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Viewing 164461 to 164490 of 185277
1969-02-01
Technical Paper
690509
F. S. Vukan, T. P. Kuebler
Tire strength and endurance are two basic tire qualities on which values have been set in various standards as a measure of their performance in actual service. This paper describes the pitfalls in the present methods of measurement and presents data to show the limitations of present equipment and methods.
1969-02-01
Technical Paper
690508
R. H. Spelman
It is necessary to establish separate test procedures that evaluate the many different performance parameters required of pneumatic tires. The ability to operate at high speeds is one of the more important requirements. This paper describes the physical properties needed for various high speed performance potentials. It also shows that, with a relationship established between laboratory and road, laboratory testing permits more accurate evaluation.
1969-02-01
Technical Paper
690510
J. F. Hutchinson, H. D. Becker
A great amount of engineering and development work is under way at the present time on the important subject of tire traction, especially under wet surface conditions. Typical facilities used in the industry for traction testing of tires are described. Tests to date have shown that by far the most important variables affecting tire traction are: 1. Speed. 2. The road surface. 3. Weather conditions as they affect the road surface (wet, dry, icy). 4. The conditions of the tire, particularly whether it is new or worn to the tread wear indicators. By comparing test tires with production tires with known traction qualities, tire manufacturers produce tires which perform satisfactorily for wet traction.
1969-02-01
Technical Paper
690415
Robert A. Taylor
Fleet planning is the joint effort of the airplane manufacturer and the airline in selecting the proper type and number of airplanes, and it involves analysis of individual airplane models, routes, and costs. When the evaluation is extended to entire fleets, it necessitates forecasts into the changing technological and marketing aspects of the industry. The subject of this paper is Boeing's Integrated Fleet Planning Program, a system which lends sophisticated computer support to airline operations.
1969-02-01
Technical Paper
690414
James E. Gorham
Air transportation by any measure is big business today, and will more than triple in size by 1980. Most of the recent growth has been under the impetus of the jet age. With greater speed and comfort available, people used air transport more and more frequently. SRI's long-range estimate is that world passenger traffic (scheduled) will exceed 900 billion passenger miles in 1980, up from 17.5 billion in 1950, 67.7 billion in 1960, and 250 billion (estimated) in 1970. Air cargo traffic is following a similar growth curve. To carry this traffic, the airlines will have to expand their investment base, mainly in a highly competitive capital market. But bigness doesn't necessarily mean efficiency or profitability. From an economics point of view, the airline industry's growth has also created some bad habits. Because reequipment cycles are geared to technological change, not to traffic service requirements, there has been a poor match between capacity growth and traffic support.
1969-02-01
Technical Paper
690420
A. S. Crossfield
The Eastern McDonnell Douglas Demonstration program proved quantitatively that a STOL transportation system can significantly reduce city-to-city block time. This advance in short haul air travel can be effected by improved STOL aircraft with integrated airborne precision navigation systems capitalizing on unique STOL characteristics to substantially reduce non-productive time, utilizing presently unused airspace, and operating from near city center landing fields. Present conventional jet aircraft block times and block speeds on EAL Air Shuttle and other Northeast Corridor operations are the result of years of experience and intensive effort by the entire air carrier industry to obtain the optimum performance from the existing system. It seems unlikely that additional improvements of appreciable magnitude can be extracted from this system. Conversely, the STOL concept possesses tremendous potential for bettering short haul transportation and will thus reduce overall air congestion.
1969-02-01
Technical Paper
690416
R. W. deDecker
This paper reviews the benefits to be derived from the implementation of a successful large scale VTOL passenger service and examines various studies, including the Northeast Corridor VTOL Investigation, which show that suitable aircraft will be available starting in the middle 70's, and that VTOL service can be economically attractive if an operating environment is created that is optimized for VTOL aircraft. If an optimized environment is not created, the implementation of successful VTOL service is very doubtful. Particularly important aspects of the operating environment, such as an air traffic control system; landing and navigation systems, vertiport location and operating regulations, are discussed.
1969-02-01
Technical Paper
690423
George J. Gunn, Robert L. Whittenberg
The contribution of engine oil analysis to the safe and economical operation of aircraft is a proven fact to the military. Until recently, however, commercial airlines have only experimented with routine oil analysis. An effective, economical system has now been devised for application to commercial aircraft incorporating EDP equipment and a refined analysis technique.
