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Piloting technique for recovery from spins

Description: "Systematic flight investigation of the spinning characteristics of various airplanes over a period of several years have given the pilots engaged in the testing a varied and extensive experience. From this experience certain general rules of procedure have been formulated, particularly for the sequence of operation of the controls in recovery from spins, and are recommended to the attention of all pilots" (p. 1).
Date: February 1936
Creator: McAvoy, W. H.
Partner: UNT Libraries Government Documents Department
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The Reduction in Drag of a Forward-Sloping Windshield

Description: "This paper gives results of a short investigation of the drag of a forward-sloping closed-cabin windshield. The drag of the windshield in both the original and a final modified form was determined from tests in the variable-density wind tunnel. The final form of the windshield was arrived at by modifying the original as the result of flow observations in the N.A.C.A. smoke tunnel. The investigation studied the utility of the N.A.C.A. smoke tunnel as applied to reducing the drag of objects for … more
Date: December 1933
Creator: Jacobs, Eastman N.
Partner: UNT Libraries Government Documents Department
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The Effect of Curvature on the Transition From Laminar to Turbulent Boundary Layer

Description: "In the flow over the upper surface of a wing, a discrepancy between the predicted and actual point of transition from laminar to turbulent boundary layer was found. This effect may be due to the comparatively small radius of curvature of the upper surface of the wing. Tests were undertaken to investigate this effect. As far as the authors know, the present investigation is the first to show that curvature has a pronounced effect on the transition of the boundary layer from the laminar to the t… more
Date: September 1937
Creator: Clauser, Milton & Clauser, Francis
Partner: UNT Libraries Government Documents Department
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Considerations of the Take-Off Problem

Description: Many technical papers on the various phases of airplane take-off have been published. Frequently, however, there appear new ideas which affect only particular scattered phases of the subject and which do not receive individual publication. It is the purpose of this paper to present several ideas of this nature which may be of considerable aid in calculating take-off performance and one idea which should correct what appears to be a popular misconception of the importance of static propeller thr… more
Date: February 1936
Creator: Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department
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The Performance of a DePalma Roots-Type Supercharger

Description: "The results of tests made to determine the performance of a DePalma-Roots supercharger are presented. The performance of the DePalma supercharger with atmospheric pressure at the discharge was compared with that of a hypothetical NACA Roots-type supercharger of the same displacement. The tests were conducted at speeds from 1,000 to 6,000 r.p.m. and at pressure differences from 0 to 15 inches of mercury" (p. 1).
Date: March 1936
Creator: Schey, Oscar W. & Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department
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Effect of Retractable-Spoiler Location on Rolling- and Yawing-Moment Coefficients

Description: "In this report are presented the results of wind-tunnel tests of retractable spoilers on the upper surface of a Clark Y wing, which have been made as part of an investigation of lateral control devices being conducted by the National Advisory Committee for Aeronautics. Spoilers with chords up to 15.0 percent of the wing chord were tested in several locations on a plain rectangular wing and in two locations on the same wing equipped with a 20.0 percent chord split flap down 60 degrees. Charts a… more
Date: July 1934
Creator: Shortal, J. A.
Partner: UNT Libraries Government Documents Department
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Resume of Air-Load Data on Slats and Flaps

Description: "A resume of the generally available test data regarding air loads on slats and flaps is presented and data attained up to the fall of 1938 are included. The data are given in the form of N.A.C.A. standard coefficients of air forces and moments on the lift-increasing device and, when available, the aerodynamic characteristics of the combined wing and high-lift device are included. Slats of the Handley Page type, fixed auxiliary airfoils, and flaps of several different types are covered" (p. 1).
Date: March 1939
Creator: Wenzinger, Carl J. & Rogallo, Francis M.
Partner: UNT Libraries Government Documents Department
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Some Elementary Principles of Shell Stress Analysis With Notes on the Use of the Shear Center

Description: "The analysis of various types of shell under combined bending and torsion is discussed. The calculation and the use of the shear center are touched upon as incidental problems. Twelve fully worked numerical examples are given in an appendix" (p. 1).
Date: March 1939
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department
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Some fundamental considerations in regard to the use of power in landing an airplane

