NASA — National Aeronautics and Space Administration

297 official documents, republished as free chaptered HTML editions.

Document type

Technical Reports

9- by 15-Foot Low Speed Wind Tunnel Acoustic Improvements Expanded OverviewThe 9- by 15-Foot Low Speed Wind Tunnel (9x15 LSWT) at NASA Glenn Research Center was built in 1969 in the return leg of the 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT). The 8x6 SWT was completed in 1949 and acoustically treated to mitigate community noise issues in 1950. This treatment included…GRC-E-DAA-TN31946
9- by 15-Foot Low-Speed Wind Tunnel Commissioning Test Using Advanced Ducted PropulsorA subscale model of an aircraft engine fan was tested in the 9- by 15-Foot Low-Speed Wind Tunnel at the NASA Glenn Research Center in 2022. The fan model was the Advanced Ducted Propulsor Fan 1 designed by Pratt & Whitney in the 1990s. It has been part of multiple wind tunnel test campaigns over…NASA/TM-20250004035
9x15 Low Speed Wind Tunnel Acoustic ImprovementsThe 9- by 15-Foot Low Speed Wind Tunnel (9x15 LSWT) at NASA Glenn Research Center was built in 1969 in the return leg of the 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT). The 8x6 SWT was completed in 1949 and acoustically treated to mitigate community noise issues in 1950. This treatment included…GRC-E-DAA-TN31484
9x15 Low Speed Wind Tunnel Improvement Update and PlansThe 9- by 15-Foot Low Speed Wind Tunnel (9x15 LSWT) at NASA Glenn Research Center was built in 1969 in the return leg of the 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT). The 8x6 SWT was completed in 1949 and acoustically treated to mitigate community noise issues in 1950. This treatment included…GRC-E-DAA-TN67410
A Dynamic Model for the Evaluation of Aircraft Engine Icing Detection and Control-Based Mitigation StrategiesAircraft flying in regions of high ice crystal concentrations are susceptible to the buildup of ice within the compression system of their gas turbine engines. This ice buildup can restrict engine airflow and cause an uncommanded loss of thrust, also known as engine rollback, which poses a…GRC-E-DAA-TN39681
A Dynamic Model for the Evaluation of Aircraft Engine Icing Detection and Control-Based Mitigation StrategiesAircraft flying in regions of high ice crystal concentrations are susceptible to the buildup of ice within the compression system of their gas turbine engines. This ice buildup can restrict engine airflow and cause an uncommanded loss of thrust, also known as engine rollback, which poses a…GRC-E-DAA-TN43977
A feasibility study for advanced technology integration for general aviationAn investigation was conducted to identify candidate technologies and specific developments which offer greatest promise for improving safety, fuel efficiency, performance, and utility of general aviation airplanes. Interviews were conducted with general aviation airframe and systems manufacturers…NASA-CR-159381
A flight and wind tunnel investigation of the effect of angle-of-attack rate on maximum lift coefficientWind tunnel tests to determine effect of angle of attack on maximum lift at stall for half-wing models, and single engine, jet propelled aircraftNASA-CR-321
A neural based intelligent flight control system for the NASA F-15 flight research aircraftA flight control concept that can identify aircraft stability properties and continually optimize the aircraft flying qualities has been developed by McDonnell Aircraft Company under a contract with the NASA-Dryden Flight Research Facility. This flight concept, termed the Intelligent Flight Control…
A pertinent solution of helicopter rotor flapping stabilityThe stability of the flapping motion of a single blade of a helicopter rotor is examined using the techniques of perturbation theory. The equation of motion studied is linear, with periodic aerodynamic coefficients due to the forward speed of the rotor. Solutions are found for four cases: small and…NASA-TM-X-62165
A Robust Uniform Control Approach for VTOL AircraftWe present a uniform control approach for transitioning vertical take-off and landing aircraft. The approach combines several well-understood linear techniques, including robust servomechanism linear quadratic regulation, control allocation, and gain scheduling, to provide a practical control…
A study of rotor broadband noise mechanisms and helicopter tail rotor noiseThe rotor broadband noise mechanisms considered are the following: (1) lift fluctuation due to turbulence ingestion; (2) boundary layer/trailing edge interaction; (3) tip vortex formation; and (4) turbulent vortex shedding from blunt trailing edge. Predictions show good agreement with available…NASA-CR-177565
A summary of hingeless-rotor research at nasa- langleyFlight and wind tunnel tests of hingeless helicopter rotorNASA-TM-X-51513
A summary of hingeless-rotor structural loads and dynamics researchResearch review on helicopter hingeless rotor structural loads and dynamicsNASA-TM-X-56726
A summary of the longitudinal and lateral stability and control characteristics obtained from rocket-model tests of a swept-wing fighter-type airplane at Mach numbers from 0.5 to 1.9Longitudinal and lateral stability and control characteristics of swept wing fighter aircraftNACA-RM-L56K19
