| Abbreviation | Definition |
|---|---|
| HFC | Heat Flow and Convection |
| HFC | Hydraulic Flight Control |
| HFCT | Hydraulic Flight Control Test |
| HFCV | Helium Flow Control Valve |
| HFDS | Hydrogen Fluid Distribution System |
| HFE | High Frequency Executive |
| HFM | Hollow Fiber Membrane |
| HFMU | High Fidelity MockUp |
| HFO | High Frequency Oscillator |
| HFS | Horizontal Flight Simulator |
| HFT | Horizontal Flight Test |
| HFTF | Horizontal Flight Test Facility |
| HFTS | Horizontal Flight Test Simulator |
| HFU | Heater Firing Unit |
| HFX | High Frequency Transceiver |
| HG | High Gain |
| HG | Hitchhiker Goddard Mission |
| Hg | Mercury |
| HGA | High Gain Antenna |
| HGAS | High Gain Antenna System |