Abstract: A cruise speed control apparatus for aircraft wherein small differences between the target Mach command and the actual Mach number of the aircraft are used to displace the aircraft from its reference altitude to either increase or decrease actual Mach number in the short term. Long term differences are corrected through a special isolation filter to separate the engine control loop and pitch control loop dynamics and an integration technique to adjust the automatic throttles about a thrust target for the commanded Mach.Large differences between the target Mach and the actual Mach or large changes in the commanded Mach are compensated for by a non-linear gain that effectively increases or decreases the target thrust to cause the aircraft to accelerate or decelerate to the commanded Mach.

Abstract: A system for the secure and rapid acquisition of a transmitted acquisition composite code composed from acquisition component codes. The acquisition composite code may, for example, be composed in accordance with a Boolean majority voting rule. Reference component codes that correlate respectively with the acquisition component codes are combined to provide a verification composite code that correlates with the acquisition composite code only when all of the reference component codes in the verification code are each in alignment with the corresponding acquisition component codes in the acquisition composite code. The verification code may, for example, be composed in accordance with a modulo-2 addition rule. Initially, the reference component codes are individually brought into alignment with the transmitted signal during the acquisition thereof.

Abstract: An automatic flight control system that is software fault tolerant fail operational in response to a first generic failure utilizes two independent subsystems each including a dual channel flight control computer. One channel in each flight control computer includes a digital processor and the other channel includes two digital processors. Cross channel monitoring is included in each flight control computer to discern disagreements between the outputs of the channels. If disagreement occurs between one of the two processing elements in the channel including two processing elements and the processing element of the channel having one processing element, the involved processing element in the two-element channel is disabled. If both processing elements in the two element channel disagree with the processing element in the other channel, the subsystem is disabled. All of the processing elements perform identical tasks.

Abstract: An adjustable mounting tray for installation of an aircraft gyroscopic and/or inertial reference apparatus, comprises, a baseplate member mounted so that it is substantially level in roll and pitch on the equipment shelf or rack of a levelled aircraft. A top plate or tray member is pivotally mounted on the baseplate for azimuthal adjustment thereon. The aircraft is pitched up or down and the top plate rotated in azimuth to remove any roll/yaw cross-axis coupling thereby assuring precision longitudinal axis alignment.

Abstract: A data compressor compresses an input stream of data character signals by storing in a string table strings of data character signals encountered in the input stream. The compressor searches the input stream to determine the longest match to a stored string. Each stored string comprises a prefix string and an extension character where the extension character is the last character in the string and the prefix string comprises all but the extension character. Each string has a code signal associated therewith and a string is stored in the string table by, at least implicitly, storing the code signal for the string, the code signal for the string prefix and the extension character. When the longest match between the input data character stream and the stored strings is determined, the code signal for the longest match is transmitted as the compressed code signal for the encountered string of characters and an extension string is stored in the string table.

Abstract: An approach to hover control system for a helicopter in which a constant deceleration is commanded at an initial approach speed and then the actual deceleration as a time function of the airspeed from the initial airspeed to a second airspeed is measured. Based on these measures, the total deceleration time to approach to a hover condition can be predicted accurately after which the commanded deceleration is removed.

Abstract: A ternary magnetic recording system wherein groups of binary input digits are transformed into corresponding groups of ternary recording code symbols utilizing a hierarchical code substitution system in which the longest valid group in the code is encoded. The code substitution system provides retention of the advantageous properties of a prior ternary recording system while significantly enhancing the automatic gain control utilized in amplitude discrimination between two of the ternary recording symbols. Anomalous detection of chained doublets is also obviated. Data recovery is effected by decoding apparatus utilizing an eight bit addressable ROM addressed with a twelve bit ternary word.

Abstract: A superconductive tunnel junction device comprises first and second superconductive electrodes with a barrier disposed therebetween where the first superconductive electrode and the barrier are formed without interruption in the same vacuum system pump down and with the first superconductive electrode subjected to sputter etching in an argon plasma before the deposition of the barrier for improving the characteristics of the device.

Abstract: A servo motor feedback fault detector that combines the motor drive voltage, the current flowing through the motor and the rotational speed of the motor and compares this combined signal with a dynamic threshold generated by combining a percentage tolerance of the motor current with a percentage tolerance of the motor rotational rate.

Abstract: A CFAR estimator-correlator comprises an estimating filter responsive to the signal-plus-noise input process for providing an estimate of the signal waveform. The estimate and the signal-plus-noise process are applied to a correlator. An amplitude limiter interposed between the signal-plus-noise input and the correlator and a bandpass amplitude limiter interposed between the estimating filter and the correlator impart a CFAR characteristic to the apparatus. An interferometer is configured by utilizing separate sensors to provide a signal-plus-noise input process and a further signal-plus-noise input process to the amplitude limiter coupled to the correlator and to the estimating filter, respectively.

Abstract: An aircraft control surface servomotor control of the pulse width modulation type with precise motor current control for providing precise torque limiting measurements.

