One embodiment includes a multistage infrared suppression exhaust system for an aircraft, including: a stage one including a first exhaust conduit to receive a first exhaust air flow at a first temperature-pressure product T.sub.1P.sub.1, a second exhaust conduit to receive a second exhaust air flow at a second temperature-pressure product T.sub.2P.sub.2, and a flow integrator mechanically configured to mix the first exhaust air flow with the second exhaust air flow in an integration chamber while preventing back pressure into the second exhaust conduit; and a stage two including a stage two cooling airflow to cool the mixed first and second exhaust air flows.

A foldable blade assembly may include a first blade, a motor configured to rotate the first blade, a second blade of which a rotation center coincides with a rotation center of the first blade, and an actuator configured to move the second blade upward or downward to selectively couple the second blade to the first blade so that the second blade and the first blade are rotated together or configured to release the coupling between the second blade and the first blade.

An aircraft includes a fuselage and an engine housed in the fuselage. A ram-air engine inlet is formed on an exterior of the fuselage. The ram-air engine inlet is defined, at least in part, by a cowling door. The cowling door is moveable between a closed position and an open position. An intake duct fluidly couples the ram-air engine inlet to the engine. A filter is disposed across the intake duct. A bypass duct is formed in the ram-air engine inlet aft of the intake duct. The bypass duct is operable to be selectively opened and closed.

A ducted-fan unmanned aerial vehicle (UAV) capable of low-energy high-rate maneuvers for both vertical roll control and horizontal pitch control. The UAV includes ducted fans which are with respective piezoelectric-actuated thrust vectoring flaps. Thrust vector control is achieved by controlling the angular positions of a plurality of thrust vector flaps pivotably coupled at respective outlets of a plurality of ducts having fan rotors at the inlets. Each thrust vectoring flap has only one degree of freedom in the frame of reference of the UAV, namely, rotation about a single axis that is perpendicular to the axis of the duct. The angular position of the flap is controlled by sending electrical signals to a piezoelectric actuator (e.g., a piezoelectric bimorph actuator) having a voltage sufficient to cause the piezoelectric actuator to bend.

A lightweight lift system for VTOL/VSTOL operation running in parallel with an existing turbine. This system distributes LP power by switching compressor flow and fuel proportionally over to the lift turbine module. As forward thrust is demanded, some of the power is transitioned back to the flight LP turbine, which can drive a variable propeller, fan or can supply jet thrust. As flight motion occurs, the power to the lift fan can be reduced to zero and lift closed off.

A panel for use in a gas turbine engine exhaust case is disclosed. The panel has an airfoil section and a flow diverting structure adjacent a leading edge, wherein the flow diverting structure directs fluid flow into an area of the airfoil that lacks sufficient internal pressure for cooling fluid flow.

A vertical take-off and landing spacecraft includes a body, a plurality of engines provided in the body to produce a jet flow and generate thrust, an abnormal signal acquiring unit that acquires an abnormal signal indicative of a presence of an abnormal engine among the plurality of engines, and an engine control unit that outputs a stop signal that stops a specific engine among a plurality of operating engines based on the abnormal signal.

A vehicle includes a main body and a gas generator producing a gas stream. At least one fore conduit and tail conduit are fluidly coupled to the generator. First and second fore ejectors are fluidly coupled to the at least one fore conduit. At least one tail ejector is fluidly coupled to the at least one tail conduit. The fore ejectors respectively include an outlet structure out of which gas from the at least one fore conduit flows. The at least one tail ejector includes an outlet structure out of which gas from the at least one tail conduit flows. First and second primary airfoil elements have leading edges respectively located directly downstream of the first and second fore ejectors. At least one secondary airfoil element has a leading edge located directly downstream of the outlet structure of the at least one tail ejector.

One embodiment is a rotor system comprising a duct ring; a hub disposed centrally to the duct ring; first and second stators each connected between the duct ring and the hub; first and second control vanes rotatably connected to the first and second stators, respectively; a structural hoop having a first end connected to the first control vane and a second end connected to the second control vane, the structural hoop for translating rotation of the first control vane about a vane axis to the second control vane; and a mechanism for restricting at least one of forward-aft movement and side-to-side movement of the structural hoop relative to the duct ring.

One embodiment is a rotor system comprising a rotor duct; at least one rotor blade, wherein the at least one rotor blade comprises an outboard end; a tip extension mechanism affixed at the outboard end of the at least one rotor blade, wherein the tip extension mechanism comprises at least one shim, the at least one rotor blade with the tip extension mechanism affixed thereto comprising an extended rotor blade; and a blade tip affixed to an outboard end of the extended rotor blade, wherein the blade tip is affixed to the extended rotor blade via at least one removable fastener.