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At least 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

An analysis of aircraft lateral-directional handling qualities using pilot models.

An analytical study of the combined pilot-aircraft system to develop a procedure for computing pilot ratings for the lateral-directional response. In the analytical procedure the pilot is represented by a linear, second-order pilot model, and the aircraft by linear equations of motion. Two levels of pilot response were described by the pilot model. The first level contains a static gain and a second-order lag function with a time constant of 0.2 second. The second level added a 1-sec lead time constant. The second level is assumed to represent a greater effort on the part of the pilot. If the system response characteristics can be achieved with the first-level pilot model, it is concluded that the aircraft will be given a pilot rating of satisfactory. If the aircraft characteristics are such that the second-level pilot model is required to achieve the prescribed system response, it is concluded that the aircraft will be rated tolerable.

Adams, J. J.↗
NASA NTRS1972

A design procedure and handling quality criteria for lateral directional flight control systems

A practical design procedure for aircraft augmentation systems is described based on quadratic optimal control technology and handling-quality-oriented cost functionals. The procedure is applied to the design of a lateral-directional control system for the F4C aircraft. The design criteria, design procedure, and final control system are validated with a program of formal pilot evaluation experiments.

Stein, G.↗
NASA NTRS1972

Effect of nozzle lateral spacing on afterbody drag and performance of twin-jet afterbody models with convergent-divergent nozzles at Mach numbers up to 2.2

Twin-jet afterbody models were investigated by using two balances to measure the thrust-minus-total drag and the afterbody drag, separately, at static conditions and at Mach numbers up to 2.2 for an angle of attack of 0 deg. Hinged-flap convergent-divergent nozzles were tested at subsonic-cruise- and maximum-afterburning-power settings with a high-pressure air system used to provide jet-total-pressure ratios up to 20. Two nozzle lateral spacings were studied, using afterbodies with similar interfairing shapes but with different longitudinal cross-sectional area distributions. Alternate, blunter, interfairings with different shapes for the two spacings, which produced afterbodies having identical cross-sectional area progressions corresponding to an axisymmetric minimum wave-drag configuration, were also tested. The results indicate that the wide-spaced configurations improved the flow field around the nozzles, thereby reducing drag on the cruise nozzles; however, the increased surface and projected cross-sectional areas caused an increase in afterbody drag. Except for a slight advantage with cruise nozzles at subsonic speeds, the wide-spaced configurations had the higher total drag at all other test conditions.

Pendergraft, O. C., Jr.↗
NASA NTRS1972

Lateral-directional aerodynamic characteristics of light, twin-engine, propeller driven airplanes

Analytical procedures and design data for predicting the lateral-directional static and dynamic stability and control characteristics of light, twin engine, propeller driven airplanes for propeller-off and power-on conditions are reported. Although the consideration of power effects is limited to twin engine airplanes, the propeller-off considerations are applicable to single engine airplanes as well. The procedures are applied to a twin engine, propeller driven, semi-low-wing airplane in the clean configuration through the linear lift range. The calculated derivative characteristics are compared with wind tunnel and flight data. Included in the calculated characteristics are the spiral mode, roll mode, and Dutch roll mode over the speed range of the airplane.

Wolowicz, C. H.↗
NASA NTRS1972

Effect of nozzle lateral spacing on afterbody drag and performance of twin-jet afterbody models with cone plug nozzles at Mach numbers up to 2.20

Twin-jet afterbody models were investigated by using two balances to measure separately the thrust minus total drag and the afterbody drag at Mach numbers of 0.0 and 0.50 to 2.20 for a constant angle of attack of 0. Translating shroud cone plug nozzles were tested at dry and maximum afterburning power settings with a high-pressure air system used to provide jet total-pressure ratios up to 20.0. Two nozzle lateral spacings were studied by using afterbodies with several interfairing shapes. The close- and wide-spaced afterbodies had identical cross-sectional area distributions when similar interfairings were installed on each. Nozzle cant angles of -5, 0, and 5 degrees were investigated. The results show that the highest overall performance was generally obtained with the close-spaced afterbody, basic interfairings (no base), and uncanted nozzles.