1969-02-01
Technical Paper
690432
R. Barber
The paper describes the principle of operation and design features of a pyrometer that has been developed to measure the surface temperature of turbine blades during flight. The pyrometer can measure temperatures above 700 C (1300 F) to an accuracy of ± 5 C (± 10 F).
1969-02-01
Technical Paper
690425
Harry W. Reynolds, Richard E. Moore
Extensive commercial airline experience coupled with state-of-the-art advances in mechanical component technology has resulted in an oil system design for the Pratt & Whitney Aircraft JT9D engine which is optimized for the simplicity, dependability, and maintainability features required by the current trend toward longer time intervals between scheduled overhauls sought by the commercial airlines.
1969-02-01
Technical Paper
690394
Stanley L. Seltzer
To evaluate area navigation techniques in the air traffic control system, a series of test programs have been undertaken by American Airlines. Operations have been conducted in various types of jet transports during the course of regular airline service. Systems used were based mainly on VOR/DME signals, but some tests involved use of an Inertial Navigation System. Further trials are currently in progress as part of the airline's STOL evaluation project in which a number of additional systems are being examined.
1969-02-01
Technical Paper
690392
Robert W. Martin
Area navigation offers a means of establishing an air route system without the constraints entailed in flying toward or away from the signal source. In terminal areas, an area navigation system of routes, combined with ATC computer-aided sequencing and airborne collision-avoidance technology, offers possibilities for establishing future methods of moving high volumes of traffic on and off a complex of multiple parallel runways. Such a system would reduce air-ground communications and controller workloads which are serious limiting factors in today's system. In the en route system, the use of area navigation will result in more efficient utilization of airspace, although regimentation of traffic will continue to be necessary in areas of high traffic density. An area navigation system, based on VOR/DME inputs is possible in the near future.
1969-02-01
Technical Paper
690402
Albert C. Martin
The growing crisis of airport congestion, both in the air and on the ground, is stimulating interest in the concept of specialized downtown airports for carriers of short-haul traffic. These carriers principally are short takeoff (STOL) and vertical takeoff (VTOL) aircraft. Although these types of aircraft have been in use for years, manufacturers are now working on development of larger and faster short-haul aircraft. At the same time, both federal and local government agencies are studying various V/STOL-port proposals. In New York City, a 10-story 2000-ft long STOL-port with dual runway is envisioned on Manhattan's Hudson River waterfront. Los Angeles has completed a plan for a down town Metroport for V/STOL aircraft, designed to reduce noise levels by directing aircraft over freeways, and to accommodate 6 million passengers by 1980.
1969-02-01
Technical Paper
690399
Thomas M. Sullivan
Using the Dallas-Fort Worth Regional Airport as a reference point, the author considers the major prerequisites of airport terminal planning. A general criterion is projected concerning expansion and automation. With passenger convenience in mind, the paper stresses the importance of building terminals in stages as increasing traffic warrants and suggests that suitable backup measures should be provided as security against automation failures. Terminal layout problems are discussed together with their possible solutions, as related to such factors as population density and available land space.
1969-02-01
Technical Paper
690406
J. A. Lee, R. P. Johannes
This paper reports the results of a limited flight evaluation of Direct Lift Control (DLC) on a modified B-52 aircraft. The evaluation was made in conjunction with concluding flights of the Load Alleviation and Mode Stabilization (LAMS) Program and represents the first flight testing of a blended closed loop DLC system on an aircraft of this size and weight. By allowing the pitch and heave motions in the longitudinal axis to be decoupled, the system provided positive control of altitude displacements while holding pitch attitude constant. In both ILS approaches and aerial refueling tasks, controllability was significantly improved and pilot workload was reduced.
1969-02-01
Technical Paper
690403
David A. Evens
This paper examines the engine main fuel and geometry control design concepts and their relation to engine requirements for a large, high bypass, aircraft turbofan engine. This class of engine is representative of those powering the new “airbus” type aircraft which are currently under development. The functional design highlights of a simple, efficient, and compact control system are discussed and related to reliability, maintainability, and weight.
1969-02-01
Technical Paper
690413
R. B. Ormsby
The total airline profit model program was developed to permit simulation and evaluation of total air cargo systems including the airplane; ground support equipment; cargo handling equipment, facilities and documentation; maintenance equipment and facilities; and personnel. To aid in the identification of major system elements and in order to determine the relative bearing of these elements on profit and return on investment two air cargo system models were developed. The Incremental Profit Model provides a measure of the incremental effect on airline profit of specific changes with respect to a baseline system. In comparison, the Airline Profit Model provides definition of the total system, identification of associated cost elements, and the capability to optimize the system for best economic operation.
