A compound engine assembly including a common air conduit having an inlet in fluid communication with ambient air, a compressor, at least one internal combustion engine having an inlet in fluid communication with an outlet of the compressor, a turbine section having an inlet in fluid communication with an outlet of the at least one internal combustion engine, the turbine section configured to compound power with the at least one internal combustion engine, and at least one heat exchanger in fluid communication with the common air conduit, each of the at least one heat exchanger configured to circulate a fluid of the engine assembly in heat exchange relationship with an airflow from the common air conduit circulating therethrough. The compressor has an inlet in fluid communication with the common air conduit upstream of the at least one heat exchanger. The internal combustion engine may be a reciprocating engine.

An aspect includes a system for pre-start motoring synchronization for multiple engines of an aircraft. The system includes a first engine starting system of a first engine and a controller. The controller is operable to synchronize a motoring time of the first engine starting system with one or more other engine starting systems of one or more other engines of the aircraft by extending the motoring time of the first engine starting system to match, within a synchronization tolerance, the motoring time of the one or more other engine starting systems in a pre-start motoring sequence.

This power generation system comprises: a gas turbine; a power generator; a first clutch that engages or disengages with the rotation shaft of the gas turbine and the rotation shaft of the power generator; a rotation drive unit that rotationally drives the gas turbine; a control unit that controls the rotation drive unit according to the exhaust temperature of the gas turbine to rotationally drive the gas turbine in a case in which the power generator is operated in synchronous phase modification while the first clutch is in a disengaged state.

A gas generator has at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. A fan drive turbine is positioned downstream of a path of the products of combustion having passed over the at least one gas generator turbine rotor. The fan drive turbine drives a shaft and the shaft engages gears to drive at least three fan rotors.

A transmission turbo machine integrates drive units and/or driven units into a machine train via a transmission. The integrated transmission substantially comprises a central large wheel with a shaft and a plurality of pinions with pinion shafts. The large wheel is operatively connected to the pinions, and the ends of the pinion shafts are operatively connected to a drive unit and/or driven unit. The shaft of the large wheel is operatively connected to a drive unit and/or driven unit. The invention is characterized in that the drive unit and/or driven unit is an axial expander which is mounted in a cantilevering manner in one or more stages.

The present invention relates to an aircraft comprising a fuselage (1) and a propulsion unit at the rear of the fuselage, the propulsion unit comprising at least one fan rotor (7, 8), a nacelle (14) fairing the fan and at least one connection means (15) connecting the nacelle to the fuselage, the fan being rotated by the energy supplied by at least one gas-turbine gas generator (2a, 2b) housed in the fuselage, said gas generator comprising auxiliary equipment cooled by a cooling circuit.

The aircraft is characterised in that said cooling circuit comprises at least one heat exchanger exchanging heat with the ambient air housed in one of said connection means (15) and/or in said nacelle (14). The cooling circuit optionally comprises also a heat exchanger exchanging heat with the ambient air, housed in the tail unit.

A gas generator has at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. A fan drive turbine is positioned downstream of a path of the products of combustion having passed over the at least one gas generator turbine rotor. The fan drive turbine drives a shaft and the shaft engages gears to drive at least three fan rotors.

The invention relates to a drive chain for driving the rotor(s) (21, 22) of a helicopter, comprising a main transmission gearbox (24) capable of driving the rotor(s) (21, 22) when said gearbox is moving, a main engine (23) for providing the power for the flight, and at least one assistance drive module (31), the main engine (23) and the assistance drive module (31) being mechanically connected to said main transmission gearbox (24) so as to induce the movement of said gearbox. The drive chain is characterised in that the assistance drive module comprises a pyrotechnic device for generating a torque on a power transmission shaft that is mechanically connected to the main transmission gearbox (24). The invention also relates to a helicopter comprising said drive chain.