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A method is described by which concentration distortion of particulates of arbitrary sizes caused by airflow around airplane fuselages can be calculated. The method accounts for effects of: three-dimensional details of the fuselage shape on airflow, angle-of-attack on airflow, altitude, interaction of the particles with the airflow, and particle settling. It has been applied to hydrometeor sampling instruments on three cloud physics airplanes: Lockheed C130A and C130E transports, and a Cessna Citation jet. Detailed results for water drops and ice columns are presented.

Recent international atmospheric research programs such as BOMEX and IFYGL have been of such a large scale that several aircraft are required to collect data, which, when combined with radiosonde and surface measurements, ultimately form a large internationally-accessible data bank. A fundamental part of the program should be an intercomparison between the measuring aircraft. This report presents results of two such intercomparison flights between the NAE T-33 and NCAR Buffalo atmospheric research aircraft, with the NCAR Sabreliner providing additional data on one of the flights. Data from these flights, which were flown at different altitudes on two days with quite different atmospheric conditions, show generally good agreement, particularly for mesoscale meteorological parameters averaged over the length of a run. Spectra of microscale variables including true gust velocity, heat and momentum flux are compared over a frequency band common to both aircraft. The spectra for longitudinal gusts and temperature fluctuations show excellent agreement between the aircraft, but discrepancies are apparent in the Buffalo vertical gust spectra and resultant fluxes during these flights.

Final results on the development of a precision and automated capability for determining dynamic data for modular aerodynamic configurations (MAC) in free-flight are presented. The system developed includes a modified single engine aircraft with bomb release and various electronic capabilities, a digital telemetry system, a telemetry receiving van with associated receiving and recording elements, and the MAC's with instrumentation devices, soft recovery parachute systems and flight safety equipment. Descriptions are given of drop test of MAC's from the aircraft and of MAC wind tunnel tests.

Covering the efforts of the United States from 1945 to September 1959 to wrestle with the unknown ramifications of space, this history includes both the civilian and military activities. An Air Force History of Space Activities presents a more detailed treatment of information published in 1960 under the title of Threshold of Space, 1945-1959. Other monographs on this subject include The Air Force in Space, 1959-1960, and (in draft) a sequel for fiscal year 1961. The author of this history begins with the work of the early pioneers in rocketry, the first satellite feasibility studies by the military, and the relationship of the ballistic missile to the space vehicle. He reviews the Russian and U.S. space programs between 1945 and 1957, during which efforts were made to create space law and the United States chose to pursue a space-for-peace policy. The conservatism of policy makers raised obstacles, but there were space projects, some of them under the Air Force. After the shock of Sputnik I, the reshaping of policy resulted in the establishment of ARPA in the Department of Defense and NASA as the civilian space agency. The authors tells of ARPA's supremacy over the military services in 1958; its loss of control to NASA in October 1958; NASA's activities from then until July 1959; the position of the Air Force after losing out to both ARPA and NASA; and the Air Force's determination to cooperate with NASA, through research, development, and the use of its facilities. Within the DoD in 1959, authority for space research and development was transferred from ARPA to DDR&E, interservice tension mounted, the Air Force struggled to regain lost projects and objected to Navy's appeal for a military space command, and the tide turned for the Air Force when the Secretary of Defense decided in September to give to it the responsibility for the development and launching of all DoD space boosters and for management of Sentry, Midas, and Discoverer.

Identifiers: X-15.A survey of maximum structural temperatures measured on the X-15 airplane during speed flights up to a Mach number of 6 is presented. Structural problems caused by local hot spots and discontinuities encountered during the flight are also discussed. In general, the hot-structure concept used for the primary structure of the X-15 airplane has proven to be satisfactory. Problems have arisen only from local hot spots and discontinuities. These problems include windshieldglass failures, airflow through openings in the external structure, and structural discontinuities. Comparison of calculated and measured internal temperatures has shown that satisfactory thermal gradients through the structure can be calculated from known heat input to the exposed surfaces.

The report provides engineering data, including results of teardown inspection, flight tests, and evaluation of flight characteristics, for two manned flexible-wing aerial utility vehicles XV-8A., Sponsored in part by the Defense Advanced Research Projects Agency.