Description: From Summary: "This note is concerned with the effect of power on landing speed and apparent maximum lift coefficient. It is shown that when secondary effects are neglected, the maximum available increase in lift due to power is equal to the thrust being developed. If the increase in lift due to power is expressed in coefficient form, very high values may be shown under conditions which, on analysis, are found to be wholly impracticable in flight."
Date: March 1939
Creator: Diehl, Walter S.
Partner: UNT Libraries Government Documents Department
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Adhesion of Ice in Its Relation to the De-Icing of Airplanes

Description: From Summary: "The various possible means of preventing ice adhesion on airplane surfaces are critically reviewed. Results are presented of tests of the adhesives forces between ice and various solid and liquid forces. It is concluded that the de-icing of airplane wings by heat from engine exhaust shows sufficient promise to warrant full-scale tests. For propellers, at least, and possibly for certain small areas such as windshields, radio masts, etc. the use of de-icing or adhesion-preventing l… more
Date: August 1939
Creator: Rothrick, A. M. & Selden, R. F.
Partner: UNT Libraries Government Documents Department
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Comparison of Profile-Drag and Boundary-Layer Measurements Obtained in Flight and in the Full-Scale Wind Tunnel

Description: "The effect of the existing turbulence in the full scale tunnel was determined from measurements of the profile drag of an N-22 section by the momentum method under corresponding conditions in flight and the tunnel. The transition-point location on the upper surface of the air-foil was also determined from velocity surveys in the boundary layer. The measurements were made at section lift coefficients from 0.480 to 0.635 with a range of Reynolds Numbers from 4,600,000 to 3,900,000. The results s… more
Date: March 1939
Creator: Goett, Harry J. & Bicknell, Joseph
Partner: UNT Libraries Government Documents Department
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Tandem Air Propellers

Description: "Tests of 2-blade, adjustable-pitch, counter rotating tandem model propellers, adjusted to absorb equal power at maximum efficiency, were made at Stanford University. The characteristics, for 15 degrees, 25 degrees, 35 degrees, and 45 degrees pitch settings at 0.75 R of the forward propeller and for 8-1/2 percent, 15 percent, and 30 percent diameter spacings, were compared with those of 2-blade and 4-blade propellers of the same blade form" (p. 1).
Date: February 1939
Creator: Lesley, E. P.
Partner: UNT Libraries Government Documents Department
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Local Instability of Centrally Loaded Columns of Channel Section and Z-Section

Description: "Charts are presented for the coefficients in formulas for the critical compressive stress at which cross-sectional distortion begins in a thin-wall member with either a channel section or a Z-section with identical flanges. The energy method of Timoshenko was used in the theoretical calculations required for the construction of the charts. The deflection equations were carefully selected to give good accuracy. The calculation of the critical compressive stress at stresses beyond the elastic ra… more
Date: August 1939
Creator: Lundquist, Eugene E.
Partner: UNT Libraries Government Documents Department
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Full-scale drag tests of landing lamps

Description: "Drag tests were conducted in the N.A.C.A. full-scale wind tunnel on full-scale models of two Army Air Corps type A-6 landing lamps mounted on an 8 by 48 foot airfoil. Drag measurements were made with the lamps in the leading edge and attached to the lower surface at the 5 and 10 percent chord positions. The drag of the lamps when faired into the airfoil was also measured. The results show that at 100 miles per hour and at the angle of minimum drag of the airfoil the unaired lamps in the leadin… more
Date: May 1934
Creator: Dearborn, C. H.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Measurements of Air Loads on Split Flaps

Description: Note presenting tests in a wind tunnel to determine the control forces and air loads acting on split flaps. Clark Y wing models were used with two different sizes of full-span split flaps, one with a medium chord and one with a narrow chord. The results indicated that at angles of attack and flap deflections for maximum lift, the lift loads on the split flaps were only 5 percent and 9 percent of the total lift for the narrow and medium-chord flaps respectively.
Date: May 1934
Creator: Wenzinger, Carl J.
Partner: UNT Libraries Government Documents Department
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Torsional stability of aluminum alloy seamless tubing

Description: Torsion tests were made on 51ST aluminum-alloy seamless tubes having diameter-to-thickness ratios of from 77 to 139 and length-to-diameter ratios of from 1 to 60. The torsional strengths developed in the tubes which failed elastically (all tubes having lengths greater than 2 to 6 times the diameter) were in most cases within 10 percent of the value indicated by the theories of Donnel, Timoshenko, and Sturm, assuming a condition of simply supported ends.
Date: March 1939
Creator: Moore, R. L. & Paul, D. A.
Partner: UNT Libraries Government Documents Department
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The Frequency of Torsional Vibration of a Tapered Beam

