Annual report submitted by the Boy Scouts of America to Congress describing highlights from 1944 activities, organizational leadership, and other information about scouting programs.

From Introduction: "In the present paper a numerical procedure for the stress analysis of flat-sheet and stringer combinations of arbitrary construction and loading is presented and applied to axially loaded panels and to the reinforced covers of box beams."

Report discusses the thrust and power characteristics of several single- and dual-rotating propellers with differing blade width and number of blades for negative-thrust operation from -45 degrees to 145 degrees blade angle. From Summary: "The tests indicate that it is possible to predict for a given propeller design characteristics in the negative-thrust range from known characteristics at a different activity factor. Adequate negative thrusts were indicated for extremely high positive as well as negative blade angles."

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By the time regular crude biscuit production was interrupted at Ames on November 9, 1944, we had made well over 100 special experimental castings by pouring the liquid metal directly from the bomb. The workmen on the regular crude production line were alternating these special castings with the regular runs without the assistance of the research group. The process had reached a state of development 'wherein the castings were made by pouring batches of about 135 pounds of liquid metal directly from the bomb into a water-cooled steel mold in the presence of air at atmospheric pressure. The pouring operation was effected through a mechanically operated valve in the bottom of the bomb. The workability of such a process has been well established, and the quality of the metal has been proved through candling and chemical tests. The first sixty billets produced by this method have been extruded successfully. A number of changes, designed to improve the quality and yield of the product and to simplify the process, have been made since producing the metal for these tests. The first set-up to test the possibility of pouring the metal directly from the bomb was made on a small scale here …

Report discussing testing to determine the cooling effect of modified baffles and auxiliary-cooling ducts on the rear-row cylinders of a double-row radial engine. The modified baffles were found to reduce the temperatures of the exhaust-valve seats, but did not have an effect on the valve-guide temperatures. The auxiliary-cooling ducts reduced temperatures of the exhaust-valve seats and rear spark plug gaskets.

Results are presented of tests of two sets of 20 curved-sheet specimens to determine the effect of normal pressure on the critical compressive and shear stress of curved sheets. It was found that normal pressure raised the critical compressive and shear stress of curved sheets except when outward bulging occurred in compression, in which case the critical stress was lowered by normal pressure. (author).

Report presenting an examination of new and used nitrided-steel piston rings by electron and X-ray diffraction in a study of the surface changes produced during engine operation. Both new and used rings, examined after degreasing, gave an electron-diffraction pattern consisting of diffuse bands: those from used rings fell at the usual positions of the bands from polished metal surfaces.

Map of eliminating the wesel pocket 3-11 march 1945.

Report discussing the effects of supercharging on the take-off thrust and useful load for a typical helicopter. Performance of the engine with the supercharger and on the rotor thrust is detailed.

Report presenting a method for calculating the stick-fixed neutral point of an airplane with the propeller windmilling, the flaps neutral, and landing gear retracted. The methods used in this report should be useful in estimating the stick-fixed neutral points of new designs for all flight conditions.

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From Summary: "The results of an experimental investigation of several low-drag wing-nacelle combinations, incorporating internal air-flow systems, are presented. The external-drag increments due to these nacelles are between one-half and two-thirds of those of conventional nacelle forms. This improvement is accomplished with only minor effects on the lift and moment characteristics of the wing. The procedure employed to determine the external shape of such low-drag nacelles is considered in detail. The design of an efficient internal-flow system with or without a blower or throttle, presents no serious problems. The energy losses in the expansion before the engine and the contraction thereafter can be kept small. It is believed that these nacelles have a wide application in housing engine pusher-propeller units and, with some alteration, jet-propulsion devices. It is probable that the low external drags may not be realized if such nacelles are used with a tractor propeller because of the high level of turbulence in the propeller slipstream."

This paper reports work carried out to determine the factors necessary to give a filterable precipitation and determine the effects of these factors on the quantitativeness of the precipitation, and how any tendency to increase the tuballoy solubility may be overcome.

The following report presents data from the investigations on discovering factors affecting the precipitation of tubanyl peroxide from Alpha and Beta gunk solutions at reduced temperatures.

Report presenting an electric torquemeter that was used to measure the power of an Allison V-1710-93 engine installed in a Bell P-63A-1 airplane. Results of maximum-available-power tests in flight at a range of density altitudes showed good agreement between the measured maximum power output and the maximum power shown on the engine manufacturer's calibration chart.

Report discussing testing on an F6F-3 with a spring-tab rudder to determine the directional stability and control characteristics. Using the spring-tab rudder was found to result in lower trim-force change with speed and lower pedal forces in sideslips than the original rudder. Pilots were found to prefer the maneuverability of this configuration.

"Results of performance measurements made in level fight with the HNS-1 (Army YR-4B) helicopter are presented. These data include torquemeter measurements of shaft power for both the main rotor and the tail rotor. The power data, in conjunction with full-scale-tunnel date on the lift and drag of the fuselage, are used to calculate the drag-lift ratio for the main rotor" (p. 1).

Report presenting statistical gust-frequency data used to determine the effect of overloading an airplane on the frequency of occurrence of gust loads that stress the airplane to or above its design applied bending moment. The analysis was made for three transport-type airplanes operating at cruising power with overloads varying from 0 to 50 percent of the design gross weight. The probability of structural failure was found to increase rapidly with overload.

"The coefficient of friction between piston ring and cylinder liner was measured in relation to gliding acceleration, pressure, temperature, quantity of oil and quality of oil. Comparing former lubrication-technical tests, conclusions were drawn as to the state of friction. The coefficients of friction as figured out according to the hydrodynamic theory were compared with those measured by tests" (p. 1).

This document details the activities of the Hanford 100 Area for the month of February 1945.

Abstract. It has been established that heating samples of graphite during exposure in a pile decreases substantially the observed changes in the elastic modulus and electrical resistance caused by the irradiation. The functional relationship between the percentage changes observed and the temperature of exposure resembles the relationship between the final percentage changes and the temperature of heat treatment after exposure (cf. report CC-1668). Anomalous results reported previously for higher temperatures in CC01669 are now shown to be attributable to a destructive influence on the graphite, probably oxidation of samples exposed in air.

Report discussing tests of a Sikorsky YR-4B helicopter, including photography of a rotor blade in forward-flight conditions at several azimuth angles for several tip-speed ratios. Fabric deformation in the form of sagging and bulging was noted. A reversal in the bending curve near the blade tip was also noted, which was hypothesized to come from losses of lift and high centrifugal force.

Report discussing an investigation of wing-inlet oil-cooler ducts on a twin-engine airplane to determine internal and external-flow characteristics of the ducting installation. Testing was also performed on revised inlets to attempt to develop a ducting system with low overall losses throughout the operating range.