Circular presenting a description of the Amiot S.E.C.M. 110 C.1, which is a single-seat pursuit monoplane. Some of the design principles that the aircraft was built from are provided. A description of the design, components, dimensions, flight characteristics, and photographs are provided.

The following examples do not take up the discussion of viewpoints to be heeded in determining the design of a framework for given external conditions. Rather they are methods for determining the forces in airplane fuselages and wings, though similar considerations are applied to certain simple cases of a different kind. The object of this treatise is to summarize and amplify these considerations from definite viewpoints.

Autogenous welding is discussed and various methods of testing those welds are presented.

Circular presenting a description of the Bernard 20 C.1, which is made of wood and has four main parts: a one-piece wing with a fuselage in the middle, a rear section with the tail surfaces, an engine mount, and a landing gear.

From introduction: The purpose of this paper is to present a detailed description of the methods employed and the equipment used, with the results obtained in the operation of this mine in the thick Freeport bed on the northern end of the field, near the Alleghegny-Butler county line in western Pennsylvania. It may be classed as a captive mine, as the largest portion of the product is consumed at the by-product plants of the parent company

"The present paper treats less of the effect of the union (of spars and ribs, namely, the reduction of the bending moment at the fixed ends of the spars) than of its influence on the torsional rigidity of the wing. The calculations are carried out for a two-spar wing of constant cross section, in which the ribs are replaced by a continuous member of constant rigidity" (p. 1).

The results of tests to determine the effect of wheel brakes on the landing run of an airplane under conditions of load and at various wind velocities are presented.

This report is on the changes in forces on each wing of a biplane cellule when either the stagger or the gap is varied. Since each test was carried up to a 90 degree angle of attack, the results may be used in the study of stalled flight and of spinning as well as in the structural design of biplane wings.

Even before the publication of the results of the Gottingen experiments on the removal of the boundary layer by suction, experiments with nozzle-slotted wings were begun. A report of those experiments will be given here. Taken collectively, the experiments show that, as regards increasing the lift values, the effect of the air flowing from the nozzle-shaped slots is similar to the effect produced in the case of ordinary slotted wings. The high lift values are attained, however, at the smaller angles of attack employed in ordinary flight.

"An adjustable blade metal propeller was tested at five different angle settings, forming a series varying in pitch. The propeller was mounted on a VE-7 airplane in the twenty-foot propeller research tunnel of the National Advisory Committee for Aeronautics. The efficiencies were found to be from 4 to 7 per cent higher than those of standard wood propellers operating under the same conditions. The results are given in convenient form for use in selecting propellers for aircraft" (p. 521).

This report presents the results of an investigation of the rolling and yawing moments due to ailerons of various chords and spans on two airfoils having the Clark Y and U. S. A. 27 wing sections. Some attention is devoted to a study of the effect of scale on rolling and yawing moments and to the effect of slightly rounding the wing tips. The results apply to level flight with the wing chord set at an angle of attack of +4 degrees and to conditions of zero pitch, zero yaw, and zero roll of the airplane. It is planned later to extend the investigation to other attitudes for monoplane and biplane combinations. The work was conducted in the 10 foot wind tunnel of the Bureau of Standards on models of 60-inch span and 10-inch chord. (author).

This investigation was conducted by the National Advisory Committee for Aeronautics at Langley Field, Va., at the request of the Army Air Corps, for the purpose of comparing the full scale lift and drag characteristics of an airplane equipped with several sets of wings of commonly used airfoil sections. A Sperry Messenger Airplane with wings of R.A.F.-15, U.S.A.-5, U.S.A.-27, and Gottingen 387 airfoil sections was flown and the lift and drag characteristics of the airplane with each set of wings were determined by means of glide tests. The results are presented in tabular and curve form.

"This investigation of the pressure distribution on the tail surfaces of a pursuit airplane in violent maneuvers was conducted for the purpose of determining the maximum loads likely to be encountered on these surfaces in flight. The information is a part of that needed for a revision of existing loading specifications to bring these into closer agreement with the actual flight conditions. A standard F6C-4 airplane was used and the pressure distribution over the right horizontal and complete vertical tail surfaces was recorded throughout violent maneuvers. The results show that the existing loading specifications do not conform satisfactorily to the loadings existent in critical conditions, and in some cases were exceeded by the loads obtained" (p. 539).

This note describes tests of the drag due to a Wright "Whirlwind" (J-5) radial air-cooled engine mounted on a cabin type airplane. The tests were made in the 20-foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics. The drag was obtained with three different types of exhaust stacks: Short individual stacks, a circular cross section collector ring, and a streamline cross section collector ring.

With an unsymmetrical wing and a rotating Magnus cylinder, the lift is produced by the superposition of parallel and circulatory flows. An explanation of the circulatory flow is furnished by the boundary-layer theory of Prandtl and the consequent vortex formation. According to this explanation, it must evidently be possible to increase the circulation either by increasing the size of the stronger (lower) vortex or by decreasing the size of the weaker (upper) vortex.

In order to experimentally study the conditions leading to ice formation on aircraft surfaces, an aircraft was equipped with small auxiliary surfaces and aerodynamic shapes similar to struts, wires, Pitot heads, etc. This airplane was flown at an altitude where a temperature of 32 F was encountered, at such times as cloud formations could be found at the coincident altitude. Here it was discovered that ice formed rapidly in regard to quantity, character, shape, and rapidity of formation.

This report records observations and recommendations resulting from an inspection trip to representative aircraft manufacturing establishments and repair stations. This inspection was made for the Navy Department and was specifically in reference to gluing practice at the various places visited. The period of the visits was between November 23, 1926 and February 16, 1927.

"The most important aerodynamical qualities that should be aimed at in wind tunnel design, are as follows: 1) constant and parallel direction of flow; 2) uniform velocity across all sections; 3) absence of turbulent motion; 4) constant velocity of flow. The above-mentioned qualities are all realized in a high degree in the Gottingen type of wind tunnel, with a parallel portion before the working section, the cross section of which is steadily reduced. It is shown in what follows, that the system can be applied to other wind tunnels, such as the N.P.L. or Eiffel type" (p. 1).

The problem of noise in aircraft is considered and some solutions are presented. The primary sources of sound explored included the engine and the propeller and some ways of insulating passengers from the noise are provided.

Having been designed as a long range aircraft, it carries 6200 liters of fuel and 280 liters of oil and has three propeller groups, each with a 180 HP Hispano-Suiza engine capable of 230 HP. Details of the design, wings, ailerons, fuselage, fuel tanks, landing gear, characteristics, performances, tests, drawings, and photographs are provided.

Brief summary of the habitat, habits, food and economic status, measurements, subfamilies, and subgenera of genera Sorex and Microsorex.

Since 1922 the further development of the glider has consisted of a very gradual and arduous improvement in regards to air resistance, weight, strength and maneuverability. This report provides an in-depth examination of these improvements.

"This report presents the results of preliminary tests made on the effects of supercharging an air-cooled engine under airplane flight conditions. Service training airplanes were used in the investigation equipped with production types of Wright J engines. A N.A.C.A. Roots type supercharger was driven from the rear of the engine. In addition to measuring those quantities that would enable the determination of the climb performance, measurements were made of the cylinder-head temperatures and the carburetor pressures and temperatures" (p. 83).

Report discussing before proceeding to discuss the preparation of dope solutions, it will be necessary to consider some of the essential properties which should be possessed of a dope film, deposited in and on the surface of an aero fabric. The first is that it should tighten the material and second it should withstand weathering.