| H | High pressure area or the centre of hight pressure |
| H24 | Continuous day and night service |
| HAPI | Helicopter approach path indicator |
| HBN | Hazard beacon |
| HDF | High frequency direction−finding station |
| HDG | Heading |
| HEL | Helicopter |
| HEMS | Helicopter Emergency Medical Service |
| HF | High frequency (3 000 to 30 000 kHz) |
| HGT | Height or height above ... |
| HJ | Sunrise to sunset |
| HLDG | Holding |
| HN | Sunset to sunrise |
| HO | Service available to meet operational requirements |
| HOL | Holiday |
| HOSP | Hospital aircraft |
| HPA | Hectopascal |
| HR | Hours |
| HS | Service available during hours of scheduled operations |
| HURCN | Hurricane |
| HVDF | High and very high frequency direction−finding stations (at the same location) |
| HVY | Heavy |
| HVY | Heavy (used to indicate the intensity of weather phenomena, e.g. HVY RA = heavy rain) |
| HX | No specific working hours |
| HZ | Haze |
| HZ | Hertz (cycle per second) |
© 2012-21 Kristina Novotna