A rotary wing aircraft control system includes an airframe, a main rotor assembly supported by the airframe, and a control system arranged in the airframe and operatively connected to the main rotor assembly. The control system includes a flight control computer (FCC), at least one control inceptor device and a touchdown orientation control system. The touchdown orientation control system includes a computer readable program code an FCC to: sense, by a sensor operatively connected to the flight control computer (FCC), an altitude of the rotary wing aircraft relative to a landing surface, determine one of a landing state rearward velocity reference limit value and a landing state lateral velocity reference limit value associated with the altitude, and selectively limit a landing state flight envelope of the rotary wing aircraft to the one of the landing state rearward velocity reference limit value and the landing state lateral velocity reference limit value.

One aspect is a flight control system for a rotary wing aircraft that includes flight control computer configured to interface with a main rotor system, a translational thrust system, and an engine control system. The flight control computer includes processing circuitry configured to execute control logic. The control logic includes a primary flight control configured to produce flight control commands for the main rotor system and the translational thrust system. Main rotor engine anticipation logic is configured to produce a rotor power demand associated with the main rotor system. Propulsor loads engine anticipation logic is configured to produce an auxiliary propulsor power demand associated with the translational thrust system. The auxiliary propulsor power is combined with the rotor power demand to produce a total power demand anticipation signal for the engine control system.

One aspect is a flight control system for a rotary wing aircraft that includes flight control computer configured to interface with a main rotor system, a translational thrust system, and an engine control system. The flight control computer includes processing circuitry configured to execute control logic. The control logic includes a primary flight control configured to produce flight control commands for the main rotor system and the translational thrust system. Main rotor engine anticipation logic is configured to produce a rotor power demand associated with the main rotor system. Propulsor loads engine anticipation logic is configured to produce an auxiliary propulsor power demand associated with the translational thrust system. The auxiliary propulsor power is combined with the rotor power demand to produce a total power demand anticipation signal for the engine control system.

A vertical takeoff and landing aircraft capable of six degree-of-freedom motion where lift, pitch, and roll are provided by multirotors oriented vertically, lateral translation is provided by a cyclorotor oriented vertically, and yaw is provided by a combination of the cyclorotor and the multirotors. The invention includes a frame, which supports the multirotors and cyclorotors. The frame also supports a payload and battery which are positioned at the extreme ends of the frame. The aircraft is capable of hovering precisely to position a payload close to or touching a target surface in the air.

A vertical takeoff and landing aircraft capable of six degree-of-freedom motion where lift, pitch, and roll are provided by multirotors oriented vertically, lateral translation is provided by a cyclorotor oriented vertically, and yaw is provided by a combination of the cyclorotor and the multirotors. The invention includes a frame, which supports the multirotors and cyclorotors. The frame also supports a payload and battery which are positioned at the extreme ends of the frame. The aircraft is capable of hovering precisely to position a payload close to or touching a target surface in the air.

A lubrication system includes a reserve housing configured to retain a lubrication fluid. A supply line in fluid communication with the reserve housing is configured to provide pressurized lubrication fluid to the reserve housing. An overflow tube has an overflow port, the overflow tube being configured to prevent the volume of the lubrication fluid from exceeding a certain amount. A metering jet is configured to allow the lubrication fluid to flow from the reserve housing onto a component, such as a bearing, in the gearbox at a predetermined rate. The metering jet provides flow of the lubrication fluid onto the bearing even when the supply line no longer provides pressurized lubrication fluid to the reserve housing.

A lubrication system includes a reserve housing configured to retain a lubrication fluid. A supply line in fluid communication with the reserve housing is configured to provide pressurized lubrication fluid to the reserve housing. An overflow tube has an overflow port, the overflow tube being configured to prevent the volume of the lubrication fluid from exceeding a certain amount. A metering jet is configured to allow the lubrication fluid to flow from the reserve housing onto a component, such as a bearing, in the gearbox at a predetermined rate. The metering jet provides flow of the lubrication fluid onto the bearing even when the supply line no longer provides pressurized lubrication fluid to the reserve housing.

A damping mechanism configured for use with a coupling of a power transmission assembly is provided including a cylindrical body having a first end and a second opposite end. The first end is configured for attachment to a first component of a power transmission assembly. A groove is formed in an exterior surface of the cylindrical body adjacent the second end. A cylindrical ring generally complementary to the groove is positioned partially within the groove such that a void exists between an inner surface of the cylindrical ring and the cylindrical body within the groove. A viscous material is arranged within the void such that non-concentric movement of the cylindrical ring relative to the cylindrical body causes displacement of the viscous material.

A damping mechanism configured for use with a coupling of a power transmission assembly is provided including a cylindrical body having a first end and a second opposite end. The first end is configured for attachment to a first component of a power transmission assembly. A groove is formed in an exterior surface of the cylindrical body adjacent the second end. A cylindrical ring generally complementary to the groove is positioned partially within the groove such that a void exists between an inner surface of the cylindrical ring and the cylindrical body within the groove. A viscous material is arranged within the void such that non-concentric movement of the cylindrical ring relative to the cylindrical body causes displacement of the viscous material.

In one embodiment, an apparatus comprises a thermal barrier configured to surround at least a portion of a driveshaft and to protect the driveshaft from heat. The thermal barrier comprises an inner wall forming a cavity in which the driveshaft lies, an outer wall enclosing the inner wall, and a space between the inner wall and the outer wall. The space is evacuated and forms a vacuum.