Abstract: A system for monitoring strain in structural joints has one or more optical ibers embedded in the joint between the structural members. The joint may be fastened using fasteners such as rivets or bonded using an adhesive. Strain on the joined members is transmitted to the fiber, deforming it. An optical reflectometer connected to one end of the fiber injects an optical signal into the fiber and detects the reflection of the signal. The time period between injection of the signal and detection of the reflection is used to localize the area of stress along the fiber.

Abstract: A method and apparatus for detecting changes in the structural strength of bonded joint. Changes in one or more dielectric properties of the bonding adhesive, such as resistance and capacitance, are monitored by a microdielectrometer. A change in a bond dielectric measurement is indicative of a moisture intrusion in the bond and a corresponding weakening of the structural integrity of the bond. A warning or indication of the bond degradation is provided in response to such changes.

Abstract: A corrosion monitoring system having one or more anode elements made of a suitable anodic material that corrodes preferentially with respect to the structure being protected. The resistance of each anode wire is continuously or periodically monitored. The presence of moisture between an anode and the structure being monitored creates a current path and causes galvanic corrosion. The anode wire will begin to corrode, but the structural members will remain uncorroded until the anode has been completely consumed. The monitoring system uses the rate of change in anode resistance to extrapolate a prediction of the time remaining before the structure being protected begins to corrode.

Abstract: A device for aligning and supporting a nutplate against the workpiece to ch it is to be fastened during the entire fastening cycle of an automatic riveting machine. The device has a base that may be mounted on the lower ram of an automatic riveting machine. A nutplate elevator moves vertically within a sleeve extending upwardly from the base. The end of the sleeve supports the workpiece lower surface. A driver anvil has pins that may be forced against the rivet tails in response to motion of the lower ram driving pin.In operation, the lower ram rises, clamping the workpiece between the end of the sleeve and the upper pressure foot. The nutplate elevator is lowered by applying air pressure to the top of a piston, which is contained within the anvil. A nutplate is placed on the elevator. The nutplate is raised by applying air pressure to the bottom of the piston, forcing the nutplate against the workpiece.

Abstract: A vehicle driven by a combustible fuel propulsion system, in which the fuel emaining upon arrival at the target is exploded to act as a warhead. The vehicle has a fuel tank incorporated into the structure, which will hold more than enough fuel to complete the mission. The residual fuel is atomized into the vacant space in the fuel tank and mixed with air or oxygen, which can be used as the driving agent for the atomization. The fuel/air mixture is then detonated. The fuel tank may be thin walled for maximum blast effect, or be of heavier structure which is grooved for fragmentation.

Abstract: An aircraft which has a very low observability visually and to radar, thel and acoustic detecting devices. The aircraft is designed to have as few edges and surfaces as possible, such as a delta wing type, the edges being straight, or near straight and the vertices rounded. All surfaces are as near flat as possible, within the limits of aerodynamic requirements, and the entire surface of the aircraft is electrically conductive with minimum discontinuity. The propulsion unit is faired into and shielded from radar by the wing. Portions of the aircraft, particularly edges, may be of radar absorbing material, and any essential openings, ducts or protruding fins are similarly shielded to minimize the radar cross section.

Abstract: An aircraft having a rotor wing which in one position is locked against the irframe for forward flight, and in another position is extended clear of the airframe. In the extended position the wing is rotated and the tip portions are controllable in the manner of a helicopter rotor. A single power source provides propulsive and wing rotation power. In the preferred form the power source is a turbojet engine and the wing is rotated by a tip jet powered drive beam, separated from the wing to avoid aerodynamic interference. For forward flight the drive beam is enclosed in the airframe as the wing is retracted to fixed position.