ALBERT

Beschreibung: A flight-test program to determine the flight characteristics of large jet transports equipped with powered-lift systems indicated the following results: Speed margins appear to be primarily related to power-on stall speeds. At these speed margins, the maneuver margins were adequate and did not appear to be a problem or limiting factor during powered-lift operation. No large detrimental effects on handling qualities were apparent but in some areas stability augmentation would be required to obtain satisfactory flight characteristics. Use of the powered-lift airplane would result in a sizable increase in the noise levels; these increases are primarily the result of higher engine power settings in the approach.

Beschreibung: During 5 1/2 years of flight research with a deflected-jet VTOL aircraft a 2 number of operational problems were experienced and investigated. These experiences can be grouped into two general categories: (1) the effects of the jet engine and its operation and (2) the restrictions imposed upon the pilot's operation due to reduced visual reference. This report is an examination of these problems and., in some cases, presents possible solutions to these problems.

Beschreibung: This paper covers the unique features and different modes of operation of V/STOL and STOL aircraft which result in new operating problems and serves to introduce the papers which deal in more detail with some of the more important V/STOL and STOL operating problems.

Beschreibung: The information of the paper is in the form of a status report on the state of knowledge of sonic-boom phenomena, dealing first with the pressure buildups in the transonic speed range and with the lateral extent of the pattern in steady flight for quiescent atmospheric conditions. There are also discussions of recent data from flight-test studies relating to atmospheric dynamic effects on the sonic-boom signatures, and finally, brief discussions of the significance of signature shape on the response of people and structures. The acceleration and lateral-spread phenomena appear to be fairly well understood and predictable for current and future aircraft. Variations in the sonic-boom signature as a result of the effects of the atmosphere can be expected during routine operations. From the data evaluated to date, very similar variations in pressure signatures are noted for both fighter and bomber aircraft. The greatest questions still exist in the area of community acceptance of sonic booms. A more definitive answer to the community-acceptance problem will have to await adequate flight experience with larger aircraft.

Beschreibung: An assessment is given of the materials problems and implications regarding the use of Ti-8Al-1Mo-IV alloy sheet for the skin of a supersonic transport. Although the assessment of this alloy in the duplex annealed condition is generally favorable, several questions remain unanswered and new ones continue to arise. The seriousness of the salt stress corrosion problem at 500 F and above under flight conditions cannot be predicted on the basis of current laboratory corrosion tests. A new potential stress corrosion problem at ambient temperatures in the presence of cracks and salt water requires investigation. The ability to withstand a 30,000-hour exposure at 550 F without undue degradation of the material or welds will remain doubtful until more long-time data are available. The substitution of a more corrosion-resistant and stable titanium alloy in the tension critical areas of the structure may prove advisable.

Beschreibung: A study of the problems anticipated with the introduction of the supersonic transport into the air traffic control system indicated that supersonic transport design allowances for time and fuel for maneuvering during climbouts may not be sufficient, that there is a greater communications-navigation work- load for the supersonic transport than for the subsonic jet transport during descent, and that use of a flight director to command pitch control guidance for the pilot would be helpful.

Beschreibung: Fixed-cockpit piloted simulator studies of delta-planform and variable-wing-sweep supersonic transport configurations are being conducted at the Ames Research Center to investigate the handling qualities and certification requirements related to the take-off maneuver. Validation of the simulation was achieved by duplicating the take-off certification program of a subsonic jet transport. Evaluation of the simulator was made by NASA pilots as well as company and FAA pilots involved in the actual certification flights of the airplane. The present paper is limited to a discussion of normal take-off, minimum control speed (ground), rotation characteristics, and initial climbout. Comparisons of the take-off characteristics are made between the supersonic transport and the current class of subsonic jet transports. Results indicate that minimum control speed (ground) characteristics are a function of thrust-weight ratio, the time provided for SST rotation should be at least as long as that for the subsonic jet transports, abused take-offs are more likely to result in tail scrapes, and climbout below the minimum drag speed requires that the pilot carefully monitor airspeed.

Beschreibung: Simulator studies of the deep-stall problem encountered with modern airplanes are discussed. The results indicate that the basic deep-stall tendencies produced by aerodynamic characteristics are augmented by operational considerations. Because of control difficulties to be anticipated in the deep stall, it is desirable that adequate safeguards be provided against inadvertent penetrations.

