Ditching Investigation of a 1/18-Scale Model of the North American B-45 Airplane (open access)

Ditching Investigation of a 1/18-Scale Model of the North American B-45 Airplane

An investigation of a 1/18-scale dynamically similar model of the North American B-45 airplane was made to observe the ditching behavior and determine the proper landing technique to be used in an emergency water landing. Various conditions of damage were simulated to determine the behavior which probably would occur in a full-scale ditching. The behavior of the model was determined from high-speed motion-picture records, time-history acceleration records, and visual observations. It was concluded that the airplane should be ditched at the maximum nose-high attitude with the landing flaps full down for minimum landing speed. During the ditching, the nose-wheel and bomb-bay doors probably will be torn away and the rear of the fuselage flooded. A violent dive will very likely occur. Longitudinal decelerations of approximately 5g and vertical accelerations of approximately -6g (including gravity) will be experienced near the pilots' compartment. Ditching braces installed in the bomb bay will tend to improve the behavior slightly but will be torn away along with the bomb-bay doors. A hydroflap installed ahead of the nose-wheel doors will eliminate the dive and failure of the nose-wheel doors, and substantially reduce the motions and accelerations.
Date: December 22, 1949
Creator: Fisher, Lloyd J. & Thompson, William C.
System: The UNT Digital Library
Theoretical antisymmetric span loading for wings of arbitrary plan form at subsonic speeds (open access)

Theoretical antisymmetric span loading for wings of arbitrary plan form at subsonic speeds

A simplified lifting-surface theory that includes effects of compressibility and spanwise variation of section lift-curve slope is used to provide charts with which antisymmetric loading due to arbitrary antisymmetric angle of attack can be found for wings having symmetric plan forms with a constant spanwise sweep angle of the quarter-chord line. Consideration is given to the flexible wing in roll. Aerodynamic characteristics due to rolling, deflected ailerons, and sideslip of wings with dihedral are considered. Solutions are presented for straight-tapered wings for a range of swept plan forms.
Date: December 22, 1949
Creator: DeYoung, John
System: The UNT Digital Library
Effects of wing flexibility and variable air lift upon wing bending moment during landing impacts of a small seaplane (open access)

Effects of wing flexibility and variable air lift upon wing bending moment during landing impacts of a small seaplane

From Summary: "A smooth-water-landing investigation was conducted with a small seaplane to obtain experimental wing-bending-moment time histories together with time histories of the various parameters necessary for the prediction of wing bending moments during hydrodynamic forcing functions. The experimental results were compared with calculated results which include inertia-load effects and the effects of air-load variation during impact. The responses of the fundamental mode were calculated with the use of the measured hydrodynamic forcing functions. From these responses, the wing bending moments due to the hydrodynamic load were calculated according to the procedure given in R.M. No. 2221. The comparison of the time histories of the experimental and calculated wing bending moments showed good agreement both in phase relationship of the oscillations and in numerical values."
Date: December 21, 1949
Creator: Merten, Kenneth F. & Beck, Edgar B.
System: The UNT Digital Library
Flight Test of the Aerojet 7KS-6000 T-27 Jato Rocket Motor (open access)

Flight Test of the Aerojet 7KS-6000 T-27 Jato Rocket Motor

"A flight test of the Aero jet Engineering Corporation's 7KS-6000 T-27 Jato rocket motor was conducted at the Langley Pilotless Aircraft Research Station at Wallops Island, Va, to determine the flight performance characteristics of the motor. The flight test imposed an absolute longitudinal acceleration of 9.8 g upon the rocket motor at 2.8 seconds after launching. The total impulse developed by the motor was 43,400 pound-seconds, and the thrusting time was 7.58 seconds" (p. 1).
Date: December 20, 1949
Creator: Bond, Aleck C. & Thibodaux, Joseph G., Jr.
System: The UNT Digital Library
A Free-Flight Technique for Measuring Damping in Roll by Use of Rocket-Powered Models and Some Initial Results for Rectangular Wings (open access)

A Free-Flight Technique for Measuring Damping in Roll by Use of Rocket-Powered Models and Some Initial Results for Rectangular Wings

