Definition

An engine-driven pump (EDP) is a pump attached to the accessory drive of a turbojet or turboprop engine.

Description

An EDP on a turbine engine can be installed to pressurize and distribute oil, fuel, or hydraulic fluid. These pumps are normally installed on the engine's accessory drive, which is connected by reduction gearing to the main engine shaft. In the case of two-shaft jet engines, the accessory drive is normally connected to the high-pressure, or N2, shaft.

In most aircraft designs, engine-driven pumps work in concert with electric pumps. In the event of electric pump failure, the EDP can serve as a backup. Conversely, if an EDP fails, the electric pump can serve as a backup.