Abstract: This disclosure illustrates and describes a system that permits a student to receive hands-on maintenance training of electronic systems without interfering with the operation of the electronic system. The students are taught how to repair and maintain the electronic system by trying to locate defective simulated components that may be used to drive and control the electronic system. The simulated components are controlled by a computer and they will only malfunction when an instructor enters an instruction into the computer which causes that particular electronic component to be defective.

Abstract: Apparatus and method for recovering and arresting an aircraft or other vele. A boom is swivelly connected to a support structure via braking mechanism. The boom is pivotally connected to the brake mechanism such that it can also pivot in a second, different plane intersecting the plane of rotation of the brake mechanism. A shear pin prevents pivoting of the boom in the second plane until the boom has experienced a predetermined load in that plane. The distal end of the boom distant from the brake mechanism is provided with structure for engaging the aircraft. When the aircraft is flown at and captured by the boom, the weight and motion of the aircraft breaks the shear pin, causing the boom to move in the second plane until engaged by a stop. This rapid change in position of the engaging end of the boom in the second plane prevents the aircraft from pendulating about the boom.

Abstract: Method and protective coating composition for preventing or minimizing costion or melting of titanium and combustible alloys thereof. Two layers of coatings are applied, the first layer preventing diffusion of the second layer into the titanium or alloy even at elevated temperatures, and the second layer suppressing titanium combustion. The first layer contains chromium, molybdenum, niobium, tantalum, vanadium, zirconium, platinum, or rhodium or a combination thereof or alloy of any of these metals. The second layer contains copper, aluminum, gold, nickel, silver, cobalt or a combination thereof or alloy of any of these metals. By preventing diffusion of the second layer into the substrate, the first layer prevents degradation of substrate engineering or mechanical properties.

Abstract: This disclosure describes a system for providing a communications channel between a master computer and a plurality of similar or dissimilar slave computers that may be separated by great distances. The foregoing system comprises a buffer unit and at least one computer linkage unit. The buffer unit acts as an interface between the master or control computer, the external hardware that is coupled to the master computer and a plurality of slave computers, and the one or more computer linkage units so that the buffer unit may act as an expandable direct memory access bus to a slave computer and provide communication with a plurality of peripheral systems. The computer linkage unit performs all of the remaining interface functions between the master computer and the plurality of slave computers that are coupled to the master computer.

Abstract: A digital synthesizer is disclosed for generating complex waveforms of seted multiple frequencies and selected phases in the time domain. A plurality of independent frequency sources each produces square waves at its selected fundamental frequency and at frequencies which are integral multiples, such as twice, four times and eight times, that of the fundamental. A sampling clock whose frequency is at least the highest frequency produced by any frequency source, multiplied by the number of fundamentals used, provides a signal to a binary counter whose output is connected to a line decoder or multiplexer which multiplexes each frequency source's signals on a time-share basis via a system of AND and OR gates. The signal produced by the OR gates is provided to address a memory device which contains a predetermined waveform in a look-up table.

Abstract: A mini boat having a first plurality of elongated gas inflatable cells sted one upon the other and bonded into a single envelopmental unit which conforms closely to the human body for providing buoyancy thereof. The unit is formed to provide a center of mass below the center of buoyancy for increased boarding ease and stability. A supplementary orally inflatable chamber formed atop the first plurality of cells provides additional freeboard for the boat perimeter. One end of the boat is arcuately configured to permit the user to recline therein, thereby protecting him from the elements and lowering his center of gravity, by means of regularly spaced and separated and vertically aligned interconnections between the first plurality of cells which provide points of easy bending.

Abstract: Apparatus for measuring thrust loading on a rotating shaft. A plurality of train gages, electrically connected in parallel and series to form one arm of a Wheatstone bridge circuit, are mounted at equal intervals on a thin strap or band formed to surround the shaft with a predetermined hoop load. Lubricating material disposed between the shaft and the band prevents transfer of friction forces from the shaft to the band. As the thrust loading increases, shaft dilation (girth increase) causes the band to stretch and increase its stress. This hoop stress is measured by the strain gages mounted on the band, and is transmitted as the output signal produced by the bridge via radio telemetry or slip rings to a remote indicator. A second arm of the Wheatstone bridge circuit, to provide compensation for temperature effects, can be provided by an additional strain gage mounted on a block of material identical to that of the shaft which block is in turn mounted on the above thin strap or band.

Abstract: Method and composition utilizing organo substituted quaternary ammonium salts to effect the solution of hexavalent chromium into organic materials such as paints, in which such inhibitors are normally insoluble, in order to upgrade the corrosion protection properties of these materials. A quantity of organo substituted quaternary ammonium salt is dissolved in organic material. A quantity of simple alkali metal chromate or dichromate is then mixed with the resulting solution and is dissolved therein.

