| 1 | HEC | Heliservicio Campeche, S.A. de C.V. | Callsign: Helicampeche, | MEX | AVCODES |
| 2 | HEC | Helicopter Corporation of India | | IND | AVCODES |
| 3 | HEC | Heliservicio Campeche | | | ICAO1 |
| 4 | HEC | Heathrow Connect | Heathrow Connect is a train service in London, connecting Heathrow Airport with Paddington station. It is a joint venture between First Great Western and BAA. The service follows the same route as the faster Heathrow Express service but serves intermediate stations on its route, thus connecting several locations in west London with each other, the airport, and central London. | GB | TRAFFIC |
| 5 | HECC | HEPSON EQUIPMENT INC | | | SCAC4 |
| 6 | HECD | HATT ENTERPRISES (2010) LTD | | | SCAC4 |
| 7 | HECE | HUMBLE EQUIPMENT CO INC | | | SCAC4 |
| 8 | HECG | HORIZON LINES OF GUAM LLC | | | SCAC4 |
| 9 | HECL | HATTENHAUER ENERGY CO LLC | | | SCAC4 |
| 10 | HECM | HECATHORN, MARGRET | | | SCAC1 |
| 11 | HECM | HECATHORN, MARGARET | | | SCAC4 |
| 12 | HECN | HELLS CANYON NAVIGATION | | | SCAC4 |
| 13 | HECQ | HOLLERBACH EQUIPMENT CO INC | | | SCAC4 |
| 14 | HECR | HECTS TRUCKS LLC | | | SCAC4 |
| 15 | HECT | Hector Rail AB | Real: HCTOR, 2004 - | S | TRAFFIC |
| 16 | HECW | HENDERSON, C W (TRAILER LOAD SERVIC | | | SCAC4 |
| 17 | HECX | Hoosier Energy REC, Inc. | added 10/1981; 1/1994-7/2005; eliminated 4/2009 | | NAKINA |
| 18 | HECX | H.E. Clark | 7/1923-7/1935 | | NAKINA |
| 19 | HECX | Hoosier Energy REC, Inc. | added 10/81; 1/94-7/2000 | | NRHS |
| 20 | HECX | *H.E. CLARK | | | PWRC |
| 21 | HECX | +HOOSIER ENERGY REC, INC. | | | PWRC |
| 22 | HECX | Hoosier Energy REC | | | RSRV |
| 23 | HECX | HOOSIER ENERGY REC, INC. | | | SCAC4 |
| 24 | HECY | HECNY TRANSPORTATION INC | | | SCAC4 |
