A vehicle used at larger airports to provide a refueling connection between an aircraft and a fuel supply piped underground to the refueling point.
Hydrant refuelers are sometimes referred to as "hydrant carts."
Unlike aircraft refuelers, they do not transport fuel. Rather, they are trucks equipped with meters, filters, hoses, and couplings. The operator makes a connection between the aircraft and a below-grade pipeline hydrant at the fueling site. Fuel is then pumped into the aircraft through this connection.