27 Matching Results

Search Results

Results: 1 - 24 next
open access

Emergency Measures for Increasing the Range of Fighter Airplanes

Description: "An analysis was made to show the relative effectiveness of streamline external fuel tanks, a fuel tank in the form of a wing mounted in a biplane position, and auxiliary wing panels attached at the wing tips to increase the span as temporary means for increasing the range of a fighter-type airplane. Figures and charts for the various devices considered show the results of calculations of range, duration of flight, and take-off distance for both land-base and carrier operation. The results indi… more
Date: May 1943
Creator: Jones, Robert T. & Wetmore, Joseph W.
Partner: UNT Libraries Government Documents Department
open access

Thermodynamic Design of Double-Panel, Air-Heated Windshields for Ice Prevention

Description: Report details the development of design equations for double-panel, air-heated windshields with ice prevention properties. The application of the equations and suggestions for experimental flight testing are described.
Date: June 1943
Creator: Kushnick, Jerome L.
Partner: UNT Libraries Government Documents Department
open access

Resume of Hinge-Moment Data for Unshielded Horn- Balanced Control Surfaces

Description: Report summarizes the available hinge-moment data for unshielded horn-balanced control surfaces. The purpose is to correlate the available data to assist with estimating the balance characteristics for use in the design and alteration of control surfaces with horn balances. Plan forms and variation of incremental hinge-moment-coefficient slopes with balance coefficients are presented.
Date: June 1943
Creator: Lowry, John G.
Partner: UNT Libraries Government Documents Department
open access

A Study of the Effects of Radii of Gyration and Altitude on Aileron Effectiveness at High Speed

Description: "The variation in the necessary aileron control and in the time required to bank to 45 degrees and 90 degrees with altitude and radii of gyration for a typical fighter or a pursuit airplane have been computed and are presented herein." The lateral motions and impact pressure for several conditions of flight are provided. The report concludes that "the aileron system...should be designed for rolling-moment requirements at high altitude and the hinge-moment limitations at low altitude".
Date: April 1943
Creator: Fehlner, Leo F.
Partner: UNT Libraries Government Documents Department
open access

NACA Procedure for Flight Tests of Aileron Characteristics of Airplanes

Description: Report describes the standard procedure that NACA used for evaluating the aileron characteristics of airplanes. The variables measured in the testing are rolling velocity, aileron positions, aileron stick forces or tangential wheel force, indicated airspeed, altitude, free-air temperature, and rudder position. The step-by-step flight procedure is described and information regarding evaluation of the control data and general suggestions is included.
Date: July 1943
Creator: Johnson, Harold I.
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Tests of a Piston-Type Control Booster on an Airfoil and Aileron Model

Description: "Measurements of control moments were made in the NACA stability tunnel to determine the operational characteristics of a piston-type control booster on an aileron. The booster was so constructed and installed that pressures picked up from the air stream below the wing acted on a pair of pistons. The data are presented in the form of curves of pressure coefficients acting on the pistons, hinge-moment coefficients, and booster coefficients plotted against aileron deflection" (p. 1).
Date: November 1943
Creator: Bird, J. D. & Mendelsohn, Robert A.
Partner: UNT Libraries Government Documents Department
open access

Some Notes on the Determination of the Stick-Fixed Neutral Point From Wind-Tunnel Data

Description: "Two methods are presented for determining the horizontal location of the stick-fixed neutral point from wind-tunnel data. One method involves the solution of a mathematical equation; whereas the other method is a graphical solution for the same mathematical equation. The combined horizontal and vertical variation of the neutral point completely describes the stick-fixed longitudinal stability of airplanes that have large allowable center-of-gravity shifts" (p. 1).
Date: September 1943
Creator: Schuldenfrei, Marvin
Partner: UNT Libraries Government Documents Department
open access

Shear Tests on DuPont Explosive Rivets With the Countersunk Head Milled Flush After Expansion

Description: Report discusses the results of shear testing in which the heads of Du Pont explosive countersunk rivets were allowed to protrude above the skin surface before expansion and the protruding portions were removed after expansion. As the height of the rivet head above the skin increases, the tightness of the rivet was found to increase. The report concludes that it may be desirable to investigating filling an entire shank with an explosive charge in order to permit greater tolerances in the drille… more
Date: May 1943
Creator: Gottlieb, Robert & Bartone, Leonard M.
Partner: UNT Libraries Government Documents Department
open access

