摘要:
A novel design and construction method for an inflatable, rigidizable wing for a terrestrial or planetary flying vehicle. The wing is caused to deploy from an initially packed condition and to assume its functional shape by means of an inflation gas. After inflation, the wing is rigidized by any of several means, such that the inflation gas is no longer required. The composite wing is fabricated from a base reinforcement material, often a fabric, which is coated with a polymer resin that hardens when exposed to a curing mechanism. Several activation mechanisms exist by which to initiate rigidization of such a structure, including elevated temperature, ultraviolet light, and chemical constituents of the inflation gas. The resultant wing has fundamental advantages compared to existing inflatable wings, including improved stiffness, and reduced susceptibility to structural failure in response to puncture.
摘要:
A helicopter stabilator having naturally high response to the main rotor wake excitation frequency in roll and yaw stabilator vibratory modes is selectively mounted so as to be detuned therefrom in antisymmetric stabilator vibratory modes without adversely affecting symmetric stabilator vibratory modes, stabilator vertical stiffness, or stabilator pitch stiffness.
摘要:
A helicopter blade position and control mechanism including a hollow rotor shaft for mounting a plurality of rotor blades with provision for pitch adjustment. A control shaft is disposed within the rotor shaft and is rotatable relative thereto and is associated with actuators for the blades such that the pitch of the blades is changed when the control shaft rotates relative to the rotor shaft. A planetary gear assembly interconnects the control shaft and a source of power fixed to the helicopter fuselage and is such that when an input to the planetary gear assembly is quiescent, the control shaft will rotate in the same direction and at the same rate as the rotor shaft to maintain a desired blade pitch. Conversely, when an input is placed on the planetary gear system, relative rotation between the control shaft and the rotor shaft will occur to provide the desired adjustment in blade pitch. The system allows accurate blade position feedback signals to be taken from a feedback device stationarily mounted on the fuselage.
摘要:
The compound helicopter is a hybrid combination of a helicopter and a fixed wing aircraft. A conventional helicopter is modified with a nose-mounted tractor propeller to provide thrust for forward flight. Wings are added to provide lift during forward flight. With the propeller providing thrust and the wings lift during forward flight, the helicopter rotor blades are unloaded during cruising flight to allow increased forward speed by avoiding limitations of conventional helicopters, including retreating rotor blade stall and maximum rotor blade tip speeds. A single powerplant drives both the main rotor and the nose-mounted propeller. The compound helicopter employs high aspect ratio wings with large flaps that may be extended to reduce vertical drag during vertical flight and hovering operations.
摘要:
An aircraft cabin construction includes a cart-storage compartment in the space between the ceiling of the passenger compartment and the upper fuselage wall for storing food-serving wheeled carts; and an elevator having a platform and a drive for lowering the carts from the cart-storage compartment to the deck of the passenger compartment, and for raising the carts from the deck to the cart-storage compartment.
摘要:
A modular approach to the manufacture of high performance military aircraft allows different aircraft to be manufactured at affordable cost and with high part number commonality. An aircraft so constructed includes a delta wing; a forebody section, including a cockpit, which is mounted to the front of the wing; and a propulsion system support frame mounted beneath the forebody section and the underside of the wing. The propulsion system is supported within this frame. The aircraft can also include an aftbody section mounted to the aft end of the wing, which includes a 2-D variable thrust vectoring nozzle and a pair of canted vertical tails. The forebody section includes a chin inlet below the cockpit. The wing is preferably constructed using thermoplastic welding.
摘要:
A bearing assembly monitoring system provides continuous, real time monitoring of the operating condition of a powertrain support bearing assembly and real time alarm signals indicative of degradation and/or impending catastrophic failure thereof. One embodiment of the monitoring system includes a vibration sensing device, first and second primary temperature sensing devices, an ambient temperature sensing device, vibration and temperature signal processing subcircuits, and an alarm subsystem. The vibration sensing device monitors complex vibration signals emanating from the bearing assembly and provides signals corresponding thereto. The vibration signal processing circuit filters such complex vibration signals to provide a predetermined bandwidth thereof that are converted to stabilized DC voltage signals which are compared to reference voltages corresponding to higher than normal and excessive vibration levels. Exceedance of such reference voltages generates a corresponding vibration alarm signal. The temperature sensing devices monitor the operating and ambient temperatures of the bearing assembly and provide signals corresponding thereto. The temperature signal processing circuit converts such temperature signals to differential temperature signals which are compared to a reference voltage corresponding to a temperature differential indicative of impending catastrophic failure. Exceedance of the reference voltage generates a temperature alarm signal. The alarm subsystem is operative in response to the vibration and/or temperature alarm signals to provide a real time early warning of degradation and/or impending catastrophic failure of the bearing assembly.
摘要:
A system which provides an increased minimum aircraft pitch attitude during take-off or go-around operations in the event that an unsafe wind shear condition is encountered. A control signal from a wind shear warning system, indicative of a dangerous wind shear condition, is fed to a switching device which controls the velocity command signal to the flight director pitch control. This switching device, in response to the wind shear signal, changes the velocity command to a lower predetermined value, such that the attitude of the aircraft is automatically increased to handle the wind shear encounter.