Theoretical and analog studies of the effects of nonlinear stability derivatives on the longitudinal motions of an aircraft in response to step control deflections and to the influence of proportional automatic control (open access)

Theoretical and analog studies of the effects of nonlinear stability derivatives on the longitudinal motions of an aircraft in response to step control deflections and to the influence of proportional automatic control

Through theoretical and analog results the effects of two nonlinear stability derivatives on the longitudinal motions of an aircraft have been investigated. Nonlinear functions of pitching-moment and lift coefficients with angle of attack were considered. Analog results of aircraft motions in response to step elevator deflections and to the action of the proportional control systems are presented. The occurrence of continuous hunting oscillations was predicted and demonstrated for the attitude stabilization system with proportional control for certain nonlinear pitching-moment variations and autopilot adjustments.
Date: December 29, 1950
Creator: Curfman, Howard J., Jr.
System: The UNT Digital Library
Free-Flight Investigation of Control Effectiveness of Full-Span 0.2-Chord Plain Ailerons at High Subsonic, Transonic, and Supersonic Speeds to Determine Some Effects of Section Thickness and Wing Sweepback (open access)

Free-Flight Investigation of Control Effectiveness of Full-Span 0.2-Chord Plain Ailerons at High Subsonic, Transonic, and Supersonic Speeds to Determine Some Effects of Section Thickness and Wing Sweepback

Report discusses the development and testing of a rocket-propelled test vehicle to investigate aerodynamic control effectiveness at high subsonic, transonic, and supersonic speeds. Modifications to the section thickness and wing sweepback to improve performance are also described. A description of the vehicle, instrumentation, accuracy, and evaluation of testing results is included.
Date: May 29, 1947
Creator: Sandahl, Carl A. & Marino, Alfred A.
System: The UNT Digital Library
Longitudinal Stability and Control Characteristics at High Subsonic Speeds of Two Models of a Transonic Research Airplane With Wings and Horizontal Tails of Aspect Ratios 4.2 and 2 (open access)

Longitudinal Stability and Control Characteristics at High Subsonic Speeds of Two Models of a Transonic Research Airplane With Wings and Horizontal Tails of Aspect Ratios 4.2 and 2

Report discussing an investigation of two transonic research airplane models at a range of Mach numbers and Reynolds numbers. The main difference between the models was the aspect ratio of the horizontal tail. Results regarding the stability, control, incremental horizontal-tail characteristics, downwash, horizontal-tail load, stability factors, and a tailless configuration are provided.
Date: September 29, 1950
Creator: Luoma, Arvo A. & Wright, John B.
System: The UNT Digital Library