1969-02-01
Technical Paper
690407
John A. Gorham
This paper describes the operational characteristics, design processes, and test programs established to produce a “fail-operative” automatic landing system for the Lockheed “TriStar.” The operational characteristics are predicated on the anticipated changes in ATC procedures during the 1970's which may lead to increased automation of the airborne elements. The design processes involve the use of new electronic voting techniques and the consideration of the total airplane systems in view of the critical aspects of failure modes and effects. The test program is outlined and the use of many iterative stages of comprehensive test facilities are described. Conclusions are made that unexpected benefits have been derived by the adoption of the total systems approach.
1969-02-01
Technical Paper
690458
Donald W. Conover, Wesley E. Woodson, Peter H. Selby, Gerald E. Miller
A human engineering survey of the control/display arrangements in 1969 passenger automobiles was conducted under contract to the National Highway Safety Bureau. Survey rationale, methodology, and preliminary findings are presented. Marked variability was noted between various control/display arrangements and certain important driver compartment dimensions. This and other findings suggest need for development of human engineering design criteria against which to base future design standards for the driver-vehicle interface.
1969-02-01
Technical Paper
690461
James J. Gumbleton, Daniel L. Frank, Stanley L. Genslak, Albert G. Lucas
General Motors Engineering Staff built and tested three small, lightweight urban cars with the numerical identity 512. These special purpose, two passenger cars are designed to provide short range personal transportation with some package carrying capability. Their top speed is limited at 30-45 mph. Separate roads or restricted driving areas would be required for these cars since they could not safely mix with full-sized cars and trucks. These small cars would help relieve urban traffic and parking problems. Their low power and energy requirements result in low vehicle emissions. The 512 car series utilizes one basic body configuration as a test bed for different powerplants. Three have been tested to date: a conventional gasoline engine, a battery-electric, and a hybrid gasoline-electric. The gasoline powertrain consists of a 19.6 cu in., 2-cyl engine coupled with an automatic variable-ratio vee-belt transmission.
1969-02-01
Technical Paper
690462
E. A. Rishavy
This paper gives the results of a feasibility study of an unusual three-wheeled commuter car. The study was one part of a General Motors program to build and evaluate a series of small special purpose cars for urban use. The 511 commuter car is intended for carrying two people from home to work at freeway speeds. Many radical design and construction features are employed. The car is small and lightweight, a combination which offers high fuel economy, low exhaust mass emissions, and some help for the parking problem. The 511 car, in its present form, is still a test vehicle. Although several major problems are unresolved, the car has demonstrated the technical feasibility of its basic concept.
1969-02-01
Technical Paper
690468
Saburo Yui, Shigeru Ohnishi
A unique process for stratified charge in a 2 stroke gasoline engine provides outstanding improvement in performance and makes possible the control of known pollutants in exhaust emission without supplementary devices. The proposed process is intended to achieve virtual control of CO, unburned hydrocarbons, and NOX while maintaining satisfactory fuel consumption without erratic or irregular operation. Thus, a large part of the disadvantages of the 2 stroke engine will be overcome. No critical relationship exists among fuel components and response is good. Coupled with these features are adequately large power values and no smoke limit to pose opacity problems.
1969-02-01
Technical Paper
690467
Barry Griffith King, Elmer C. Paul, Carl R. Spitznagel
Percentile distributions of children's body measurements are presented for use in design and sizing of automobile restraint devices and as a basis for guiding parents in the selection of makes and models suitable for the child. The influence of these measurements on the stability, protection, and surrounding clearance dimension requirements for seating systems for children weighing less than 50 lb and those more than 50 lb are discussed.
1969-02-01
Technical Paper
690469
G. P. Blair, J. R. Goulburn
Wave effects in exhaust systems can strongly influence the performance of an engine. Predictions of pressure-time variations at the exhaust valve by graphical methods, based on experience and the assumption that exhaust pulses will act as sound waves, have been of no design value with multicylinder engines. Now a numerical method, developed from the graphical has been programmed for a computer making possible rapid calculation on nonsteady flow properties of an exhaust system. When augmented by experimental testing of three disparate exhaust systems, such calculation proved useful in the design of exhaust systems for multicylinder automobile engines. This Paper describes the engine investigations of the three systems involved and the derived design conclusions.
