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Slotted-Wing Airplanes: Different applications of the slotted-wing principle are discussed as well as the advantages of using them. Slotted-wings are provided as a promising solution to the problem of needing to increase flight speed for aircraft while also decreasing landing speed.
Flight Measurements of Flying Qualities of a P-47D-30 Airplane (AAF No. 43-3441) to Determine Longitudinal Stability and Control and Stalling Characteristics: "Flight tests have been made to determine the longitudinal stability and control and stalling characteristics of the P-47.E-30 airplane. The teat results show the airplane to be unstable stick free in any power-on condition even at the most forward center-of-gravity position tested. At the rearward center-of-gravity position tested the airplane also had neutral to negative stick-fixed stability with power on. The characteristics in accelerated flight were acceptable at the forward center-of-gravity position at low and high altitudes except at high speed where the control-force variations with acceleration were high" (p. 1).
Glider Construction and Design: The endeavor to draw a strict line between gliders and soarers as been recently abandoned and the following classification adopted: 1) gliders controlled by shifting the weight of the body; 2) gliders controlled by rudders; 3) gliders controlled by wings. The different classes are discussed as well as materials and parts used in construction.
Preliminary Results of British Nene II Engine Altitude-Chamber Performance Investigation. I - Altitude Performance Using Standard 18.75-Inch-Diameter Jet Nozzle, 1, Altitude Performance Using Standard 18.75-Inch-Diameter Jet Nozzle: An investigation is being conducted to determine the altitude performance characteristics of the British Nene II engine and its components. The present paper presents the preliminary results obtained using a standard jet nozzle. The test results presented are for conditions simulating altitudes from sea level to 60,000 feet and ram pressure ratios from 1.0 to 2.3. These ram pressure ratios correspond to flight Mach numbers between zero and 1.16 assuming a 100 percent ram recovery.
Increasing Lift by Releasing Compressed Air on Suction Side of Airfoil: The investigation was limited chiefly to the region of high angles of attack since it is only in this region that any considerable change in the character of the flow can be expected from such artificial aids. The slot, through which compressed air was blown, was formed by two pieces of sheet steel connected by screws at intervals of about 5 cm. It was intended to regulate the width of the slot by means of these screws. Much more compressed air was required than was originally supposed, hence all the delivery pipes were much too small. This experiment, therefore, is to be regarded as only a preliminary one.
Calculating Thrust Distribution and Efficiency of Air Propellers: I am now proposing a method for the preliminary approximate calculation of the thrust distribution and efficiency of air propellers under any operating conditions. Our task becomes the following, namely, to determine the speed relations and the forces developed on a section with a given direction and velocity of the air current, a problem which can be solved with the aid of the momentum theory.
Metal Aircraft Construction at Vickers: Some Interesting New Forms Developed: This report contains descriptions of construction techniques at the Vickers plant including the building of the "wandering web," the spar flange, and the Vickers spars.
Summary of Free-Flight Zero-Lift Drag Results from Tests of 1/5-Scale Models of the Convair YF-102 and F-102A Airplanes and Several Related Small Equivalent Bodies at Mach Numbers from 0.70 to 1.46: From Summary: "One-fifth-scale rocket-propelled models of the Convair YF-102 and F-102A airplanes were tested to determine free-flight zero-lift drag coefficients through the transonic speed range at Reynolds numbers near those to be encountered by the full-scale airplane. Trim and duct characteristics were obtained along with measurements of total-, internal-, and base-drag coefficients. Additional zero-lift drag tests involved a series of small equivalent-body-of-revolution models which were launched to low supersonic speeds by means of a helium gun."
Safety in Airplane Flight: This report presents methods to reduce the incidence of aviation accidents. Some of the methods discussed include enlistment and training of aviators, improvement of controls and control surfaces, and upgrading of power plants.
"Gloster" High Lift Biplane Wings: "The main object of these wings was to obtain a high lift without increasing the total drag, and the idea was conceived that, by using a deep high-lift section for the top wing and a medium section for the bottom wing, the mutual interference between the two would be such as to give greater efficiency of the combination as compared with two wings of equal section" (p. 1).
Duralumin - Defects and Failures: It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.
Experiments on Airfoils With Aileron and Slot: The present report contains the results of a few experiments on three airfoils to which the rear portions, having chords respectively 1/4, 1/3, and 2/5 of the total chords, are hinged so as to form ailerons, especial attention being given to the shape of the slot between the aileron and the main portion of the aileron.
