AIRCRAFT COMPRISING A CABIN BLOWER SYSTEM

An aircraft comprises a turbofan engine 201A, a cabin blower system 210 and a PEM fuel cell stack 242. The cabin blower system 210 includes a cabin blower compressor 216 arranged to be driven by mechanical power derived from a shaft 205 of the turbofan engine 201A. A ducting system 220 delivers respective portions of the mass flow rate of compressed air output by the cabin blower system to a cabin space 230 of the aircraft via an air-conditioning unit 228 and to the cathode input 241 of the fuel cell stack 242. An electric motor 246 receives electrical power from the fuel cell stack 242 and provides mechanical power to the compressor 216 via a drive arrangement 211, 214, 215 of the cabin blower system. Power associated with excess capacity of the cabin blower system is recovered to the cabin blower compressor, thereby mitigating or eliminating the fuel consumption penalty on the turbofan engine associated with the excess capacity.