The paper reports on the design, construction, instrumentation and preliminary testing performed on the highlift wing of the MARVELETTE aircraft in a two-dimensional wind tunnel. The wind tunnel, 12 feet high and 2 feet 9 inches wide was fitted over a section of the aircraft wing to the shrouded propeller at the rear of the vehicle. When operating with this arrangement, wind tunnel velocities up to 60 miles per hour were obtainable in the test section. The tunnel provided more data in a few weeks of operation than would have been obtained in a number of months using a flight program with a considerable number of flights close to minimum flight speeds., See also AD608187.

The report presents calculated installed performance characteristics for the U. S. Army XV-5A propulsion system. The propulsion system consists of two General Electric X353-5B power-plants, one G. E. X376 pitch control fan, and associated ducting, controls and accessory equipment. Installed performance of turbojet mode is presented for ARDC Standard Day and ANA 421 Hot Day for one and two engine operation. Performance data include gross thrust, propulsion system drag, net thrust, fuel flow and cooling system drag. A sea level static thrust of 4,920 pounds is estimated for an ARDC Standard Day. For ANA 421, Hot Day conditions at 2,500 feet altitude, static thrust is 4,250 pounds. A detailed analysis of J85 engine operation at near idle condition (47% to 60% rpm) showed that exhaust gas temperature increased rapidly with increasing engine air inlet temperature and shaft power extraction. Thus, to preclude exceeding exhaust gas temperature limits, due to reingestion of hot engine exhaust gases and/or varying power extraction for system checkout, a minimum rpm of 70% for the J85 engines is recommended for XV-5A fan mode operation. The engine air inlet shows excellent performance throughout its required operating envelope. A minimum total pressure recovery of 98.4% is available for static operation and the pressure recovery exceeds 99% for high speed cruise flight at Mach 0.7. (Author), Rept. on XV-5A Lift Fan Flight Research Aircraft Program. See also AD647386.

A program was conducted to determine the feasibility of the augmented jet ejector concept for attaining a VTOL capability for aircraft. During the flight test program, the actual vertical thrust realized was only about 93 percent of that predicted, and consequently the aircraft, the XV-4A, had a marginal lift capability. This marginal lift capability severely limited the capability to conduct quantitative data gathering during the flight test program. The report presents the limited quantitative results obtained and a brief summary of the aircraft design, systems, flight test program, VTOL lift improvement program, and small-scale and full-scale wind tunnel programs. The feasibility of the augmented jet ejector concept was demonstrated; however, this concept is not considered to be competitive with other concepts for attaining a VTOL capability.

This volume of the FWT report presents photographs with a brief identification of hardware condition and discrepancies found after completion of tests described in Specifications number 114 and 115. Certificates of inspection are included. Clearance checks were identical with original assembly values., Rept. on VZ-11 Lift Fan Flight Research Aircraft Program. See also AD0634950.

This specification defines the acceptance test requirements for the X376, ducted, pitch trim control fan conforming to Specification No. 113., Revision of document submitted 18 April 1962. Report on VZ- 11 Lift Fan Flight Research Aircraft Program. See also AD0634944.

This specification defines the flightworthiness rating test requirements for the X353-5B convertible, ducted lift fan propulsion system. The X353-5B propulsion system is comprised of a J85-GE-5 turbojet engine, less afterburner, used as a gas generator plus two additional major components: a diverter valve to direct the gas flow; and an X353-5B lift fan., Report on VZ-11 Lift Fan Flight Research Aircraft Program. See also AD0634944.

VZ-11 Lift Fan Flight Research Aircraft Program.

An X353-5B propulsion system comprised of two J85-GE-5 turbojet engines without afterburners, two X353-5B diverter valves, one X353-5 lift fan and one X376 pitch trim control fan was assembled and tested. The specified testing was completed. The J85 gas generators were unaffected by the presence of the X353-5B propulsion system. The diverter valves and the pitch fan met or exceeded performance requirements at all operating conditions. The lift fan met or exceeded performance requirements at all but one condition (single engine lift). There were only minor discrepancies found in the diverter valve and pitch fan hardware at disassembly. The lift fan had considerable damage resulting from the shedding of a small metal tab from the rotor during the last endurance cycle of the test. Lift fan aluminum inlet vanes and exit louvers were of generally poor manufacturing quality and did not satisfactorily complete the test. It was recommended that a flightworthiness rating be assigned to the X353-5B propulsion system upon satisfactory completion of a 10-hour penalty test of new lift fan inlet vanes and exist louvers., Report on VZ-11 Lift Fan Flight Research Aircraft Program. See also AD0634950.