Low-Speed Longitudinal Stability and Lateral-Control Characteristics of a 0.3-Scale Model of the Republic RF-84F Airplane at a Reynolds Number of 9x10(exp 6): From Summary: "An investigation was conducted in the Langley 19-foot pressure tunnel on a 0.3-scale model of the Republic RF-84F airplane to determine modifications which would eliminate the pitch-up that occurred near maximum lift during flight tests of the airplane. The effects of high-lift and stall-control devices, horizontal tail locations, external stores, and various inlets on the longitudinal characteristics of the model were investigated. For the most part, these tests were conducted at a Reynolds number of 9.0 x 10(exp 6) and a Mach number of 0.19. The results indicated that from the standpoint of stability the inlets should possess blunted side bodies. The horizontal tail located at either the highest or lowest position investigated improved the stability of the model."
Flight Results from a 1/10-Scale Rocket Model of the Lockheed XF-104 Airplane at Transonic Mach Numbers: "A 1/10-scale rocket model of the Lockheed XF-104 with faired inlets has been flown over a Mach number range from 0.80 to 1.45 to determine low-lift drag and a limited amount of stability data. The center-of-gravity locations were 4.0 and 1.5 percent of the mean aerodynamic chord before and after sustainer firing, respectively. Oscillations induced by pulse rockets were used to determine stability data. The external transonic drag coefficient increased from a value of 0.0160 at Mach number 0.80 to a maximum of 0.0432 near Mach number 1-13, with a drag rise Mach number of about 0.93. At Mach numbers where it could be determined, the model exhibited stable dynamic and static stability characteristics at low lift" (p. 1).
Results of Aerodynamic Tests on Slotted Airfoils in the Aerotechnical Laboratory (S.T. Ae.) of Rhode St. Genese, Brussels: Report investigating the maximum lift obtainable with slotted airfoils derived from a symmetrical airfoil. These should have a smaller profile drag than other slotted airfoils.
Mechanical properties of some materials used in airplane construction: Since lightness is desirable in airplane construction, greater stresses must be tolerated than in other kinds of construction. It is therefore necessary to have a more accurate knowledge of the greatest stresses that may occur and of the actual properties of the materials used. The Aeronautic Research Laboratories took the limit of elasticity as the basis of the strength calculations. Many tests were made of different steels, woods, aluminum alloys, and fabrics.
Aviation Fuels (With Especial Reference To "White Spirit"): Gasoline, the fuel now used, is an extremely volatile and inflammable liquid capable of forming explosive mixtures, the cause of many catastrophes in aviation. It is therefore of special interest to investigate the possibility of using fuels which, while being less volatile than gasoline, would nevertheless enable this engine to function satisfactorily.
Motion of Fluids With Very Little Viscosity: Report presenting a discussion of the laws of motion of a fluid with very low viscosity. Mathematical formulas that have been created in order to compensate for this lack of viscosity and the circumstances under which viscosity can be disregarded are provided.
Note on Research Work by Helmholtz and Wien Relating to the Form of Waves Propagated Along the Surface of Separation of Two Liquids: This report presents a clearer understanding of Helmholtz's work on the calculation of waves along the separation of two different liquids.
Aerodynamic Characteristics in Pitch and Sideslip at High Subsonic Speeds of a 1/14-Scale Model of the Grumman XF104 Airplane with Wing Sweepback of 42.5 Degrees: "An investigation has been made at high subsonic speeds of the aerodynamic characteristics in pitch and sideslip of a 1/l4-scale model of the Grumman XF10F airplane with a wing sweepback angle of 42.5. The longitudinal stability characteristics (with the horizontal tail fixed) indicate a pitch-up near the stall; however, this was somewhat alleviated by the addition of fins to the side of the fuselage below the horizontal tail. The original model configuration became directionally unstable for small sideslip angles at Mach numbers above 0.8; however, the instability was eliminated by several different modifications" (p. 1).