Abstract: A notched-energy absorber for attenuating high level accelerations such as ould occur during aircraft crashes, thereby avoiding injury to a user. The energy absorber force-displacement curve has a large initial spike, followed by a valley or "notch" and then by a constant force level intermediate the spike and valley levels. In one embodiment, a conventional square-response type shock absorber is connected between a vehicle seat and the vehicle body by a shearable diaphragm fixed to vehicle structure. The diaphragm shears at a notch when it experiences an initial high force, after which the conventional absorber moves freely without deforming until it encounters a stop. The conventional absorber then elongates or compresses in a conventional manner. In an alternative embodiment, a spring is connected between the seat and the vehicle body. Initially, the spring is compressed by experienced forces until at a predetermined force level it forces out a retaining clip or ring.

Abstract: Apparatus and method for producing maps of thickness or elastic constant iations of nominally plane sheet or plate materials. Amplitude variation at a set frequency on a normal resonance peak is recorded to determine resonance peak variation and thus specimen thickness or elastic constant variation. A mechanical scanner moves a transducer across the material submerged in a water tank for performing an ultrasonic C-scan. A transmitter or pulse generator repeatedly pulses the transducer to produce a focused narrow pulse of ultrasound which reverberates within the material. Echoes from the material in response to the pulse are received by the same or another synchronously moving transducer, whose resulting signal then passes through a gate, which removes extraneous signals and selects the number of multiple echoes and thus amplitude range desired, and a variable filter controlled by a function generator which selects the desired frequency, to a pen recorder.

Abstract: A gas generator which separates a gas such as oxygen from a gas mixture such as air using a sorbent process. A sorbent contained in a fixed cooled bed absorbs the gas from the mixture; simultaneously a second bed of sorbent which previously absorbed the gas is heated and the gas is thereby desorbed from the sorbent. After a given time, the functions of the beds are exchanged. Heating and cooling of the two sorbent beds is accomplished by means of coolant which passes through each bed. Immediately after the functions of the beds are switched, the cool coolant first flows through and cools the absorbing bed, then is valved to a pump and to the heater for heating and then is valved to heat the second sorbent bed before being valved to a cooler for cooling.

Abstract: A laser device for generating high input power by minimization of surface flection losses between adjacent elements of the device. A laser medium having an index of refraction substantially greater than 1.5 is fluid cooled in a sealed tube by an optically clear cooling medium having a substantially lower refractive index. The indices of the laser and cooling mediums are matched to each other by thin film coatings of index matching material attached to the laser medium, each coating having a thickness of one quarter of the lasing wavelength.

Abstract: A mixture of nondeuterated and partially or fully deuterated hydrocarbon ricants. Such a mixture exhibits substantially improved bearing performance life and oxidation resistance, without having fully deuterated the entire lubricant.

Abstract: A device for disconnectably linking a plurality of force producing or recing means such as a mechanical control system. The device comprises a coaxial array of a plurality of positive locking clutches, each clutch including two clutch halves. A single shaft passing through all clutch halves disengages and engages all clutches together as a motor connected thereto is actuated. The shaft is fail-safe spring loaded to the disengaged position, so that the spring will disengage all clutches if there is a power or motor failure.

Abstract: An object detection system capable of receiving and processing an omnidirional signal and two directional signals to produce a digitized omnidirectional signal, and digitized directional signals which have been corrected to magnetic north. The directional hydrophones produce sin .theta. and cos .theta. signals, where .theta. is the bearing angle of the sensed target from the directional hydrophones' y-axis. Each of the three signals is picked up by a separate hydrophone and is passed through an associated preamplifier and a shaper amplifier and low pass filter before being simultaneously sampled by separate sample/hold circuits. The three sampled signals are multiplexed to an analog to digital converter. The signal produced by a digital magnetic compass is converted to sin .theta. and cos .theta. values by appropriate function generators, where .theta. is the angle between the y-axis and magnetic north. The digital sin .theta., cos .theta., sin .phi. and cos .phi.

Abstract: A system for rapidly disengaging, with minimum nuisance disengagements, a nventional autopilot system upon detecting hardover failure, which is defined as any autopilot failure which results in rapid and sustained displacement of an aircraft aerodynamic control surface. The aircraft pitch rate is measured and compared with established limits. If these limits are exceeded, the system causes automatic disengagement. Disengagement is inhibited for gust disturbances by deriving a nose up or down signal from the pitch rate signal which is then compared with a signal indicating the direction of elevator hinge moment; if the two directions are opposing, disengagement is inhibited. Disengagement is also inhibited in the event of pilot action. Also, the autopilot pitch axis command line is monitored and a disengagement overriding any inhibits is generated when the signal on that line exceeds certain limits for the altitude hold mode and for the attitude hold mode of the autopilot.