This specification defines the acceptance test requirements for the lift fan and diverter value components of the X353-5B convertible, ducted, lift fan propulsion system conforming to Specification No. 112., Revision of document submitted 15 Apr 1962. Report on VZ-11 Lift Fan Flight Research Aricraft Program. See also AD0634945.

This specification defines the flightworthiness rating test requirements for the X376, ducted, pitch trim control fan. The General Electric X376 pitch fan is designed for supplying augmented control and trim force in V/ STOL systems. It is comprised of a single stage, tip-turbine driven fan supplied with turbojet exhaust gas bleed through two separated nozzle scrolls. The double scroll arrangement provides single-engine operating capability in a two-engine, cross-ducted lift propulsion system., Revision of document submitted 25 Mar 62. Report on VZ-11 Lift Fan Flight Research Aircraft Program. See also AD0634944.

This specification covers the characteristics of the X376 Pitch Fan intended for use in a piloted flight research airplane. The General Electric X376 Pitch Fan is a high liftweight ratio gas-driven lift fan for supplying augmented control and trim force in V/STOL systems. The X376 Pitch Fan comprises a single stage, tip-turbine driven lift fan supplied with turbojet exhaust gas bleed through two separate nozzle scrolls. The double scroll arrangement provides single-engine operating capability in a two-engine, cross- ducted lift propulsion system., Report on VZ-11 Lift Fan Flight Research Aircraft Program. See also AD634946.

Representatives of the Air Force Command and the Ministry of Heavy Industry attended the first flight of a new turbine-driven helicopter built in Poland. It was based on the project of the Soviet constructor Prof. Mikhail Mil' Technical processes unknown in Poland were applied for the first time by the Transportation Equipment Plant in Swidnik, where extensive research has been undertaken to develop this and future aircraft. The new helicopter is fully equipped with radio-navigational and technical-exploitation devices. (Author), Unedited rough draft trans. from Zolnierz Wolnosci (Poland) p1, 31 Aug 65, by L. Marokus.

The report presents the results of an investigation of performance evaluation and comparison methods as applied to V/STOL aircraft. Attention is given to a number of aircraft having different sizes, gross weights, geometric configurations, and propulsion systems. Particular regard is given to the use of thermal fuel energy as a common basis for evaluation and comparison of V/STOL performance. The performance capabilities of typical V/STOL aircraft are presented and compared using both dimensional and nondimensional parameters containing fuel flow rate as a variable. In addition, three aircraft of different configurations are analyzed with regard to the effects of altitude, gross weight, and payload-to-fuel load ratio on the performance capability of each aircraft as indicated by both new and conventionally used methods. The total energy concept is discussed with regard to the optimization of climb schedules, and consideration is given to the limitations which apply to the use of nondimensional parameters which are used to describe the flow regimes of V/ STOL aircraft.

The report describes the preliminary design of the Army VTOL Rotary Wing Composite Research Aircraft (CRA). The vehicle is configured to meet the requirements, and satisfy the objectives, of this program. This CRA design was the result of combining the most desirable features of a helicopter with those of a fixed-wing aircraft. The vehicle derived was capable of hovering as a helicopter with low rotor downwash velocity and yet cruise at high speed with economy and little noise or vibration. Use of the rigid-rotor system supplied positive control moments, in-flight rotor stop/start capability, and a simple blade-folding/stowing mechanism. The CRA can fly up to the conversion speed in the helicopter mode transfer lift and control to the conventional fixed-wing surfaces, stop the rotor, fold the blades and retract the rotor and blades into the top of the fuselage. This process is reversible to convert from the fixed-wing configuration to the helicopter. The results of the study indicate that the CRA is feasible and additional study and development should be undertaken. (Author)

The component tests included fatigue tests of the blade root-end and constant section areas, hub gimbal system, spar-to-segment and root-fitting-to- spar attachments, and material evaluation tests of the blade spars. Sealing tests were conducted on the joint between the Y-duct and tri-duct in the hub area, the joint area between the gas generator and diverter valve, and the fixed-duct joint on the rotor blade. Blade natural frequency tests were conducted to ensure that the natural frequencies of the rotor blade would not be in a critical frequency range. The instrumented flight blade was calibrated in a test fixture before the flight test program., See also AD621684.

