An aircraft gas turbine engine fuel metering unit incorporating a memory
device for storing data relevant to that unit, and an electrical
connection arrangement whereby data can be read from and/or written to
said memory device by an associated electronic engine controller, said
stored data including data relating to at least one of the performance,
the identification, the health, and the service life of that fuel
metering unit. The invention further resides in an aircraft gas turbine
engine fuel supply system and a method of operating such a system.