Report presenting a simplified method for obtaining free-flight measurements of damping in roll through the use of rocket-powered models. Initial configurations have been tested for a range of Mach numbers. Results regarding the rolling velocity with two different airfoil sections and damping-in-roll coefficient are provided.
Date: December 20, 1949
Creator: Edmondson, James L. & Sanders, E. Claude, Jr.
System: The UNT Digital Library
Comparison of Effectiveness of Coordinated Turns and Level Sideslips for Correcting Lateral Displacement During Landing Approaches (open access)

Comparison of Effectiveness of Coordinated Turns and Level Sideslips for Correcting Lateral Displacement During Landing Approaches

Memorandum presenting a calculation of the amount of possible correction for coordinated turns with limited bank angle and level sideslips for a large transport airplane, the C-54D. The results indicate that for all instances from the end of the runway, coordinated turns are the more effective maneuver.
Date: December 15, 1949
Creator: Faber, Stanley
System: The UNT Digital Library
Low-Speed Investigation of Deflectable Wing-Tip Ailerons on an Untapered 45 Degrees Sweptback Semispan Wing With and Without an End Plate (open access)

Low-Speed Investigation of Deflectable Wing-Tip Ailerons on an Untapered 45 Degrees Sweptback Semispan Wing With and Without an End Plate

Report presenting a low-speed wind-tunnel investigation to determine the characteristics of deflectable wing-tip ailerons on an untapered 45 degree sweptback semispan wing. Ailerons with triangular and parallelogram plan forms with a maximum chord of 0.625 wing chord and a flat-plat profile were investigated. The aerodynamic characteristics in pitch and lateral control characteristics are included.
Date: December 14, 1949
Creator: Fischel, Jack & Watson, James M.
System: The UNT Digital Library
Preliminary Investigation of a Variable Mass-Flow Supersonic Nose Inlet (open access)

Preliminary Investigation of a Variable Mass-Flow Supersonic Nose Inlet

Memorandum presenting a method for varying the mass flow of supersonic inlets with a circular cross section and a central body. The method consists of changing the size of the entering stream tube by means of an inflatable boot on the surface of the central body.
Date: December 13, 1949
Creator: Hayes, Clyde
System: The UNT Digital Library
Comparative Tests of the Rolling Effectiveness of Constant-Chord, Full-Delta, and Half-Delta Ailerons on Delta Wings at Transonic and Supersonic Speeds (open access)

Comparative Tests of the Rolling Effectiveness of Constant-Chord, Full-Delta, and Half-Delta Ailerons on Delta Wings at Transonic and Supersonic Speeds

Report presenting comparative tests of the rolling power of plain constant-chord, full-delta, and half-delta ailerons on delta wings with varying degrees of sweepback were tested on rocket-propelled test vehicles. Results regarding the effect of leading-edge sweepback, a comparison of rolling effectiveness, and comparison with theory are provided.
Date: December 12, 1949
Creator: Sandahl, Carl A. & Strass, H. Kurt
System: The UNT Digital Library
Experimental investigation at supersonic speeds of side scoops employing boundary-layer suction (open access)

Experimental investigation at supersonic speeds of side scoops employing boundary-layer suction

Report presenting the pressure-recovery characteristics of a model with two scoops situated on the aft position of a long forebody and connected through diffusors to a common settling chamber at a range of Mach numbers. The effects of interaction between the flow in the two air-induction systems and of varying the mass flow through the boundary-layer scoops were studied. Results at several different angles of attack are provided.
Date: December 12, 1949
Creator: Edwards, Sherman S.
System: The UNT Digital Library
The effects of scale and test technique on the validity of small-scale measurements of the aerodynamic characteristics of a wing with the leading edge swept back 63 degrees (open access)

The effects of scale and test technique on the validity of small-scale measurements of the aerodynamic characteristics of a wing with the leading edge swept back 63 degrees

Report presenting the lift and pitching-moment characteristics of two wings of the same plan form measured over a range of Mach and Reynolds numbers using the wing-flow method. One wing had a symmetrical airfoil section and no twist, while the other was cambered and twisted to support a uniform load distribution at a lift coefficient of 0.25 at Mach number 1.5. A comparison with previous testing is also provided.
Date: December 9, 1949
Creator: Rolls, L. Stewart
System: The UNT Digital Library
An empirical criterion for fin stabilizing jettisonable nose sections of airplanes (open access)

An empirical criterion for fin stabilizing jettisonable nose sections of airplanes

