Abstract: Composite rotor blades are constructed from a honeycombed polymer interior core structure having a bonded glass skin covering associated with the top and bottom surfaces thereof. Over time, environmental conditions lead to cracks or fissures in the glass skin coverings allowing moisture to accumulate in the interior honeycomb core of the blade. The present apparatus and method removes this accumulated moisture from composite rotor blades as well as from other objects constructed of polymer composite materials in general and includes an atmospherically sealed container of sufficient size to house the rotor blades or other objects within the container. The apparatus includes support fixturing for holding the rotor blades or other objects suspended within the container, a dehumidifier to reduce the moisture level of the air cycled through the container, a heater to control the temperature within the container, and a vacuum mechanism for controlling the pressure inside the container.

Abstract: A method for assessing quality of a coating process includes providing a facsimile assembly, the facsimile assembly having a fixture holding an audit coupon, and coating the facsimile assembly to form a coating thereon. The assembly is then disassembled, and the coating on the audit coupon is inspected.

Abstract: The invention comprises a reflective blade or a reflective blade with a picture which fits over a ceiling fan blade or a mirror cut in the shape of a ceiling fan and used in place of a ceiling fan. The device may be an applique of reflective materials which can be patched over the ceiling fan blades and may have cutouts and peel away edges in varying degrees in order to allow it to fit over the ceiling fan blades of various sizes. Likewise, sets of different size mirrors may be sold for the same purpose.

Abstract: A marine propeller includes a hub defining an axial direction of the propeller, a plurality of adjustable propeller blades disposed around the hub, and a blade setting adjusting arrangement. Each blade includes a blade-part and a root-part, the root-part being mounted in the hub and being turnable about an axis that defines an angle with the axial direction of the propeller.

Abstract: An electric fan mounted overhead for universal adjustment of the air flow direction. A mounting plate clamped to an overhead beam carries a sleeve that rotatively receives a vertical column. The lower end of the column pivotally connects with a mounting arm which carries the fan. A rotation motor can rotationally adjust the column to adjust the lateral direction in which the fan faces. A linear actuator pivots the mounting arm up and down to adjust the tilt angle of the fan.

Abstract: An improved blade positioning mechanism for folding a helicopter blade attached to a pitch control housing permits a controlled folding of the main rotor blade for increased safety and decreased risk of damage to the helicopter or other equipment. The invention also folds the main rotor blade while the blade remains attached to the pitch control housing, thus eliminating the need to rebalance the blade. In an embodiment of the invention blade positioning mechanism comprises a pitch control housing connection, a rotor blade clamp, and a clamp positioner. The pitch control housing connection is adapted to temporarily attach to the pitch control housing of the helicopter and pivot with two degrees of freedom relative to the pitch control housing. The rotor blade clamp is adapted to temporarily attach to the rotor blade of the helicopter. The clamp positioner is attached to the rotor blade clamp and the pitch control housing connection.

Abstract: An apparatus for detecting the pitch angle of a propeller blade comprises a sensor and two transmitters. The transmitters are strategically located so as to identify a first fixed reference point on the propeller hub and a second movable point on the propeller blade. The sensor is mounted on a non-moving reference such as the engine housing. The sensor detects the time difference in signal arrival from each magnetic transmitter as they rotate on the propeller assembly and pass by the sensor. The fixed transmitter, although spinning with the propeller hub, does not move relative to the hub itself, and is mounted in a fixed position relative to the hub such as on the bulkhead plate. Each time the fixed transmitter passes by the sensor it generates a reference signal. The movable transmitter moves with the propeller blade as it rotates about the pitch axis thus changing the distance between the two transmitters.

Abstract: Illuminated controls for use with air moving products such as fans and humidifiers wherein the controls for motor speed, temperature, or humidity are illuminated by an electroluminescent panel to show the location and settings.