Beschreibung: This paper describes the NASA noise-survey instrumentation system presently in use at Edwards Air Force Base, California, and presents preliminary noise data from an F-104 airplane. Also presented are noise measurements of the XB-70 and 707-131B airplanes obtained with essentially the same equipment at another location. The difference between measured noise levels for the XB-70 and 707 is illustrated and comparisons of perceived noise levels are made. The adequacy of noise predictions -Ls discussed briefly.

Beschreibung: A research program to study in flight the display, sensor, and computer requirements for airborne, manually piloted zero-zero landing systems is being undertaken at the Ames Research Center. An evaluation has been made, on a flight simulator, of the display which will be used in the flight tests. Results show that on the simulator the pilots performed at least as well when they used the display for zero-zero approaches and landings as they did when they made simulated ILS approaches followed by simulated VFR breakouts and landings. In some aspects, particularly in the presence of crosswind, performance for the zero-zero display landings was somewhat better than for the ILS-VFR landings. Eight configurations of the display were studied in an attempt to evaluate the several elements in the display. There was no evident difference among the eight display configurations. The pilots who participated in the simulator program doubt that this result will carry over into flight.

Beschreibung: Turbulence data obtained from recent flights of the U-2 airplanes and from the National Severe Storms Project agree in general with the results obtained in previous investigations. The data show that nonstorm turbulence decreases in intensity and amount with increasing altitude. Less than 2 percent of the flight distance was in turbulence at altitudes above 50,000 feet. It also appears that the root-mean-square gust velocities of the composite turbulence patches may be 15 to 20 percent lower than previous estimates.

Beschreibung: Recent studies of NASA research related to aircraft operating problems on rough runways are presented. Some of these investigations were conducted cooperatively with the airport operators, with the Federal Aviation Agency, and with the U.S. Air Force. The studies show that criteria based on power spectral levels of runway-profile data are not sufficient to define acceptable levels of runway roughness from the piloting viewpoint. Because of the large variation in response characteristics between various types of aircraft, a runway may be acceptable for some aircraft and unacceptable for others. A criterion for roughness, therefore, should be expressed in terms of aircraft response - preferably, cockpit acceleration. A criterion suggested is that the maximum vertical acceleration in the cockpit should not exceed +/- 0.4 g for sections of the runway where precise aircraft control is required.

Beschreibung: A summary on spinning is presented to point out the state of the art and the most important parameters', and to show the effects of these parameters on the spin and spin-recovery characteristics. The discussion presented applies to the fully developed spin, but does not apply to the spin entry, or incipient spin. The principal factors in spinning are mass distribution, which is by far the most important single parameter, and tail design, which is particularly important for conditions of zero or near-zero loading. By knowing the mass distribution and tail design, it is possible in many cases to predict whether an airplane has satisfactory spin-recovery characteristics. In other cases, however, it is necessary to make spin tests to assure satisfactory recovery.

Beschreibung: A study has been made, using a piloted moving simulator, of the effects of the yaw-coupling parameters N(sub p) and N(sub delta(sub a) on the lateral-directional handling qualities of a large transport airplane at landing-approach airspeed. It is shown that the desirable combinations of these parameters tend to be more proverse when compared with values typical of current aircraft. Results of flight tests in a large variable-stability jet transport showed trends which were similar to those of the simulator data. Areas of minor disagreement, which were traced to differences in airplane geometry, indicate that pilot consciousness of side acceleration forces can be an important factor in handling qualities of future long-nosed transport aircraft.

Beschreibung: Although the major NASA research effort is directed toward XB-70-2, which will not enter its flight program until the summer of 1965, a limited amount of information is available from the early flights of the XB-70-1 airplane. Initial take-off and landing performance data have generally substantiated predictions and indicate no unforeseen problems for this class of vehicle. Vertical velocities at impact are of the same order of magnitude as those being experienced by present-day subsonic jets. The XB-70 distances from brake release to lift-off graphically illustrate the advantage of the increased thrust-weight ratio of the supersonic cruise vehicle. The landing loads are well within the design limits up to the highest vertical velocities encountered to date, and recorded data show the response at the pilot station to be somewhat greater than that recorded at the center of gravity. Persistent shaking has been encountered in flight at subsonic speed. The cause of the excitation is not known at present but the oscillation does not appear to be conventional buffeting. The oscillation occurrence drops off appreciably at supersonic speeds and can be correlated with atmospheric turbulence. The stability and control characteristics at subsonic speeds appear satisfactory with stability augmentation on and off. A longitudinal trim discrepancy from predictions has been noted in the transonic region which appears to be decreasing with increasing supersonic speed. The supersonic handling qualities are considered adequate with stability augmentation off; however, sensitive lateral control has resulted in small pilot-induced oscillations.

