System for performing staging control of a multi-stage combustor

A fuel supply system for feeding fuel to a multi-stage combustor of a gas turbine engine, the fuel supply system comprising:

• a plurality of fuel manifolds which distribute fuel to respective stages of the combustor, a fuel metering valve operable to control the rate at which fuel passes to the fuel manifolds, an actuating arrangement which splits the fuel flow from the fuel metering valve between the fuel manifolds, and a control system for performing staging control of the combustor;
• wherein the control system includes:
• a fuel pressure sensor arrangement which senses the fuel pressure at entry to the actuating arrangement, and/or in one or more of the fuel manifolds;
• and
• a controller which commands the fuel metering valve to supply fuel to the combustor at a given flow rate, and which repeatedly:
• calculates a fuel split between the fuel manifolds based on the sensed fuel pressure(s), and issues a command signal to the actuating arrangement to implement the calculated fuel pressure-based fuel split.