Abstract: A monitor for detecting overheating of a critical component in a combustion turbine is provided. The monitor, when used in conjunction with a closed-loop cooling system, comprises a coating comprising an indicator material having an activation temperature. The coating is situated on the internal cooling passages of the critical component. The monitor further comprises a sensor connected to an outlet conduit of the cooling system for determining the amount of degradation of indicator material by monitoring the cooling fluid flowing through the outlet conduit. Embodiments further comprising “sniffer” tubes for use with open-loop air cooling systems also are provided. In alternative embodiments, auxiliary cooling systems for supplying auxiliary cooling to critical components at certain activation temperatures also are provided.

Abstract: A technique for providing a signal representative of blade vortex interaction (BVI) noise for a multi-blade rotorcraft. The fluid (air) pressure at one, two, or more predetermined locations on a rotor blade is measured during at least one predetermined azimuthal segment of blade rotation during operation to provide respective pressure measurements. The pressure measurements are processed to provide a signal for use as a control variable in a control system for the active control of BVI noise. The pressure measurements are made within 10% blade chord length of the blade leading edge and preferably two or more are made between 65% and 95% of blade radial-length. The pressure measurements are filtered and the band of retained frequencies is between 20 and 48 times the rotor rotation frequency. An algorithm operative over a determined blade frequency range optimizes the signal for control use.

Abstract: A steam turbine different material welded rotor, constructed by rotors of different materials being jointed together by welding has the strength of a jointed portion increased and inspection of the jointed portion facilitated. A bearing portion rotor 1 and high temperature portion rotor 2 are jointed at weld portion A, the high temperature portion rotor 2 and low temperature portion rotor 3 at weld portion B and the low temperature portion rotor 3 and bearing portion rotor 4 at weld portion C. Cavity portions 5, 6 are formed in the weld portions B, C, respectively. Inspection holes 7, 8 are also provided in the weld portions B, C. The high temperature portion rotor 2 is made of high heat resistant 12Cr steel and other rotors are made of low alloy steel, wherein the rotor 1 is of 2.multidot.1/4 CrMoV steel and the rotors 3, 4 are of 3.multidot.1/2 NiCrMoV steel.

Abstract: A fan assembly (10) includes first and second housing sections (70, 72) which, when mated by a first set of fasteners, define a plurality of circumferentially spaced openings (162) that lead to an internal housing chamber (82). The fan assembly (10) also includes a plurality of blade units (140), each of which includes an integral support stem (142) having a journal portion (148) rotatably mounted within a respective one of the openings (162), an enlarged flange portion (144) and a radial post portion (138) rotatably supported by a hub member (106) within the internal chamber (82). Each blade unit (140) preferably has a thrust bearing (156), bushing sleeve (158) and fan blade (152) integrated with the support stem (142), with the fan blade (152) being preferably molded to the support stem (142) following positioning of the thrust bearing (156) and bushing sleeve (158) to form an integral component.

Abstract: A system for controlling propeller blade pitch is disclosed. The system comprises a transfer tube, wherein the transfer tube defines an element of the rotatable portion and wherein the transfer tube is non-translating relative the rotatable and non-rotatable portions. A transfer bearing for providing hydraulic fluid to and interfacing with the transfer tube is also used, wherein the transfer bearing is located on the non-rotatable portion. The system further includes a pitch change actuator and a mechanism form for actuating the pitch change actuator, wherein the mechanism is fluidically connected to and translatable relative to the transfer tube. A device for measuring blade angle of the propeller blade is also provided, wherein the device is separate and distinct from the transfer tube.

Abstract: A monitor for detecting overheating of a critical component in a combustion turbine is provided. The monitor, when used in conjunction with a closed-loop cooling system, comprises a coating comprising an indicator material having an activation temperature. The coating is situated on the internal cooling passages of the critical component. The monitor further comprises a sensor connected to an outlet conduit of the cooling system for determining the amount of degradation of indicator material by monitoring the cooling fluid flowing through the outlet conduit. Embodiments further comprising "sniffer" tubes for use with open-loop air cooling systems also are provided.

