VARIABLE DISPLACEMENT PUMP WITH BACK-UP

A system includes a variable displacement pump (VDP) (102) with a pump inlet (104) and a pump outlet (106). The VDP is configured to receive a flow at the pump inlet at a first pressure and to outlet a flow from the pump outlet at a second pressure elevated relative to the first pressure. A second pump (200) is in fluid communication to receive flow at the pump inlet at the first pressure and to outlet flow from an auxiliary outlet (202). A backup selector (204) is in fluid communication with the pump outlet and with the auxiliary outlet. The backup selector is configured to operate in a normal mode to supply the the pump outlet from the VDP and to supply the auxiliary outlet from the second pump. The backup selector is configured to switch to a backup mode to supply the pump outlet from the second pump upon failure of the VDP.