Beschreibung: An investigation of several factors which may contribute to the problem of piloting jet transport aircraft in heavy turbulence was conducted by using a piloted simulator that included the most significant airplane response and cockpit vibrations induced by rough air. Results indicated that the primary fuselage structural frequency contributed significantly to a distracting cockpit environment, and there was obtained evidence of severely reduced instrument flight proficiency during simulated maneuvering flight in heavy turbulence. It is concluded that the addition of similar rough-air response capabilities to training simulators would be of value in pilot indoctrination in turbulent-flight procedures.

Beschreibung: Recent results obtained from NASA V-G and VGH recorders installed on commercial turbine-powered transports have indicated that exceedances of placard speeds appear to have been significantly reduced since the placard speeds have been redefined and changes made in the aural warning. Oscillatory accelerations and unusual events, such as large or rapid departures from the planned flight profile, occur less frequently. Landing-impact accelerations are higher for turbine transports than for piston transports and vary with operator. The total in-flight acceleration experiences for turbine transports, however, are not significantly different from those for four-engine piston transports.

Beschreibung: Factors relating to the airport-community noise problem are discussed herein. The noise problems are associated with aircraft landing approaches, take-offs, and climbouts in communities near commercial airports. The main objectives are to identify the significant factors involved in the problem, to define some of their interrelationships, and to present recent related research information from NASA in-house and contract studies. Changes in the types of aircraft power plants, the aircraft operating procedures, and the community itself are all judged to be important; however, these changes should not be made without understanding the associated human-response implications.

Beschreibung: Various methods of providing runway information in the cockpit during the take-off and landing roll have been proposed. The most reliable method has been to use runway distance markers when visible. Flight tests were used to evaluate the feasibility of using weak radio-active sources to trigger a runway distance counter in the cockpit. The results of these tests indicate that a weak radioactive source would provide a reliable signal by which this indicator could be operated.

Beschreibung: Preliminary studies of steep instrument approaches have been conducted with three conventional aircraft. Six-degree approach paths were found to be acceptable. A margin of 3 deg to 4 deg in maximum glide slope was available to allow for flight-path corrections. Control of the lateral-directional axis was the most difficult problem for pilots making either steep or conventional approaches; split-axis control reduced the pilot workload during this operation.

Beschreibung: The effects of surface temperature and imperfections on the drag of the supersonic transport are discussed. The relationships among surface temperature, emissivity, and skin friction are reviewed and the importance of manufacturing and maintenance imperfections is indicated.

Beschreibung: This volume describes subsonic, transonic, and supersonic facilities called wind tunnels in the classical sense; that is, facilities which provide essentially continuous steady streams of gas which are cool enough so there is no significant dissociation, and in which test models are generally stationary translationally. Ames facilities for gasdynamic tests in which model translation provides a significant portion of the test speed are described in Volume I, "Guns and Ranges." For quick reference, this volume includes a tabular summary of Ames subsonic, transonic, and supersonic wind tunnels. The table is followed by more detailed descriptions. Tabulated information on most major wind tunnels in the United States can be found in Reference 1.

Beschreibung: An investigation is currently under way to determine the operational practices and load experiences of general aviation aircraft performing five basic types of operations: twin-engine executive, single-engine executive, personal, instructional, and commercial survey. Limited data obtained to date from aircraft engaged in these operations indicate that aircraft are generally being operated within the limits to which they were designed.

Beschreibung: Studies of a number of STOL aircraft show that relatively high maximum lift-coefficients and large increases in lift due to power are within the present state of the art. With these lift characteristics, approach speeds of the order of 60 knots for aircraft of moderate wing loading can be realized. Full advantage of the STOL performance of aircraft such as those discussed herein may not be realized on a routine operational basis, however, without some form of damping augmentation system because of lateral-directional handling considerations, particularly for large aircraft operating under instrument flight conditions. Satisfactory characteristics can be obtained by use of only a servodriven rudder. Additional experience is needed to determine how the STOL aircraft is to be operated before more firm requirements for augmentation systems can be established.

