An investigation was made to determine the aerodynamic characteristics of three deep-step (92 percent of beam) planing-tail flying-boat hulls differing only in the amount of step fairing and of a transverse-step hull with extended afterbody. Minimum drag coefficients, which include the interference effects of the support wing, were 0.0066 for the transverse-step hull - about the same as for a conventional hull - and 0.0057 or 14 percent less for the hull with a deep unfaired step. The hulls with step fairing had up to 44 percent less drag. Longitudinal and lateral stabilty was about the same as for a conventional hull.

An investigation was made to determine the aerodynamic characteristics of three planing-tail flying-boat hulls which differed only in the amount of step fairing. The hulls were derived by altering the step and afterbody of a conventional flying-boat hull having a transverse step.

An investigation was made in the Langley 300-mph 7- by 10-foot tunnel to determine the aerodynamic characteristics of a refined deep-step planing-tail hull with various forebody and afterbody shapes and, for comparison, a streamline body simulating the fuselage of a modern transport airplane. The results of the tests indicated that the configurations incorporating a forebody with a length-beam ratio of 7 had lower minimum drag coefficients that the configurations incorporating a forebody with length-beam raito of 5. The lowest minimum drag coefficients, which were considerably less than that of a conventional hull and slighly less than that of a streamline body, were obtained on the length-beam-ratio-7 forebody, alone and with round center boom. Drag coefficients and longitudinal- and lateral-stability parameters presented include the interference of a 21-percent-thick support wing.

Wear and sliding friction properties of a number of nickel alloys operating against hardened SAE 52100 steel were studied. The alloys were cast beryllium nickel, heat-treated beryllium nickel, cast Inconel, Nimonic 80, Inconel X, Refractalloy 26, and Discaloy. Some of the allows studied may be useful as material for cages of rolling-contact bearings that operate at high speeds with temperatures above 600 degrees F in projected aircraft turbine engines or for bearings that operate in corrosive mediums. Desirable operating properties and the absence of extreme mass welding of all the materials could be associated with the development of the sliding surfaces of a naturally formed film of nickel oxide. On the basis of wear and friction properties, cast Inconel performed very well in these experiments and compares favorably with nodular iron. Nimonic 80 also showed promise as a possible cage material.