In airports with high air traffic density, and where the demand in fuel is high, a refuelling system known as the Hydrant Refuelling System (HRS) is used. The main characteristic of this system is that fuel from the airport depot is supplied, under pressure, directly to the apron through a system of pits connected to a network of lines. The fuel is then loaded into the aircraft using a Servicer fitted with a supply monitoring station.

In the airport depot, fuel is stored in large capacity tanks which are normally filled by pipelines connected directly to the refineries and/or depots. In terms of quality, the HRS complies with practically the same Jet A-1 handling and control procedures in force in regular aviation depots.

The major advantages compared with refuelling carried out using refuelers are:
• practically no limits in quantity to be loaded on board aircraft;
• quicker fuelling procedures;
• safer for airports, since there are no refuelers circulating with fuel on board.