A preliminary design study of a hot cycle rotor/wing composite research aircraft is described. The hot cycle rotor/wing uses a single lightweight lifting surface which functions as both a rotor for takeoff and a fixed wing for horizontal flight. The rotary/wing is essentially an equilateral delta wing with short feathering blades at the three corners. The rotor is powered by a tip-jet hot cycle drive, and the turbojet exhaust is diverted from the rotor to provide forward propulsion. The hot cycle rotor/wing provides the advantages of hovering efficiency, low downwash velocity, and helicopter-like flying qualities for vertical and low-speed flight, in addition to the high- speed capability and cruise efficiency of the jet airplane. Its simplicity and light weight are made possible through the combined use of the all-pneumatic hot cycle drive system and the dual-purpose rotor/wing lift system. This eliminates the need for heavy and complex mechanical drive components and anti-torque tail rotor; it permits flight as a helicopter and as an airplane without recourse to duplicate lifting systems or to folding, tilting, or retracting of lift systems to effect conversion.

Supersedes AD401523.

Hydrogen peroxide of 90 percent purity was catalytically decomposed in experimental equipment simulating the LR-99 engine gas generator system in the X-15 aircraft. The performance of peroxides produced by three different methods was evaluated.

The structural analyses of the fuselage space frame, engine mounts and the propulsion system supports of the U. S. Army XV-5A Lift Fan Research Aircraft are presented. The space frame internal loads analysis was performed utilizing the IBM 704 computer program developed in conjunction with the XV-5A wing basic components analysis. Therefore, much of the report is made up of the deflections and internal member loads program output for the several loading conditions investigated. The space frame member critical loads are summarized and member allowables and margins of safety are presented. The propulsion system, including crossover ducts, tailpipe and forward engine support is reviewed and supporting structure analyzed for critical loading conditions., Rept. on XV-5A Lift Fan Flight Research Aircraft Program. See also Volume 1, AD653563.

Contents: Present and Future Helicopter Dynamic Loads Research; Dynamic Loads Problems; Status of Helicopter Dynamic Load Problems at Hiller Aircraft Company; Dynamic Loads Research; Helicopter Dynamic Loads Research Requirements; Dynamic Load Problems Associated with V/STOL Aircraft; Unresolved Dynamic Loads Problems Associated with V/STOL Aircraft of Conventional Structural Configurations; Dynamic Load Problems Associated with V/STOL aircraft; Two XV-5A Dynamic Load Characteristics; and Dynamic Load Problems of V/STOL Aircraft., See also Volume 1, AD819970. Prepared in cooperation with Cornell Aeronautical Lab.

This specification covers the characteristics of the X353-5B convertible V/STOL propulsion system intended for use in a piloted flight research airplane. The General Electric X353-5B Engine is a high lift-weight ratio convertible engine for turbojet operation and augmented lift operation. The basic X353-5B Engine comprises a turbojet engine modified for non-reheat operation, a tip-turbine lift fan augmenting turbojet thrust for V/STOL lift and propulsive thrusts, a gas diverter valve for selecting engine operating mode, and associated engine controls and accessories. The two part scroll on each lift fan permits incorporation of the X353-5B into an airplane powerplant configuration comprising two (2) basic X353-5B convertible engines pneumatically coupled such that each turbojet provides half of the required driving power for each of the lift fans. Rotors of the two lift fans rotate in opposite directions to minimize gyroscopic relations. All performance figures, weights, quantities, etc., in this specification are given for one X353-5B (one turbojet engine, one fan, one diverter valve) unless specifically stated otherwise., Report on VZ-11 Lift Fan Flight Research Aircraft Program. See also AD0634944.

