Abstract: This invention relates to the exchange, removal or addition, as applicable, of media and/or power between the individual shafts of an engine, between individual engines and between the engines and the aircraft. Thus, the present invention provides for additional degrees of freedom enabling engine parameters to be addressed in terms of a reduction or avoidance of negative resonances or beats. It also provides an ability to alter thrust from engines of a multi-engined aircraft to reduce rudder trim.