Abstract: An improved electronic hydraulic propeller control designed as a retro-fit kit for existing Hamilton Standard Division 54460 and 54H60 propeller controllers includes an apparatus for controlling the pitch angle of a propeller blade. The retro-fit kit includes an electro-hydraulic servo valve, an electronic controller, a protection valve, and a propeller maintenance interface panel. These components functionally replace the existing hydromechanical propeller control system without reconfiguration of the existing interface. The apparatus converts mechanical inputs of the propeller and airframe systems to electronic signals, which can be measured by the electronic control. The apparatus also receives and converts the electronic control's commands into hydraulic pressure and flow changes through an electro-hydraulic servo valve. The electronic controller performs the required calculations to interpret and then react to changes in the propeller/airframe systems.

Abstract: A turbine blade (18) for a gas turbine engine includes a machining datum (60) that extends radially from a pocket (54) in the outer shroud (36) of the blade. The datum is spaced from a sidewall (64) of the pocket so that the datum is peripherally continuous irrespective of whether the blade is in a prefinished state or in a completely finished state. Because the datum's peripheral continuity survives the original manufacturing process, the datum is available for use in post-manufacturing inspection and repair operations.

Abstract: A variable-pitch marine propeller system has a propeller unit for mounting on a drive shaft, and a power unit including a stationary annular hydraulic cylinder for operating the propeller unit, a hydraulic remote control unit being fluid-coupled to the power unit. An annular piston of the hydraulic cylinder is coupled to a ring-shaped actuator yoke by a roller thrust bearing, the actuator yoke axially displacing a mating yoke of the propeller unit with which the actuator yoke is allowed to rotate. The piston operates in a sealed environment for the exclusion of water from the separately sealed surfaces of the cylinder itself. In one configuration, the propeller unit is replaceable without disturbing the sealed environment of the annular piston. The control unit includes a hydraulic control cylinder that is operated by a rotatably mounted barrel that engages a threaded piston rod. Alternatively, the control cylinder is actuated by a lever having biasing springs and an adjustable brake.

Abstract: A device for detecting fractures or corrosion in a workpiece having a non-conductive outer surface. A thin film layer of metallic material comprising a plurality of separate crack detection wires is bonded to the non-conductive surface of the workpiece. A top coating of protective material is applied to the thin film layer to protect the detection wires from abrasion and corrosion. When an electrical current is transmitted through the detection wires, a predictable resistivity pattern is viewable on a monitor. As a fracture propagates through the workpiece causing the crack detection wires to break one-by-one, the change in resistivity of the wires can be monitored and the existence and extent of any fracture or corrosion to the wires determined.

Abstract: Fan blade covers which are particularly useful for covering ceiling fan blades. The covers are easily removed and cleaned providing a safe means for cleaning ceiling fan blades. The covers are provided in numerous colors and decorative patterns allowing the selection of covers which match a room decor. The covers also comprise a balancing arrangement for the fan which includes a pocket positioned on the upper surface of the cover and a dispensing arrangement for dispensing and distributing deodorant throughout a room which includes a vented pocket for receiving a deodorant canister while the vented pocket and canister includes a visual deodorant depletion indicator.

Abstract: A fan speed indicator is provided including a conventional fan with a pull cord adapted to change a speed at which the fan is running upon being pulled. Further provided is mechanical mechanism for mechanically indicating the speed at which the fan is currently running.

Abstract: A blade angle feedback system for use with a propulsion system having a plurality of angularly adjustable blades, wherein each of the blades has an axis of rotation and is rotatable about the axis of rotation through a plurality of blade angles. The system includes a mechanism for indicating blade angle position of each of the sensed blades. The mechanism for indicating is movable through the plurality of blade angles with the blades, wherein the mechanism for indicating has a plurality of identities depending on and indicative of the blade angle. Mechanisms for designating a plurality of reference positions on the blades of the propulsion system and relative the mechanism for indicating are also provided.