A system for varying the stability and control of a deflected-jet fixed-wing vtol aircraftVariable control power and augmented stability for hovering VTOL aircraftNASA-TN-D-2700
A Terminal Area Icing Remote Sensing SystemNASA and the National Center for Atmospheric Research (NCAR) have developed an icing remote sensing technology that has demonstrated skill at detecting and classifying icing hazards in a vertical column above an instrumented ground station. This technology is now being extended to provide…NASA/TM-2014-218417
A theoretical analysis of airplane longitudinal stability and control as affected by wind shearThe longitudinal equations of motion with wind shear terms were used to analyze the stability and motions of a jet transport. A positive wind shear gives a decreasing head wind or changes a head wind into a tail wind. A negative wind shear gives a decreasing tail wind or changes a tail wind into a…NASA-TN-D-8496
A wind tunnel flight correlation of Apollo 16 sonic boomA correlation of sonic boom pressure signatures recorded during reentry of the Apollo 16 command module with wind-tunnel signatures extrapolated to flight distances was made for Mach numbers of 1.83 and 9.71. The flight pressure signatures were recorded by microphones located onboard ships…NASA-TM-X-62073
Abort Flight Test Project OverviewA general overview of the Orion abort flight test is presented. The contents include: 1) Abort Flight Test Project Overview; 2) DFRC Exploration Mission Directorate; 3) Abort Flight Test; 4) Flight Test Configurations; 5) Flight Test Vehicle Engineering Office; 6) DFRC FTA Scope; 7) Flight Test…
Acoustic Improvements to the 9- by 15-Foot Low Speed Wind TunnelA major refurbishment of the 9- by 15-Foot Low Speed Wind Tunnel at NASA Glenn Research Center was undertaken between 2016 and 2019 to improve the acoustic measurement capability of the facility. The principal objective was to lower the background noise in the test section so quiet aircraft…
Acoustic Measurements from Wind Tunnel Test of AMELIA - Advanced Model for Extreme Lift and Improved AeroacousticsA wind tunnel test has been conducted to measure the aerodynamic and acoustic performance of an active circulation-control aircraft with leading- and trailing- edge slot blowing. The 11 Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA) model was tested in the Arnold Engineering…NASA/TM-2014-218862
Acoustic Testing of the Tiltrotor Test Rig in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind TunnelThe Tiltrotor Test Rig (TTR) was tested in the National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Foot Wind Tunnel from 2017 to 2018. The rotor system can be configured in airplane mode, with the rotor plane perpendicular to the wind flow, and in helicopter mode, with the rotor plane…ARC-E-DAA-TN62155
Acoustical characteristics of the NASA Langley full scale wind tunnel test sectionThe full-scale wind tunnel at NASA-Langley Research Center was designed for low-speed aerodynamic testing of aircraft. Sound absorbing treatment has been added to the ceiling and walls of the tunnel test section to create a more anechoic condition for taking acoustical measurements during…NASA-CR-132604
Adaptive Control and Scaling Approach for the Emulation of Dynamic Sub-scale Torque LoadsPrevious research by the authors proposed a control and scaling approach for emulating dynamic sub-scale torque loads. This approach produced an emulation controller that successfully regulated the dynamic behavior of a sub-scale electro-mechanical system intended to be a dynamical representation…
Adaptive Control and Scaling Approach for the Emulation of Dynamic Subscale Torque LoadsPrevious research by the authors proposed a control and scaling approach for emulating dynamic sub-scale torque loads. This approach produced an emulation controller that successfully regulated the dynamic behavior of a sub-scale electro-mechanical system intended to be a dynamical representation…
Adaptive Control of a Transport Aircraft Using Differential ThrustThe paper presents an adaptive control technique for a damaged large transport aircraft subject to unknown atmospheric disturbances such as wind gust or turbulence. It is assumed that the damage results in vertical tail loss with no rudder authority, which is replaced with a differential thrust…ARC-E-DAA-TN806
Adaptive Flight Control for Aircraft Safety EnhancementsThis poster presents the current adaptive control research being conducted at NASA ARC and LaRC in support of the Integrated Resilient Aircraft Control (IRAC) project. The technique "Approximate Stability Margin Analysis of Hybrid Direct-Indirect Adaptive Control" has been developed at NASA ARC to…ARC-E-DAA-TN-219
Adjustment of Adaptive Gain with Bounded Linear Stability Analysis to Improve Time-Delay Margin for Metrics-Driven Adaptive ControlThis paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control…ARC-E-DAA-TN528
Advanced control technology and its potential for future transport aircraftThis document is a compilation of papers presented at a symposium on advanced control technology held in Los Angeles, Calif. , July 9 to 11. 1974. Papers were presented by representatives of industry, the Air Force, and various NASA Centers. The topics covered included fly by wire, digital control,…NASA-TM-X-3409
