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The development of higher performance and reliability in aircraft weapon systems depends to a large extent upon the environmental limits within which this performance and reliability must be obtained. It is the intent of this presentation to show the need for and importance of accurate and realistic environmental design and test criteria, for each weapon system. Further, that existing Military environmental procedures and Specifications are incompatible with requirements for non-piloted weapon systems; not by intent, but by content, and the manner in which they are used by Contractor and Customer alike. A concrete approach to solution of this problem is proposed. One that would define environmental criteria for an individual weapon system by comparing its mission and performance requirements with known global climatic environment, and with the environment created within the system. The Military are asked to provide the means by which that proposed can be accomplished.

The value of systems environmental tests is discussed in regard to flight safety, functional improvement and economic considerations. Environmental tests of mechanical, hydraulic, and pneumatic systems in the laboratory supplement the components tests and provide worthwhile design data prior to first flight. Typical examples of systems extreme temperature and altitude tests conducted at Lockheed Aircraft Corporation, California Division, are illustrated.

Differences in human body size can sometimes have serious implications for the efficiency and safety, as well as the comfort, of vehicle drivers. The fundamental aim of this report has been to outline methods whereby data on human body size may be systematically incorporated into vehicular design. It is believed that previous considerations of this problem have been hampered by a lack of information on the specific size range of drivers to be accommodated. The engineer cannot design adequately on the basis of an “average” man taken from the general population. Nor can he design properly if he does not know precisely how “big” or how “small” his drivers will be. In addition he must know not only the human body dimensions, but also how these measurements vary in dynamic situations.

IN this lecture, which Sir Harry Ricardo gave after receiving the Horning Memorial Award for 1953, he relates some of his early experiences with the internal-combustion engine. He goes back to the days when, as an undergraduate at Cambridge, he assisted Prof. Bertram Hopkinson in research on rate of flame propagation, preignition, and knock. He describes his early work with a 2-stroke engine of his own design, which he finally, reluctantly abandoned in favor of the 4-stroke engine. He tells of his investigations of fuels and engines for the British Air Ministry and the Ministry of Munitions during World War I, and how, in 1917, he organized a small private company to carry on his research and development work. The Ricardo variable-compression engine E35, a special fuel for racing cars, and various designs of combustion chamber are only a few of the many accomplishments of this company.

AN investigation to determine why the hydrocarbon content of automobile exhaust gas increases abruptly during deceleration and how this can be prevented is described in this paper. High-speed motion pictures of the flame, taken through a quartz-window cylinder head, show that residual-gas dilution is the major cause of incomplete combustion under these conditions. The concentration of hydrocarbons in the exhaust can be reduced either by admitting extra air and fuel to the intake manifold to limit vacuum attained during deceleration or by shutting off the fuel during deceleration.

LIMITED capacity of the atmosphere in the Los Angeles Basin to disperse gaseous wastes accounts for its peculiar susceptibility to smog. While much has been done to determine actual sources of smog, the author contends that nothing has yet been definitely proved. He tells here of the wide variety of investigative programs-covering meteorology, chemistry, combustion products, aerometric surveys, statistics, physical measurements, rubbish disposal, and other vital apects - undertaken by APF, a nonprofit organization sponsored by local industry, business, and civic groups. Discussion of this paper starts on p. 618.

A THEORETICAL analysis indicated that a charging air system of exhaust-driven turbo-charger, engine-driven Roots-type blower, and aftercooler would permit increasing the output of the General Motors Model 16-278A 2-srroke-cycle diesel engine from 1600 to 3000 bhp at 750 rpm. Using a mechanism to control engine compression ratio relative to engine output would further improve thermal efficiency at lower loads. Tests with a simulated turbocharged installation proved the accuracy of the analysis. Thermal efficiency from 1500 to 3000 bhp was better than that at the original 1600-bhp rating. Tests are now under way adapting turbo-chargers to the engine and developing manifolding to duplicate the simulated turbocharged operation.

THIS report of the Tractor Test Codes Subcommittee of the CIMTC consists of separate papers by various members of the subcommittee. The need for a tractor test code and the objectives of this code are covered in one paper included here. Another paper discussing the instrumentation used in the tests is based on reports about the ERDL dynamometer truck, the Good-year dynamometer truck, and the Allis-Chalmers dynamometer equipment. An evaluation of field-test results, discussed in another paper of this report, indicates that there is general accuracy and correlation among the three types of measuring equipment and that the accuracy tolerances given in the code can be met. The test codes for reserve tractive ability and vehicle drag are also given here.

THIS paper discusses the following phases of the residual stress problem, each section containing copious references to work done in the field: 1. General effects of residual stresses. 2. Classification of control measures. 3. Control of residual-stress failures due to mechanical loads plus chemical factors. 4. Control of season cracking and related failures. 5. Control of residual stress to raise fatigue strength. 6. Control in parts loaded statically and in impact. 7. Strengthening of parts by shrinking and overstraining. 8. Dimensional stability and other physical properties.

CONTACT wear of diesel-engine cylinder bores and piston rings is the subject of this paper. The problem of wear is approached through discussion of those conditions most closely associated with wear: the temperature of the moving parts, their materials and design, and the characteristics of the lubricant used on these surfaces.