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A decompression chamber for testing automotive diesel engines at simulated altitudes up to 12,000 ft is described. Results obtained on seven naturally aspirated and one turbocharged diesel engine are discussed in relation to the day-to-day correction of engine performance and to site rating of engines. Comparisons are made between experimental results and existing correction methods, and modifications or replacements of the latter are suggested. Results are assessed in terms of the correction method proposed in SAE standard J816. Attention is drawn to the different bases which may be used in correcting engine performance (for example, constant fuel delivery or constant exhaust smoke density) and the need to consider changes of exhaust smoke density or fuel consumption depending on the correction basis chosen.

An engine is sensitive to its fuel and lubricant. This suggests such problems as wear and deposits, and the modifying conditions of environmental effects which cause cold starting and vapor lock. Another environmental condition not often considered is altitude. This paper discusses very briefly a test facility at Aberdeen Proving Ground that can be used to evaluate the full load performance of an engine at varying altitudes. Altitudes of 12,000 ft can be simulated with a 150 hp engine while maintaining temperatures from −65 F to +120 F. Results for six engines operated in this facility are presented. These engines are all military engines but most have commercial counterparts. Data show the advantage of turbocharged engines over naturally aspirated engines. However, unless turbocharger is properly matched to engine and environment, gains are negligible.

Several examples are presented where x-ray stress measurements were made with a portable unit. The examples include the measurement of stresses in a welded rocket motor case (maraging steel), heat-treat stresses in a machined part (7079-T611), and stresses in a spot-welded panel (Ti-8Al-IV-1Mo). Each application emphasizes the advantages of stress analysis by x-ray diffraction by the portable method. For the spot-welded panel there is a direct comparison of x-ray diffraction stress measurements and stress measurements by the compliance method. The results show good agreement between the two methods.

A control system requirement is defined for an advanced direct lift engine designed for a typical Mach 2 fighter aircraft. The characteristics of the control system (performance, weight, reliability and maintainability, cost) are shown to be predominantly a function of the degree of simplicity of the control system requirements and somewhat less a result of the mechanization employed to meet those requirements.

This paper reviews various environments established by the aircraft gas turbine itself, by the aircraft, and by new aircraft engine specifications within which fuel and control systems must operate. Emphasis is on the design requirements placed on controls to assure satisfactory operation in these environments. The influences on design choices and the demands for special testing are discussed for several components. As its objectives, the paper identifies specific areas which may prove troublesome as controls are designed to meet the new requirements. Recognition of potential problem areas is suggested as a first step toward successful design.

Discipline in an airlines organization is essential to the providing of safe, economical air transportation. Such discipline is reflected in leadership, sound organization, firm company policies, professional ability and standards, and a logical and efficient working group. American Airlines is implementing three basic programs in the flight performance area in an effort to reduce risks: centralized flight training, line flying checks in the hands of Flight Standards superintendents, and routine surveillance of operations by use of flight performance recorders and accompanying computer programs.

New systems and techniques in aircraft maintenance had to be developed to cope with the rapid increase in workload and the changing nature of aircraft systems, parts, and material. Some of those that developed were from the science of mathematics dealing with sampling and the improvement of performance reliability and maintenance costs. Science and industry developed new material fabrication and machining techniques that enable us to work with materials that did not exist 10 years ago. This paper deals with maintenance concepts developed since we acquired turbine aircraft. It mentions a few of the new shop techniques that meet demands of reliability, costs, and new types of materials. It lists some needs of our business in the near future that will enable us to continue moving toward greater dependability and better control of costs.

This paper describes potential applications of space vehicle checkout procedures and philosophy to near-future transport aircraft. Specific areas of application include incipient failure detection, failure localization, and contingency rescheduling. Examples of recent NASA sponsored advances in the state of the art are stressed, with emphasis on defining the role of man and computer and on the technical and economic benefits to be gained by further development and/or adaptation of these techniques to airline operations.

An extensive analysis of aircraft technician training levels, methods, and equipments has been developed. This analysis positively indicates trending of the generally skilled into specialties. It has uncovered areas of serious undertraining in specialty due to lack of specialty training equipments. Dominant among the factors influencing this negative trend is the compounding complexity presented training tool and method developers, wherein general type equipment and methods must now be replaced by multiple individual specialty program equipment training packages. Compact series of specialty method tools are being devised to reverse trend in training deficiencies in specialty, prior to advent of second generation jets.