Advanced instrumentation for aircraft icing researchA compact and rugged probe based on the phase Doppler method was evaluated as a means for characterizing icing clouds using airborne platforms and for advancing aircraft icing research in large scale wind tunnels. The Phase Doppler Particle Analyzer (PDPA) upon which the new probe was based is now…NASA-CR-185225
Advanced turboprop testbed systems study. Volume 1: Testbed program objectives and priorities, drive system and aircraft design studies, evaluation and recommendations and wind tunnel test plansThe establishment of propfan technology readiness was determined and candidate drive systems for propfan application were identified. Candidate testbed aircraft were investigated for testbed aircraft suitability and four aircraft selected as possible propfan testbed vehicles. An evaluation of the…NASA-CR-167928-VOL-1
Advancement of proprotor technology. Task 2: Wind-tunnel test resultsAn advanced-design 25-foot-diameter flightworthy proprotor was tested in the NASA-Ames Large-Scale Wind Tunnel. These tests, have verified and confirmed the theory and design solutions developed as part of the Army Composite Aircraft Program. This report presents the test results and compares them…NASA-CR-114363
Advances in Aero-Propulsive Modeling for Fixed-Wing and eVTOL Aircraft Using Experimental DataSmall unmanned aircraft and electric vertical takeoff and landing (eVTOL) aircraft have recently emerged as vehicles able to perform new missions and stimulate future air transportation methods. This dissertation presents several system identification research advancements for these modern aircraft…
Advances in Fatigue and Fracture Mechanics Analyses for Aircraft StructuresThis paper reviews some of the advances that have been made in stress analyses of cracked aircraft components, in the understanding of the fatigue and fatigue-crack growth process, and in the prediction of residual strength of complex aircraft structures with widespread fatigue damage.…
Advances in Fatigue and Fracture Mechanics Analyses for Metallic Aircraft StructuresThis paper reviews some of the advances that have been made in stress analyses of cracked aircraft components, in the understanding of the fatigue and fatigue-crack growth process, and in the prediction of residual strength of complex aircraft structures with widespread fatigue damage.…NASA/TM-2000-210084
Aero-Propulsive Damping Characterization for eVTOL Aircraft Using Free Motion Wind-Tunnel TestingThis paper describes an electric vertical takeoff and landing (eVTOL) aircraft system identification method applied using three degree-of-freedom (3DOF) free motion wind-tunnel testing. The approach, similar to flight-test system identification, allows for efficient mathematical model development…
Aero-Propulsive Modeling for eVTOL Aircraft Using Wind Tunnel Testing with Multisine InputsA novel approach for modeling the aero-propulsive characteristics of an electric vertical takeoff and landing (eVTOL) aircraft was developed and demonstrated in wind tunnel testing. The approach was applied to the NASA LA-8 tandem tilt-wing eVTOL aircraft, using an efficient, hybrid experiment…
Aerodynamic Characteristics at High and Low Subsonic Mach Numbers of the NACA 0012, 64(sub 2)-015, and 64(sub 3)-018 Airfoil Sections at Angles of Attack from -2 Degrees to 30 DegreesAn investigation has been made in the Langley low-turbulence pressure tunnel of the aerodynamic characteristics of the NACA 0012, 64(sub 2)-015, and 64(sub 3)-018 airfoil sections. Data were obtained at Mach numbers from 0.3 to that for tunnel choke, at angles of attack from -2deg to 30deg, and…NACA-RM-L54H06a
Aerodynamic Characteristics of a Number of Modified NACA Four-Digit-Series Airfoil SectionsTheoretical pressure distributions and measured lift, drag, and pitching moment characteristics at three values of Reynolds number are presented for a group of NACA four-digit-series airfoil sections modified for high-speed applications. The effectiveness of flaps applied to these airfoils and the…NACA-RM-L7I22
Aerodynamic characteristics of forebody and nose strakes based on F-16 wind tunnel test experience. Volume 1: Summary and analysisThe YF-16 and F-16 developmental wind tunnel test program was reviewed. Geometrical descriptions, general comments, representative data, and the initial efforts toward the development of design guides for the application of strakes to future aircraft are presented.NASA-CR-3053
Aerodynamic characteristics of forebody and nose strakes based on F-16 wind tunnel test experience. Volume 2: Data baseThe YF-16 and F-16 developmental wind tunnel test program was reviewed and all force data pertinent to the design of forebody and nose strakes extracted. A complete set of these data is presented without analysis.NASA-CR-158922
Aerodynamic Characteristics of Four NACA Airfoil Sections Designed for Helicopter Rotor BladesNACA-WR-L-29
Aerodynamic Characteristics of Four Republic Airfoil Sections from Tests in Langley Two-Dimensional Low-Turbulence TunnelsFour airfoils sections, designed by the Republic Aviation Corporation for the root and tip sections of the XF-12 airplane, were tested in the Langley two-dimensional low-turbulence tunnels to obtain their aerodynamic characteristics. Lift characteristics were obtained at Reynolds numbers of…NACA-MR-L5I19