Description: "A solution for the equation of torsional vibration of tapered beams has been found in terms of Bessel functions for beams satisfying the following conditions: (a) the cross sections along the span are similar in shape; and (b) the torsional stiffness of a section can be expressed as a power of a linear function of distance along the span. The method of applying the analysis to actual cases has been described. Charts are given from which numerical values can be immediately obtained for most cas… more
Date: March 1939
Creator: Coleman, Robert P.
Partner: UNT Libraries Government Documents Department
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Propeller Tests to Determine the Effect of Number of Blades at Two Typical Solidities

Description: "Propellers with equal total blade area, but with different numbers, were tested at Stanford University. The tests show generally that, for equal total blade area, propellers with the larger number of blades absorb the greater power and, provided hubs have equal drag, develop the higher efficiency. It is shown that the differences found are in agreement, qualitatively, with what might be predicted from simple blade-element theory" (p. 1).
Date: April 1939
Creator: Lesley, E. P.
Partner: UNT Libraries Government Documents Department
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Tests of an N.A.C.A. 23012 Airfoil with a slotted deflector flap

Description: Section aerodynamic characteristics of a large-chord N.A.C.A. 23012 airfoil with a slotted deflector flap were obtained in the N.A.C.A. 7- by 10-foot wind tunnel. The characteristics of an N.A.C.A. slotted flap and of a simple split flap are included for comparison. The slotted deflector flap was found to have a somewhat lower maximum lift coefficient and somewhat higher drag at high lift coefficients than the N.A.C.A. slotted flap. The high drag of the open slot with the deflector flap neutral… more
Date: April 1939
Creator: House, R. O.
Partner: UNT Libraries Government Documents Department
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Physical Properties of Synthetic Resin Materials

Description: "A study was made to determine the physical properties of synthetic resins having paper, canvas, and linen reinforcements, and of laminated wood impregnated with a resin varnish. The results show that commercial resins have moduli of elasticity that are too low for structural considerations. Nevertheless, there do exist plastics that have favorable mechanical properties and, with further development, it should be possible to produce resin products that compare favorably with the light-metal all… more
Date: March 1939
Creator: Fishbein, Meyer
Partner: UNT Libraries Government Documents Department
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The Effects of Surface Waviness and of Rib Stitching on Wing Drag

Description: "Surface waviness and rib stitching have been investigated as part of a series of tests to determine the effects on wing drag of common surface irregularities. The tests were made in the N.A.C.A. 8-foot high-speed wind tunnel at Reynolds Numbers up to 17,000,000. The results of the tests showed that the waviness common to airplane wings will cause no serious increase in drag unless the waviness exists on the forward part of the wing, where it may cause premature transition or premature compress… more
Date: August 1939
Creator: Hood, Manley J.
Partner: UNT Libraries Government Documents Department
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The Effects of Some Surface Irregularities on Wing Drag

Description: "The N.A.C.A. has conducted tests to provide more complete data than were previously available for estimating the effects of common surface irregularities on wing drag. The irregularities investigated included: brazier-head and countersunk rivets, spot welds, several types of sheet-metal joints, and surface roughness. Tests were also conducted to determine the over-all effect of manufacturing irregularities incidental to riveted aluminum alloy and to spot-welded stainless-steel construction" (p… more
Date: March 1939
Creator: Hood, Manley J.
Partner: UNT Libraries Government Documents Department
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Tank Tests to Determine the Effects of the Chine Flare of a Flying-Boat Hull N.A.C.A. Model Series 62 and 69

Description: Note presenting testing of twenty-two models of flying-boat hulls for the purpose of determining the effects on water resistance and spray of 13 variations in the transverse section of the bottom of the forebody and of three variations in the form of the afterbody. Generally, the effect of chine flare on the resistance was small, although the resistance of force with chine flare was generally less than the resistance of the form without chine flare.
Date: August 1939
Creator: Bell, Joe W. & Olson, Roland E.
Partner: UNT Libraries Government Documents Department
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A Study of the Factors Affecting the Range of Airplanes

Description: A study was made of the most important factors affecting the range of airplanes. Numerical examples are given showing the effects of different variables on the range of a two-engine airplane. The takeoff problems of long-range airplanes are analyzed.
Date: February 1937
Creator: Biermann, David
Partner: UNT Libraries Government Documents Department
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