National Advisory Committee for Aeronautics (NACA) - Browse

On the elementary relation between pitch, slip, and propulsive efficiency
The author examines the current theory on the importance of reducing slip in airplane propellers. The author feels an exaggerated importance is attached to this supposition and feels that the increase in friction by an increase in propeller area or number of revolutions can't be discounted.
Recent developments in light alloys
This report is intended to cover the progress that has been made in both the manufacture and utility of light alloys in the United States since the first part of 1919. Duralumin is extensively discussed both as to manufacture and durability.
Tests of artificial flight at high altitudes
If we wish to form an accurate idea of the extraordinary progress achieved in aeronautics, a comparison must be made of the latest altitude records and the figures regarded as highest attainable limit some ten years ago. It is desirable, for two reasons, that we should be able to define the limit of the altitudes that can be reached without artificial aid. First, to know to what extent the human body can endure the inhalation of rarified air. Second, the mental capacity of the aviator must be tested at high altitudes and the limit known below which he is able to make reliable observations without being artificially supplied with oxygen. A pneumatic chamber was used for the most accurate observations.
Variable pitch propellers
In this report are described four different types of propellers which appeared at widely separated dates, but which were exhibited together at the last Salon de l'Aeronautique. The four propellers are the Chaviere variable pitch propeller, the variable pitch propeller used on the Clement Bayard dirigible, the variable pitch propeller used on Italian dirigibles, and the Levasseur variable pitch propeller.
Dependence of propeller efficiency on angle of attack of propeller blade
In order to determine the maximum and the most favorable pitch for a propeller, it was found desirable to investigate the dependence of propeller efficiency on the angle of attack of the propeller blade. The results of a few experiments are given to show that propeller blades conduct themselves just like airplane wings with reference to the dependence of their efficiency on their angle of attack.
The Oehmichen Peugeot helicopter
The first flights of the Oehmichen helicopter are detailed as well as various aspects of the construction.
Study of the resistance offered by propellers rotating on an airstream
This report presents a series of tests conducted to verify the formula for thrust P = q(exp 2) D(exp 2) V(exp 2), where P represents thrust, V the velocity of the airstream, D the diameter of the propeller, and q the lifting quality of a comparative propeller which is called the conjugate propeller.
Commercial aviation in Germany : past and future
This review of commercial aviation includes postal delivery, package transport, and passenger transport. Both airplanes and airships are covered in this review.
Abacus giving the variation of the mean pressure of an aviation engine as a function of its speed of rotation
Comparing the results of the calculations for computing the mean pressure of an aviation engine for any number of revolutions, with those of experiment, the writer, by numerous examples, shows the perfect agreement between them. This report will show that, by means of a special abacus, an engineer can instantly plot the characteristics of an engine.
Analytical methods for computing the polar curves of airplanes
This report presents a method of calculating polar curves which is at least as precise as graphical methods, but it more rapid. Knowing the wind tunnel test of a wing and the performances of an airplane of the same profile, it is easy to verify the characteristic coefficients and, at the same time, the methods determining induced resistances.
The art of writing scientific reports
As the purpose of the report is to transmit as smoothly and as easily as possible, certain facts and ideas, to the average person likely to read it, it should be written in a full and simple enough manner to be comprehended by the least tutored, and still not be boring to the more learned readers.
The Goebel rotary engine
This report presents a table of specifications of the rotary engine and a very brief description of some of the notable features such as the exhaust valves controlled by means of a fixed cam gear.
The law relating to air currents
In the subdivided wing section profile, the diagram of the current is entirely changed and the harmful formation of eddies is avoided through premature deflection. Pressure equalization does not occur between the upper and under sides. This report presents a discussion of the various laws relating to wing design with the conclusion being that lift increases with more acute angles of attack.
The Rumpler passenger airplane
This report details the Rumpler Limousine which was a further development of the well known type 5 A 2. The fuselage, engine, cabin, wings, controls, and landing gear are all discussed.
Development of aeronautical engines by the Army and Navy
Different aircraft engines are categorized as being of interest to only the Army or Navy or to both armed services. A listing of the different engines is presented along with some statistics, namely, horsepower.
The coupling of engines
This report examines the idea of coupling numerous engines together to turn a single propeller, which the author feels would free aircraft design from the problems of multi-engine and propeller design.
On the definition of the standard atmosphere
On April 15, 1920, the under Secretary of State for Aeronautics and Aerial Transport decided to adopt as Standard Atmosphere for official airplane tests in France, the atmosphere defined by the following law, known as the Law of the S.T.You.(Technical Section of Aeronautics): From 0 to 11,000 m. - 0=15-0.0065 Z and above 11,000 m. - 0= -56.5 degrees being the temperature in centigrade degrees at altitude Z expressed in meters. For altitude 0 the pressure is 760 mm of mercury. In the magazine "L'Aeronautique" Mr. A. Toussaint has already written at length on the first studies which led to the elaboration of this law. Since that time the results obtained have been confirmed by fuller and more abundant data which have justified the official adoption of the Law of the S.T. You. The object of the present article is to give a summary exposition and discussion of the ideas and documents which form the basis of the question.
Rates for flights organized by the state
No Description Available.
