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THIS paper discusses the use of heat recovered from engine exhaust for heating airplane cabins and flight decks, as well as for anti-icing of aerodynamic surfaces and propellers. The author shows that some of the objections to the use of exhaust gas are more apparent than real and that increased comfort, safety, and utility of transport airplanes will be achieved by using recent developments.

THE White hydro torque drive is described here by Mr. Brunken, who states that the unit is extremely flexible: it “knows” exactly when to shift under all conditions and obeys the command of the driver instantly. A few of the many advantages claimed by the author for this drive are: 1. Hydraulic drive at all times. 2. No lag in full- or part-throttle starting. 3. Correct torque ratio available at all times. 4. Stays in low gear if desired. 5. Can be assembled and disassembled by the average mechanic.

THIS paper includes the results of a study to determine how best to fabricate aircraft components made from precipitation-hardening aluminum alloys so as to take full advantage of the superior mechanical properties of these materials, and yet have parts that can be fabricated readily with a minimum of shop difficulties. The following characteristics of these alloys and problems incidental to their use are studied: mechanical properties, heat-treating operations, effects of cold work, problems connected with various forming operations, methods of attachment, machinability, finish requirements, means of inspection and identification of the various materials and their several tempers, and shop assembly procedures. The following shop fabrication procedures are recommended: 1. In cases where design dictates the use of precipitation-hardening aluminum alloys, the detail parts should be formed, whenever practicable, in the as-quenched solution heat-treated condition. 2.

DURING 1945 many new ideas and developments started to be put in practice in the civil air transport industry. A large portion of these, along such lines as automatic flight control, emergency equipment, airport design, and instrument landing development, came from the vast experimental work carried on by the military during the war. Mr. Kelly in this paper summarizes and reviews the important points in the papers sponsored by the SAE Air Transport Activity during 1945. He mentions that the airlines are increasing their engineering staffs and he believes that these staffs should cooperate to the fullest extent in the future with the manufacturers. He stresses the need for adequate training programs in the airline industry. He tells the new problems that are present in the industry today and some possible solutions to them. This is a comprehensive paper of the progress made in the air transport industry.

PERFORMANCE characteristics of the German BMW-003 and Jumo 004 engines as a whole, as well as of their principal parts, are presented here. This paper, the authors point out, is not the result of experimental determinations in this country, but is rather a résumé of data obtained from German sources. The discussion is divided as follows: 1. Performance of complete machine. 2. Compressor performance. 3. Combustion-chamber performance. 4. Turbine performance. 5. Miscellaneous operating characteristics.

FOR the benefit of those who, though interested, have been unable to follow recent developments in ice-prevention equipment, Mr. Jones summarizes the results of research over the past few years. An excellent series of photographs is included to show both the various forms of ice accumulation and the use of thermal equipment to overcome this hazard. The conclusion reached is that properly designed thermal devices properly operated can satisfactorily prevent most icing of airplane surfaces where such prevention is necessary.

ALONG with further improvements in the form of increased flow and pressure ratio for gas turbines with centrifugal compressors, the author looks forward to an improvement in efficiency, this latter factor being more important in gas turbines than in aircraft turbosuperchargers. As an aid to the realization of this aim, the author presents here a method of determining approximate gas turbine performance at various operating conditions.

PRESENTED here is an interpretation of some of the results of stress analysis -including a few of the many methods whereby the life of machine parts can be improved. Machine parts, the author states, generally contain a sufficient amount of material, but the material is often inefficiently distributed. The author points out that in designing it is important to proportion parts so as to take advantage of beneficial prestress.

THIS paper describes a test program being conducted for the evaluation of highly loaded sleeve bearings. It lists the specific properties of bearings being investigated and describes in detail the test equipment and procedure used. Curves and tables are included showing the test results obtained. The usefulness of laboratory test rigs in accelerating the development of new bearing materials and designs is stressed by the authors, who point out that the labor and expense involved in testing bearings is greatly reduced by the use of such rigs.

SAFETY in private flying will result, the author claims, not from simplified airplanes but from a simplified method of operating them. The author offers as a solution to this problem of operational simplicity a general specification for private airplanes such that the operation will make maximum use of the conditioned reflexes of an automobile driver. The problem resolves itself, according to the author, into the following factors: 1. Elimination of need for coordination. 2. Elimination of need for depth perception. 3. Elimination of nose-down contact with ground. 4. Reduction of minimum cruising speed to decrease need for visibility. 5. Reduction of landing speed. 6. Reduction of temptation to carelessness. Let us cease trying to mold people to fit the airplane, the author pleads, and let us fit the airplane to people as they are.

