A Wind-tunnel Evaluation of Analytical Techniques for Predicting Static Stability and Control Characteristics of Flexible Aircraft

A Wind-tunnel Evaluation of Analytical Techniques for Predicting Static Stability and Control Characteristics of Flexible Aircraft

PDF A Wind-tunnel Evaluation of Analytical Techniques for Predicting Static Stability and Control Characteristics of Flexible Aircraft Download

  • Author: Irving Abel
  • Publisher:
  • ISBN:
  • Category : Airplanes
  • Languages : en
  • Pages : 76

An experimental evaluation of analytical techniques for predicting certain stability and control characteristics of a large flexible aircraft is presented. Analytical methods based on both the model approach and flexibility influence coefficients are developed to predict the aerodynamic characteristics of a flexible airplane. These methods are then applied to a flexibly scaled model of a supersonic transport configuration. Comparisons of wind-tunnel data, calculations based on the model approach, and flexibility influence coefficients are presented over the Mach number range from 0.6 to 2.7. An examination of the results obtained from this study indicates that both analytical techniques predict reasonably well the effect of flexibility on the basic longitudinal characteristics and that both techniques give generally comparable results.


Methods for Predicting the Aerodynamic and Stability and Control Characteristics of STOL Aircraft

Methods for Predicting the Aerodynamic and Stability and Control Characteristics of STOL Aircraft

PDF Methods for Predicting the Aerodynamic and Stability and Control Characteristics of STOL Aircraft Download

  • Author: M. I. Goldhammer
  • Publisher:
  • ISBN:
  • Category : Short take-off and landing aircraft
  • Languages : en
  • Pages : 262

This volume describes engineering methods for the prediction of the aerodynamic and stability and control characteristics of STOL aircraft employing internally ducted jet flaps, externally blown jet flaps, and mechanical flap systems with vectored thrust. These methods are intended to be used in conjunction with the theoretical methods and the associated computer program (STOL Aerodynamic Methods Computer Program) discussed in Volumes I and II, respectively. These engineering methods are intended to provide a rational approach for the aerodynamic analysis of complete STOL aircraft configurations and to provide semi-empirical methods to account for those effects not treated by the theoretical methods. These methods have been applied to configurations representative of each of the powered high-lift concepts, and the results of these analyses have been presented along with available experimental data to indicate the validity and range of applicability of the methods.


A Method for Predicting the Stability in Roll of Automatically Controlled Aircraft Based on the Experimental Determination of the Characteristics of an Automatic Pilot

A Method for Predicting the Stability in Roll of Automatically Controlled Aircraft Based on the Experimental Determination of the Characteristics of an Automatic Pilot

PDF A Method for Predicting the Stability in Roll of Automatically Controlled Aircraft Based on the Experimental Determination of the Characteristics of an Automatic Pilot Download

  • Author: Robert Thomas Jones
  • Publisher:
  • ISBN:
  • Category : Airplanes
  • Languages : en
  • Pages : 20

A method is suggested for predicting the stability of automatically controlled aircraft by a comparison of calculated frequency-response curves for the aircraft and experimentally determined frequency-response curves for the automatic pilot. The method is applied only to stabilization in roll. The method is expected to be useful as a means of establishing the specifications of the performance required of the automatic control devices for pilotless aircraft designed as missiles.


Methods for Obtaining Desired Helicopter Stability Characteristics and Procedures for Stability Predictions

Methods for Obtaining Desired Helicopter Stability Characteristics and Procedures for Stability Predictions

PDF Methods for Obtaining Desired Helicopter Stability Characteristics and Procedures for Stability Predictions Download

  • Author: F. B. Gustafson
  • Publisher:
  • ISBN:
  • Category : Aeronautics
  • Languages : en
  • Pages : 722

Part 1 of this report presents a brief review of methods available to the helicopter designer for obtaining desired stability characteristics by modifications to the airframe design. The discussion is based on modifications made during the establishment of flying-qualities criteria and includes sample results of theoretical studies of additional methods. The conclusion is reached that it is now feasible to utilize combinations of methods whereby stability-parameter values are realized which in turn provide the desired stability characteristics. Part 2 reviews some of the methods of predicting rotor stability derivatives. The procedures by which these rotor derivatives are employed to estimate helicopter stability characteristics have been summarized.