Resume of the theory of naval and aerial propulsive propellers and of airplanes in the rectilinear flight
Though dissimilar, these two subjects have been united because they have some points in common. The computation of the movement of an airplane can only be correctly established if we are in a position to know exactly the thrust and resisting torque of the propeller for the various values of slip, which may vary greatly according to circumstance. The first part of the work concerns propellers and introduces as a fundamental variable, the true slip (delta) with respect to the effective pitch, which is the advance per revolution of the propeller corresponding to no thrust. The second part deals with characteristic curves of an airplane.
Sixth meeting of the members of the German Scientific Association for Aeronautics
No Description Available.
Some new tests at the Gottingen laboratory
The tests at the Gottingen laboratory included: friction tests on a surface treated with omelette, verification tests on the M.V.A. 356 wing, and comparative tests of wing no. 36 at the Eiffel laboratory. The examination of all these experiments leads to the belief that, at large incidences, the speeds registered by the suction manometer of the testing chamber of the Eiffel laboratory wind tunnel are, owing to pressure drop, greater than the actual speeds. Therefore, the values of k(sub x) and k(sub y) measured at the Eiffel laboratory at large incidences are too low.
The technical development of the transport airplane.Report of the Aero-Technical Conference of the Scientific Association for Aeronautics, March 5, 1919
The abolition of military qualifications gives free scope to new technical possibilities in the development of transport airplanes. This report notes the various considerations that must be made when designing aircraft to meet the needs of commercial passengers. Comfort and safety must be emphasized.
Transport airplanes
No Description Available.
British certificates of airworthiness
This report details the rules and regulations for obtaining a British airworthiness certificate. Aircraft loading and construction are especially important.
No Description Available.
The dynamometer hub and the flywheel of the engine
No Description Available.
Flexibility of bearing surfaces and stress on fabrics
No Description Available.
Observations on the method of determining the velocity of airships
To obtain the absolute velocity of an airship by knowing the speed at which two routes are covered, we have only to determine the geographical direction of the routes which we locate from a map, and the angles of routes as given by the compass, after correcting for the variation (the algebraical sum of the local magnetic declination and the deviation).
Simple means for saving fuel on traffic flights
No Description Available.
Abacus for the reduction of English measures to the metric system and vice versa
This report presents a description of the abacus as well as construction details. There is also a detailed description on how to use the abacus.
The drawing of experimental curves
This report presents a discussion of how to determine the location of a line or surface from experimental data. What we desire to know practically is the number of ordinates required to obtain a certain probable precision in drawing a line or surface.
Flexible petrol pipe
No Description Available.
Calculation of wing spars
The author presents a comparison and combination of the numerical and geometrical determinations of the maximum M, when calculating the maximum bay moment.
Calculation of wing spars
A simplified formula for calculating wing spars is presented.
Calculation of wing spars
The author presents a comparison and combination of the numerical and geometrical determinations of the maximum M, when calculating the maximum bay moment.
High efficiency of seaplanes
A table is presented which includes data for calculating the index of efficiency. The author uses this data to conclude that seaplanes cannot be considered inferior to terrestrial airplanes.
Large German airship stations
No Description Available.
Shape and strength of seaplane under-structures with special regard to seaworthiness
This report presents experiments and calculations for the purpose of determining the landing gear requirements upon the water. Moving pictures are given which furnish data and also may give both the magnitude and direction of the forces acting. Different classes of seaplanes are examined and proposals for calculation instructions are given.
The 1000 HP traffic airplane of the Zeppelin Works in Staaken
No Description Available.
Competition for safety fuel tanks
No Description Available.
Glossary of terms used in flying boat hull construction
No Description Available.
Lift theory of supporting surfaces : second article
No Description Available.
A new dynamometer brake
The mechanism here described belongs to the class of dynamometer brake in which the motive power is transformed into heat in the brake itself. This mechanism was invented by the writer for the purpose of measuring forces in which the two factors, torque and speed, vary within broad limits, the mechanism itself being of simple construction and of still simpler operation.
Preliminary calculation of cylinder dimensions for aircraft engines
It is extremely important in building aircraft engines to determine the requisite cylinder dimensions as accurately as possible, in order that the weight required for a given power shall not be excessive. This report presents a calculation method that depends on the air requirement of the fuel.
The small diesel engine as an automotive engine
Essential principles for building small diesel engines and also structural details so far as feasibility are presented.
Influence of struts and stays on the speed of an airplane
No Description Available.
A petrol-proof flexible tubing at last: an invention of the greatest importance to aviation
No Description Available.
Some remarks concerning soaring flight
The publication of the following details is due to the desire of the editor to have the problems of soaring flight treated on the occasion of the Rhone Soaring Flight Contest.
Tin soldering of aluminum and its alloys
A method is presented for soldering aluminum to other metals. The method adopted consists of a galvanic application to the surface of the light-metal parts to be soldered, of a layer of another metal, which, without reacting electrolytically on the aluminum, adheres strongly to the surface to which it is applied, and is, on the other hand, adapted to receive the soft solder. The metal found to meet the criteria best was iron.
Aeronautic instruction in Germany
This report contains a list of the courses relating to aeronautics announced in Germany, both in the technical high schools and in the universities.