An improved gas turbine engine

A gas turbine engine for an aircraft comprises a compressor, a combustor, and a turbine, with a first electric machine 210 being rotationally connected to the turbine configured to generate electrical energy and an electrical storage unit 230 to store the generated energy. The product of the energy storage capacity (Wh) and the maximum generated electrical power (W) divided by the maximum dry thrust (N) may be 20,000-300,000. The product of the maximum charge rate (h-1) and the maximum generated electrical power (W) divided by the maximum dry thrust (N) may be 20-400. The product of the maximum discharge rate (h-1) and the maximum generated electrical power (W) divided by the maximum dry thrust (N) may be 40-400. A fan assembly 130 may comprise a fan with a diameter between 0.3m and 2.0m and may have two or more fan stages with a plurality of blades. A second electric machine 220 may be rotationally connected to the fan assembly. The electrical storage unit may be a battery or capacitor. A heat exchanger 120 in fluid communication with the engine may comprise a hub and plurality of heat transfer elements extending radially outward. An associated method of operation is also disclosed.