Aircraft support structures, systems, and methods are disclosed. In one embodiment, an aircraft system includes a rotating component and a support (e.g. strut) that supports the rotating component. The support includes a locking assembly (P1) that is configured to lock, automatically, an inner member (214) of the support with respect to an outer member (208) of the support for stiffening the support in response to reaching or exceeding a predetermined threshold amount of displacement, load, stress, or rotation. The aircraft support structures, systems, and methods herein utilize self-locking and self-unlocking supports (e.g. struts) for increasing or decreasing a stiffness of the support.

Propulsion system (8) for a single-engine helicopter (1), comprising: a main engine (9) connected to a front drive shaft (5) and a rear drive shaft (7), respectively, suitable for driving a main gearbox (4) referred to as MGB (4) and a tail gearbox (6) referred to as TGB (6); an assistance device (10) attached to the main engine (9); characterised in that said propulsion system (8) is designed in order that the assistance device (10) can mechanically drive the TGB and MGB (6, 4) by introducing power to the rear drive shaft (7).

A method for securing an engine using an adjustable mounting assembly is provided including adjusting an extendible element of the adjustable mounted assembly from a first position to a second position. Another extendible element of the adjustable mounting assembly is adjusted from a third position to a fourth position. The engine is mounted using the adjustable mounted assembly with the extendible element in the second position and another extendible element in the fourth position.

A system for driving an environmental control system (ECS) of a vehicle with ground-based electrical power may include a turbine engine on board the vehicle, coupled to the ECS to pneumatically drive the ECS, and an electric machine, on board the aircraft, mechanically coupled to the turbine engine, to drive the turbine engine. A control system such that the electric machine provides motoring assistance to the turbine engine, and that the motoring assistance is limited to match the available current from the ground-based electrical power.

The invention relates to an auxiliary system for mechanically driving a relay shaft (8) of a helicopter propulsion system, comprising: a hydraulic motor (7), mechanically connected to said relay shaft (8); a hydraulic circuit (10) for supplying a pressurised liquid to said hydraulic motor(7) a controlled, fast-opening hydraulic valve (11) arranged on the hydraulic circuit (10); a pyro-hydraulic storage unit (9) driven by a control unit (12) and connected to said hydraulic valve (11), said pyro-hydraulic storage unit (9)comprising: an enclosure (20) including a piston (16) that defines a main compartment (17) having at least one solid propellant cartridge (19) and a compartment (18) for a liquid supply; an ignition charge (25) connected to said main compartment (17) and suitable for initiating the combustion of at least one solid propellant cartridge (19) upon receiving a command from said control unit (12).

A system and method for controlling a position of an inlet door of an auxiliary power unit are provided. A first control signal comprising instructions for opening the inlet door to a selected one of at least a first position and a second position is output. A possible failure in a feedback signal associated with the selected one of the at least first position and second position is detected and a second control signal comprising instructions for opening the inlet door to the other one of the at least first position and second position is then output.

This invention concerns an aircraft propulsion system in which an engine has an engine core comprising a compressor, a combustor and a turbine driven by a flow of combustion products of the combustor. At least one propulsive fan generates a mass flow of air to propel the aircraft. An electrical energy store is provided on board the aircraft. At least one electric motor is arranged to drive the propulsive fan and the engine core compressor. A controller controls the at least one electric motor to mitigate the creation of a contrail caused by the engine combustion products by altering the ratio of the mass flow of air by the propulsive fan to the flow of combustion products of the combustor. The at least one electric motor is controlled so as to selectively drive both the propulsive fan and engine core compressor.

An integrated fire suppression system receives inert gas from onboard gas generators and water effluent from onboard water generators. The inert gas and water effluent are mixed in a gas-water mixer to generate an inert aerosol. The inert aerosol is provided to a fire suppressant distribution network and sprayed into areas of the aircraft requiring fire suppression to provide cooling and to prevent reignition.

A pressure control system includes an overboard valve in indirect communication with a first enclosed environment and in direct communication with a second enclosed environment. The first environment is suitable for human occupancy and configured to receive pressurized air from an environmental control system. The second environment is configured to receive the pressurized air from the first environment. An inboard valve is configured to supply a discharge of pressurized air from the second environment. An outflow valve is configured to regulate a discharge of air from the first environment to an area outside the first and second environments. A positive pressure relief valve configured to regulate a discharge of air from the first environment. A negative pressure relief valve configured to regulate an ingress of air into the first environment. A control valve is configured to regulator and supply pressurized air from the first environment to a compressor.

An aircraft with an auxiliary power unit attached to the aircraft fuselage via an attachment system. The auxiliary power unit is placed inside the aircraft fuselage structure. The attachment system comprises a plurality of structural wires that link the auxiliary power unit to the aircraft fuselage structure. An attachment device is located at the end of each structural wire to connect the structural wire to the aircraft fuselage structure. Each attachment device comprises a metallic plate adjacent to the aircraft fuselage structure and a layer of damping elastomeric material adjacent to the metallic plate. The metallic plate is placed between the layer of damping elastomeric material and the aircraft fuselage structure. The attachment device is joined to the aircraft fuselage structure by attachment fasteners.