"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.
System: The UNT Digital Library
Investigation of a Thin Wing of Aspect Ratio 4 in the Ames 12-Foot Pressure Wind Tunnel 5: Static Longitudinal Stability and Control Throughout the Subsonic Speed Range of a Semispan Model of a Supersonic Airplane (open access)

Investigation of a Thin Wing of Aspect Ratio 4 in the Ames 12-Foot Pressure Wind Tunnel 5: Static Longitudinal Stability and Control Throughout the Subsonic Speed Range of a Semispan Model of a Supersonic Airplane

Memorandum presenting wind-tunnel tests of a semispan model of a hypothetical supersonic airplane to determine the static longitudinal stability and control characteristics of the airplane throughout the range of subsonic Mach numbers up to 0.95. The model had a long slender fuselage and a wing and horizontal tail of aspect ratio 4 and taper ratio 0.5. Results regarding the force and moment characteristics, wing wake and effective downwash at the horizontal tail, effects of compressibility, and longitudinal characterisitcs with the flaps deflected are provided.
Date: December 8, 1949
Creator: Johnson, Ben H., Jr. & Rollins, Francis W.
System: The UNT Digital Library
Full-Scale Hydrodynamic Evaluation of a Modified Navy J4F-2 Amphibian with a 0.425-Scale XP5M-1 Hull Bottom: TED No. NACA DE325 (open access)

Full-Scale Hydrodynamic Evaluation of a Modified Navy J4F-2 Amphibian with a 0.425-Scale XP5M-1 Hull Bottom: TED No. NACA DE325

"An investigation was made to evaluate the hydrodynamic qualities of a 0.425-scale model of the Navy XP5M-1 hull, which was installed on a modified Navy J4F-2 amphibian. Longitudinal and directional stability during take-off and landing, low-speed maneuverability, spray characteristics, and take-off performance were investigated. The behavior of the airplane in moderately rough water was also observed. The opinions of three pilots have been correlated with the data" (p. 1).
Date: December 7, 1949
Creator: Land, Norman S.; Elliott, John M. & Christopher, Kenneth W.
System: The UNT Digital Library
Aerodynamic Study of a Wing-Fuselage Combination Employing a Wing Swept Back 63 Degrees: Effects at Subsonic Speeds of a Constant-Chord Elevon on a Wing Cambered and Twisted for a Uniform Load at a Lift Coefficient of 0.25 (open access)

Aerodynamic Study of a Wing-Fuselage Combination Employing a Wing Swept Back 63 Degrees: Effects at Subsonic Speeds of a Constant-Chord Elevon on a Wing Cambered and Twisted for a Uniform Load at a Lift Coefficient of 0.25

Report presenting testing of a cambered and twisted wing with constant-chord elevons with a slender fuselage to determine the longitudinal and lateral control from the elevons for a range of Mach numbers. Results regarding lift, drag, pitching-moment, and rolling-moment characteristics for various elevon deflections are provided.
Date: December 5, 1949
Creator: Jones, J. Lloyd & Demele, Fred A.
System: The UNT Digital Library
Investigation of altitude performance of AN-F-58 fuels in annular combustor of J34-WE-22 engine (open access)

Investigation of altitude performance of AN-F-58 fuels in annular combustor of J34-WE-22 engine

From Summary: "An investigation was conducted in the combustor of a 3000-pound-thrust turbojet engine to determine the altitude performance characteristics of AN-F-58 fuels. Three fuels conforming to AN-F-58 specification were prepared in order to determine the influence of boiling-temperature range and aromatic content on altitude performance. The performance of the three AN-F-58 fuels was compared with the performance of AN-F-48 (grade 100/130) fuel in the range of simulated altitudes from 20,000 to 55,000 feet, corrected engine speeds from 6000 to 12,500 rpm, and flight Mach numbers of 0.2 and 0.6."
Date: December 5, 1949
Creator: Tischler, Adelbert O. & Scull, Wilfred E.
System: The UNT Digital Library
Survey of two-dimensional data on pitching-moment changes near maximum lift caused by deflection of high-lift devices (open access)

Survey of two-dimensional data on pitching-moment changes near maximum lift caused by deflection of high-lift devices

Report presenting a survey of two-dimensional data on trim changes near maximum lift resulting from deflection of various types of leading-edge and trialing-edge high lift devices. Results regarding pitching-moment coefficients, pitching-moment increments, and maximum lift coefficients are provided.
Date: December 2, 1949
Creator: Bidwell, Jerold M. & Cahill, Jones F.
System: The UNT Digital Library
Aerodynamic characteristics of the NACA 8-H-12 airfoil section at six Reynolds numbers from 1.8 x 10(exp 6) to 11.0 x 10(exp 6) (open access)