Dynamic Structural Aeroelastic Stability Testing of the XV-15 Tilt Rotor Research Aircraft

Dynamic Structural Aeroelastic Stability Testing of the XV-15 Tilt Rotor Research Aircraft

PDF Dynamic Structural Aeroelastic Stability Testing of the XV-15 Tilt Rotor Research Aircraft Download

  • Author:
  • Publisher:
  • ISBN:
  • Category :
  • Languages : en
  • Pages : 26

For the past 20 years, a significant effort has been made to understand and predict the structural aeroelastic stability characteristics of the tilt rotor concept. Beginning with the rotor-pylon oscillation of the XV-3 aircraft, and the problem was identified and then subjected to a series of theoretical studies, plus model and full-scale wind tunnel tests. From this data base, methods were developed to predict the structural aeroelastic stability characteristics of the XV-15 Tilt Rotor Research Aircraft. This paper examines the predicted aeroelastic characteristics in light of the major parameters effecting rotor-pylon-wing stability; describes flight test techniques used to obtain XV-15 aeroelastic stability; presents a summary of flight test results; compares the flight test results to the predicted values; and presents a limited comparison of wind tunnel results, flight test results, and their correlation with predicted values.


FLEXSTAB

FLEXSTAB

PDF FLEXSTAB Download

  • Author: E. N. Tinoco
  • Publisher:
  • ISBN:
  • Category :
  • Languages : en
  • Pages : 52


Comparison of the Control Anticipation Parameter and the Bandwidth Criterion During the Landing Task

Comparison of the Control Anticipation Parameter and the Bandwidth Criterion During the Landing Task

PDF Comparison of the Control Anticipation Parameter and the Bandwidth Criterion During the Landing Task Download

  • Author: David A. Kivioja
  • Publisher:
  • ISBN: 9781423583783
  • Category : Airplanes
  • Languages : en
  • Pages : 167

Many handling qualities criteria have been developed which predict pilot opinion of landing aircraft. MIL-STD-1797A, 'Flying Qualities of Piloted Aircraft' lists six different criteria. However, applying all six criteria to one aircraft can lead to conflicting results. The Air Force Institute of Technology (AFIT) along with the Flight Dynamics Laboratory have conducted research to evaluate differences among the handling qualities criteria in MIL- STD-1797A. The overall objective of this thesis was to determine similarities and discrepancies between the Control Anticipation Parameter (CAP) and bandwidth criteria, and to evaluate the advantage of including a dropback criterion with the bandwidth criterion. Results of this research will be used to derive a more clear-cut, generally acceptable, comprehensive flying qualities criteria predicting pilot opinion for the next revision of MIL-STD-1797A. Research was conducted in two phases. Phase I was conducted at AFIT. There the CAP domain was mapped onto the bandwidth and bandwidth with dropback criteria revealing where the criteria agreed and disagreed. Phase II was conducted at the USAF Test Pilot School. The test team used the Variable-Stability In-Flight Simulator Test Aircraft (VISTA) to simulate aircraft and obtain actual pilot opinion in the areas of agreement and conflict found in Phase I.


NASA SP.

NASA SP.

PDF NASA SP. Download

  • Author:
  • Publisher:
  • ISBN:
  • Category : Aeronautics
  • Languages : en
  • Pages : 316


Index to ... NASA Tech Briefs

Index to ... NASA Tech Briefs

PDF Index to ... NASA Tech Briefs Download

  • Author:
  • Publisher:
  • ISBN:
  • Category : NASA tech briefs
  • Languages : en
  • Pages : 146