Abstract: Line patterning apparatus for use with a vector generator comprises a memory storing a plurality of addressable line pattern bit strings. Each string comprises a series of ones and zeros defining a predetermined pattern of dots and/or dashes. Associated with each pattern string is a pattern restart string defining the length of the pattern. The bits of an addressed pattern string and the associated pattern restart string are serially provided by the memory in response to an addressing counter. The bits of the pattern string are utilized for video inhibition to superimpose the pattern on a vector being generated. The bits of the pattern restart string are utilized to clear the counter when a preset restart bit is encountered in the string by the counter.

Abstract: Superconductive tunnel junctions are manufactured with precise junction areas by defining a narrow-line junction of precise width utilizing a narrow-line mask of precise width and thereafter applying a second narrow-line mask of precise width at an angle to the narrow-line junction to define a junction area with dimensions precisely controlled by the widths of the narrow-line masks. "Edge lithography" is preferably utilized to provide the narrow-line masks.

Abstract: Josephson junction integrated circuits of the current injection type and magnetically controlled type utilize a superconductive layer that forms both Josephson junction electrode for the Josephson junction devices on the integrated circuit as well as a ground plane for the integrated circuit. Large area Josephson junctions are utilized for effecting contact to lower superconductive layers and islands are formed in superconductive layers to provide isolation between the groundplane function and the Josephson junction electrode function as well as to effect crossovers. A superconductor-barrier-superconductor trilayer patterned by local anodization is also utilized with additional layers formed thereover. Methods of manufacturing the embodiments of the invention are disclosed.

Abstract: A cruise speed control apparatus in an aircraft performance management system wherein target Mach command is supplied to the engine automatic throttle controls to establish an engine thrust to overcome and equate to the aircraft nominal drag characteristics at that commanded Mach speed and simultaneously the difference between the actual Mach number speed and the target Mach command speed is supplied to the automatic pilot pitch axis control to cause the aircraft to maintain the commanded Mach speed through change in pitch attitude and altitude. The integral of any altitude standoff is used to adjust required thrust to achieve the commanded Mach target and reduce the standoff to zero. If necessary, filtered altitude error may be used to provide dynamic damping of the throttle control loop and compensation for long term degradation in the aircraft's drag characteristic with time is provided by measuring the drag degradation ratio and adjusting the target Mach command in accordance therewith.

Abstract: The vector generator comprises X and Y digital-to-analog converters providing X and Y deflection voltages to a cathode ray tube display. X and Y digital accumulators provide respective inputs to the X and Y digital-to-analog converters. The word lengths of the accumulators are wider than those of the digital-to-analog converters and the digital-to-analog converters derive their inputs from the most significant digits of the accumulators. X rate and Y rate signals proportional to the sine and cosine of the vector angle are applied as inputs to the respective accumulators which accumulate the rate signals with the present contents of the accumulators so as to generate linearly changing X and Y deflection signals. The vector angle is adjusted by changing the ratio of the sine to cosine inputs to the accumulators and the vector speed is controlled by increasing and decreasing the sine and cosine signals but maintaining the ratio therebetween the same.

Abstract: The Controlled Return to A.C. (CRA) magnetic recording and reproducing system applies a high frequency erase signal continuously to the write head except at the detents. At the detents polarity controlled interruptions of the high frequency erase signal are embedded therein. A positive interruption, a negative interruption and the absence of an interruption provides a ternary recording capability at the detent. The high frequency erase signal is controlled in phase to provide polarity coherent interruptions. A CRA cell includes two controlled interruptions providing a mapping of three binary digits into two CRA digits. The controlled interruption results in an opposite polarity pulse pair upon readback.

Abstract: A compressor parses the input data stream into segments where each segment comprises a prefix and the next symbol in the data stream following the prefix. The prefix of a segment is the longest match with a previously parsed segment of the data stream. The compressor constructs a search tree data base to effect the parsing and to generate a pointer for each segment pointing to the previous segment matching the prefix. The search tree comprises internal nodes including a root and external nodes denoted as leaves. The nodes are interconnected by branches representative of symbols of the alphabet. Each parsed segment of the input data is represented by a path from the root to a leaf. The tree is adaptively constructed from the input data such that as each new segment is parsed, one new internal node of the tree is created from a leaf and new leaves are defined, one for each symbol already encountered by the encoder plus an additional branch to represent all potential but unseen symbols.

Abstract: A hybrid analog/digital autopilot utilizing analog inner loops in each control axis of the aircraft and a digital processor for providing outer loop commands and inner loop gain augmentation commands to the inner loops. The command from the processor to each inner loop is buffered by an adaptive rate limit circuit that initially transmits high frequency commands and over a predetermined time interval limits the command rate to a safe low value. Alternatively, the adaptive rate limit buffer transmits the high frequency command up to a predetermined attitude limit and thereafter transmits a command limited to a low safe rate.

Abstract: Josephson junction integrated circuits of the current injection type and magnetically controlled type utilize a superconductive layer that forms both Josephson junction electrode for the Josephson junction devices on the integrated circuit as well as a ground plane for the integrated circuit. Large area Josephson junctions are utilized for effecting contact to lower superconductive layers and islands are formed in superconductive layers to provide isolation between the groundplane function and the Josephson junction electrode function as well as to effect crossovers. A superconductor-barrier-superconductor trilayer patterned by local anodization is also utilized with additional layers formed thereover. Methods of manufacturing the embodiments of the invention are disclosed.