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Wind-Tunnel Investigation of the Stability of the Jettisonable Nose Section of the X-3 Airplane

Description: "Because previous work has indicated that jettisonable nose sections of airplanes may be inherently unstable, and thus may cause dangerous centripetal accelerations on a pilot after jettisoning during high-speed flight, an investigation has been conducted in the Langley 20-foot free-spinning tunnel to determine the behavior in descent of a model of the jettisonable nose section of the Douglas X-3 airplane. The effects of varying the center-of-gravity position, of attaching fins of various sizes, and of installing a stabilizing parachute were investigated. In the investigation the model descended with its front and trimmed 36 deg above the horizontal and rotated about a vertical wind axis while rolling about its longitudinal body axis" (p. 1).
Date: December 8, 1946
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

An analytical investigation of airplane spin-recovery motion by use of rotary-balance aerodynamic data

Description: From Introduction: "Many investigations have been made in the Langley 20-foot free-spinning tunnel in which the natures of airplane spins and recoveries have been determined experimentally with dynamically scaled-down models. The results of some of these investigations are presented in references 1 to 5."
Date: June 1954
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Analysis of a spin and recovery from time histories of attitudes and velocities as determined for a dynamic model of a contemporary fighter airplane in the free-spinning tunnel

Description: From Introduction: "In this paper are presented descriptions of the camera setups and associated equipment, the equations and methods used in determining the model attitudes and motions from the film, and time-history curves of the variables of the spin and recovery investigated. Discussions of the nature of the spin and recovery obtained and of factors ostensibly affecting these motions are included."
Date: April 1956
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Effect of 40 degree sweepback on the spin and recovery characteristics of a 1/25-scale model of a typical fighter-type airplane as determined by free-spinning-tunnel tests

Description: Note presenting free-spinning-tunnel tests performed with a model of a typical fighter-type airplane to determine the effect of a 40 degrees sweepback on the spin and recovery characteristics. The characteristics were obtained for both a swept-wing and an unswept-wing configuration for a range of typical fighter loading conditions and two tail designs. The results indicated that for the model with a tail design considered unsatisfactory as regards spin recovery, sweeping the wings back 40 degrees improved the recovery characteristics.
Date: April 1947
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Estimated deceleration of airplane nose section jettisoned at various altitudes and airspeeds

Description: Memorandum presenting calculations made to determine the deceleration at any time after jettisoning of an airplane nose-section design typical of those which have been proposed as escape devices for high-speed airplanes. The decelerations were determined by two methods, one using successive approximations requiring graphical integration and the other giving reasonably close approximations by direct computation.
Date: January 8, 1951
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Pilot escape from spinning airplanes as determined from free-spinning-tunnel tests

Description: Procedure for pilot escape from spinning airplanes has been determined by means of tests in which pilot escape was simulated from 21 airplane models spinning in the Langley 20-foot free-spinning tunnel. The results in general indicated that the pilot should bail out of the outboard side. Calculated centripetal accelerations acting on the pilot during a spin are presented.
Date: October 1951
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

An empirical criterion for fin stabilizing jettisonable nose sections of airplanes

Description: "Investigations in the Langley 20-foot free-spinning tunnel of models of five jettisonable nose sections have shown that the airplane nose sections are inherently unstable but can be stabilized by the addition of suitable fins. An empirical criterion has been developed which indicates the fin area required for stabilizing an airplane jettisonable nose section" (p. 1).
Date: December 8, 1949
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Pilot's loss of orientation in inverted spins

Description: Note presenting a discussion of the nature of inverted spins, the optimum control technique for recovery, and some of the apparent reasons for a pilot's loss of orientation, which can lead to accidents. Results regarding testing in the free-spinning-tunnel, airplane experiences, and a description of a new spinning simulator rig designed to investigation the orientation loss problem are provided.
Date: October 1955
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the behavior of parachutes in close proximity to one another

Description: Memorandum presenting an investigation in which the behavior of parachutes in close proximity to one another was studied by using small parachutes attached to thin wires in the 20-foot free-spinning tunnel. The results indicate that the parachutes, when side by side, generally had little effect on one another and may sometimes have had slight repelling effects.
Date: August 13, 1953
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the effects of various asymmetric canopy modifications on the behavior of descending parachutes

Description: Report presenting an investigation in the free-spinning tunnel to study the behavior in descent of hemispherical and quasi-conical parachutes, some with symmetrical canopy modifications and all with a right circular cylinder suspended by one end below the parachute. Results indicated that a lateral flight component during descent could be obtained by using a circular cutout in the side of the canopy of a hemispherical parachute and a large slit between two panels of a quasi-conical parachute.
Date: February 15, 1952
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the stability of jettisoned nose sections of the D-558 airplane: phases I and II