Beschreibung: Some aspects of V/STOL operation in a terminal area have been presented. A V/STOL instrument approach with present-day displays and guidance systems requires about 5 minutes at low speeds, but this time could be cut to 1 1/2 to 2 minutes if the displays and guidance systems were improved. In order to keep approach-pattern time to a minimum, the conversion process should be simplified by interconnecting as many operations as possible with one control. Adequate vectoring for the lifting system, attitude stabilization to prevent excessive wandering, and automatic glide-path control for approaches over 6 deg. will also be required.

Beschreibung: This paper presents a discussion of the sensitivity of supersonic-transport design and operation to sonic-boom considerations and shows the necessity for a study of these problems early in the development program. Methods of predicting pressure signatures are outlined and examples of the correlation of these estimates with wind-tunnel and flight measurements are shown. Estimates of sonic-boom characteristics for a representative supersonic transport show that in the critical transonic acceleration portion of the flight, overpressures somewhat lower than estimated by the use of far-field assumptions may be expected. Promising design possibilities for the achievement of further overpressure reductions are explored.

Beschreibung: An analysis of the interaction of operational environment and aircraft characteristics of the supersonic transport (SST) in the areas of design-range and reserve-fuel requirements has been made. Design-range requirements are considered in relation to the effects of wind, temperature, flight-level assignment, and payload variation. An approach toward combining en route and holding reserve requirements while maintaining protection equivalent to that provided subsonic jet transport operations by the present civil air regulation en route plus holding reserves is given. This approach results in a savings in reserve fuel over that required by separate requirements.

Beschreibung: The purpose of this brief introduction is to define the objectives of the program and to describe the manner in which it is being pursued. The study is directed toward problems anticipated with the introduction of the supersonic transport into the air-traffic-control system. The primary objectives are: (1) The determination of the effects of the SST (supersonic transport) on requirements of the ATC (air traffic control) system. (2) The determination of the effects of the ATC system on requirements for the SST design and for its equipment. Basically, the program is a simulation effort involving equipment both at Langley and at the NAFEC facility. A block diagram illustrating the manner in which the equipment of the two agencies has been integrated to carry out the program. The Langley equipment includes a cockpit, or flight compartment that is generally representative of transport equipment, and an analog computer for solving the six-degree-of-freedom motion equations for an aircraft having the characteristics of the SST design under study.

Beschreibung: A wind-tunnel research program has been under-taken by the NASA to study the aerodynamic characteristics of T-tail aircraft at high angles of attack. The program was designed to show the effects on longitudinal stability and control of several configuration variables. The results to date do not allow the formulation of general design rules, but the effects of several configuration variables have been noted to have a prime influence on the post-stall characteristics. An increase in tail size, changes in the location of fuselage-mounted engine nacelles, and reduced fuselage-forebody lift were all found to have a beneficial effect on static longitudinal stability at high angles of attack.

Beschreibung: A flight program, utilizing a Convair 880 and a Boeing 720 airplane, was conducted in conjunction with wind-tunnel and simulator programs to study problems related to jet-transport upsets and operation in a turbulent environment. During the handling-qualities portion of the program the basic static stability of the airplanes was considered to be satisfactory and the lateral-directional damping was considered to be marginal without damper augmentation. An evaluation of the longitudinal control system indicated that this system can become marginal in effectiveness in the high Mach number and high dynamic-pressure range of the flight envelope. From the upset and recovery phase of the program it was apparent that retrimming the stabilizer and spoiler deployment were valuable tools in effecting a positive recovery; however, if these devices are to be used safely, it appears that a suitable g-meter should be provided in the cockpit because the high control forces in recovery tend to reduce the pilot's sensitivity to the actual acceleration loads. During the turbulence penetrations the pilot noted that the measured vibrations of 4 to 6 cps in the cockpit considerably disrupted their normal scan pattern and suggested that an improvement should be made in the seat cushion and restraint system. Also it was observed that the indicator needles on the flight instruments were quite stable in the turbulent environment.

Beschreibung: Calculations and experiments have been undertaken to determine the property of the backscattered laser-return signal that undergoes the most significant change in a turbulent region as compared with a nonturbulent region. If the turbulent region is composed mainly of air molecules, the detection of a shift in the frequency property appears to be the most promising. Therefore at this time the main effort at the Ames Research Center is focused on the implementation and laboratory evaluation of a clear-air turbulence detector utilizing a laser source and observing the frequency change.