Aerodynamic Characteristics of NACA 23012 and 23021 Airfoils with 20-Percent-chord External-Airfoil Flaps of NACA 23012 SectionReport presents the results of an investigation of the general aerodynamic characteristics of the NACA 23012 and 23021 airfoils, each equipped with a 0.20c external flap of NACA 23012 section. The tests were made in the NACA 7 by 10-foot and variable-density wind tunnels and covered a range of…NACA-TR-573
Aerodynamic data banks for Clark-Y, NACA 4-digit and NACA 16-series airfoil familiesWith the renewed interest in propellers as means of obtaining thrust and fuel efficiency in addition to the increased utilization of the computer, a significant amount of progress was made in the development of theoretical models to predict the performance of propeller systems. Inherent in the…NASA-CR-176883
Aerodynamic Effects Caused by Icing of an Unswept NACA 65A004 AirfoilThe effects of ice formations on the section lift, drag, and pitching-moment coefficients of an unswept NACA 65A004 airfoil section of 6-foot chord were studied.. The magnitude of the aerodynamic penalties was primarily a function of the shape and size of the ice formation near the leading edge of…NACA-TN-4155
Aerodynamic Parameters of High Performance Aircraft Estimated from Wind Tunnel and Flight Test DataA concept of system identification applied to high performance aircraft is introduced followed by a discussion on the identification methodology. Special emphasis is given to model postulation using time invariant and time dependent aerodynamic parameters, model structure determination and…NASA/TM-1997-207993
Aerodynamic stability and control of ducted- propeller aircraftTest results from studies of small and large powered models of a dual, tandem, ducted-propeller VTOL design are reviewed, with emphasis on stability and control characteristics through the transition speed range. The characteristics are generally satisfactory. Stability augmentation may be…
Aeroelastic Deformation: Adaptation of Wind Tunnel Measurement Concepts to Full-Scale Vehicle Flight TestingThe adaptation of a proven wind tunnel test technique, known as Videogrammetry, to flight testing of full-scale vehicles is presented. A description is presented of the technique used at NASA's Dryden Flight Research Center for the measurement of the change in wing twist and deflection of an F/A-18…NASA/TM-2005-213790
Aeroelastic Deformation: Adaptation of Wind Tunnel Measurement Concepts to Full-Scale Vehicle Flight TestingThe adaptation of a proven wind tunnel test technique, known as Videogrammetry, to flight testing of full-scale vehicles is presented. A description is presented of the technique used at NASA's Dryden Flight Research Center for the measurement of the change in wing twist and deflection of an F/A-18…RTO-MP-AVT-124
Aeroelastic model helicopter rotor testing in the Langley TDTWind-tunnel testing of a properly scaled aeroelastic model helicopter rotor is considered a necessary phase in the design development of new or existing rotor systems. For this reason, extensive testing of aeroelastically scaled model rotors is done in the Transonic Dynamics Tunnel (TDT) located at…NASA-TM-86440
Aeroservoelastic Control Law Development for the Integrated Adaptive Wing Technology Maturation Wind-Tunnel TestThe NASA Advanced Air Transport Technology (AATT) Project seeks to “explore and develop technologies and concepts for improved energy efficiency and environmental compatibility for fixed wing subsonic transports” [1]. The IAWTM project is a subproject within AATT and is a joint Boeing/NASA effort…
Aeroservoelastic wind-tunnel investigations using the Active Flexible Wing Model: Status and recent accomplishmentsThe status of the joint NASA/Rockwell Active Flexible Wing Wind-Tunnel Test Program is described. The objectives are to develop and validate the analysis, design, and test methodologies required to apply multifunction active control technology for improving aircraft performance and stability. Major…NASA-TM-101570
Aeroservoelastic Wind-Tunnel Test of the SUGAR Truss Braced Wing Wind-Tunnel ModelThe Subsonic Ultra Green Aircraft Research (SUGAR) Truss-Braced Wing (TBW) aeroservoelastic (ASE) wind-tunnel test was conducted in the NASA Langley Transonic Dynamics Tunnel (TDT) and was completed in April, 2014. The primary goals of the test were to identify the open-loop flutter boundary and…NF1676L-18944
Aircraft digital flight control technical reviewThe Aircraft Digital Flight Control Technical Review was initiated by two pilot induced oscillation (PIO) incidents in the spring and summer of 1992. Maj. Gen. Franklin (PEO) wondered why the Air Force development process for digital flight control systems was not preventing PIO problems.…
Aircraft Engine Icing Event Avoidance and Mitigation Through Real-Time Simulation and ControlsA process for mitigating or proactively avoiding an aircraft engine icing event may include detecting ice crystals in the atmosphere using one or more sensors on board an aircraft in real time. The process may also include modulating one or more engine operating conditions to proactively change an…Patent Number: US-Patent-10,184,405