Abstract: A control system has an HHC actuator having a basal portion and a movable portion. A load acting on the control system is detected by a semiconductor gauge. The load detected by the semiconductor gauge is compared with a threshold value in a computer. If the detected load is larger than the threshold load, the movable portion is fixed to the basal portion by a fixing mechanism. By detecting the sign of stall of blades, the HHC actuator is fixed in a neutral position, allowing safe flight. A fixing switch is provided for allowing the fixing mechanism to operate regardless of the result of the comparison with the computer.

Abstract: A device for engaging a remote control unit to a ceiling fan which has a motor for mechanically actuating blades connected thereto and a rod with a head which extends upwardly from the motor, a fixing element fixedly engaged to the floor and having a C-shaped portion for engagement with the head of the rod, a middle plate having a central hole for the rod to extend therethrough and having at least two sockets extending from an underside thereof, the middle plate received in a bowl which has a hole for the rod to extend therethrough and at least two studs extending from a bottom thereof for engagement with the sockets, electrical elements for remote controlling the ceiling fan disposed in the bowl which is engaged to the fixing element by bolts such that the remote control unit can be repaired simply by disengaging the bowl from the fixing element.

Abstract: An off state demonstrating device on a line-pulling switch for a ceiling fan, is characterized in that a display or demonstrating device is jumper connected at the off position of the switch, so that when the switch is in an off state, the display or demonstrating device can be turned on and a user can be advised that the ceiling fan is in an off state.

Abstract: A method and device using a single-throw switch for controlling the revolving speed of the ceiling fan and light assembly and the light intensity of its lamps. The method obtains a 60 Hz square wave of cycle 16.67 ms from a typical alternating current power supplied from an electric power company and provides a working direct current voltage to a microprocessor through a direct current power supply circuit. When power is turned off and on (a switching cycle) by the single-throw switch, the microprocessor calculates the interrupting time during each switching cycle and regulates the revolving speed of the ceiling fan or the light intensity of the lamps based on the calculated result.

Abstract: A pitch link having an adjustable length is constructed as a diamond-shaped frame by coupling and fixing four flexible beams same in length and rigidity each at end portions thereof. Spherical bearings are provided on opposite ends with the longer diagonal line as an axis of the pitch link. A turnbuckle shaft is screwed into vertex portions on the shorter diagonal line, which is turned so as to adjust a length of the shorter diagonal line, thereby adjusting a length of the pitch link. The turnbuckle shaft is rotated by a detachable motor. Vibrations of a body and the rotational position of a rotor are detected by a vibrosensor and a phase detector respectively while an aircraft equipped with the pitch link is flying, an amount for adjusting the pitch link is calculated by a vibration analyzer from the electrical signals, and the motor is driven through a FM data transmitter/receiver to adjust the pitch link.

Abstract: A cover for a pressure sensor for indicating cracks in a hollow aircraft blade, the sensor having a shaft carrying a radiation source, with the shaft sliding in a housing between a first position with the radiation source within the housing and a second position with the radiation source external of the housing, the cover including a sleeve for positioning around the sensor and having an open end for engaging a shoulder of the sensor and having a closed end spaced from the sensor when the open end is engaging the sensor shoulder, and a plunger slidably mounted in the closed end and movable between an outer position and an inner position, with the plunger out of engagement with the sensor shaft when in the outer position and engaging the sensor shaft when in the inner position to move the shaft into the sensor and reset the sensor, with the sleeve being of a material absorbing the radiation of the source.

Abstract: An actuator for varying the pitch of a plurality of propeller blades mounted on a propeller blade hub comprising an electric motor driving a drive gear, a reduction gear set driven by the drive gear and driving an externally threaded drive spool, an internally threaded pitch ring including a tangential slot, a pin received within the tangential slot and disposed on a blade hub to which the propeller blade is secured. Rotary movement of the drive gear, the reduction gear set, and the drive spool results in translational movement of the pitch ring. Translational movement of the pitch ring causes movement of the pin within the tangential slot, resulting in rotation of the propeller blade.