PRESENTED here is a description of the apparatus and procedure developed for the performance testing of wheel-bearing lubricants. This work was conducted by the Program and Analysis Group Working on Grease Projects of the CLR General Division of CRC, in response to a request by the U. S. Army Ordnance Department. Dr. Adams was appointed chairman of the special panel for this project.

CONSIDERATIONS of aircraft-engine installation singular to the inverted, in-line, aircooled type of engine are presented here in the light of current engineering development in this field. Items of this installation technique discussed are: cooling aspects, cowling arrangements, oil cooling systems, induction systems, engine mounts, and exhaust systems. Much of the information presented is based upon experience gained from wind tunnel and flight tests with Ranger engines. The application of design considerations discussed under the cooling aspects of the aircooled engine has been proved satisfactory in flight test operations. Latest methods of treatment of these factors are described. Substantial advancement has been made in handling the ever-present cooling problem common to all types of engines. This has been achieved by applying the design knowledge gained through considerable wind tunnel and flight research.

HE lubricating possibilities of silicones are summarized by the authors as follows: 1. Silicone fluids offer possible solutions to lubrication problems involving heat stability, oxidation resistance, nonvolatility, and low change of viscosity with change in temperature. 2. Different types of silicone fluids vary in their lubricating ability and in their behavior toward various rubbing metal surfaces. Some silicone fluids approach petroleum oils in ability to reduce wear. 3. Silicone greases, because of their oxidation resistance and low volatility, should find application in the operation of ball bearings under severe conditions and in permanently lubricated ball bearings where long service life is essential.

WITHIN 10 years, Mr. Brower predicts, airlines will use over 1,000,000,000 gal of fuel annually, consequently, what the airlines want and expect in the way of aviation fuels is of major importance. The author stresses particularly that airlines would like less talk of so-called “super fuels,” especially at premium prices, and more interest in down-to-earth, realistic development of economical and safe fuels of good quality. After presenting a resumé of the grades of fuel that he expects will be required in the future. Mr. Brower expresses the thought that to obtain these results, the cooperation that has developed between the fuel refiner, the engine and airframe manufacturers, and the air transport operators must be maintained.

THE need for refrigeration in aircraft air conditioning has not been generally recognized in the past. Shown here are the reasons why refrigeration is a necessity. Three different methods of accomplishing it are also presented. The cooling requirements of the Lockheed Constellation are used as a basis for the study.

THE author divides this discussion of the problems likely to be encountered in the installation of the turbo-jet engine to very high-speed aircraft as follows: 1. Coordination of the design of the engine air inlet duct so as to bring the air to the engine inlet with minimum loss in total pressure and maintain even distribution across the face of the engine inlet. 2. Engine suspension. 3. Engine fuel system. 4. Engine lubrication system. 5. Instrumentation necessary to check proper engine operation. 6. Cooling of engine accessories. 7. Turbo-jet engine control system. He also mentions briefly the problems involved in turbine-propeller engine installations.

A STUDY of possible economic advantages to the aircraft operator of utilizing the internal cooling potentialities of water to assist aircraft-engine cooling and increase detonation limited powers is presented here. Cost analysis is made of three methods of increasing airplane performance by water injection, namely: 1. By increasing cruising bmep's while maintaining engine cooling requirements at the value for conventional cruising bmep's. 2. By decreasing cruise power cooling requirements with the addition of water. 3. By increasing cruise powers up to meto at a constant F/A ratio while maintaining low cooling requirements and avoiding detonation with the use of water. It is concluded by the author that if the water to be used for cooling does not displace an equivalent weight of payload, a maximum saving of 7% at sea level and 18% at 25,000 ft can be realized in direct operating cost with water.

THE use of reverse-pitch propellers to assist in braking of large, high-performance landplanes, the authors report, has many advantages for commercial airline operators. Weight savings are appreciable. For instance, they state that by applying reverse-pitch propellers to the 100,000-lb B-32 airplane, a net weight saving of 407 lb weight empty is realized. There are other advantages, however, that the authors say can be attained, such as greater safety, efficiency, and passenger comfort. For these advantages to be gained, the authors warn that the proper techniques of landing, using the reverse-pitch mechanism and brakes, must be used. They also believe it to be desirable that positive control surface locks be installed and that power steering be used. It appears further that steel blades should be used to withstand normal and sometimes severe abrasions.