The X353-5B propulsion system consists of a J85-GE-5 turbojet engine (less afterburner) used as a gas generator, a diverter valve to direct the gas flow, and an X353-5B lift fan equipped with vectorable discharge louvers. The X376 pitch trim control fan derives its power from turbine discharge bleed of J85-GE-5 turbojet engines (less after-burners). The X376 is a partial admission tip turbine-driven fan which is connected to the J85 engines through airframe- provided ducting. The fan employs two separate scrolls containing the turbine inlet nozzles; this feature provides for one-engine-out operation., Rept. on XV-5A Lift Fan Flight Research Aircraft Program.

This report covers the nine-month period from 1 April 1969 through essential program completion 31 December 1969. Activities were highlighted with two major milestones in the second quarter of 1969, the final Military Pilot Evaluation (MPE) and the aircraft acceptance by NAVAIR. The remainder of the period represented effort completing final reports, the 'live' storage of the X- 22A pending new contract flying, and the disassembly of Aircraft No. 1 for salvageable spare parts. During April, the Phase II final MPE (Figure 1) took place. Following ground school training and cockpit checks, eleven flights totaling twelve hours were flown on six consecutive days with five military pilots flying the aircraft., See also Monthly progress rept. no. 63, AD0837097. Also includes Flight Test Summary.

The Propulsion System Test Stand operated 6.3 hours. Installations of the reworked shafts, couplings, viscous mounts, and Beta control were completed. The stand was also stiffened to eliminate stand vibration at high engine speeds. Phase II variable pitch operation was initiated. Using the Master Control and Beta System, the propeller speed control was checked satisfactorily. The Flight Control-Hydraulic System Test Stand was completed and checked, less the duct rotation system installation. The Feel System overdrive and Elevon instability were investigated. The Test Stand was used, excluding these trouble areas, to perform development testing. In the shop, aircraft No. 1 progressed with Wing and Fin permanent installations. Systems fabrication and installation moved satisfactorily. Fuselage No. 2 was removed from the basic fixture into aircraft No. 2 final assembly. After cleanup, systems installations were started. Fuselage No. 3 for static test was begun. Major components for aircraft No. 1 are essentially completed. Components for No. 2 are in final phases and No. 3 for static test are progressing.

A 1/6-scale unpowered model of a ducted-propeller, V/STOL aircraft (Bell X-22A) was tested in an 8 by 10-foot, rectangular, atmospheric wind tunnel. During this test numerous modifications were made to the initial configuration selected during phase I investigation. Most of these modifications involved detail changes of the vertical tail in order to develop satisfactory aerodynamic stability characteristics. The test was restricted to the cruise regime. Data are presented in tabular form as aerodynamic coefficients in the stability axes system and in the body axes system.

For the forward flight regime, a limited comparison is made between theoretical predictions of duct pressure distributions and data obtained from one-third and full scale model tests of the X-22A ducted propeller unit. The theoretical calculations are based upon previous studies of ducted propellers with finite blade number. It is found that the theory is in reasonable agreement with experiment and generally tends to underestimate the measured pressures. Also, the characteristic shape of the predicted distribution agrees well with the measured distribution.

A 1/6-scale model of a ducted-propeller V/STOL aircraft (Bell X-22A0 was tested in an 8- by 10-foot, rectangular, atmospheric wind tunnel. The investigation was restricted to the cruise regime in which longitudinal stability and directional stability of various configurations of the basic aircraft were studied. These modifications to the vertical tail and the wing trailing edge were investigated in an attempt to improve stability. Tabulated data are presented in both stability axes and body axes systems.

Rerigging the aileron droop system reduced the lateral unbalance and improved the stall of the model 309A-309C airplane. The stall was brought to normal by changing the horizontal tail incidence from -3 deg to -1.25 deg. The breakdown, climb, and approach speeds were determined for conditions with the boundary-layer-control system on and off; the elevator area was increased by a 3-in. Al strip added to the trailing edge. Efforts will be directed toward developing the demonstrator airplane rather than the research airplane, because of difficulties envisaged in the installation of a 2-cycle gasoline engine in the research plane. The model 319A demonstrator plane will consist of an L-19 fueslage, a thicker wing to accommodate the fans, a 225-hp Continental engine, and a Hartzell constant-speed propeller. Hydraulic motors driven by a hydraulic pump belted to the engine were considered the most promising source of motive power for the 2 axial fans from the standpoint of mechanical efficiency and availability. Calculations indicated that the hydraulic system will afford a 20% decrease in take-off distance over a 50-ft obstacle.