Abstract: A pitch adjustment assembly (100) for a bearingless rotor assembly (20) which includes a torque tube member (36) enveloping a flexbeam connector (22), which torque tube member (36) defines a geometric center (120) and is operative to impart pitch motion to the rotor blade assembly (20).

Abstract: A method and apparatus for controlling a propulsion engine output in a vessel, based on the net axial force on a propeller shaft in the vessel. The apparatus includes a regulating loop with a computer which continuously controls the delivery of fuel to the vessel's engine, and optionally controls the attack angle of the vessel's propeller blades. Control of the fuel delivery is performed in accordance with predetermined control algorithms, and optionally, by operator-set parameter values and maneuvering operations. The apparatus further includes at least one force sensor mounted to a bearing which supports the vessel's propeller shaft. The force sensor, which is preferably mounted to a thrust bearing, detects a net axial force on the propeller shaft. The net axial force detected is then used as a parameter in the control algorithms and therefore as a factor in controlling the delivery of fuel.

Abstract: Mechanical assembly for transmitting forces along an axis driven by a substantially axial movement in translation under the effect of a thrust load. This mechanical assembly comprises a transmitting part of the thrust load input movement and a receiving part of the thrust load output movement, said mechanical assembly comprising a detector for detecting the passing of a force threshold represented by a predetermined value of the thrust load, and including an elastic element and an indicator part arranged in such a way that when the thrust load exceeds the threshold value, the thrust load acts on the elastic element and modifies its axial dimension allowing the indicator part to move to the warning position.

Abstract: A rotor blade recorder system for accumulating the total number of hours that the rotor blades of a helicopter have been rotating at operational speeds. An hour meter and a switch are attached to the outer surface of a mounting rod running through the root end of each of the two blades comprising the main rotor. The switch has a calibrated weight at the end of the switch arm to close the contacts of the switch when the main rotor reaches operational speed. Closing the contacts energizes the self-contained power source in an hour meter. Remote readout terminals permit the hour meter to be read from outside without disturbing the blade assembly. As long as the rotor continues at the operating speed, the hour meter continues to record the time at work.

Abstract: A system is provided for determining tracking error in a propeller or rotor driven aircraft by determining differences in the aerodynamic loading on the propeller or rotor blades of the aircraft. The system includes a microphone disposed relative to the blades during the rotation thereof so as to receive separate pressure pulses produced by each of the blades during the passage thereof by the microphone. A low pass filter filters the output signal produced by the microphone, the low pass filter having an upper cut-off frequency set below the frequency at which the blades pass by the microphone. A sensor produces an output signal after each complete revolution of the blades, and a recording display device displays the outputs of the low pass filter and sensor so as to enable evaluation of the relative magnitudes of the pressure pulses produced by passage of the blades by the microphone during each complete revolution of the blades.

Abstract: An accessory (10) mounted for relative rotation with respect to a conventional ceiling fan (100); wherein, the accessory (10) includes a housing unit (13) suspended from the ceiling fan (100) and bearing visual elements (60) whose appearance will change relative to a stationary viewer, in response to the rotation of the housing unit (13) due to air currents generated by the ceiling fan (100) impinging upon a propulsion unit (14) contained within the housing unit.

Abstract: Setting pitch on a windmill airfoil having a longitudinal axis, a rotor blade and a rotor base secured to the rotor blade is accomplished by marking a windmill rotor hub for receiving the rotor base with a reference mark at a location corresponding to a first plane parallel to a plane of rotation of the windmill airfoil in use. The airfoil is positioned along a second plane relative to and substantially completely intersecting the longitudinal axis of the airfoil. The rotor base is marked at a location substantially parallel to the second plane. The airfoil is positioned relative to the windmill rotor hub so that the rotor base is in substantial engagement with the hub. The airfoil is moved relative to the hub so that the mark on the rotor base is aligned with the reference mark on the windmill rotor hub and the rotor base is secured to the windmill hub. An apparatus for marking pitch on a windmill airfoil is also provided.