Aerodynamic characteristics of the NACA 8-H-12 airfoil section at six Reynolds numbers from 1.8 x 10(exp 6) to 11.0 x 10(exp 6)

Report presenting an investigation in the two-dimensional low-turbulence pressure tunnel to determine the aerodynamic characteristics of the NACA 8-H-12 airfoil section at four Reynolds numbers. The section lift, drag, and pitching-moment characteristics are presented for smooth and rough surface conditions. Generally, no unusual scale effects are present for either condition.
Date: December 1949
Creator: Schaefer, Raymond F. & Smith, Hamilton A.
System: The UNT Digital Library
Analysis of means of improving the uncontrolled lateral motions of personal airplanes (open access)

Analysis of means of improving the uncontrolled lateral motions of personal airplanes

From Summary: "The purpose of this investigation was to determine whether such airplanes could be made to fly uncontrolled for an indefinite period of time without getting into dangerous attitudes and for a reasonable period of time (one to three minutes) without deviating excessively from their original course. The results of this analysis indicated that the uncontrolled motions of a personal airplane could be made safe as regards spiral tendencies and could be greatly improved as regards maintenance of course without resort to an autopilot."
Date: December 1949
Creator: McKinney, Marion O., Jr.
System: The UNT Digital Library
Effect of airfoil section and tip tanks on the aerodynamic characteristics at high subsonic speeds of an unswept wing of aspect ratio 5.16 and taper ratio 0.61 (open access)

Effect of airfoil section and tip tanks on the aerodynamic characteristics at high subsonic speeds of an unswept wing of aspect ratio 5.16 and taper ratio 0.61

Report presenting an investigation of the effect of two wing sections and a tip tank on the aerodynamic characteristics of a rigid unswept wing in the high-speed tunnel over a Mach number range of 0.60 to 0.90. Results regarding the effect of original airfoil sections, effect of modifications to Section B, effect of tip tank, and characteristics of the tip tank in the presence of the wing are provided.
Date: December 1, 1949
Creator: Silvers, H. Norman & Spreeman, Kenneth P.
System: The UNT Digital Library
Experimental Investigation of Flutter of a Propeller With Clark Y Section Operating at Zero Forward Velocity at Positive and Negative Blade-Angle Settings (open access)

Experimental Investigation of Flutter of a Propeller With Clark Y Section Operating at Zero Forward Velocity at Positive and Negative Blade-Angle Settings

Report presenting an investigation of the flutter of a small one-blade wooden propeller with a Clark Y section. The highest flutter speeds were found in the vicinity of the angle of zero aerodynamic moment, with flutter speed increasing in this region with decreasing pressure.
Date: December 1949
Creator: Baker, John E. & Paulnock, Russell S.
System: The UNT Digital Library
Landing Procedure in Model Ditching Tests of Bf 109 (open access)

Landing Procedure in Model Ditching Tests of Bf 109

The purpose of the model tests is to clarify the motions in the alighting on water of a land plane. After discussion of the model laws, the test method and test procedure are described. The deceleration-time-diagrams of the landing of a model of the Bf 109 show a high deceleration peek of greater than 20g which can be lowered to 4 to 6g by radiator cowling and brake skid.
Date: December 1949
Creator: Sottorf, W.
System: The UNT Digital Library
On Internal Damping of Rotating Beams (open access)

On Internal Damping of Rotating Beams

Note presenting an investigation to derive the implications of a previously derived equation for rotating beams.
Date: December 1949
Creator: Morduchow, Morris
System: The UNT Digital Library
Plastic buckling of a long flat plate under combined shear and longitudinal compression (open access)

Plastic buckling of a long flat plate under combined shear and longitudinal compression

Report presenting the condition for plastic buckling of a long flat plate under combined shear and longitudinal compression is obtained by using the theory of plastic buckling developed for simple loading, provided the ratio of shear to longitudinal compression is assumed constant during the loading process. A detailed calculation for a number of simply supported plates made of a typical aluminum alloy shows that an approximate algebraic relationship provided in the paper will suffice for determination of buckling stress.
Date: December 1949
Creator: Stowell, Elbridge Z.
System: The UNT Digital Library