Longitudinal Control Characteristics of a 1/20-Scale Model of the Convair F-102 Airplane at Transonic Speeds: "The effects of elevator deflections from 0 degrees to -20 degrees on the force and moment characteristics of a 1/20-scale model of the Convair F-102 airplane with chordwise fences have been determined at Mach numbers from 0.6 to 1.1 for angles of attack up to 20 degrees in the Langley 8-foot transonic tunnel. The configuration exhibited static longitudinal stability throughout the range tested, although a mild pitch-up tendency was indicated at Mach numbers from 0.85 to 0.95. Elevator pitch effectiveness decreased rapidly between the Mach numbers of 0.9 and 1.0, however, no complete loss or reversal was indicated for all conditions tested" (p. 1).
Hydrodynamic Investigation of the the Take-Off Characteristics of a 1/10-Scale Dynamic Model of the Convair XF2Y-1 Airplane: "An investigation was made of the take-off characteristics of a 1/10-scale dynamic model of the Convair XF2Y-1 airplane. This airplane is a water-based, jet-propelled, delta-wing fighter incorporating a hydro-ski landing gear. Tests were made with the original configuration, with the beaching wheels removed, and with the wheels installed and fairings added in front of the wheels" (p. 1).
Experiments With a Wing From Which the Boundary Layer Is Removed by Pressure or Suction: 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.
The Span as a Fundamental Factor in Airplane Design: 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.
Additional Results on the Static Longitudinal and Lateral Stability Characteristics of a 0.05-Scale Model of the Convair F2Y-1 Airplane at High Subsonic Speeds: "Additional results on the static longitudinal and lateral stability characteristics of a 0.05-scale model of the Convair F2Y-1 water-based fighter airplane were obtained in the Langley high-speed 7- by 10-foot tunnel over a Mach number range of 0.50 to 0.92. The maximum angle-of-attack range (obtained at the lower Mach numbers) was from -2 degrees to 25 degrees. The sideslip-angle range investigated was from -4 degrees to 12 degrees" (p. 1).
Wheel Brakes and Their Application to Aircraft: "The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls" (p. 1).
Ditching Investigation of a 1/14-Scale Model of the XC-123 Airplane: "An investigation of a 1/14 scale dynamically similar model of the XC-123 airplane was made in calm water to observe the ditching behavior and to determine the safest procedure for making an emergency water landing, The behavior of the model was determined from motion-picture records, time-history deceleration records, and visual observations, Various scale-strength simulations were made to determine if the fuselage would be damaged and, if so, to determine the extent and location" (p. 1).
Spatial Burnout in Water Reactors with Nonuniform Startup Distributions of Uranium and Boron: "Spatial burnout calculations have been made of two types of water moderated cylindrical reactor using boron as a burnable poison to increase reactor life. Specific reactors studied were a version of the Submarine Advanced Reactor (sAR) and a supercritical water reactor (SCW). Burnout characteristics such as reactivity excursion, neutron-flux and heat-generation distributions, and uranium and boron distributions have been determined for core lives corresponding to a burnup of approximately 7 kilograms of fully enriched uranium" (p. 1).
The Diesel as a Vehicle Engine: The thorough investigation of a Dorner four-cylinder, four-stroke-cycle Diesel engine with mechanical injection led me to investigate more thoroughly the operation of the Diesel as a vehicle engine. Aside from the obvious need of reliability of functioning, a high rotative speed, light weight and economy in heat consumption per horsepower are also indispensable requirements.
Wind-Tunnel Investigation of the Republic F-105 Inlet with Various Modifications at Mach Numbers 1.41, 1.81, and 2.01: "A 1/13-scale Republic F-105 wing-root inlet configuration in which inlet components were varied was tested in the Langley 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1,41, 1.81, and 2,01 corresponding to Reynolds numbers per foot of 4,19 X 10(exp 6) , 3.74 X 10(exp 6) , and 3.46 x 10(exp 6) respectively. Angles of attack ranged from -4 deg to 15 deg and a few configurations were tested in a sideslip range from -8 deg to 4 deg. Inlet performance and engine-face flow distortions as affected by pitch, sideslip, inlet-lip sweep, contraction ratio, boundary-layer control, and engine bypass are presented and discussed" (p. 1).
Ignition and Combustion Phenomena in Diesel Engines: Evidences were found that neither gasification nor vaporization of the injected fuel occurs before ignition; also that the hydrogen coefficient has no significance. However the knowledge of the ignition point and of the "time lag" is important. After ignition, the combustion proceeds in a series of reactions, the last of which at least are now known.