Abstract: A turbine or compressor blade designed for deliberate, controlled failure in a gas turbine engine during testing of the engines, includes a lower-strength tubular insert in an axial through bore in the root portion of the blade, which insert fails at preselected conditions to induce blade failure.

Abstract: A turbine or compressor blade designed for deliberate, controlled failure in a gas turbine engine during testing of the engines, includes a lower-strength tubular insert in an axial through bore in the root portion of the blade, which insert fails at preselected conditions to induce blade failure.

Abstract: A cover for a propeller is disclosed which is intended to be used while a boat on which the propeller is mounted is being transported on a trailer. The cover is either made of a reflective material or is covered with a reflective material and is intended to reflect light from headlights of vehicles following the trailer to provide an added safety factor when a boat is being towed by a vehicle.

Abstract: A device for mounting a data transmission apparatus to a rotating, tapered and instrumented shaft is provided. This device permits attachment without interfering with shaft rotation or the accuracy of data output, and prevents both radial and axial slippage of the data transmission apparatus. The mounting device consists of a sleeve assembly which is attached to the shaft with clamps that are situated at some distance removed from the instrumented area of the shaft. The data transmission device is secured to the sleeve such that the entire assembly rotates with the shaft. Shim adjustments between sleeve sections assure that a minimum compressive load is transferred to the instrumented area of the shaft and a rubber lining is affixed to a large portion of the interior surface of the sleeve to absorb vibration.

Abstract: A propeller blade tip path plane-inclining device which is provided with a fuselage, a propeller including a center piece rotating unitary with a rotation shaft in association therewith and a plurality of blades extending substantially horizontally from the center piece and differing the variation in pitch during the rotation thereof from one another, a motor for driving the propeller for rotation, a position detector for detecting the position of the propeller in the propeller rotation plane, and a control device for controlling the motor in accordance with an output signal of the position detector.

Abstract: A method and apparatus are provided for determining the amount and type of permanent deformation experienced by a turbomachine blade. According to the invention, small holes are drilled in at least three blades of the blade row. One hole is drilled in the inlet face of the blade shroud and another hole is drilled in the inlet face of the blade root. In addition, third and fourth holes are drilled in the exit face of the shroud and a sixth hole is drilled in the exit face of the root. Measurements are taken between the shroud holes on the middle blade and the root holes on the outer blades in the row on both the inlet and exit faces. The measurements are use to form triangles indicating the blade geometry. By comparing the changes in these triangles after substantial operating time, both the type and amount of permanent deformation can be determined.

Abstract: Pitch adjustment in a feathering propeller employing a planet gear engagement between a pinion hub keyed on the drive shaft and planet pinions at the base of the blades of the propeller which are rotatably mounted through holes of the wall of a hub's casing may be easily performed manually by registering the relative angular position of a second portion of casing in respect to a first portion of the casing housing the planet gear. The registration of the pitch takes place by parting the second portion of casing from the first portion against the resistance of a push-back spring for a distance sufficient to disengage a coupling between the second portion and first portion of the casing or the pinion hub, rotating the second portion so disengaged in respect to the first portion of the casing before releasing the pull causing again the engagement of the two portions in a modified relative angular position.

Abstract: A wind turbine is arranged to provide for a front torroidal plate mounted from and spaced relative to a rear solid plate coaxially securing a deflecting cone coextensively and coaxially between the front and rear plate, with a series of equally spaced arcuate impeller blades mounted adjacent a periphery of the front and rear plates exteriorly of the cone to direct air flow through the turbine plates from the cone structure. The impeller also has a fluidic rotation indicator. The indicator is a set of arcuate liquid chambers which contain two different fluids of different colors and specific gravities. When the impeller is stationary, the two different fluids separate, indicating two colors. However, when the impeller rotates, the two fluids mix and indicate a single third color.

