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THIS paper outlines a method for obtaining the performance of a gas turbine powerplant with a variable exhaust nozzle, based upon a graphical process for matching the turbine and compressor. The method is general in that it may be employed for all operating points at any altitude and speed. The deviations from the ideal static sea-level operation are determined on an h-s diagram from increments of entropy produced by pressure losses through the system and by pressure gains due to velocity.

DATA exist now for the design of heated wings on a fundamental wet-air basis. The design method takes into consideration three factors: 1. Meteorological and flight conditions. 2. Area of water impingement, and rate and distribution of impingement. 3. Rate of evaporation. All of the water intercepted by a wing which is to be heated only in the leading-edge region must be dispersed by evaporation. The design method provides for determining the heat required and the extent of heated area needed to evaporate the intercepted water.

DESCRIBED here is an intake metering injection system suitable for low-horsepower aircraft engines. Gasoline injection is said to have many advantages over carburetion for this class of engines, such as: 1. Complete elimination of manifold icing-one of the most troublesome problems in light engines equipped with carburetors. 2. Better idling characteristics. 3. Faster engine acceleration. 4. Lower maximum cylinder-head temperatures. 5. Better fuel economy. 6. Higher power. 7. Longer periods between overhauls. 8. Simplified engine cooling. 9. Flatter engine designs are possible.

DESIGN of stable turboprop control systems is greatly speeded up by the WAC electronic analog. This computing device simulates the physical relationship between the five prime variables involved: speed, torque, temperature, fuel flow, and propeller blade angle. Although as many as 25 design characteristics may be involved in a control system, the analog can determine the optimum values for them in the course of one day. The analog computing technique might be equally valuable in a number of other uses.

THIS discussion of the problems encountered in designing the installation for the TG-180 in the P-84 Thunderjet is presented in the hope that other engineers designing installations for other turbojets may benefit from Republic's experiences. Problems discussed include provision for quick engine replacement; reduction of losses in the long inlet duct; development of a strong, tight joint for the tail pipe and engine; choice of thermal protection for the fuselage; provision for adjusting tail pipe area; and design of the fuel system. Several suggestions are made for improving the design of the engine from the installation standpoint.

TEST results on the Allison V-1710 exhaust-turbine compounded reciprocating aircraft engine showed that compounding markedly increased power output and, at the same time, decreased specific fuel consumption. One compounded engine, the Allison Model V-1710-E27, was built and tested. Compounding boosted power from 1200 to 1530 bhp at 30,000 ft and 3200 rpm. Despite the promising test results on compounding, development was dropped. It was felt that the engineering manpower needed to develop a turbine capable of withstanding maximum exhaust-gas temperatures would be better employed on turboprop development.

The modern all-metal transport airplane is in general inherently well protected from lightning damage. The metal surface of the airplane forms an inherent safe path for lightning currents around occupants and equipment in the interior. Certain external elements such as movable control surfaces, plastic sections, and outside antennas require protection against lightning. Therefore a thorough knowledge of the character of the lightning discharge and its various effects is of importance. This paper gives an introductory brief discussion of the nature of the lightning discharge phenomena and possible effects on aircraft.

A review is made of several wind-tunnel investigations dealing with the effect of ice on the aerodynamic efficiency of a propeller, as compared to the efficiency loss associated with a heated-air anti-icing system. The propeller aerodynamic characteristics, thrust coefficient, and efficiency with and without the simulated ice are presented. A heated-air thermal anti-icing system for propellers is discussed and the results of an analysis of the losses inherent in such a system for an idealized case is presented. Two wind-tunnel investigations of propellers incorporating internal-flow systems are described: for one investigation the system was simplified almost to the ideal case, in the other investigation a propeller with a complete heated-air anti-icing system was used. The measured losses of efficiency are shown to be in good agreement with those predicted by theory.