Abstract: A hybrid engine including features to meet aircraft thrust, passenger airflow, and fuel cell requirements. The engine includes a combustor burning the same fuel as the fuel cell. The engine has electric motors to utilize the power output of the fuel cell. The engine shafts have sprags to allow motors to drive the compressors and over run the turbines. The engine has variable flowpath geometry to bypass the combustor.

Abstract: A compact inlet design including a single bulkhead and/or an acoustic panel extending into nacelle lip region for noise reduction.

Abstract: Compressors having multi-speed gearboxes are disclosed. The apparatus comprises: a fluid channel to convey a fluid, a compressor fluidly coupled to the fluid channel, a gearbox operatively coupled to the compressor, the gearbox to control the compressor using a first gear ratio and a second gear ratio different from the first gear ratio to vary a flow rate of fluid in the fluid channel, and clutches to vary the gearbox between the first gear ratio and the second gear ratio.

Abstract: A hybrid engine including features to meet aircraft thrust, passenger airflow, and fuel cell requirements. The engine includes a combustor burning the same fuel as the fuel cell. The engine has electric motors to utilize the power output of the fuel cell. The engine shafts have sprags to allow motors to drive the compressors and over run the turbines. The engine has variable flowpath geometry to bypass the combustor.

Abstract: A hybrid engine including features to meet aircraft thrust, passenger airflow, and fuel cell requirements. The engine includes a combustor burning the same fuel as the fuel cell. The engine has electric motors to utilize the power output of the fuel cell. The engine shafts have sprags to allow motors to drive the compressors and over run the turbines. The engine has variable flowpath geometry to bypass the combustor.

Abstract: Engine bleed air power recovery systems and related methods are disclosed. An example power recovery system for an aircraft engine includes a power recovery turbine coupled to aa shaft-driven device. A bleed air valve coupled between the power recovery turbine and a bleed air source. A controller configured to operate the bleed air valve to allow bleed air to flow to the power recovery turbine when the aircraft engine operates in a predetermined mode of operation.

Abstract: An aircraft launching system and method include a first lifting sub-system including a first tether that removably couples to an aircraft, and a second lifting sub-system including a second tether that couples the first lifting sub-system to the second lifting sub-system.

Abstract: An aerodynamic brake includes a rigid panel having a panel leading edge portion and a panel trailing edge portion. The aerodynamic brake also includes a flexible sheet having a sheet lower edge portion coupled to the vehicle body, and a sheet upper edge portion coupled to the panel leading edge portion. The aerodynamic brake further includes a panel actuator configured to move the rigid panel between a stowed position and a deployed position. In the stowed position, the rigid panel is located proximate the vehicle body and covers the flexible sheet in a folded state. In the deployed position, the panel leading edge portion is moved away from the vehicle body and the flexible sheet is in an open state exposable to an oncoming airflow for generating aerodynamic drag for slowing the vehicle.

Abstract: Drag modification systems for aircraft and related methods. An example system for modifying drag on an aircraft includes a boundary layer intake plenum and an eductor. The eductor defines a primary inlet to receive a primary fluid, a secondary inlet in fluid communication with the intake plenum to receive a secondary fluid entrained from the intake plenum, and an outlet to exhaust a mixed flow including the primary fluid and the secondary fluid. The primary fluid is a motive fluid having flow parameters to generate a suction at the secondary inlet.

Abstract: Compressors having multi-speed gearboxes are disclosed. The apparatus comprises: a fluid channel to convey a fluid, a compressor fluidly coupled to the fluid channel, a gearbox operatively coupled to the compressor, the gearbox to control the compressor using a first gear ratio and a second gear ratio different from the first gear ratio to vary a flow rate of fluid in the fluid channel, and clutches to vary the gearbox between the first gear ratio and the second gear ratio.

