Many modern types of commercial airliners, from the Vickers VC10 of the 1960s,[2] are equipped with RATs. A ram air turbine driving an electrical generator was chosen for the VC10 because of its use of "packaged" hydraulically-powered flying controls, rather than a centralised hydraulic system. The individual package units of the VC10 were each powered electrically and so emergency redundancy for the VC10 relied on quadruple generators and a backup RAT generator at a time when most RATs drove hydraulic pumps.[3]