKA LLC | | | SCAC4 |
| 4566 | HRZL | HORIZON LINES OF ALASKA LLC | | | SCAC4 |
| 4567 | HRZM | HORIZON MOVING SYSTEMS OF ARIZONA I | | | SCAC4 |
| 4568 | HRZN | HORIZON MOVING SYSTEMS OF SIERRA VI | | | SCAC4 |
| 4569 | HRZP | HORIZON LINES OF PUERTO RICO INC | | | SCAC4 |
| 4570 | HRZR | HORIZON RESOURCES | | | SCAC4 |
| 4571 | HRZS | HORIZON SHIPPING LTD | | | SCAC4 |
| 4572 | HRZT | HARTZ TRUCKING CO | | | SCAC4 |
| 4573 | HRZU | MATSON NAVIGATION COMPANY, INC | | USA | BIC |
| 4574 | HRZU | Matson Navigation | | | RSRV |
| 4575 | HRZU | HORIZON LINES LLC | | | SCAC4 |
| 4576 | HRZZ | HORIZON LINES LLC | | | SCAC4 |
| 4577 | HS | Skyways Regional AB | ICAO: HIL, Callsign: Highland, Name changed to Svenska Direcktflyg AB. Name changed from Highland Air AB | S | AVCODES |
| 4578 | HS | Highland Air AB | ICAO: HIL, Callsign: Highland, Name changed to Skyways Regional AB | S | AVCODES |
| 4579 | HS | Svenska Direktflyg AB | ICAO: HIL, Callsign: Highland, ICAO designator changed to SKH, ICAO callsign changed to Skyreg. Name changed from Skyways Regional AB | S | AVCODES |
| 4580 | HS | Svenska Direktflyg AB | ICAO: SKH, Callsign: Skyreg, ICAO designator changed to HSV. ICAO designator changed from HIL, ICAO callsign changed from Highland. Name changed from Skyways Regional AB | S | AVCODES |
| 4581 | HS | Svenska Direktflyg AB | ICAO: HSV, Callsign: Highswede, ICAO designator changed from SKH, ICAO callsign changed from Skyreg. Flight also operated by AIS Airlines (IS/PNX). Website shows flight using IATA designator W2 (FlexFlight ApS). Name changed from Skyways Regional AB | S | AVCODES |
| 4582 | HS | Beechcraft Sales (PTY) Ltd. | Callsign: Beechsales, | ZA | AVCODES |
| 4583 | HS | Hansung Airlines | ICAO: HAN, Callsign: Hansung Air, Rebranded as T'Way Airline. Suspended operations October 2008. | ROK | AVCODES |
| 4584 | HS | SprintAir SA | ICAO: SRN, Callsign: Sprintair, IATA designator changed to P8. Founded in 2003. | PL | AVCODES |
| 4585 | HS | Heli Securite Helicopter Airline | ICAO: HLI, Callsign: Heli Saint-Tropez, Designator H4 recalled by IATA. | F | AVCODES |
| 4586 | HS | Chattahoochee Bay Rd., Inc. | added 4/2007 | | NAKINA |
| 4587 | HS | H&S R.R. Co. | added 10/1992; 1/1994-7/2005 | | NAKINA |
| 4588 | HS | Hartford and Slocomb R.R. Co. | 1/1975; added 10/1975; 1/1980; eliminated 10/1992 | | NAKINA |
| 4589 | HS | Hartford and Slocomb R.R. Co. | 1/75-1/80; eliminated 10/92 | | NRHS |
| 4590 | HS | H&S R.R. Co. | added 10/92; 1/94-7/2000 | | NRHS |
| 4591 | HS | *H & S RAILROAD [HARTFORD & SLOCOMB RAILROAD COMPANY, INC.; HOUSATONIC SOUTHERN] | | | PWRC |
| 4592 | HS | +CHATTAHOOCHEE BAY RD., INC. | | | PWRC |
| 4593 | HS | Housatonic Southern (H and S Railroad) | | | RSRV |
| 4594 | HS | Hartford and Slocomb R.R. Co. | | USA | TRAFFIC |
| 4595 | HSA | East African Safari Air Limited | IATA: RX, Callsign: Car Hire, IATA designator changed to S9. Name changed from CHS Aviation Limited | EAK | AVCODES |
| 4596 | HSA | CHS Aviation Limited | Callsign: Car Hire, Name changed to East African Safari Air Limited | EAK | AVCODES |
| 4597 | HSA | East African Safari Air Limited | IATA: S9, Callsign: Car Hire, IATA Prefix: 895, ICAO Callsign changed to Duma. IATA designator changed from RX*. Name changed from CHS Aviation Limited | EAK | AVCODES |
| 4598 | HSA | East African Safari Air Limited | IATA: S9, Callsign: Duma, IATA Prefix: 895, Ceased operations. ICAO Callsign changed from Car Hire. IATA designator changed from RX*. Name changed from CHS Aviation Limited | EAK | AVCODES |
| 4599 | HSA | East African Safari Air | IATA: S9 | | ICAO1 |
| 4600 | HSA | High Speed Alliance | | NL | VKM |
