An air intake including an air duct inside an aircraft, an inlet at one end of the air duct, a flap door and driving mechanism that moves the flap door between closed and open positions. The flap door includes a barrier filter configured to filter an incoming airflow into the air duct, and wherein the driving mechanism is configured to pivot the flap door about a first end of the door.

An inlet flow distortion control system employs a plurality of flow control devices forming at least one array integrated into an internal surface of the inlet. The at least one array extends over an azimuthal range relative to a normal flow axis of the inlet and has a plurality of circumferential rows spaced at increasing distance from a highlight of the inlet. A control system is operably connected to the flow control devices and adapted to activate flow control devices in selected subarrays of the array responsive to a predetermined flight condition.

An inlet flow distortion control system employs a plurality of flow control devices forming at least one array integrated into an internal surface of the inlet. The at least one array extends over an azimuthal range relative to a normal flow axis of the inlet and has a plurality of circumferential rows spaced at increasing distance from a highlight of the inlet. A control system is operably connected to the flow control devices and adapted to activate flow control devices in selected subarrays of the array responsive to a predetermined flight condition.

A propulsion system comprising a nacelle with an air channel along a longitudinal direction, an electric motor whose output drives a propeller, and a fuel cell, comprising a core outside the air channel, open channels, each of which has an inlet and an outlet opening in the air channel, and, for each open channel, a fuel chamber, an electrolyte between the open channel and the fuel chamber, a cathode, and an anode, each open channel having an inlet surface area which is less than the surface area of an intermediate area between the inlet and the outlet, the surface area of the outlet being smaller than the surface area of the intermediate area. Such a system makes it possible to have the fuel cell close to the electric motor, thereby reducing the lengths of the electrical conductors between them, and consequently improving the operation of the fuel cell.

An assembly for an aircraft propulsion system includes a variable area inlet with a fixed structure and a moveable structure. The variable area inlet is configured to open and close an airflow inlet passage into the aircraft propulsion system. The moveable structure is configured to move axially along a centerline between an aft position and a forward position. The moveable structure includes an inlet lip structure and a deflector. When the moveable structure is in the aft position, the airflow inlet passage is closed, and the deflector is at least partially recessed into the fixed structure. When the moveable structure is in the forward position, the airflow inlet passage is opened axially between an aft end of the inlet lip structure and a forward end of the fixed structure, and a forward end of the deflector is disposed axially at the forward end of the fixed structure.

An assembly for an aircraft propulsion system includes a variable area inlet with a fixed structure and a moveable structure. The variable area inlet is configured to open and close an airflow inlet passage into the aircraft propulsion system. The moveable structure is configured to move axially along a centerline between an aft position and a forward position. The moveable structure includes an inlet lip structure and a deflector. When the moveable structure is in the aft position, the airflow inlet passage is closed, and the deflector is at least partially recessed into the fixed structure. When the moveable structure is in the forward position, the airflow inlet passage is opened axially between an aft end of the inlet lip structure and a forward end of the fixed structure, and a forward end of the deflector is disposed axially at the forward end of the fixed structure.

There is provided a system and a method for operating a multi-engine rotorcraft. When the rotorcraft is cruising in an asymmetric operating regime (AOR) at least one engine is an active engine and is operated in an active mode to provide motive power to the rotorcraft and at least one second engine is a standby engine and is operated in a standby mode to provide substantially no motive power to the rotorcraft, at least one of a power level of the at least one second engine is increased and at least one variable geometry mechanism of the at least one second engine is moved to shed any ice accumulation on the at least one second engine.

A gas turbine engine for an aircraft includes a core engine assembly including a compressor section communicating air to a combustor section where the air is mixed with fuel and ignited to generate a high-energy gas flow that is expanded through a turbine section. The turbine section is coupled to drive the compressor section. A free turbine is configured to be driven by gas flow from the core engine. A propulsor section aft of the core engine and is driven by the free turbine. An exhaust duct routes exhaust gases from the core engine to the free turbine. The free turbine is disposed aft of the propulsor section and the exhaust duct includes an outlet aft of the propulsor section communicating gas flow to drive the free turbine. An aircraft is also disclosed.

A gas turbine engine for an aircraft includes a core engine assembly including a compressor section communicating air to a combustor section where the air is mixed with fuel and ignited to generate a high-energy gas flow that is expanded through a turbine section. The turbine section is coupled to drive the compressor section. A free turbine is configured to be driven by gas flow from the core engine. A propulsor section aft of the core engine and is driven by the free turbine. An exhaust duct routes exhaust gases from the core engine to the free turbine. The free turbine is disposed aft of the propulsor section and the exhaust duct includes an outlet aft of the propulsor section communicating gas flow to drive the free turbine. An aircraft is also disclosed.

Embodiments described herein relate to a vertical take-off and landing aircraft, specifically an electric or hybrid electric aircraft having a plurality of ducted fans. The aircraft includes a plurality of axially oriented fans, laterally oriented fans, forward air intakes, side exit ports and rear exhaust ports. The aircraft achieves flight by capturing air in the intakes and diverting the air through the axially oriented fans or the laterally oriented fans through the channels selectively.