Aircraft icing research at NASAResearch activity is described for: ice protection systems, icing instrumentation, experimental methods, analytical modeling for the above, and in flight research. The renewed interest in aircraft icing has come about because of the new need for All-Weather Helicopters and General Aviation…NASA-TM-82919
Aircraft Icing Weather Data Reporting and Dissemination SystemThe long-term operational concept of this research is to develop an onboard aircraft system that assesses and reports atmospheric icing conditions automatically and in a timely manner in order to improve aviation safety and the efficiency of aircraft operations via improved real-time and forecast…NASA/CR-2002-211800
Aircraft landing control systemUpon aircraft landing approach, flare path command signals of altitude, vertical velocity and vertical acceleration are generated as functions of aircraft position and velocity with respect to the ground. The command signals are compared with corresponding actual values to generate error signals…Patent Number: US-PATENT-4,357,661
Aircraft Loss of Control: Research and Technology DirectionsAircraft loss of control is a leading cause of fatal accidents across all transport airplane and operational classes. Aircraft loss-of-control (LOC) accidents are highly complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. Hence,…NF1676L-18905
Aircraft stability and control dataAircraft stability and control dataNASA-CR-96008
Aircraft System Identification from Multisine Inputs and Frequency ResponsesA frequency-domain approach is described for estimating parameters, such as stability and control derivatives, in aircraft flight dynamic models from measured input and output data. The approach uses orthogonal phase-optimized multisines for moving the aircraft control effectors, Fourier analysis…NF1676L-33221
Airfoil section characteristics as affected by protuberancesThe drag and interference caused by protuberance from the surface of an airfoil have been determined in the NACA variable-density wind tunnel at a Reynolds number approximately 3,100,000. The effects of variations of the fore-and-aft position, height, and shape of the protuberance were measured by…NACA-TR-446
Algorithms for output feedback, multiple-model, and decentralized control problemsThe optimal stochastic output feedback, multiple-model, and decentralized control problems with dynamic compensation are formulated and discussed. Algorithms for each problem are presented, and their relationship to a basic output feedback algorithm is discussed. An aircraft control design problem…
An Analysis of the Autorotative Performance of a Helicopter Powered by Rotor-Tip Jet UnitsThe autorotative performance of an assumed helicopter was studied to determine the effect of inoperative jet units located at the rotor-blade tip on the helicopter rate of descent. For a representative ramjet design, the effect of the jet drag is to increase the minimum rate of descent of the…NACA-TN-2154
An Assessment of the Icing Blade and the SEA Multi-Element Sensor for Liquid Water Content Calibration of the NASA GRC Icing Research TunnelThe Icing Research Tunnel at NASA Glenn has recently switched to from using the Icing Blade to using the SEA Multi-Element Sensor (also known as the multi-wire) for its calibration of cloud liquid water content. In order to perform this transition, tests were completed to compare the Multi-Element…GRC-E-DAA-TN31930
An Assessment of the Icing Blade and the SEA Multi-Element Sensor for Liquid Water Content Calibration of the NASA GRC Icing Research TunnelThe Icing Research Tunnel at NASA Glenn has recently switched from using the Icing Blade to using the SEA Multi-Element Sensor (also known as the multi-wire) for its calibration of cloud liquid water content. In order to peform this transition, tests were completed to compare the Multi-Element…GRC-E-DAA-TN33093
An Assessment of the SEA Multi-Element Sensor for Liquid Water Content Calibration of the NASA GRC Icing Research TunnelThe NASA Glenn Icing Research tunnel has been using an Icing Blade technique to measure cloud liquid water content (LWC) since 1980. The IRT conducted tests with SEA Multi-Element sensors from 2009 to 2011 to assess their performance in measuring LWC. These tests revealed that the Multi-Element…GRC-E-DAA-TN23357
An evaluation of the handling qualities of seven general-aviation aircraftHandling qualities and stability and control characteristics of general-aviation aircraftNASA-TN-D-3726
An experimental investigation of feasibility of a V/STOL test section in UWAL 8 x 12 wind tunnel by using a 1/8 scale model of the tunnelFeasibility of V/STOL test section in wind tunnel by using one eighth scale model of tunnelNASA-CR-69663
An Experimental Investigation of the Effect of Propellers Used as Aerodynamic Brakes on Stability and ControlTests were made of a model representative of a single-engine tractor-type airplane for the purpose of determining the stability and control effects of a propeller used as an aerodynamic brake. The tests were made with single-and dual-rotation propellers to show the effect of type of propeller…NACA-ARR-5C01
