Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “LATERAL STABILITY AND CONTROL”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13

Predicted flight characteristics of the augmentor wing jet STOL research aircraft

An existing deHavilland C-8A airplane has been modified into an augmentor wing flight test vehicle. Research objectives are to verify the augmentor flap concept and to produce data for STOL airworthiness criteria. The Modified C-8A provides the means for jet-STOL flight research down to a 60 knot approach speed. The airplane has a high thrust-to-weight ratio, high-lift flap system, vectored thrust, powerful flight controls, and lateral-directional stability augmentation system. Normal performance and handling qualities are expected to be satisfactory. Analysis and piloted simulator results indicate that stability and control characteristics in conventional flight are rated satisfactory. Handling qualities in the STOL regime are also generally satisfactory, although pilot workload is high about the longitudinal axis.

Spitzer, R. E.↗

Flight Measurements of the Longitudinal Stability and Control Characteristics of the Grumman F8F-1 Airplane, TED No. NACA 2379

A series of flight tests have been made at the Langley Flight Research Division at the request of the Bureau of Aeronautics, Department of the Navy, to determine the flying qualities of the Grumman F8F-1 air- plane. This paper presents the test results necessary to determine the longitudinal stability and control characteristics end the stalling characteristics. These tests were made between February and June of 1947- The range of Mach numbers covered in this investigation was approximately 0.10 to 0.62, and no attempt was made to investigate compressibility effects at higher Mach numbers. The lateral and directional stability and control characteristics of the subject airplane have already been reported (reference 1). Also presented in this paper is a discussion of the normal accelerations induced by yawing velocity and sideslip which were considered ob,jectionable by the pilot for this airplane. A discussion of the undesirable accelerations has been included with a view towards formulating some flying-qualities requirements limiting them.

Assadourian, Arthur↗

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part II - Basic Lateral Stability Characteristics TED No. NACA DE308: Basic Lateral Stability Charactistics, TED No. NACA DE308 - Part 2

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The basic lateral stability characteristics of the complete model with undeflected control surfaces are presented in the present report with a very limited analysis of the results.

Kemp, William B., Jr.↗

Aerodynamic Characteristics in Sideslip of a Large-Scale 49 deg Sweptback Wing-Body-Tail Configuration with Blowing Applied Over the Flaps and Wing Leading Edge

An investigation has been conducted in the Langley full-scale tunnel to determine the aerodynamic characteristics in sideslip of a large-scale 490 sweptback wing-body-tail configuration having wing leading- edge and flap-blowing boundary-layer control. The wing and tails had an aspect ratio of 3.5, a taper ratio of 0.3, and NACA 65AO06 airfoil sections parallel to the plane of symmetry. The tests were conducted over a range of angles of attack of about -5 deg to 28 deg for sideslip angles of 0 deg, -5.06 deg, -10.15 deg, and -15.18 deg. Lateral and longitudinal stability and control characteristics were obtained for6a minimized blowing rate. The Reynolds number of the tests was 5.2 x 10(exp 6), corresponding to a Mach number of 0.08. The results of the investigation showed that sideslip to angles of about -15 deg did not require, from a consideration of the longitudinal characteristics, blowing rates over the wing leading edge or flap greater than that established as minimum at zero sideslip. The optimum configuration was laterally and directionally stable through the complete lift-coefficient range including the stall; however, maximum lift for sideslip angles greater than about 50 was seriously limited by a deficiency of lateral control. Blowing over the leading edge of the retreating wing in sideslip at a rate greater than that established as minimum at zero sideslip was ineffective in improving the lateral control characteristics. The optimum configuration at zero sideslip had no hysteresis of the aerodynamic parameters upon recovery from stall.

McLemore, H. Clyde↗

Analysis of lateral stability of X-29 drop model using system identification methodology

A 22-percent dynamically scaled replica of the X-29 forward-swept-wing aircraft is currently being flown in radio-controlled drop tests at NASA Langley's Plumtree Test Site. Flight data were recorded from early flights in the test program, which consisted mainly of large amplitude maneuvers over wide angle-of-attack ranges with several uncontrolled wing rock episodes. A system identification study of the recorded data was undertaken to examine the stability and control derivatives which influence the lateral behavior of this vehicle with particular emphasis on the wing rock phenomenon. All major lateral stability derivatives and the damping-in-roll derivative were identified for 5-80 deg angle-of-attack by using a data partitioning methodology and a modified stepwise regression algorithm. No control effectiveness derivatives could be identified from the flights conducted so far.

Raney, David L.↗

Stability and control derivatives of the lifting body vehicles

Predictions of the flight characteristics of lifting bodies have been based almost exclusively on wind-tunnel data for small-scale models. A need thus exists to compare the results from small-scale and full-scale wind-tunnel tests with results from flight tests to establish some measure of the accuracy of the predictions and to assess the sensitivity of the vehicle's handling qualities to typical discrepancies between flight and wind-tunnel results. Comparisons of these types have been one of the primary objectives of the M2-F2, HL-10, and X-24A flight programs. In this paper the more important longitudinal and lateral-directional aerodynamic stability and control derivatives obtained from flight are compared with small- and full-scale wind-tunnel results where applicable. Significant trends and important differences are pointed out, and the implications discussed.

