A twin-engined rotorcraft having an installation for feeding fuel to fuel-burning engines of a power plant of the rotorcraft, the engines including main engines suitable individually for driving at least one rotor of the rotorcraft while in flight, and an auxiliary power unit mechanically connected to the rotor while nevertheless being unsuitable on its own for driving it in flight. The auxiliary power unit is fed with fuel by auxiliary pumps drawing fuel from each of main fuel tanks from which the main engines are respectively fed with fuel.