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Results are reported of drilling and tapping tests on the high cobalt alloy steel, MX-2, hardened to 50-56 Rockwell C. The empirical data are presented and discussed, and conclusions are drawn as to best shop practice. 52 Rc has been found to be a nominal upper limit to the use of steel cutting tools. At and below this limit, this material may be drilled readily and tapped under appropriate cutting conditions; above 52 Rc, special procedures are required to attain adequate life from high-speed steel tools.

Fabricating studies have been conducted on high-strength titanium alloy 13V-11Cr-3A1 in solution treated and aged condition--workpiece hardness was 45 Rc. The aged alloy was found to be less sensitive to strain hardening during machining than the solution treated form. This material is quite abrasive to cutting tools, when turning this alloy, use of a large side cutting edge angle is advantageous. A 5% aqueous solution of barium hydroxide was far superior to other turning fluids tested. The relationships between the cutting forces and the parameters feedrate and depth of cut have been established; a similar equation has been derived for unit horsepower. For drilling and tapping, a highly chlorinated cutting oil was the best fluid tested. A grinding method which minimizes residual stresses and distortion has been developed. Rough and finish grinding conditions are recommended which result in grinding ratios of 10–20 respectively.

The results of emprical investigations of the drilling, tapping, and surface grinding characteristics of D6aC alloy steel hardened to 54 Rc are reported. This material is machined readily by these processes under appropriate cutting conditions; however, this hardness level appears to be an upper limit to the use of steel drills and taps. A new type of tap, characterized by a unique land geometry, has been developed and tested; this has proved substantially superior to conventional geometries for the present application. Recommendations are formulated for machining this material by each of these processes, and for certain design limitations attendant thereto.

Recent studies and developments in VTOL aircraft by the U. S. Army have been to fill the requirement for a surveilance or observation aircraft. The low speed helicopter not being satisfactory for the mission, two recent experimental craft incorporate the lift fan principle. Answers to many technical problems have yet been answered, in technical research and operational analysis. Actual operation of Army experimental craft may provide the answers needed.

Viewed against the background of a defense policy which requires the nation to be prepared at any instant to mount military operations ranging from a mere show of force to all out nuclear war, the possible role of V/STOL aircraft in the military organization is examined. A number of potential missions are projected and analyzed in order to obtain an indication of the probable routes of development that will be followed. The still existing technical difficulties and the areas of required research and development are discussed with an eye to eliminating the gap between the initial, or exploratory research, and the final development of a weapons system.

Turbo-supercharging for altitude performance is a new application for light planes. It extends their usefulness by permitting greater speed at higher altitudes with economy and reliability. The experience and results obtained from application of turbochargers is related and comparison with other configurations are made. The new methods for automatically controlling power are also discussed.

A program sponsored by NASA, is under way in the Middlewest to determine effective ways of speeding up the transfer of space-related technical developments to industry. Over 600 firms are now being supplied information about latest developments in operating techniques, materials, processes, and products. First-year findings indicate strong interest in relatively new technical areas, cost-reduction possibilities, and NASA inventions and patents; less interest in totally new products.

Direct and indirect evidence for the nature of lunar surface materials are examined and compared with theoretical predictions. Conclusions are then drawn concerning the most probable character of these materials. It is concluded that the lunar surface is covered with a layer of rubble of highly variable thickness and block size. The rubble in turn is mantled with a thin layer of highly porous dust with a complex surface and no significant coherence. Surface roughness at a meter scale remains in doubt.