Robert W Kempel↗

A preliminary look at the effects of coupled lateral modes on aircraft handling qualities

Analytic and six-degree-of-freedom motion base simulator studies have been conducted to better understand how the coupled roll-spiral and coupled roll-aileron actuator modes affect aircraft handling qualities. The results reported herein are preliminary and are subject to change until other aircraft and several more data points can be examined. The results obtained thus far indicate that when the roll-spiral coupled mode is brought about by unusual values of an aircraft's stability and control derivatives, the lateral-directional handling qualities will invariably be degraded. However, when the roll spiral coupling is brought about by a roll-rate command/roll-attitude hold stability and control augmentation system (SCAS), the requirements for satisfactory handling qualities can be correlated to the natural frequency and the damping of the coupled mode. Satisfactory handling qualities were also achieved when the lateral SCAS brought about a coupling of the roll mode with the aileron actuator mode. In this case, the pilot ratings indicate that the handling qualities may be correlated to the natural frequency of the coupled roll-aileron mode.

Ruflin, S. J.↗

Lateral stability analysis for X-29A drop model using system identification methodology

A 22-percent dynamically scaled replica of the X-29A forward-swept-wing airplane has been flown in radio-controlled drop tests at the NASA Langley Research Center. A system identification study of the recorded data was undertaken to examine the stability and control derivatives that influence the lateral behavior of this vehicle with particular emphasis on an observed wing rock phenomenon. All major lateral stability derivatives and the damping-in-roll derivative were identified for angles of attack from 5 to 80 degrees by using a data-partitioning methodology and a modified stepwise regression algorithm.

Raney, David L.↗

A design support simulation of the augmentor wing jet STOL research aircraft

The modification of a C-8A (De Havilland Buffalo) aircraft to a STOL configuration is discussed. The modification consisted of the installation of an augmentor-wing jet flap system. System design requirements were investigated for the lateral and directional flight control systems, the lateral and directional axes stability augmentation systems, the engine and Pegasus nozzle control systems, and the hydraulic systems. Operational techniques for STOL landings, control of engine failures, and pilot techniques for improving engine-out go-around performance were examined. Design changes have been identified to correct deficiencies in areas of the airplane control sytems and to improve the airplane flying qualities.

Rumsey, P. C.↗

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.↗

Experimental low-speed and calculated high-speed aerodynamic characteristics of a hypersonic research airplane concept having a 65 deg swept delta wing

An experimental wind-tunnel investigation has been carried out to determine the static longitudinal, lateral, and directional stability and control characteristics of a model of a large-body, delta-wing hypersonic research airplane concept at low speed. This investigation was conducted at a dynamic pressure of 239.4 Pa (5 psf) and a Reynolds number, based on fuselage length, of 2 million. The configuration variables included vertical fins, engine modules, canards, and a canopy. The aerodynamic results of a computer study at Mach numbers of 3 to 12 are presented.

Penland, J. A.↗

Wind tunnel and ground static investigation of a large scale model of a lift/cruise fan V/STOL aircraft

An investigation was conducted in a 40 foot by 80 foot wind tunnel to determine the aerodynamic/propulsion characteristics of a large scale powered model of a lift/cruise fan V/STOL aircraft. The model was equipped with three 36 inch diameter turbotip X376B fans powered by three T58 gas generators. The lift fan was located forward of the cockpit area and the two lift/cruise fans were located on top of the wing adjacent to the fuselage. The three fans with associated thrust vectoring systems were used to provide vertical, and short, takeoff and landing capability. For conventional cruise mode operation, only the lift/cruise fans were utilized. The data that were obtained include lift, drag, longitudinal and lateral-directional stability characteristics, and control effectiveness. Data were obtained up to speeds of 120 knots at one model height of 20 feet for the conventional aerodynamic lift configuration and at several thrust vector angles for the powered lift configuration.

Source record↗

Experimental results of winglets on first, second, and third generation jet transports

The results of wind tunnel investigations of winglets on four jet transport configurations are presented. Performance and wing root bending moment data were given. Additionally, detailed aerodynamic characteristics are presented at the design condition and also at several off design conditions for one configuration. Results of the investigations indicate that the winglets improve the cruise lift to drag ratio between 4 and 8 percent. These data also show that the ratios of relative aerodynamic gain to relative structural weight penalty for winglets are 1.5 to 2.5 times the ratios for wing tip extensions. The comprehensive investigation of the effects of winglets indicated that winglets produce no adverse effects on buffet onset, lateral directional stability, and aileron control effectiveness.

Flechner, S. G.↗