On the flying qualities of helicopters (open access)

On the flying qualities of helicopters

Report presenting the flying qualities problems of current helicopters, including instability with angle of attack in forward flight, control sensitivity in hovering, and control forces following control movement in maneuvers. Some possible solutions to these issues are presented.
Date: January 27, 1949
Creator: Reeder, John P. & Gustafson, F. B.
System: The UNT Digital Library
Wind-tunnel investigation of horizontal tails. 5: 45 degree swept-back plan form of aspect ratio 2 (open access)

Wind-tunnel investigation of horizontal tails. 5: 45 degree swept-back plan form of aspect ratio 2

Report presenting the results of a wind-tunnel investigation of the low-speed aerodynamic characteristics of a 45 degree sweptback horizontal-tail model of aspect ratio 2 and a comparison of these results with results for a model of the same aspect ratio with an unswept hinge line. Results regarding the lift and hinge-moment parameters, static longitudinal stability, effect of Reynolds number, effect of standard roughness, effect of removing elevator nose seal, and visualization of the air flow are provided.
Date: September 27, 1949
Creator: Dods, Jules B., Jr.
System: The UNT Digital Library
Flight Investigation From High Subsonic to Supersonic Speeds to Determine the Zero-Lift Drag of a Transonic Research Vehicle Having Wings of 45 Degree Sweepback, Aspect Ratio 4, Taper Ratio 0.6, and NACA 65A006 Airfoil Sections (open access)

Flight Investigation From High Subsonic to Supersonic Speeds to Determine the Zero-Lift Drag of a Transonic Research Vehicle Having Wings of 45 Degree Sweepback, Aspect Ratio 4, Taper Ratio 0.6, and NACA 65A006 Airfoil Sections

Report presenting rocket-powered flight tests from high subsonic to supersonic speeds and at high Reynolds numbers to determine the zero-lift drag of a transonic wing-body and body-alone configuration. The configuration tested featured a wing of 45 degree sweepback, aspect ratio 4, taper ratio 0.6, and an NACA 65A006 airfoil section, and a body of fineness ratio of 10 and a frontal area equal to 6.06 percent of the wing-plan-form area.
Date: October 27, 1949
Creator: Katz, Ellis
System: The UNT Digital Library
Experimental Pressure Distributions Over Wing Tips at Mach Number 1.9 1 - Wing Tip With Subsonic Leading Edge (open access)

Experimental Pressure Distributions Over Wing Tips at Mach Number 1.9 1 - Wing Tip With Subsonic Leading Edge

An investigation was conducted at a Mach number of 1.91 to determine spanwise pressure distribution over a wing tip in a region influenced by a sharp subsonic leading edge swept back at 70 degrees. Except for pressure distribution on the top surface in the immediate vicinity of the subsonic leading edge, the maximum difference between linearized theory and experimental data was 2 1/2 percent (of free-stream dynamic pressure) for angles of attack up to 4 degrees and 7 percent for angles of attack up to 8 degrees. Pressures on the top surface nearest the subsonic edge indicated local expansions beyond values predicted by linearized theory.
Date: January 27, 1949
Creator: Jagger, James M. & Mirels, Harold
System: The UNT Digital Library
Lateral-Control Investigation on a 37 Degree Sweptback Wing of Aspect Ratio 6 at a Reynolds Number of 6,800,000 (open access)

Lateral-Control Investigation on a 37 Degree Sweptback Wing of Aspect Ratio 6 at a Reynolds Number of 6,800,000

Memorandum presenting the low-speed lateral-control characteristics of a 37 degree sweptback semispan wing of aspect ratio 6 and NACA 64-series airfoil sections in the 19-foot pressure tunnel. The investigation included the measurement of the hinge-moment characteristics of an aileron and the rolling-effectiveness characteristics of the aileron and two configurations of spoilers.
Date: January 27, 1949
Creator: Graham, Robert R. & Koven, William
System: The UNT Digital Library
Effects of Mach number and sweep on the damping-in-roll characteristics of wings of aspect ratio 4 (open access)

Effects of Mach number and sweep on the damping-in-roll characteristics of wings of aspect ratio 4

An investigation of the damping-in-roll characteristics of three wings with an aspect ratio of 4, a taper ratio of 0.6, three sweep angles at the quarter chord line, and the NACA 65A006 section as determined through a range of Mach numbers and angles of attack.
Date: June 27, 1949
Creator: Kuhn, Richard E. & Myers, Boyd C., II
System: The UNT Digital Library
Dynamics of a turbojet engine considered as a quasi-static system (open access)

Dynamics of a turbojet engine considered as a quasi-static system

From Summary: "A determination of the dynamic characteristics of a typical turbojet engine with a centrifugal compressor, a sonic-flow turbine-nozzle diaphragm, and fixed area exhaust nozzle is presented. A generalized equation for transient behavior of the engine was developed; this equation was then verified by calculations using compressor and turbine performance charts extrapolated from equilibrium operating data and by experimental data obtained from an engine operated under transients in fuel flow."
Date: July 27, 1949
Creator: Otto, Edward W. & Taylor, Burt L., III
System: The UNT Digital Library
Hovering and Low-Speed Performance and Control Characteristics of the Kaman Helicopter Rotor System as Determined on the Langley Helicopter Tower. TED No. NACA DE 205 (open access)

Hovering and Low-Speed Performance and Control Characteristics of the Kaman Helicopter Rotor System as Determined on the Langley Helicopter Tower. TED No. NACA DE 205

From Summary: "An investigation has been conducted with the Langley helicopter tower to obtain basic performance and control characteristics of the Raman rotor system. Blade-pitch control is obtained in this configuration by utilizing an auxiliary flap to twist the blades. Rotor thrust and power required were measured for the hovering condition and over a range of wind velocities from 0 to 30 miles per hour. The control characteristics and the transient response of the rotor to various control movements were also measured."
Date: September 27, 1949
Creator: Carpenter, Paul J. & Paulnock, Russell S.
System: The UNT Digital Library
Take-Off Stability Characteristics of a 1/13-Scale Model of the Consolidated Vultee Skate 7 Seaplane (TED No. NACA DE 338) (open access)

Take-Off Stability Characteristics of a 1/13-Scale Model of the Consolidated Vultee Skate 7 Seaplane (TED No. NACA DE 338)

The take-off stability characteristics of a Consolidated Vultee Aircraft Corporation Skate 7 seaplane were determined in the Langley tank no. 2. Trim limits of stability, trim tracks, and elevator limits of stability are presented.
Date: April 27, 1949
Creator: McKann, Robert; Coffee, Claude W. & Arabian, Donald D.
System: The UNT Digital Library