Engineering development has always been restricted by the limitations of structural materials. In the development of large fan stage compressor blades, material of high strength to density and modulus to density ratios have been required. This paper discusses use of titanium in the 170 and 190 ksi yield strength alloys in these applications. Materials, procedures, and results of the Pratt & Whitney development program are discussed. The Ti-6Al-6V-2Sn alloy appears most promising in meeting the desired 170 ksi yield strength while maintaining reasonable fracture toughness. The relationship between toughness, fatigue, and other mechanical properties is incompletely understood. However, with high tensile preloads, a strong positive correlation between toughness and fatigue strength seems quite probable.

Training requirements of the current commercial subsonic jet programs and those of the manned space flight projects have dictated rapid expansion in the state of the art of simulation development. A concept of flight realism, before unknown, is being developed into our future simulators. These concepts are being formulated using past experience as a foundation to determine our needs; and technology developed in the space age to be our tools. The realization of training transfer to the high degree required will come with the further development of simulation environment, instrument presentation, motion systems with 6 degrees of freedom for “g” force inputs, and real world visual presentation. Many of these are already realized; the rest are in advanced development stages.

A historical review of developments in flight simulator computation methods indicates that the computation load has been increasing by about a factor of ten every ten years for the last thirty years. From a brief analysis of computation methods used on a typical modern digital flight simulator it is concluded that these methods are more than adequate for the simulation task as presently defined. Additional new simulation requirements such as computer-aided instruction methods and computer-based navigation techniques apparently will require very large additional simulator computer capacity in the near future.

For the Boeing SST, flight simulators are providing important insight into problems of stability, control, and flight information display in advance of the actual cutting of metal for flying hardware. Simulator investigations have yielded tentative solutions to several flight instrumentation problems: the optimum scale factor for the pilot's pitch indicator; the economical evaluation of experimental landing displays through the use of CRT line-writing techniques; and the development of a display system for informing the pilot of his situation with respect to a prescribed sonic-boom-limited climb or descent profile.

The methodology employed in the derivation of simulation equipment requirements for a Deep Submergence Vehicle DS/V is described, together with an outline of the hardware design concepts adopted or considered. The parallel is drawn between methodology and equipment used for a DS/V simulator, and that found in most aircraft or spacecraft simulators. In order to understand better the parallel, a brief discussion of the history and operation of a DS/V is included.

This paper deals with concepts of motion systems which have not been fully utilized for training flight simulators, and which promise to provide a more accurate motion system representation. An examination of the vestibular system is made and the information it gives to the pilot is shown to be of a “phase advance nature” Some programming considerations of motion systems are presented. The desirability of custom designing the motion system to aid in training the pilot for specific tasks is also discussed.

Visual simulation has added a new dimension to flight training simulators. Monochrome T.V. projection preceded the early colour displays which are, in turn, superseded by high definition colour systems incorporating features such as full runway and approach lighting. The paper outlines the progress in visual simulation and high definition colour systems which we have today. The requirements of all-weather operation are detailed. New developments are discussed which will further advance the art of visual simulation.

This paper covers the history of flight simulator acceptance in the United Kingdom. Two key years are 1951 and 1960. In 1951, the Ministry of Civil Aviation allowed the use of Redifon/BOAC Stratocruiser flight simulators to conduct Statutory instrument rating renewal tests. In 1960, the use of simulators was extended to biannual competency tests for pilots and flight engineers. The paper also explains why, with the advent of SSTs and jumbo jets, flight simulators will play an even larger part in pilot training and checking.

This paper outlines the major factors involved in designing simulators that have “practical” fidelity without being overdesigned. A closed-loop logic for the development and use of simulation is set forth. The simulation approach is developed around three basic design categories -- the basic computer and servomechanism technology, the human engineering criteria, and control information. The control-information category is discussed extensively, and respresentative fixed- and moving-base research simulators in use at the Langley Research Center are presented to describe specific display designs and motion-cue effects.

Programmed instruction, a method of teaching subject-matter without the intervention of a human instructor, is being used profitably in civilian and military aerospace applications. A more sophisticated technique which utilizes time-sharing computer systems, Computer-Assisted Instruction (CAI), provides a learner-machine relationship not previously obtainable. The evolving roles of the participants are discussed: learner, instructor, instructional programmer, computer programmer, computer operator, and training director. Reference is made to CAI software systems and languages, and the development of “Elements of EYBOL,” a missile orientation training program is described in detail.

The Supersonic Transport Training Program is being defined through engineering, experimental and operations research and analysis programs. Dynamic simulation of future environment and performance parameters--to be updated later with flight test experience--are developing tomorrow's skills, procedures, and equipment essential to the safe and efficient operation of the SST as a total system.