Simulated Altitude Performance of Combustors for the Westinghouse 24C Jet Engine I-24C-2 Combustor: "A Westinghouse 24C-2 combustor was investigated at conditions simulating operation of the 24C Jet engine at zero ram over ranges of altitude and engine speed. The investigation was conducted to determine the altitude operational limits, that is, the maximum altitude for various engine speeds at which an average combustor-outlet gas temperature sufficient for operation of the jet engine could be obtained. Information was also obtained regarding the character of the flames, the combustion efficiency, the combustor-outlet gas temperature and velocity distributions, the extent of afterburning, the flow characteristics of the fuel manifolds, the combustor inlet-to-outlet total-pressure drop, and the durability of the combustor basket" (p. 1).
On Improvement of Air Flow in Wind Tunnels: "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).
An Evaluation of the Roll-Rate Stabilization System of the Sidewinder Missile at Mach Numbers from 0.9 to 2.3: "A linear stability analysis and flight-test investigation has been performed on a rolleron-type roll-rate stabilization system for a canard-type missile configuration through a Mach number range from 0.9 to 2.3. This type damper provides roll damping by the action of gyro-actuated uncoupled wing-tip ailerons. A dynamic roll instability predicted by the analysis was confirmed by flight testing and was subsequently eliminated by the introduction of control-surface damping about the rolleron hinge line" (p. 1).
Technical Progress Shown in the 1927 Rhon Soaring-Flight Contest: 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.
Investigation of Drag and Static Longitudinal and Lateral Stability and Control Characteristics of 1/20-Scale Model of McDonnell F4H-1 Airplane at Mach Numbers of 1.57, 1.87, 2.16, and 2.53: Phase II Model: Tests were performed in the Langley Unitary Plan wind tunnel to determine the drag and static longitudinal and lateral stability and control characteristics of a 1/20-scale model of the McDonnell F4H-1 airplane at Mach numbers of 1 57, 1 87, 2.16, and 2.53. This is the second phase in a series of tests performed on this model. The Reynolds numbers for these tests, based on the mean aerodynamic chord of the wing, are 1.446 x 10 (exp 6), 1.269 x 10 (exp 6), 1.116 x 10 (exp 6), and 0.714 x 10 (exp 6) at Mach numbers of 1.57, 1.87, 2.16, and 2.53, respectively.
Windmills in the Light of Modern Research: The chief contribution of modern research in the field of windmills is a better understanding of the phenomena and of the available means for the accomplishment of certain results, but also of the natural limits to their productive capacity.
Recent Researches on the Air Resistance of Spheres: The following conclusions on air resistance of spheres are drawn: 1) disturbances in front of the sphere and even single fine wires affect the critical Reynolds Number; 2) disturbances around the sphere increased the drag of the sphere without martially affecting the value of the Reynolds Number(sub crith); 3) great disturbances of the boundary layer of the sphere likewise change R.N.(sub crith); 4) turbulence of the approaching air stream lowers critical R.N.
Free-Flight Zero-Lift Drag Results from a 1/5-Scale Model and Several Small-Scale Equivalent Bodies of Revolution of the Convair F-102 Configuration at Mach Numbers up to 1.34: From Summary: "A 1/5-scale, rocket-propelled model of the Convair F-102 configuration was tested in free flight to determine zero-lift drag at Mach numbers up to 1.34 and at Reynolds numbers comparable to those of the full-scale airplane. This large-scale model corresponded to the prototype airplane and had air flow through the duct. Additional zero-lift drag tests involved a series of small equivalent bodies of revolution which were launched by means of a helium gun."
Synopsis of French Aeronautic Equipment: Aeronautic Instruments: Different control instruments are discussed such as: air-speed indicators; angle-of-attack indicators; longitudinal inclinometers; turn indicators; stall indicators; and drift indicators.
The Cells of Giant Airplanes: This report presents a discussion of the Rohrbach type of giant airplane. The problems considered are structural drag, wing loading and divided power plants.
Airplane Strength Calculations and Static Tests in Russia: An Attempt at Standardization: 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.