Proposal for a Propeller Side-Force Factor

Description: Report discusses a proposal for propeller manufacturers to consider the side-force factor with the activity factor as a fundamental parameter for all blade designs and for the side-force factor to be included in all reports of powered models in wind tunnels. The proposal includes a method for calculating the side-force factor and how it can be used in propeller development. It is shown to be a good index of the relative effectiveness per blade of a yawed propeller in developing side force.
Date: December 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department
open access

The belt method for measuring pressure distribution

Description: "The measurement of pressure distribution may be accomplished rapidly for any number of locations deemed necessary in model or full-scale investigations by use of the 'belt' method. Reasonable accuracy may be obtained by careful use of this method" (p. 1).
Date: February 1943
Creator: Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department
open access

Test Data on the Shear Strength of Joints Assembled With Round-Head and Brazier-Head Rivets

Description: Report discusses data obtained from testing shear of joints riveted with round-head and brazier-head rivets. The tightness of the rivets is also compared for one value of rivet diameter. The load-displacement curves and comparison of load at various values of permanent displacement are presented for both types of rivets.
Date: June 1943
Creator: Mandel, Merven W. & Schuette, Evan H.
Partner: UNT Libraries Government Documents Department
open access

A Preliminary Study of Machine-Countersunk Flush Rivets Subjected to a Combined Static and Alternating Shear Load

Description: Report discusses the results of an investigation to study the effect of the height of a rivet head on the number of cycles required to cause failure of a machine-countersunk flush-riveted joint under a combined static and alternating shear load. A tight joint and a loose joint were tested and the number of cycles to failure and location of fatigue failure were compared.
Date: December 1943
Creator: Crate, Harold
Partner: UNT Libraries Government Documents Department
open access

Critical Compressive Stress for Curved Sheet Supported Along All Edges and Elastically Restrained Against Rotation Along the Unloaded Edges

Description: "A formula is given for the critical compressive stress for slightly curved sheet with equal elastic restraints against rotation along the unloaded edges. The theory of small deflections is used and the formula reduces to that given by Timoshenko for the case of simply-supported edges. For larger curvatures, a modification of Redshaw's formula to include the effect of edge restraint is suggested" (p. 1).
Date: September 1943
Creator: Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department
open access

An Approximate Method of Shear-Lag Analysis for Beams Loaded at Right Angles to the Plane of Symmetry of the Cross Section

Description: Report discussing strain measurements made on a box beam of triangular cross section and on two beams of D-section under transverse bending. Information about the arrangement of the beams and experimental and calculated stresses for different boxes.
Date: September 1943
Creator: Kuhn, Paul & Brilmyer, Harold G.
Partner: UNT Libraries Government Documents Department
open access

Effect of Powered Propellers on the Aerodynamic Characteristics and the Porpoising Stability of a Dynamic Model of a Long-Range Flying Boat

Description: Report discusses the results of two tests: "1) aerodynamic tests to determine the effect of the slipstream and thrust from the powered propellers on the lift and trimming-moment characteristics, and 2) hydrodynamic tests to determine the effect of the powered propellers on the range of stable locations of the center of gravity (from Introduction)." Large differences in the stable range between half-thrust and full-thrust conditions were observed. Three effects of power were also involved in the… more
Date: May 1943
Creator: Land, Norman S.
Partner: UNT Libraries Government Documents Department
open access

Notes on the Skipping of Seaplanes

Description: Report discusses five tests related to seaplane skipping and attempts to prevent it by changing the depths of step to avoid large suction force on the afterbody generated by the flow behind a shallow step. Flying boats of various sizes and weights were tested during landing and several degrees of trim were tested for boats that had a particularly shallow step. Design suggestions for future flying boats are also included.
Date: September 1943
Creator: Parkinson, John B.
Partner: UNT Libraries Government Documents Department
open access

Preliminary Tests to Determine the Dynamic Stability Characteristics of Various Hydrofoil Systems for Seaplanes and Surface Boats