Berrier, B. L.↗
NASA NTRS1973

A low speed wind tunnel test of the 0.050 scale NASA-JSC shuttle orbiter 089B to determine the longitudinal and lateral directional effects of control surface modifications

Wind tunnel tests to determine the longitudinal and lateral-directional effects of control surface modifications on the space shuttle orbiter aerodynamic characteristics are discussed. A total of 103 data runs were made which consisted of pitch runs through a range of zero to 28 degrees at a zero yaw angle and yaw runs from minus 6 to plus 6 degrees at various fixed pitch angles. At each data point, data from an internal strain gage balance was sampled with the digital data system. Also recorded were the model angles of pitch and yaw and the test section static pressure. Results are presented in the form of tabulated aerodynamic coefficient data about the model reference center.

Oldenbuttel, R. H.↗
NASA NTRS1973

Effect of nozzle lateral spacing, engine interfairing shape, and angle of attack on the performance of a twin-jet afterbody model with cone plug nozzles

Twin-jet afterbody models were investigated by using two balances to measure separately the thrust minus total axial force and the afterbody drag at Mach numbers from 0 to 1.3. Angle of attack was varied from minus 2 deg to 8.5 deg. Translating shroud cone plug nozzles were tested at dry-power and maximum-afterburning-power settings with a high-pressure air system used to provide jet total-pressure ratios up to 9.0. Two nozzle lateral spacings were studied by using afterbodies with several interfairing shapes. The close- and wide-spaced afterbodies had identical cross-sectional area distributions when similar interfairings were installed on each. The results show that the highest overall performance was obtained with the close-spaced afterbody and basic interfairings. Increasing angle of attack decreased performance for all configurations and conditions investigated.

Berrier, B. L.↗
NASA NTRS1973

Low-speed wind tunnel investigation of the lateral-directional characterisitcs of a large-scale variable wing-sweep fighter model in the high-lift configuration

The low-speed characteristics of a large-scale model of the F-14A aircraft were studied in tests conducted in the Ames Research Center 40- by 80-Foot Wind Tunnel. The primary purpose of the present tests was the determination of lateral-directional stability levels and control effectiveness of the aircraft in its high-lift configuration. Tests were conducted at wing angles of attack between minus 2 deg and 30 deg and with sideslip angles between minus 12 deg and 12 deg. Data were taken at a Reynolds number of 8.0 million based on a wing mean aerodynamic chord of 2.24 m (7.36 ft). The model configuration was changed as required to show the effects of direct lift control (spoilers) at yaw, yaw angle with speed brake deflected, and various amounts and combinations of roll control.

Eckert, W. T.↗
NASA NTRS1974

Lateral static and dynamic aerodynamic parameters of the Kestrel aircraft (XV-6A) extracted from flight data

Flight test data have been used to extract the lateral static and dynamic aerodynamic parameters of the Kestrel aircraft. The aircraft configurations included thrust-jet angles of 0 deg, 15 deg, and 30 deg, and the test Mach numbers were 0.43, 0.62, and 0.82. The results showed that most of the parameters varied linearly with trim normal-force coefficient. The directional stability parameter showed a small increase with increasing trim normal-force coefficient and also with nozzle deflection. The effective-dihedral parameter, the damping-in-roll parameter, and damping-in-yaw parameter all increased (became more negative) with increasing trim normal-force coefficient. For the latter three parameters, the effect of nozzle deflection was dependent on the trim normal-force coefficient.

Suit, W. T.↗
NASA NTRS1974

Lateral-directional stability characteristics of a wing-fuselage configuration at angles of attack up to 44 deg

An investigation has been conducted to determine the effects of configuration variables on the lateral-directional stability characteristics of a wing-fuselage configuration. The variables under study included variations in the location of a single center-line vertical tail and twin vertical tails, wing height, fuselage strakes, and horizontal tails. The study was conducted in the Langley high-speed 7-by 10-foot tunnel at a Mach number of 0.30, at angles of attack up to 44 deg and at sideslip angles of 0 deg and plus or minus 5 deg.

Henderson, W. P.↗
NASA NTRS1974

Extraction from flight data of lateral aerodynamic coefficients for F-8 aircraft with supercritical wing

A parameter-extraction algorithm was used to determine the lateral aerodynamic derivatives from flight data for the F-8 aircraft with supercritical wing. The flight data used were the recorded responses to aileron or rudder pulses for Mach numbers of 0.80, 0.90, and 0.98. Results of this study showed that a set of derivatives were determined which yielded a calculated aircraft response almost identical with the response measured in flight. Derivatives extracted from motion resulting from rudder inputs were somewhat different from those resulting from aileron inputs. It was found that the derivatives obtained from the rudder-input data were highly correlated in some instances. Those from the aileron input had very low correlations and appeared to be the more reliable.