Description: Report presenting an investigation of the stability of models of the jettisonable nose sections of D-558 airplanes in two phases. The effects of center-of-gravity location and stabilizing fins of various sizes were also determined. The noses were found to tumble end over end at an approximately horizontal axis, which may be dangerous to the pilot if the nose is jettisoned while the airplane is traveling at a high rate of speed.
Date: January 14, 1948
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the opening characteristics, drag, and stability of several hemispherical parachutes

Description: Report presenting an investigation to determine the opening characteristics of several hemispherical parachutes at airspeeds up to 200 miles per hour and to study the influence of the parachute design variables on the opening characteristics. The effects of design variables on the drag and stability characteristics of the parachutes were also evaluated.
Date: April 1949
Creator: Scher, Stanley H. & Gale, Lawrence J.
Partner: UNT Libraries Government Documents Department

The effects of stability of spin-recovery tail parachutes on the behavior of airplanes in gliding flight and in spins

Description: Note presenting an investigation with airplane models in the free-flight and 20-foot free-spinning tunnels to determine whether a stable parachute could be safely towed behind an airplane in flight and whether it would be effective as a spin-recovery device. Results regarding the parachute characteristics, behavior in gliding flight, spin-recovery effectiveness, and effect of increasing towline length are provided.
Date: May 1950
Creator: Scher, Stanley H. & Draper, John W.
Partner: UNT Libraries Government Documents Department

Stability of bodies of revolution having fineness ratios smaller than 1.0 and having rounded fronts and blunt bases

Description: Memorandum presenting an investigation of the stability of several bodies of revolution having fineness ratios smaller than 1.0 and having rounded fronts and blunt bases. Free-drop tests were made in the vertical 20-foot free-spinning tunnel to determine the behavior of the various bodies in descent.
Date: January 29, 1953
Creator: Scher, Stanley H. & Bowman, James S., Jr.
Partner: UNT Libraries Government Documents Department

Free-Spinning-Tunnel Tests of a 1/27-Scale Model of the Douglas XF3D-1 Airplane, TED No. NACA DE 312

Description: Free-spinning-tunnel tests have been made on a 1/27-scale model of the Douglas XF3D-1 airplane to confirm a preliminary evaluation made of the airplane spin and recovery characteristics and previously reported. Recovery characteristics were satisfactory for erect and inverted spins when the model was in the clean condition. When the slow-down brakes were open, recoveries were slow. The pedal force necessary to reverse the airplane rudder during a spin will be within the physical capabilities of the pilot. A 10-foot-diameter parachute attached to the tail of the airplane (laid-out-flat diameter, drag coefficient 0.7) or a 4.5-foot-diameter parachute attached to the outboard wing tip will be satisfactory for emergency spin recovery from demonstration spins. If it becomes necessary for the crew to abandon the airplane during a spin, they should leave from the outboard side of the cockpit. The test results indicated spin and recovery characteristics generally similar to those indicated in the preliminary evaluation.
Date: 1947
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Preliminary Evaluation of the Spin and Recovery Characteristics of the Douglas XF3D-1 Airplane

Description: "A preliminary evaluation of the spin and recovery characteristics of the XF3D-1 airplane has been made, based primarily on the results of the free-spinning tunnel tests of a model which closely simulated the XF3D-1 in tail design, tail length, and mass loading. Estimates have been made of the rudder-pedal force that may be encountered in effecting recovery from a spin and of the spin recovery parachute requirements of the airplane for demonstration spins. The method of bail-out which should be used if it becomes necessary for the crew to abandon the airplane during a spin is indicated" (p. 1).
Date: July 3, 1947
Creator: Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Status of spin research for recent airplane designs

Description: Report presenting the status of spin research for recent airplane designs as interpreted. Some of the major problem areas discussed include interpretation of results of spin-model research, analytical spin studies, techniques involved int he measurement of various parameters in the spin, effectiveness of controls during spins and recoveries, influence of long noses, strakes, and canards on spin and recovery characteristics, and correlation of airplane and model spin and recovery characteristics.
Date: August 16, 1957
Creator: Neilhouse, Anshal I.; Klinar, Walter J. & Scher, Stanley H.
Partner: UNT Libraries Government Documents Department

Free-spinning-tunnel investigation of a 1/20-scale model of the Douglas A4D-1 airplane: TED No. NACA DE 389

Description: Report presenting an investigation of the spin and recovery characteristics of a 1/20-scale dynamic model of the Douglas A4D-1 attack airplane in the 20-foot free-spinning tunnel. Erect spins and recoveries were investigated with the model in the clean condition and the loading condition, which includes a center external store with and without two external wing fuel tanks installed. Results regarding several conditions, including erect spins, no external stores, horizontal-tail incidence, 4 degrees leading edge up; erect spins, stores installed; landing conditions, inverted spins, spin-recovery parachute tests, and recommended recovery technique and control forces are provided.
Date: January 19, 1955
Creator: Klinar, Walter J.; Scher, Stanley H. & Healy, Frederick M.
Partner: UNT Libraries Government Documents Department