Beschreibung: Several points of interest to the operator of aircraft are reviewed. Rates of crack propagation are shown to be high, and residual static strength is shown to decrease more significantly in high strength materials than in lower strength materials. Ground-air-ground and other negative loadings produce much more dn.mage than previously recognized or predicted. In first approximation, fatigue life is used in units corresponding to the number of flights, rather than to miles or hours as is commonly thought. Regular inspection for cracks is the only real way to assure safe operation of flight structures.

Beschreibung: Recent work on the traction of pneumatic tires on wet runways is discussed, and it is shown that a loss of tire traction adversely affects cross-wind landings. The effect of runway surface texture is discussed,, and a simple method for measuring surface texture is described. A preliminary correlation of tire traction with surface texture is shown. Results of work at Langley Research Center on the use of air jets to improve tire traction on wet or flooded runways indicate that this is a promising approach for alleviating the large losses in tire braking and sideways traction that occur when tire hydroplaning occurs on a flooded runway.

Beschreibung: Symbols for analog and hybrid computer signal flow diagrams

Beschreibung: Description and operational analysis of Fucino ground communication and satellite tracking station

Beschreibung: Measurement of neutral and ionized components of atmosphere during lunar explorations, and development of sensitive mass spectrometric devices

Beschreibung: Geochemical, mineralogical, and petrological studies during lunar explorations

Beschreibung: Lunar exploration program to determine surface and interior physical properties of moon - heat flow measurements, seismology, traverse logging, and instruments for deep probes and surface use

Beschreibung: Titantium alloy miniaturized flareless tube connectors with reduced weight and size for advanced space vehicles

Beschreibung: News conference on initial scientific interpretation of Mariner IV photography

Beschreibung: Magnetic classification of metallic materials for spacecraft components

Beschreibung: In-orbit operational aspects of Relay I satellite and requirements for satellite command and for real time telemetry data reduction

Beschreibung: Effect of micrometeoroids on emittance of solids

Beschreibung: Decrease in intensity of cosmic rays during magnetic storms

Beschreibung: Large geomagnetic pulsations in Soviet Arctic - geophysics

Beschreibung: Development tests on large rocket engine sound suppressor models

Beschreibung: Variation of electromagnetic field from fluxmetric and earth current measurements - period, time, and amplitude

Beschreibung: Communications and radiation experiments with Telstar II satellite

Beschreibung: Corrosion effects of boiling potassium and liquid sodium-potassium on refractory metal alloy tubing of power reactor

Beschreibung: Frequency and time synchronization at NASA TRACKING stations

Beschreibung: Phase comparison properties of dual-mode spiral antenna, and applications to passive direction finding system

Beschreibung: Simulation of space vacuum environment, and effects from corona, heat transfer, sublimation and evaporation, decomposition, and liberation of gases

Beschreibung: Three-coil and four-coil systems for homogeneous magnetic fields in testing of spacecraft magnetic properties and instruments

Beschreibung: Solid state satellite payload separation sequence timer

Beschreibung: Test methods, equipment, and computer programs for improved quality control in space vehicle stage checkout

Beschreibung: Support Program for Extraterrestrial Research designed for utilization of resources to support space program

Beschreibung: Empirical correlations for weights of environmental-control systems

Beschreibung: Chemical and structural properties of lunar geothermal deposits for possible use as energy sources

Beschreibung: Orthonormalization procedure for multivariable function approximation

Beschreibung: Methods of generating Liapunov method for application to practical nonlinear dynamical systems

Beschreibung: Heat flux measurement techniques and devices - slug-type sensor and steady-state sensor, radiation and convection devices, and heat flux transducers

Beschreibung: Feasibility of automating postflight test data

Beschreibung: Unified treatment to predict turbulent fluxes in hot and multicomponent flows around launch vehicles

Beschreibung: Economic analysis of oxygen and fuel production with and without lunar resources

Beschreibung: Evaluation of extraterrestrial resources to supply propellants for refueling rockets at various stations during interplanetary flight

Beschreibung: Petrologic processes in lunar igneous rocks and lunar logistics

Beschreibung: Method and instruments for measuring seismic energy propagation, velocity, attenuation, frequency spectra, and shear wave velocity in lunar surface rock