Abstract: Aircraft environmental control systems having electrically powered ram circuit fans are described herein. An example environmental control system includes an air cycle machine to produce cabin air for a cabin of the aircraft. The air cycle machine includes a turbine and a heat exchanger. The environmental control system also includes a ram circuit. The heat exchanger is disposed in the ram circuit. The environmental control system further includes a fan in the ram circuit to control air flow through the ram circuit and across the heat exchanger, an electric motor, and an overrunning clutch operatively coupled between the turbine and the electric motor to enable the turbine to drive the fan during a first mode of operation and to enable the electric motor to drive the fan during a second mode of operation.

Abstract: Systems to produce cabin supply air for aircraft and related methods are described herein. An example system includes an air conditioning pack including a heat exchanger including a first flow path and a second flow path isolated from the first flow path. The second flow path is to receive cabin exhaust air from a cabin of an aircraft. The cabin exhaust air is to reduce a temperature of the cabin supply air flowing through the first flow path of the heat exchanger. The system also includes a turbine to receive the cabin supply air from the heat exchanger. The turbine is to reduce a temperature and pressure of the cabin supply air. A turbine outlet of the turbine is fluidly coupled to the cabin to provide the cabin supply air to the cabin. The system further includes a fan to direct the cabin exhaust air from the heat exchanger.

Abstract: A hybrid engine including features to meet aircraft thrust, passenger airflow, and fuel cell requirements. The engine includes a combustor burning the same fuel as the fuel cell. The engine has electric motors to utilize the power output of the fuel cell. The engine shafts have sprags to allow motors to drive the compressors and over run the turbines. The engine has variable flowpath geometry to bypass the combustor.

Abstract: Compressor valves for aircraft are described herein. An example valve for a compressor includes a first end plate, a second end plate, and a first sleeve valve disposed between the first and second end plates. The first the first sleeve valve is operable between a closed state and an open state. The example valve also includes a second sleeve valve disposed between the first and second end plates and within the first sleeve valve such that a plenum is formed between the first end plate, the second end plate, the first sleeve valve, and the second sleeve valve. The plenum is to receive outlet air from an outlet of the compressor. A passageway is formed through a center of the valve to be fluidly coupled to an inlet of the compressor. The second sleeve valve is operable between a closed state and an open state.

Abstract: A ground service vehicle system employs autonomous vehicles that can be reconfigured with interchangeable service modules to provide different services. The autonomous service vehicles can be remotely controlled and dispatched in swarms to provide different services at a location.

Abstract: Apparatus and methods to deploy a fluid flow channel are disclosed herein. An example apparatus includes a first loop coupled to an outside surface of a vehicle via a first fastener, a second loop coupled to the vehicle and disposed a distance from the first loop, and a flexible material having a first end coupled to the first loop and a second end coupled to the second loop, where the flexible material is to form a fluid flow channel between the first loop and the second loop.

Abstract: Braking systems for aircraft are disclosed. An example braking system includes a brake pad movably coupled to a lower section of a fuselage of the aircraft. The brake pad is movable between a stowed position and a deployed position. An actuator is configured to deploy the brake pad from the fuselage during an emergency braking event. The brake pad to engage a surface of a runway and increase frictional force to reduce a speed of the aircraft during the emergency braking event.

Abstract: A compact inlet design including a single bulkhead and/or an acoustic panel extending into nacelle lip region for noise reduction.

Abstract: Engine bleed air power recovery systems and related methods are disclosed. An example power recovery system for an aircraft engine includes a power recovery turbine coupled to aa shaft-driven device. A bleed air valve coupled between the power recovery turbine and a bleed air source. A controller configured to operate the bleed air valve to allow bleed air to flow to the power recovery turbine when the aircraft engine operates in a predetermined mode of operation.

Abstract: Braking systems for aircraft are disclosed. An example braking system includes a fan cowl having a leading edge and a trailing edge. The braking system includes a hinge assembly coupled between the leading edge and a fan cage of an aircraft engine to enable the fan cowl to move between a stowed position and a deployed position. An actuator is coupled to the leading edge of the fan cowl, and the actuator is to move the fan cowl via the hinge from the stowed position to the deployed position in a direction away from the aircraft engine and toward a fore end of the aircraft to provide an air brake during a braking event.