An experimental low Reynolds number comparison of a Wortmann FX67-K170 airfoil, a NACA 0012 airfoil and a NACA 64-210 airfoil in simulated heavy rainWind tunnel experiments were conducted on Wortmann FX67-K170, NACA 0012, and NACA 64-210 airfoils at rain rates of 1000 mm/hr and Reynolds numbers of 310,000 to compare the aerodynamic performance degradation of the airfoils and to attempt to identify the various mechanisms which affect performance…NASA-CR-181119
An experimental study of the aerodynamics of a NACA 0012 airfoil with a simulated glaze ice accretionAn experimental study was conducted in the Ohio State University subsonic wind tunnel to measure the detailed aerodynamic characteristics of an airfoil with a simulated glaze ice accretion. A NACA 0012 model with interchangeable leading edges and pressure taps every one percent chord was used.…NASA-CR-179897
An experimental study of transonic flow about a supercritical airfoil. Static pressure and drag data obtained from tests of a supercritical airfoil and an NACA 0012 airfoil at transonic speeds, supplementSurface static-pressure and drag data obtained from tests of two slightly modified versions of the original NASA Whitcomb airfoil and a model of the NACA 0012 airfoil section are presented. Data for the supercritical airfoil were obtained for a free-stream Mach number range of 0.5 to 0.9, and a…NASA-TM-81336-SUPPL
An exploratory investigation of factors affecting the handling qualities of a rudimentary hingeless rotor helicopterFlight investigation of control qualities of rudimentary hingeless rotor helicopterNASA-TN-D-3418
An in-Time Aviation Safety Management System Concept of Operations and Modernization of the National Airspace SystemThe National Airspace System (NAS) is growing in complexity of aircraft, missions, and operations. In response, many organizations have published papers and concepts of operations (ConOps) for new and enhanced safety systems. The National Academies’ vision for an In-time Aviation Safety Management…
An In-time Aviation Safety Management System Concept of Operations and Modernization of the National Airspace SystemThe National Airspace System (NAS) is growing in complexity of aircraft, missions, and operations. In response, many organizations have published papers and concepts of operations (ConOps) for new and enhanced safety systems. The National Academies’ vision for an In-time Aviation Safety Management…
An Integrated Approach to Swept Wing Icing SimulationThis presentation describes the various elements of a simulation approach used to develop a database of ice shape geometries and the resulting aerodynamic performance data for a representative commercial transport wing model exposed to a variety of icing conditions. Methods for capturing full…GRC-E-DAA-TN44209
An Integrated Approach to Swept Wing Icing SimulationThis paper describes the various elements of a simulation approach used to develop a database of ice shape geometries and the resulting aerodynamic performance data for a representative commercial transport wing model exposed to a variety of icing conditions. This effort included testing in the…GRC-E-DAA-TN44244
An Investigation of Glaciated Cloud Capabilities in the NASA Glenn Icing Research TunnelIn 2015 the FAA added Appendix D to Part 33 engine certification requirements that included Mixed Phase and Ice Crystal Icing to aircraft engine certification. Replicating the ice crystal environment that is seen in nature has proven to be a challenge, which multiple engine ground testing…GRC-E-DAA-TN58311
An investigation on the effect of second-order additional thickness distributions to the upper surface of an NACA 64 sub 1-212 airfoilAn investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of an NACA 64 sub 1 - 212 airfoil. Additional thickness distributions employed were in the form of two second-order polynomial arcs which have a…NASA-CR-137701
An investigation on the effect of second-order additional thickness distributions to the upper surface of an NACA 64-206 airfoilAn investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of an NACA 64-206 airfoil. Additional thickness distributions employed were in the form of two second-order polynomial arcs which have a specified…NASA-CR-137702
An overview of NASA research on positive displacement general-aviation enginesThe research and technology program related to improved and advanced general aviation engines is described. Current research is directed at the near-term improvement of conventional air-cooled spark-ignition piston engines and at future alternative engine systems based on all-new spark-ignition…
An unsteady helicopter rotor: Fuselage interaction analysisA computational method was developed to treat unsteady aerodynamic interactions between a helicopter rotor, wake, and fuselage and between the main and tail rotors. An existing lifting line prescribed wake rotor analysis and a source panel fuselage analysis were coupled and modified to predict…NASA-CR-4178
Analysis of Aviation Safety Reporting System Incident Data Associated with the Technical Challenges of the System-Wide Safety and Assurance Technologies ProjectThe Aviation Safety Program (AvSP) System-Wide Safety and Assurance Technologies (SSAT) Project asked the AvSP Systems and Portfolio Analysis Team to identify SSAT-related trends. SSAT had four technical challenges: advance safety assurance to enable deployment of NextGen systems; automated…NASA/TM-2015-217899