Description: Report discusses the results of testing on the dynamic stability characteristics of various hydrofoil systems for seaplanes, including a flat-hydrofoil tandem system, a 20 degree V-hydrofoil tandem system, a curved-hydrofoil tandem system, a flat-hydrofoil ladder system, a Guidoni S.V.A.-type hydrofoil on a streamline spindle, and several self-propelled models, including the Tietjens hydrofoil system. The instability and spray were compared for the different systems.
Date: November 1943
Creator: Benson, James M. & King, Douglas A.
Partner: UNT Libraries Government Documents Department
open access

XC-35 gust research project: Preliminary analysis of the lateral distribution of gust velocity along the span of an airplane

Description: Report presenting measurements of the lateral distribution of effective gust velocity along the span of the XC-35 airplane in a variety of weather conditions. Six standard shapes were determined from the distributions: triangular, rectangular, first trapezoidal, second trapezoidal, unsymmetrical, and double triangular.
Date: March 1943
Creator: Moskovitz, A. I.
Partner: UNT Libraries Government Documents Department
open access

Effect of Normal Pressure on the Critical Shear Stress of Curved Sheet

Description: "In order to determine the critical stresses caused by an outward acting pressure on the upper surface of a wing due to the difference in internal and external pressures, torsional tests were made on two curved-sheet specimens subjected to an outward acting normal pressure. Results show that an outward acting normal pressure appreciable raises the critical shear stress for an unstiffened curved sheet; the absolute increase in critical shear stress is slightly greater for a 30 in. rib spacing th… more
Date: January 1943
Creator: Rafel, Norman
Partner: UNT Libraries Government Documents Department
open access

Use of Stagnation Temperature in Calculating Rate of Heat Transfer in Aircraft Heat Exchangers

Description: "Theoretical and experimental investigations of the effect of frictional heat on the rate of heat transmission at high fluid velocities are briefly reviewed. On the basis of these investigations, calculations are made which show that the use of the stagnation temperature of the cooling air as the effective temperature for heat transfer in an aircraft heat exchanger is sufficiently accurate" (p. 1).
Date: October 1943
Creator: Wood, George P.
Partner: UNT Libraries Government Documents Department
open access

Flight Tests of a Glider Model Towed by Twin Parallel Towlines

Description: "The stability characteristics of a glider towed by twin parallel towlines have been studied in the NACA free-flight tunnel. A preliminary theoretical analysis of the stability of a glider restrained from yawing was followed by an experimental investigation of the stability of a model towed from fixed tunnel points in such a way as to simulate tow in level flight. The results of the tests confirm the theoretical analysis and indicate that a pilotless, stable, towed-glider system is possible whe… more
Date: April 1943
Creator: Pitkin, Marvin & McKinney, Marion O., Jr.
Partner: UNT Libraries Government Documents Department
open access

Hydrodynamic-stability tests of a model of a flying boat and of a planing surface having a small downward projection (hook) on the planing bottom near the step

Description: Report presenting stability testing of two dynamic models in tank no. 1 in order to investigate the effects of adding a small projection, or hook, on the planing bottom of the forebody near the step of a seaplane. Tests with two different projections had a rather large effect on all of the trim limits and the landing stability.
Date: January 1943
Creator: Benson, James M.
Partner: UNT Libraries Government Documents Department
open access

A simplified chart for determining Mach number and true airspeed from airspeed-indicator readings

Description: "The determination of flight Mach number from measurements of indicated airspeed and pressure altitude is shown to be relatively simple and leads to direct and accurate computation of true airspeed. A simplified chart is presented for determining flight Mach number and true airspeed for a range of values of indicated airspeed, pressure altitude, and air temperature. A table of standard atmospheric values is included" (p. 1).
Date: March 1943
Creator: Baals, Donald D. & Ritchie, Virgil S.
Partner: UNT Libraries Government Documents Department
open access

Effect of Varying Percentages of Exhaust Gas on Engine Performance

Description: "These tests were run to determine the effect that mixing engine exhaust gas with engine intake air has on fuel knock limit, specific fuel consumption, and air consumption." Information about the effect on pressure, air consumption, and fuel consumption is detailed.
Date: April 1943
Creator: Sanders, Newell D. & Barnett, Henry C.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen