Abstract: A generator housing including a housing module having at least one relatively complex internal passage formed therein and housing flow control components for circulating a fluid coolant through the generator. The housing module is formed by forming a plurality of sub-components each having at least one relatively simple passage formed therein for defining part of the at least one relatively complex internal passage. The sub-components are combined together as by bonding to form the housing module with at least one relatively complex internal passage. The flow control components are contained in bores within the housing module in fluid communication with the relatively complex internal passage therein. The housing module if formed of a relatively lightweight, non-metallic material to enable reduction in the weight of the generator housing in cost-effective and technically accepted manner thereby providing an improved generator which can be used in aircraft.