Flight Test of the Lateral Stability of a 0.133-Scale Model of the Convair XFY-1 Airplane with Windmilling Propellers at Mach Numbers from 0.70 to 1.12 (TED No. NACA DE 369): A flight test of a rocket-propelled model of the Convair XFY-1 airplane was conducted to determine the lateral stability and control characteristics, The 0.133-scale model had windmilling propellers for this test, which covered a Mach number range of O.70 to 1.12. The center of gravity was located at 13.9 percent of the mean aerodynamic chord. The methods of analysis included both a solution by vector diagrams and simple one- and two-degree-of-freedom methods. The model was both statically and dynamically stable throughout the speed range of the testa The roll damping was good, and the slope of the side-force curve varied little with speed. The rudder was effective throughout the test speed range, although it was reduced to about 43 percent of its subsonic value at supersonic speeds.
Preliminary Results of the Determination of Inlet-Pressure Distortion Effects on Compressor Stall and Altitude Operating Limits of the J57-P-1 Turbojet Engine: "During an investigation of the J57-P-1 turbojet engine in the Lewis altitude wind tunnel, effects of inlet-flow distortion on engine stall characteristics and operating limits were determined. In addition to a uniform inlet-flow profile, the inlet-pressure distortions imposed included two radial, two circumferential, and one combined radial-circumferential profile. Data were obtained over a range of compressor speeds at an altitude of 50,000 and a flight Mach number of 0.8; in addition, the high- and low-speed engine operating limits were investigated up to the maximum operable altitude" (p. 1).
Research on the Control of Airplanes: Our task is to endeavor to obtain precise experimental records of the motion of stalled airplanes, both when left to themselves and when the pilot is trying to control them. The apparatus which we use consists of a box containing tree gyroscopes which are slightly deflected against a spring control when the airplane is turning.
Supplementary Free-Spinning-Tunnel Investigation of a 1/30-Scale Model of the Grumman XF10F-1 Airplane in the Swept-Wing Configuration with Slats Extended: "A supplementary investigation has been conducted in the Langley 20-foot free-spinning tunnel of a 1/30 -scale model of the Grumman XF10F-1 airplane to determine what effect full-span slats would have on the spin-recovery characteristics of the swept-wing version of the XF10F-1 airplane, which had previously been indicated as possessing undesirable spin-recovery characteristics without slats. The effects of extended nose-wheel doors and of fairing the air-duct inlets were also determined" (p. 1).
Effect of Various Blade Modifications on Performance of a 16-Stage Axial-Flow Compressor 2 - Effect on Over-All Performance Characteristics of Increasing Twelfth through Fifteenth Stage Stator-Blade Angles 3 Degrees: The stator-blade angles in the twelfth through fifteenth stages of a 16-stage axial-flow compressor were increased 3O. The over-all performance of this modified compressor is compared to the performance of the compressor with original blade angles. The matching characteristics of the modified compressor and a two-stage turbine were obtained and compared to those of the compressor with original blade angles and the same turbine.
Effect of Rotor- and Stator-Blade Modifications on Surge Performance of an 11-Stage Axial-Flow Compressor 1 - Original Production Compressor of XJ40-WE-6 Engine: "An investigation to increase the compressor surge-limit pressure ratio of the XJ40-WE-6 turbojet engine at high equivalent speeds was conducted at the NACA Lewis altitude wind tunnel. This report evaluates the compressor modifications which were restricted to (1) twisting rotor blades (in place) to change blade section angles and (2) inserting new stator diaphragms with different blade angles. Such configuration changes could be incorporated quickly and easily in existing engines at overhaul depots" (p. 1).
Landing and Braking of Airplanes: In the numerical examples, we have considered an airplane landing in calm air in a fixed direction after crossing the border (with its obstacles) at a height of 30 m. Its stopping point is at a distance D from the obstacle, comprising: a distance D(sub 1) in regular gliding flight; a distance D(sub 2) in levelling off; a distance D(sub 3) in taxying on the ground. The calculations enable us to make out the following table, which gives an idea of the improvements to be expected in the use of various possible methods of braking in the air and on the ground.
Coolant-Flow Calibrations of Three Simulated Porous Gas-Turbine Blades: "An investigation was conducted at the NACA Lewis laboratory to determine whether simulated porous gas-turbine blades fabricated by the Eaton Manufacturing Company of Cleveland, Ohio would be satisfactory with respect to coolant flow for application in gas-turbine engines. These blades simulated porous turbine blades by forcing the cooling air onto the blade surface through a large number of chordwise openings or slits between laminations of sheet metal or wire. This type of surface has a finite number of openings, whereas a porous surface has an almost infinite number of smaller openings for the coolant flow" (p. 1).

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