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An empirical equation is developed by which changes in drag coefficients due to ice formations on an NACA 65A004 airfoil may be calculated from known icing and flight conditions; this equation is then extended to include available data for other airfoils up to 15-percent thickness ratio. The correlation was obtained primarily by use of ice heights and ice angles measured on the 4-percent thick airfoil. The final equation, however, does not include the ice measurements, but relates changes in drag coefficients due to ice with the following variables: icing time, airspeed, air temperature, liquid-water content, cloud droplet-impingement efficiencies, airfoil chord, angles of attack, and leading-edge radius-of-curvature.

While there has been considerable interest shown by the aircraft industry in high temperature electronic components, little information has been made generally available as to the weight penalty which can be tolerated to obtain such increased high temperature performance. This paper presents, first, a prognostication of what environmental temperatures will be encountered by what date. It then relates those temperature environments to the weight penalties for cooling, thereby arriving at a rough rule-of-the-thumb figure that, unless the average weight increase for temperature improvement of electronic elements can be held to less than l5 to 30%, not much interest will be shown by the aircraft industry. This percentage figure is based on a supersonic mission time of about one hour and on increasing the temperature resistance to the 500-600 F range required for the next generation of aircraft. Longer high speed mission times or higher speeds will justify greater weight increases.

Types of problems which are encountered by using liquid oxygen as the source of breathing oxygen are discussed; and, it is noted that today's liquid oxygen systems are workable solutions for military aircraft. The question is raised whether today's systems are the end result or simply a step in the right direction. Schematics of the typical oxygen systems are introduced, and it is concluded that the basic shortcomings of the current systems are complication and the degree of reliability. In order to stimulate thinking toward the solutions of the basic problems; methods of decreasing leakage, improving filling time, and presenting oxygen quantity in more useful terms are discussed in the light that frequent re-appraisal leads to improvement changes.

BUICK's 1956 twin-turbine Dynaflow transmission incorporates a fixed-blade stator between the two turbine elements. Added to the twin turbine (introduced in 1953) and the variable-pitch stator (introduced in 1955), the author says, this has made an important contribution to reduction in engine rpm, increased low-end performance, and improved efficiency. Stall ratio has been increased from 2.45/1 to 3.5/1, and “getaway” on low-end car performance has improved.

SINCE its introduction in 1939, during which time over 7,000,000 units have been produced, Hydra-matic has regularly added such improvements as the cone friction reverse to enable rocking, and the dual-range transmission to improve performance and economy. The 1956 model, the authors report, is completely redesigned. The basic engineering concept involved, they explain, is substitution of a small fluid coupling for the multiple-plate clutch in conjunction with the front unit gear set. The new transmission is reputed to retain all of the desirable features of the former Hydra-matic, at the same time offering new driving ease and performance.

END results of development efforts and problems on the new American Motors V-8 engine are discussed here. The problem of constructing an engine that is economical, low in weight, durable, and flexible is approached through redesign of the complete engine.

REVIEW is given of some representative current configurations and propulsion arrangements for VTOL aircraft. Support is urged for a comprehensive development program on VTOL aircraft to cover the spectrum of aircraft flight speeds and promising propulsion arrangements. Special effort and support is needed on ducted-propeller and ducted-fan types, the author says, as these show considerable promise for commercial and military transport use. Development of this type is dependent upon the availability of suitable powerplants. Efforts to reduce the landing and take-off distance requirements of conventional fixed-wing airplanes should continue, he feels, but it should not be accepted as an interim step toward or a substitute for true VTOL aircraft development.

FUNDAMENTAL considerations which govern the power and fuel requirements, maximum speed, safety, and practical utility of types of VTOL aircraft are enumerated and discussed. The most interesting types of VTOL aircraft such as the helicopter are discussed and evaluated in regard to their probable applicability to the various fields of usefulness in view of these fundamental considerations. The question whether vertical take-offs and landings are really necessary is considered. It is recognized that there is an advantage in the power-controlled approaches of VTOL aircraft from small airports under all weather conditions. It is realized that there is research still needed to make the VTOL a more satisfactory aircraft.