Analysis of Control Strategies for Aircraft Flight Upset RecoveryThis paper proposes a framework for studying the ability of a control strategy, consisting of a control law and a command law, to recover an aircraft from ight conditions that may extend beyond the normal ight envelope. This study was carried out (i) by evaluating time responses of particular ight…NF1676L-14058
Analysis of general aviation single-pilot IFR incident data obtained from the NASA aviation safety reporting systemData obtained from the NASA Aviation Safety Reporting System (ASRS) data base were used to determine problems in general aviation single pilot IFR operations. The data examined consisted of incident reports involving flight safety in the National Aviation System. Only those incidents involving…NASA-TM-80206
Analysis of general aviation single-pilot IFR incident data obtained from the NASA Aviation Safety Reporting SystemAn analysis of incident data obtained from the NASA Aviation Safety Reporting System (ASRS) has been made to determine the problem areas in general aviation single-pilot IFR (SPIFR) operations. The Aviation Safety Reporting System data base is a compilation of voluntary reports of incidents from…
Analysis of ram-jet engine performance including effects of component changesCalculated design-point performance of ram-jet engines using JP-4 fuel is presented for a wide range of engine total-temperature ratios and combustion-chamber-inlet Mach numbers for flight numbers from 1.5 to 4.0. The results include engine thrust, drag, fuel consumption, and area ratios. Data are…NACA-RM-E56D20
Analysis of the free-tip rotor wind-tunnel test resultsThe results from a wind tunnel test of a small scale free-tip rotor are analyzed. The free-tip rotor has blade tips that are free to weathervane into the tip's relative wind, thus producing a more uniform lift around the azimuth. The free-tip assembly, which includes the controller, functioned…NASA-TM-86751
Analysis of the wind tunnel test of a tilt rotor power force modelTwo series of wind tunnel tests were made to determine performance, stability and control, and rotor wake interaction on the airframe, using a one-tenth scale powered force model of a tilt rotor aircraft. Testing covered hover (IGE/OCE), helicopter, conversion, and airplane flight configurations.…NASA-CR-137529
Analysis of Wind Tunnel Lateral Oscillatory Data of the F-16XL AircraftStatic and dynamic wind tunnel tests were performed on an 18% scale model of the F-16XL aircraft. These tests were performed over a wide range of angles of attack and sideslip with oscillation amplitudes from 5 deg. to 30 deg. and reduced frequencies from 0.073 to 0.269. Harmonic analysis was used…NASA/TM-2004-213246
Analysis of wind tunnel test results for a 9.39-per cent scale model of a VSTOL fighter/attack aircraft. Volume 1: Study overviewThe ability of current methodologies to accurately predict the aerodynamic characteristics identified as uncertainties was evaluated for two aircraft configurations. The two wind tunnel models studied horizontal altitude takeoff and landing V/STOL fighter aircraft derivatives.NASA-CR-152391-VOL-1
Analytic development of improved supersonic cruise aircraft based on wind tunnel dataData obtained from the MDC/NASA cooperative wing tunnel program were used to develop empirical corrections to theory. These methods were then used to develop a 2.2M supersonic cruise aircraft configuration with a cruise trimmed maximum L/D of 10.2. The empirical corrections to the theory are…
Analytical evaluation of tilting proprotor wind tunnel test requirementsSpecific test requirements related to the wind tunnel testing of the XV-15 advanced tilt rotor research aircraft were determined. The following analytical tools were developed: (1) digital simulation of the XV-15, incorporating a simplified tunnel support model, control system loop, measurement…NASA-CR-137826
Analytical investigation of a helicopter rotor driven and controlled by a jet flapDriving and controlling helicopter rotor by deflectable jet flap - theoretical study of jet-flat rotor characteristicsNASA-TN-D-3028
Analytical investigation of ram-jet-engine performance in flight Mach number range from 3 to 7An analytical investigation was made of the performance of isolated ram-jet engines in the flight Mach number range from 3 to 7 for two types of diffuser, a high-efficiency diffuser, and a normal-shock diffuser. The fuel was assumed to be a hydrocarbon similar to gasoline. The conclusions reached…NACA-RM-E51H02
Analytical Models for Rotor Test Module, Strut, and Balance Frame Dynamics in the 40 by 80 Ft Wind TunnelA mathematical model is developed for the dynamics of a wind tunnel support system consisting of a balance frame, struts, and an aircraft or test module. Data are given for several rotor test modules in the Ames 40 by 80 ft wind tunnel. A model for ground resonance calculations is also described.NASA-TM-X-73153
Application of a Comprehensive Analytical Model of Rotor Aerodynamics and Dynamics (CAMRAD) to the McDonnell Douglas AH-64A helicopterA model of the AH-64A helicopter was generated in a Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD) in an effort to validate its analytical capabilities for modeling a current advanced Army helicopter. The initial phase of the effort involved the generation of CAMRAD…NASA-CR-177455
