A study of factors affecting the steady spin of an airplane

Data from wind-tunnel tests on a model of the NY-1 airplane were used in a study of the effect on the steady spin of a number of factors considered to be important. The factors were of two classes, mass distribution effects and aerodynamic effects. The study indicated that mass extended along the longitudinal axis has no detrimental effect or is even slightly beneficial, mass extended along the lateral axis is detrimental if the airplane spins with the inner wing tip far down, and mass extended along the normal axis, if of considerable magnitude, has a strong favorable effect. The aerodynamic effects considered in terms of rolling, pitching, and yawing moments added to those for a conventional airplane showed that added stable rolling moment could contribute favorable effect on the spin only in decreasing the amount of inward sideslip required for equilibrium. Negative pitching moment of moderate magnitude has unfavorable effect on a high-angle-of-attack spin, and stable yawing moment has pronounced beneficial effect on the spin. Experimental data from various sources were available to verify nearly all the deductions resulting from the study of the curves. When these results were considered for the purpose of deciding upon the best means to be developed for controlling the spin, the yawing-moment equilibrium was found to offer the most promising field for research. The wing-cellule yawing moment, of which the shape of the chord-force curve is an approximate measure, should be made as small as possible in the unstable sense and the damping yawing moment of the tail should be made as large as possible. The most serious unfavorable effect on the damping yawing moment of the tail is the blanketing of the vertical surfaces by the other parts of the tail

Fast and optimal solution to the Rankine-Hugoniot problem

A new, definitive, reliable and fast iterative method is described for determining the geometrical properties of a shock (i.e., theta sub Bn, yields N, V sub s and M sub A), the conservation constants and the self-consistent asymptotic magnetofluid variables, that uses the three dimensional magnetic field and plasma observations. The method is well conditioned and reliable at all theta sub Bn angles regardless of the shock strength or geometry. Explicit proof of uniqueness of the shock geometry solution by either analytical or graphical methods is given. The method is applied to synthetic and real shocks, including a bow shock event and the results are then compared with those determined by preaveraging methods and other iterative schemes. A complete analysis of the confidence region and error bounds of the solution is also presented

A preliminary determination of normal accelerations on racing airplanes

Rules and methods for insuring safe structural strength of racing airplanes used in the major air meets in this country have recently been considered. Acceleration records made in racing airplanes during actual air races were therefore considered desirable, and the NACA undertook the measurement of acceleration of loads on airplanes during all conditions of flight. Accelerations were measured on four airplanes at the Miami All-American Races in January 1934 and January 1935. The airplanes were representative of the fastest limited and unlimited displacement racing airplanes in current use in this country. Records during two races, or flights, on the race course were obtained with each airplane. The maximum normal acceleration recorded was 6.2g and the minimum was -1.2g

The Effect on Lift, Drag, and Spinning Characteristics of Sharp Leading Edges on Airplane Wings

An investigation with special reference to auto rotation and spinning was conducted in two wind tunnels and in flight to find the aerodynamic effects of adding a sharp leading edge to a wing sector

Scale lengths in quasi-parallel shocks

Examples of an interplanetary and the bow shock illustrate the small relative size of the electrostatic layer relative to the scale of the magnetic fluctuations in quasi-parallel shocks. While both examples are supercritical, the interplanetary example is marginally so, showing a thickness in absolute and convected ion larmor radii units that is thicker (approximately 13 U/omega sub ci) than at the bow shock (approximately omega sub ci). The fluid speed changes abruptly in the quasi-parallel shock on this shorter scale. The increase in electron and ion random energies also is clearly seen on this shorter scale. In the interplanetary example the scale of the electric layer is certainly less than 1/60th that of the up or downstreams magnetic fluctuations. The thickness of the earth's bow shock deceleration layer is dramatically narrower than any domain of upstream waves as controlled by reflected, intermediate, or diffuse ions

Tunisia Renewable Energy Project systems description report

In 1979, the Agency for International Development (AID) initiated a renewable energy project with the Government of Tunisia to develop an institutional capability to plan and institute renewable energy technologies in a rural area. The specific objective of the district energy applications subproject was to demonstrate solar and wind energy systems in a rural village setting. The NASA Lewis Research Center was asked by the AID Near East Bureau to manage and implement this subproject. This report describes the project and gives detailed desciptions of the various systems

A flight investigation of the effect of mass distribution and control setting on the spinning of the XN2Y-1 airplane

The investigation of the effect of mass distribution on the spinning of airplanes initiated with tests on the NY-1 airplane has been continued by tests on another airplane in order to increase the scope of the information and to observe particularly the behavior of an airplane that shows considerable change in sideslip angle for its various conditions of spinning. The XN2Y-1 naval training biplane was used for the present tests in which changes of ballast along the longitudinal and lateral axes and changes of aileron, stabilizer, and elevator settings were made. The effects of these changes on the steady spin were measured in flight

A flight investigation of the spinning of the NY-1 airplane with varied mass distribution and other modifications, and an analysis based on wind-tunnel tests

This report presents the results of an investigation of the spinning characteristics of NY-1 naval training biplane. The results of flight tests and an analysis based on wind-tunnel test data are given and compared. The primary purpose of the investigation was the determination in flight of the effect of changes in mass distribution along the longitudinal axis, without change of mass quantity or centroid. Other effects were also investigated, such as those due to wing loading, center-of-gravity position, dihedral of wings, control setting, and the removal of a large portion of the fabric from the fin and rudder. The wind tunnel test results used in the numerical analysis were obtained in the 7 by 10 foot wind tunnel through an angle-of-attack

The forces and moments acting on parts of the XN2Y-1 airplane during spins

The magnitudes of the yawing moments produced by various parts of an airplane during spins have previously been found to be of major importance in determining the nature of the spin. Discrepancies in resultant yawing moments determined from model and full-scale tests, however, have indicated the probable importance of scale effect on the model. In order to obtain data for a more detailed comparison between full-scale and model results, flight tests were made to determine the yawing moments contributed by various parts of an airplane in spins. The inertia moment was determined by the usual measurement of the spinning motion, and the aerodynamic yawing moments on the fuselage, fin, and rudder were determined by pressure-distribution measurements over these parts of the airplane. The wing yawing moment was determined by taking the difference between the gyroscopic moment and the fuselage, fin, and rudder moments. The numerical values of the wing yawing moments were found to be of the same order of magnitude as those measured in wind tunnels

6th Annual Idaho Public Policy Survey

This monograph presents the results from the sixth annual Idaho Public Policy Survey. As in the past, the research presented here builds on the past surveys by asking many of the same questions that were asked in previous years. 1995, however, marked a major change in the direction of the Idaho Public Policy Survey. In order to further develop its public affairs mission, the university sought to develop a collaborative relationship with the community. To expand public participation in developing the survey questions, the Survey Research Center invited the public to form the Idaho Public Policy Survey Group (IPPSG). The IPPSG is a consortium of all interested state and local government agencies, nonprofit organizations, and the private sector