The present invention relates to an integrated aircraft system which comprises an aircraft frame (4), a primary gas turbine engine (14) mounted within the nacelle cowl (12), a secondary power system (30) incorporated within the nacelle cowl and being driven by a flow of air created by or through the engine, and an electrical power and cooling unit for supplying electrical power and cabin cooling air. The electrical power and cooling unit is pneumatically driven by engine bleed air.