1969-02-01
Technical Paper
690470
Hiroshi Hayashi
A method to evaluate the heat dissipating capacity of the lubricating oil system of the automotive internal combustion engine has been developed. By introducing new parameters that control the heat dissipation of the lubricating oil system, it becomes possible to evaluate the heat dissipating capacity of the lubricating oil system by bench test. In this paper, the method and some results obtained by applying it to an engine are described.
1969-02-01
Technical Paper
690434
M. Markels, J. M. Spurlock, J. D. Robb, J. R. Stahmann
Results of investigation to develop a technological basis for overcoming aircraft lightning-strike hazards associated with turbojet aircraft fuel vents are discussed. Flame propagation and arrester experiments were performed with high-voltage and high-current facilities and repeated in a combustion research facility using a drive tube to simulate impulse effects of natural lightning. Flame propagation through actual aircraft vent systems containing flammable fuel-air mixtures was demonstrated, and characteristic flame propagation properties were measured and duplicated in laboratory apparatus. Preliminary assessment of problems involved in designing effective flame arresters and explosion suppression systems was made. Lightning-stroke patterns in fuel vent region were analyzed as to inferable hazard significance.
1969-02-01
Technical Paper
690436
William T. Westfield
Ignitions of aircraft flammable fluids that result from contact with hot surfaces of an engine are influenced by the characteristics of the secondary cooling air and engine surfaces, ventilation rates of the nacelle engine compartment, direction and changes of direction of the cooling air, and changes in engine power while leakage is occurring. The temperatures of the engine surfaces are much higher in installations of the new generation high bypass-high compression ratio turbofan engines and magnify the hot surface ignition problem. The effects of these advanced technology engines on hot surface ignition of aircraft fuels and a petroleum-base hydraulic fluid were investigated under simulated flight conditions in a fire test program on a modified current turbofan engine installation. All hot surface ignitions occurred in the form of explosions of varying degrees of severity.
1969-02-01
Technical Paper
690443
S. K. Rhee, R. M. Rusnak, W. M. Spurgeon
A drag dynamometer was used to evaluate the performance of automotive brake drums made from four kinds of materials with different thermal conductivities. In the order of decreasing thermal conductivity they are chromium copper, aluminum/cast iron composite, cast iron, and nickel-aluminum bronze. All of the drums were of the standard configuration used in SAE J 661a, or closely approximated it. The drums were run in conjunction with three types of lining materials: nonabrasive, moderately abrasive, and highly abrasive. Temperatures near the lining/drum interface, coefficients of friction, and lining wear were measured and compared. For a given amount of work done, the temperature near the drum surface was found to be lowest for the chromium copper drums, with progressively higher temperatures in the aluminum/cast iron composite, nickel-aluminum bronze, and cast iron drums. Relative lining wear and coefficient of friction varied with the type of lining tested.
1969-02-01
Technical Paper
690437
K. R. Bragg, C. C. Kimmel, P. H. Jones
This paper presents a solution to the problems of fuel tank fire protection by means of nitrogen inerting. Background relationships with the successful XB-70 inerting system, which led to the development of the commercial inerting system, are also discussed. Specifically, this paper shows how aircraft inerting system design is influenced by the release of air from the fuel at high altitudes. Data are presented to show the likelihood of air saturated fuel, the way in which it is released from the fuel at high altitudes, and the effect of this release on the inert atmosphere in the fuel tanks. Problems created by this air release are discussed. Test data are presented on a scrubbing device that predictably provides controlled release and dilution of dissolved air from the fuel, thereby allowing the inert atmosphere to be maintained. Data are presented on the effect of this controlled air release on the fuel boost pump operation.
1969-02-01
Technical Paper
690451
Ernest S. Starkman, Anthony Bonora
Engine noise of the type related to a bending vibration of the crankshaft was investigated in a V-8 spark ignition engine. Abnormally high rates of combustion pressure rise were induced by introduction of carbon particles into the intake manifold, thereby providing multiple ignition sources in one cylinder. It was determined that wide variations in oil temperature and viscosity had no influence on the occurrence of vibration or the apparent magnitude of the accompanying noise. However, lubricating oil bulk temperature and viscosity did each have some measurable effect on the magnitude of the crankshaft deflection. Upon completion of the investigation, examination of the bearing disclosed damage, caused by the protracted inducement of bending vibration, apparently while operating with oil at very low viscosity.

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