We are here giving a summary of the rules established by the Theoretical Section of the Central Aerodynamic Institute of Moscow for the different calculation cases of an airplane. It appears the engineers of the Aerodynamic Institute considered only thick or medium profiles. For these profiles they have attempted to increase the safety when the center of pressure moves appreciably toward the trailing edge.

Circular describing the Armstrong-Whitworth "Starling", which is a single seat fighter that can be used for day fighting and night fighting. Details of the wings, wing bracing, lift characteristics, construction, internal components, characteristics, drawings, and photographs are provided.

Tested at the end of March, 1928, the C.A.M.S. 54 G.R. was built for the purpose of crossing the Atlantic from Europe by way of the azores. It has a biplane construction with wings mounted above the hull. It is powered by two new series 500 HP. geared Hispano Suiza V type engines.

This report presents a discussion of the Rohrbach type of giant airplane. The problems considered are structural drag, wing loading and divided power plants.

The propeller cannot be considered alone, but the mutual interference between propeller and airplane must be considered. These difficulties are so great when the joint action of propeller and airplane is considered, that the aerodynamic laboratory at Gottingen originally abandoned the idea of applying the efficiency conception of the test results. These difficulties and the methods by which they are overcome are outlined in this report.

An investigation was conducted to determine the injection lag, duration of injection, and spray start and cut-off characteristics of a fuel injection system operated on an engine and injecting fuel into the atmosphere. The results indicated that for the injection system investigated, the injection lag, in crank degrees, decreased with increase in engine speed for a constant quantity of fuel discharged, but was not affected at constant engine speed by varying the fuel quantity from approximately one-half to full load fuel quantity.

This report is concerned with the importance of the flat-top lift curve as a factor contributing to safety and control at low speed. An analysis of existing airfoil data indicated definite relations between the shape of the lift curve and certain section dimensions. The shape of the lift curve at maximum lift appears to be of sufficient importance to justify additional investigation with the view of developing a section with satisfactory efficiency and moment characteristics.

Previous theoretical investigations of steady curvilinear flight did not afford a suitable criterion of "maneuverability," which is very important for judging combat, sport and stunt-flying airplanes. The idea of rolling ability, i.e., of the speed of rotation of the airplane about its X axis in rectilinear flight at constant speed and for a constant, suddenly produced deflection of the ailerons, is introduced and tested under simplified assumptions for the air-force distribution over the span. This leads to the following conclusions: the effect of the moment of inertia about the X axis is negligibly small, since the speed of rotation very quickly reaches a uniform value.

The Widgeon Wapiti is a military aircraft suitable for a variety of roles. It is a normal tow-bay wire-braced biplane and can be powered by a variety of the Bristol Jupiter series engines.

"Tests were conducted on the 6-inch wind tunnel of the National Advisory Committee for Aeronautics to form a part of a research on open-throat wind tunnels. The primary object of this part of the research was to study a type of air pulsation which has been encountered in open-throat tunnels, and to find the most satisfactory means of eliminating such pulsations. In order to do this it was necessary to study the effects of different variable on all of the important characteristics of the tunnel" (p. 399).