Williams, J. L.↗
NASA NTRS1974

Results of differential elevon/aileron deflection for lateral control optimization and elevon hinge moment investigations on an 0.015-scale model (49-0) of the space shuttle orbiter in the NASA/Langley Research Center 8 foot TPT (OA116)

Aerodynamic investigations were conducted in a transonic pressure tunnel on an 0.015 scale model of the space shuttle orbiter. Major test objectives were to determine: (1) transonic differential elevon/aileron lateral control optimization; (2) transonic elevon hinge moments; (3) transonic effects of the baseline 6 inch elevon/elevon and elevon/fuselage gaps; and (4) transonic effects of the short OMS pods. Six-component aerodynamic force and moment, and elevon hinge moment data, were recorded over an angle-of-attack range form -2 to +22 degrees.

Lindsey, A. I.↗
NASA NTRS1975

On the oscillation of the laterally heterogeneous earth, 1

The perturbative effects, as cause by lateral inhomogeneities in the earth structure and by Coriolis force, contaminate the originally toroidal and spheroidal earth's oscillations, making them of mixed type. For this reason, in order to make the computation of the perturbations more uniform and homogeneous, it was suggested that the earth's free oscillations be expanded into a series in terms of generalized harmonics familiar from the theory of angular momentum in quantum mechanics. Making use of Gibbsian symbolism and of some operators from the theory of angular momentum, explicit expressions were deduced for the perturbative terms in the differential equation of the earth's free oscillations. Decomposition of the strain tensor in terms of canonical vectors was also obtained.

Musen, P.↗
NASA NTRS1975

Differential elevon effectiveness lateral control optimization and elevon hinge moment investigation on a 0.015 scale space shuttle orbiter model 49-0 (140A/B/C modified) in the AECD VKF wind tunnel A (0A115)

Experimental aerodynamic investigations were conducted in the Arnold Engineering Development Center (AEDC) Von Karman Facility Tunnel A on a scale model of the space shuttle orbiter. The objectives of this test were: (1) determine supersonic differential elevon/aileron lateral control optimization, (2) determine supersonic elevon hinge moments, (3) determine the supersonic effects of the new baseline 6-inch elevon/elevon and elevon/fuselage gaps, and 4) determine the supersonic effects of the new short (VL70-008410) OMS pods. Six-component aerodynamic force, moment, and elevon hinge moment data were recorded.

Esparza, V.↗
NASA NTRS1975

A study of pilot behavior during controlling the lateral directional motion of airplanes in turbulent air

The pilot behaviors controlling the lateral directional motion of airplanes in turbulent air have been investigated by using the pilot transfer function which has been obtained by the analysis of flight test data. The pilot uses the gains for the aileron manipulation proportionally to bank angle so as to minimize r.m.s. of bank angle. The pilot rudder manipulations are done proportionally to rolling velocity, yawing velocity, and yaw angle. Namely, the pilot carries out the cross control for the rudder.

Beppu, G.↗
NASA NTRS1974

Fine structural changes in the lateral vestibular nucleus of aging rats

The fine structure of the lateral vestibular nucleus was investigated in Sprague-Dawley rats, that were sacrified at 4 weeks, 6-8 weeks, 6-8 months, and 18-20 months of age. In the neuronal perikaria, the following age-associated changes were seen with increasing frequency with advancing age: rodlike nuclear inclusions and nuclear membrane invaginations; cytoplasmic dense bodies with the characteristics of lipofuscin; and moderate disorganization of the granular endoplasmic reticulum. Dense bodies were also seen in glial cells. Rats 18 to 20 months old showed dendritic swellings, axonal degeneration, and an apparent increase in the number of axosomatic synaptic terminals containing flattened vesicles (presumed to be inhibitory in function).

Johnson, J. E., Jr.↗
NASA NTRS1975

Wind modeling and lateral control for automatic landing

For the purposes of aircraft control system design and analysis, the wind can be characterized by a mean component which varies with height and by turbulent components which are described by the von Karman correlation model. The aircraft aero-dynamic forces and moments depend linearly on uniform and gradient gust components obtained by averaging over the aircraft's length and span. The correlations of the averaged components are then approximated by the outputs of linear shaping filters forced by white noise. The resulting model of the crosswind shear and turbulence effects is used in the design of a lateral control system for the automatic landing of a DC-8 aircraft.

Holley, W. E.↗