Report discussing the results of an investigation to determine the low-speed power-off stability and control characteristics of a model of the Bell D-188A VTOL airplane. The static stability and control characteristics were generally satisfactory except above certain angles of attack and aileron effectiveness dropped off as the angle of attack was increased. Modifications for increasing the directional stability by altering the vertical tails are also described.

"An investigation was conducted to determine the electric power requirements necessary for ice protection of inlet guide vanes by continuous heating and by cyclical de-icing. Data are presented to show the effect of ambient-air temperature, liquid-water content, air velocity, heat-on period, and cycle times on the power requirements for these two methods of ice protection. The results showed that for a hypothetical engine using 28 inlet guide vanes under similar icing conditions, cyclical de-icing can provide a total power saving as high as 79 percent over that required for continuous heating" (p. 1).

Report presenting an investigation in the transonic pressure tunnel to determine the afterbody pressure distribution and fin loading characteristics of two configurations of the TX-21 special weapon. The only different in the two configurations was the nose contour, with one having a hemispherical-flat shape and one with a double-radius ogive-flat shape. Results regarding the pressure port, fin loads, and force measurements are provided.

Report discussing various inlet design philosophies based on the results of testing at Mach numbers up to 5. The most ideal inlet design was found to be one with combined external-plus-internal compression due to problems noted with both external-only and internal-only inlets.

Report discussing an evaluation of a series of half-conical side inlets mounted on the fuselage of a supersonic aircraft at various Mach numbers. Information about the maximum total-pressure recovery, asymmetrical operation of the twin-duct system, potential reduction in stable mass-flow range, boundary-layer diverter height, and engine mass flow is described.

Effect of variation of combustion chamber length and inlet temperature on low pressure-loss sea level afterburner. A 70-percentage-point reduction in combustion efficiency resulted when the combustion-chamber length was reduced from 62 to 10 inches.

Report presenting an investigation of the aerodynamic characteristics of a model of the Grumman F9F-9 airplane in the transonic tunnel. Results regarding the transonic drag-rise increment, drag analysis, and effective downwash angle are provided.

Report discussing the influence of forces and moments on a fighter-bomber airplane with an open bomb bay and on two bluff bomb shapes in various positions below the fuselage and plane of symmetry. The wing was found to have a noticeable effect on bomb forces and that bluff bombs affect the longitudinal characteristics of the wing-fuselage combination.

Memorandum presenting an assessment of the importance of the addition lag of the monowing versus a cruciform shape on a missile.

Report presenting testing regarding the Bell X-2 supersonic research airplane, which is equipped with a skid main landing gear and nose wheel, to determine the low-speed handling qualities and landing characteristics. Results regarding the landing approach pattern, time histories, and final resting position of the airplane at landing are provided.

"This document contains reproductions of technical papers presented by staff members of the NACA Laboratories at the NACA Conference on Aerodynamics of High-Speed Aircraft held at the Langley Aeronautical Laboratory November 1, 2, and 3, 1955. The primary purpose of the conference was to convey to contractors of the military services and others concerned with the design of aircraft the results of recent research and to provide those attending with an opportunity to discuss these results. The papers in this document are in the same form in which they were orally presented at the conference to facilitate their prompt distribution" (p. vii).

A series of 11 fuels ranging in volatility and including various types of hydrocarbons were tested in a single tubular combustion chamber of a turbojet engine under inlet-air conditions simulating engine operation at two speeds at an altitude of 40,000 feet. Temperature-rise data at various fuel-air ratios were obtained for each set of air-flow conditions. Results regarding the effect of combustor inlet-air conditions on temperature rise, four different series of tests, and a review of some general considerations are provided.

Report presenting a procedure for calculating pressure distributions over airfoils at supercritical Mach numbers. Only the forward portion of the airfoil, where interaction between local boundary-layer thickness and local-pressure distribution is negligible, is considered in detail. The method cannot be considered definitive because it requires that certain characteristics regarding pressure distributions and geometric properties be known.

Report presenting a preliminary theoretical and experimental investigation of the supersonic characteristics of blunt-trailing-edge airfoils. Results regarding the drag measurements at zero lift, measurements at angle of attack, and a general discussion of the theoretical and experimental results is provided.

Report discussing a wing-alone and wing-fuselage configuration with particular characteristics as part of a series of tests of wings using the transonic-bump test technique. Lift, drag, pitching moment, and root bending moment were obtained for the configurations. The effective downwash angles and dynamic-pressure characteristics in the tail region are also described.

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.

The results of an experimental investigation of the downwash and wake characteristics behind a rectangular plan-form wing of aspect ratio 3.5 are presented. The airfoil section was a 5-percent-thick, symmetrical double wedge. The tests were made at a Mach number of 1.53 and a Reynolds number of 1.25 million. A comparison between experimental and theoretical values of the downwash angles is made.

Memorandum presenting an investigation conducted to evaluate the effectiveness of a simple internal regenerative fuel preheater for a 20-inch-diameter ram jet. Data obtained at subsonic sea-level conditions indicated that fuel could be successfully preheated in this manner.

Report presenting the results of an experimental investigation of rim cracking in a welded-blade composite gas-turbine wheel, in two carbon-steel disks, and five tool-steel disks. Various characteristics were investigated, including the effectiveness of holes in preventing crack propagation and the influence of hardness and various types of notch on rim cracking.

Report presenting the results of an experimental investigation to determine the pressure-recovery and mass-flow characteristics of single and twin NACA submerged intakes on the sides of a fuselage at various angles of sideslip. Tests were conducted with single and twin submerged intakes on a model of a fighter-type airplane.

Report presenting measurements of elevator-stabilizer effectiveness and trim of the X-1 airplane at 40,000 feet altitude at a range of Mach numbers and normal-force coefficients.

Report presenting a rocket-powered model of the X-3 configuration flown through a range of Mach numbers to determine the response of the model to rapid deflections of the horizontal tail and its effects on lift, drag, longitudinal stability and control, and longitudinal-trim change. The model was found to remain statically and dynamically stable through the lift-coefficient and Mach number range of the test.

Report presenting an investigation of the overall performance of the J35-A-23 compressor, which is a 16-stage compressor designed to produce a total-pressure ratio of 8.75 at an equivalent flow of 155 pounds per second and an equivalent speed of 6100 rpm. Tests were run at a range of flows and speeds. Notes on installation and characteristics of the compressor are also provided.

Report presenting an experimental investigation of pyramidal, wedge-like bodies as devices for delaying separation of a turbulent boundary layer. Within certain limits, effective boundary-layer control was obtainable with wedges of different geometry, but the drag of the wedges was high, making it desirable to keep their size to a minimum. Greater maximum lift was obtainable by placing the wedges well forward along the chord and by allowing open spaces between adjacent wedges.