Abstract: An inboard servo for a controllable pitch propeller of the force rod type comprises a feedback device comprising a feedback ring located externally of the propeller drive shaft, affixed to the force rod for rotation and axial translation therewith and having a planar surface perpendicular to the propeller drive shaft axis, and a distance-measuring device for substantially continuously detecting the position of the ring, and therefore the position of the force rod. The distance-measuring device directs a high frequency pulsed signal onto the ring surface from a fixed position spaced apart therefrom, detects the signal as it is reflected by the ring surface from a fixed position spaced apart therefrom, and processes the directed and reflected signals to produce a signal indicative of the position of the ring surface based on the time difference between the pulses directed onto the ring surface and the pulses reflected from the ring surface.

Abstract: Apparatus indicates changes in blade pitch of variable pitch blades by detecting relative displacements of first and second members of a blade pitch actuator. The members are selectively displaced to change the pitch of the blades. The apparatus includes sensors which provide output signals to a microprocessor, which determines displacement of each member with respect to a frame of reference. The microprocessor takes the difference between the displacements of the two members to determine the relative displacement, which is indicative of a change in blade pitch.

Abstract: The invention is a helicopter blade crack detection system for blades that are hollow and pressurized or evacuated to a low pressure A rotating assembly having a rotating indicator assembly photo-optically communicates to an airframe detection assembly providing high reliability, ease of maintenance, and EMI secured.

Abstract: A wind force-operated cycling ornament, comprising a body shaped like a cyclist and mounted on a base, which can be mounted on a flat surface by screws or a double-sided adhesive tape, two wheels mounted on said body at two opposite sides and connected by a wheel axle, a fan mounted on said body and forced by the power of wind to rotate said wheels through a transmission gear set, and a pair of driven plates and a pair of driving plates movably mounted between a pair of pegs on said body and two contact points on said wheel, and wherein said driven plates are respectively shaped like the upper part of the leg, and said driving plates are respectively shaped like the lower part of the leg; rotating said fan causes said driven and driving plates to alternatively rotate back and forth.

Abstract: A low pitch alarm assembly 70 comprises a capped sleeve 72 disposed about the distal end 55 of the rotating and translating fluid delivery tube 50 so as to define a chamber 75 receiving the end 55 of the fluid delivery tube for axial translation therein, a fluid supply conduit 80, a pressure drop orifice 82 disposed in the fluid supply conduit 80, and a pressure switch 90 opening to the supply conduit downstream of the pressure drop orifice. The sleeve 72 has relatively large flow area outlet holes 74 opening through the capped end 76 of the sleeve 72 to a low pressure and a relatively small flow area inlet opening 73 through the sleeve side wall 78 connected to the fluid supply conduit 80. The pressure switch 90 generates an alarm signal whenever the end 55 of the fluid delivery tube 50 passes out of registration with inlet opening 73.

Abstract: A calibration device for a pitch change link (10) for a helicopter rotor grip where the link (10) includes a bearing (12) and includes a plurality of sequential reference numbers (22) equally spaced apart and concentrically disposed around the link (10). An indexing device (30) is mounted to the bearing (12) and is disposed adjacent to the plurality of sequential reference numbers (22) for locating one of the plurality of reference numbers (22) representing the length of the link (10). The indexing device (30) includes a window (40) which indexes one of the plurality of reference numbers (22) as the link (10) rotates.

Abstract: A method for detecting a crack in the main load bearing spar of a hilicopter rotor blade consists of attaching a capillary tube along an external surface of the spar and connecting the interior of the tube to a supply of colored liquid contained in a reservoir at a root end of the blade, whereby a crack in the spar causes a corresponding crack in the capillary tube resulting in visible leakage of the colored liquid.