1,437 research outputs found

    Flight-test evaluation of STOL control and flight director concepts in a powered-lift aircraft flying curved decelerating approaches

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    Flight tests were carried out to assess the feasibility of piloted steep curved, and decelerating approach profiles in powered lift STOL aircraft. Several STOL control concepts representative of a variety of aircraft were evaluated in conjunction with suitably designed flight directions. The tests were carried out in a real navigation environment, employed special electronic cockpit displays, and included the development of the performance achieved and the control utilization involved in flying 180 deg turning, descending, and decelerating approach profiles to landing. The results suggest that such moderately complex piloted instrument approaches may indeed be feasible from a pilot acceptance point of view, given an acceptable navigation environment. Systems with the capability of those used in this experiment can provide the potential of achieving instrument operations on curved, descending, and decelerating landing approaches to weather minima corresponding to CTOL Category 2 criteria, while also providing a means of realizing more efficient operations during visual flight conditions

    Flight experiments using the front-side control technique during piloted approach and landing in a powered lift STOL aircraft

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    The essential features of using pitch attitude for glidepath control in conjunction with longitudinal thrust modulation for speed control are described, using a simple linearized model for a powered-lift STOL aircraft operating on the backside of the drag curve and at a fixed setting of propulsive lift. It is shown that an automatic speed-hold system incorporating heave-damping augmentation can allow use of the front-side control technique with satisfactory handling qualities, and the results of previous flight investigations are reviewed. Manual control considerations, as they might be involved following failure of the automatic system, are emphasized. The influence of alternative cockpit controller configurations and flight-director display features were assessed for their effect on the control task, which consisted of a straight-in steep approach flown at constant speed in simulated instrument conditions

    Flight evaluation of the STOL flare and landing during night operations

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    Simulated instrument approaches were made to Category 1 minimums followed by a visual landing on a 100 x 1700 ft STOL runway. Data were obtained for variations in the aircraft's flare response characteristics and control techniques and for different combinations of aircraft and runway lighting and a visual approach slope indication. With the complete aircraft and runway lighting and visual guidance no degradation in flying qualities or landing performance was observed compared to daylight operations. elimination of the touchdown zone floodlights or the aircraft landing lights led to somewhat greater pilot workload; however, the landing could still be accomplished successfully. Loss of both touchdown zone and aircraft landing lights led to a high workload situation and only a marginally adequate to inadequate landing capability

    Re United Cork Linoleum & Plastic Workers, Local 380, and Union Carbide Canada Ltd

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    Employee Grievance claiming improper application of seniority provisions. The issues in this case are therefore: Where the company has the right under the collective agreement to deny promotion to the grievor, who is the senior man, on the ground that he does not satisfy educational qualifications unilaterally prescribed by the company. If the company is successful in issue, can it be said that the grievor does not in fact have the qualifications prescribed by the company in this case

    Re International Association of Machinists, Lodge 717, and Orenda Ltd

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    Employee Grievance alleging failure by the company to provide weekly indemnity for non-occupational sickness. The facts: On June 19, 1968, Mr. Garden, the grievor, went to Orenda\u27s plant doctor for an examination. He was referred to his family doctor. That same day, and again on June 24th, he consulted Dr. W.K. Taylor who had been his doctor for some years. On June 25th, Dr. Taylor signed an Attending Physician\u27s Statement for submission to the company in support of a claim by the grievor for weekly indemnity for non-occupational sickness. The statement noted under the heading diagnosis the following: neurodermatitis both hands, duodenal ulcer symptoms . It is also noted on the statement that the patient has been totally disabled (unable to work) from June 19, 1968, and that he should be able to return to work on July 2, 1968. Under the heading how long will the patient be partially disabled? the answer given is for the same period

    Flight evaluation of advanced flight control systems and cockpit displays for powered-lift STOL Aircraft

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    A flight research program was conducted to assess the improvements, in longitudinal path control during a STOL approach and landing, that can be achieved with manual and automatic control system concepts and cockpit displays with various degrees of complexity. NASA-Ames powered-lift Augmentor Wing Research Aircraft was used in the research program. Satisfactory flying qualities were demonstrated for selected stabilization and command augmentation systems and flight director combinations. The ability of the pilot to perform precise landings at low touchdown sink rates with a gentle flare maneuver was also achieved. The path-control improvement is considered to be applicable to other powered-lift aircraft configurations

    Colour tunable electrochromic devices based on PProDOT-(Hx)2 and PProDOT-(EtHx)2 polymers

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    The most commonly used method to tune the colour transition states of an ECD is to modify the chemical structure of the electrochromic polymers to achieve the desired transparent to dark state switching colours. However, this approach can present significant synthetic challenges that typically result in a compromise in device performance parameters such as contrast range or stability as well as solvent processability. In this study we have investigated tuning the dark-state colour of an ECD (at +0.8 V) by solution mixing poly(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT-(Hx)2), which has an excellent contrast performance but with an esthetically undesirable purple colour transition, with poly(3,3-bis(2-ethylhexyl)-3,4-dihydro-2H-thieno [3,4-b][1,4]dioxepine) (PProDOT-(EtHx)2), a material with a poorer contrast range but with more esthetic blue colour transition. The influence of mixtures of two cathodically colouring materials, PProDOT-(Hx)2 and PProDOT-(EtHx)2, on the spectroelectrochemistry and assembled ECDs was explored. Photopic contrast, electrochemical properties and the influence of the type of ionic liquid electrolyte employed in the device assembly were also investigated to determine how the dark-state colour of ECDs can be tuned while maintaining device contrast over 55%

    The influence of poly (2-methoxyaniline-5-sulfonic acid) on the electrochemical and photochemical properties of a highly luminescent ruthenium complex

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    Immobilisation of a luminescent material on an electrode surface is well known to substantially modulate its photophysical and electrochemical properties. Here a positively charged ruthenium metal complex ([Ru(bpy)(3)](2+)) is immobilised on all electrode surface by ion paring with a sulfonated conducting polymer poly(2-methoxyaniline-5-sulfonic acid), (PMAS). Significantly, our study reveals that the electron transport between the ruthenium metal centres can be greatly enhanced due to the interaction with the conducting polymer when both are surface confined. Charge transfer diffusion rates in the present system are an order of magnitude faster than those found where the metal centre is immobilised within a non-conducting polymeric matrix. Electron transport appears to be mediated through the PMAS conjugated structure, contrasting with the electron hopping process typically observed in non-conducting metallopolymers. This increased regeneration rate causes the ruthenium-based electrochemiluminescence (ECL) efficiency to be increased. The impact of these observations on the ECL detection of low concentrations of disease biomarkers is discussed. (c) 2007 Published by Elsevier Ltd

    ADGS-2100 Adaptive Display and Guidance System Window Manager Analysis

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    Recent advances in modeling languages have made it feasible to formally specify and analyze the behavior of large system components. Synchronous data flow languages, such as Lustre, SCR, and RSML-e are particularly well suited to this task, and commercial versions of these tools such as SCADE and Simulink are growing in popularity among designers of safety critical systems, largely due to their ability to automatically generate code from the models. At the same time, advances in formal analysis tools have made it practical to formally verify important properties of these models to ensure that design defects are identified and corrected early in the lifecycle. This report describes how these tools have been applied to the ADGS-2100 Adaptive Display and Guidance Window Manager being developed by Rockwell Collins Inc. This work demonstrates how formal methods can be easily and cost-efficiently used to remove defects early in the design cycle
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