Application of Bounded Linear Stability Analysis Method for Metrics-Driven Adaptive ControlThis paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics-driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control…ARC-E-DAA-TN-289
Application of Forebody Strakes for Directional Stability and Control of Transport AircraftA brief overview of a cooperative NASA/Boeing research effort, Strake Technology Research Application to Transport Aircraft (STRATA), intended to explore the potential of applying forebody strake technology to transport aircraft configurations for directional stability and control at low angles of…AIAA Paper 98-4448
Aspects of investigating STOL noise using large scale wind tunnel modelsThe applicability of the NASA Ames 40- by 80-ft wind tunnel for acoustic research on STOL concepts has been investigated. The acoustic characteristics of the wind tunnel test section has been studied with calibrated acoustic sources. Acoustic characteristics of several large-scale STOL models have…NASA-TM-X-62164
ASRS for Unmanned Aviation SystemsThis presentation provides an overview of NASA's Aviation Safety Reporting System (ASRS) for Unmanned Aviation Systems / drones
Assessment of a Conceptual Flap System Intended for Enhanced General Aviation SafetyA novel multielement trailing-edge flap system for light general aviation airplanes was conceived for enhanced safety during normal and emergency landings. The system is designed to significantly reduce stall speed, and thus approach speed, with the goal of reducing maneuveringflight accidents and…NASA-TM-2017-219639
Assessment of Some IASMS-relevant Data Sources for Aviation SafetyAn In-time Aviation Safety Management System (IASMS) [1,2] is a set of services, functions, and capabilities (SFCs) necessary for monitoring known hazards and emergent risks, assessing safety data for anomalies, precursors, and trends, mitigating hazards that reach safety thresholds, and assuring…
Audio-Visual Situational Awareness for General Aviation PilotsWeather is one of the major causes of general aviation accidents. Researchers are addressing this problem from various perspectives including improving meteorological forecasting techniques, collecting additional weather data automatically via on-board sensors and "flight" modems, and improving…
Aviation Safety Reporting System (ASRS)This overview of the NASA Aviation Safety Reporting System (ASRS) will describe the genesis of the program, report processing procedures, and safety products that are produced from the ASRS data.
B-52 stability augmentation system reliabilityThe B-52 SAS (Stability Augmentation System) was developed and retrofitted to nearly 300 aircraft. It actively controls B-52 structural bending, provides improved yaw and pitch damping through sensors and electronic control channels, and puts complete reliance on hydraulic control power for rudder…
Background Oriented Schlieren (BOS) of a Supersonic Aircraft in FlightThis article describes the development and use of Background Oriented Schlieren on a full-scale supersonic jet in flight. A series of flight tests was performed in October, 2014 and February 2015 using the flora of the desert floor in the Supersonic Flight Corridor on the Edwards Air Force Base as…ARC-E-DAA-TN32991
Best Practices for Training the Structures Flight Test EngineerThe Structures Flight from 412th Test Wing and the Aerostructures Branch at NASA Armstrong Flight Research Center at Edwards Air Force Base have developed a set of best practices for training a structures flight test engineer. These practices represent the hard-won lessons learned and best…AFRC-E-DAA-TN56429
Bimodal SLD Ice Accretion on a NACA 0012 Airfoil ModelThis presentation describes the results of ice accretion measurements on a NACA 0012 airfoil model, from the NASA Icing Research Tunnel, using an icing cloud composed of a bimodal distribution of Supercooled Large Droplets. The data consists of photographs, laser scans of the ice surface, and…GRC-E-DAA-TN43197
Boeing Smart Rotor Full-scale Wind Tunnel Test Data ReportA full-scale helicopter smart material actuated rotor technology (SMART) rotor test was conducted in the USAF National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel at NASA Ames. The SMART rotor system is a five-bladed MD 902 bearingless rotor with active trailing-edge flaps. The flaps…NASA/TM-2016-216048
Bounded Linear Stability Margin Analysis of Nonlinear Hybrid Adaptive ControlThis paper presents a bounded linear stability analysis for a hybrid adaptive control that blends both direct and indirect adaptive control. Stability and convergence of nonlinear adaptive control are analyzed using an approximate linear equivalent system. A stability margin analysis shows that a…ARC-E-DAA-TN119
Cabin Safety Issues Related to Pre-Departure and Inflight IssuesThe Aviation Safety Reporting System (ASRS) in a partnership between the National Aeronautics and Space Administration (NASA), the Federal Aviation Administration (FAA), participating carriers, and labor organizations. It is designed to improve the National Airspace System by collecting and…ARC-E-DAA-TN13827
Calculated and Measured Pressure Distributions over the Midspan Section of the NACA 4412 AirfoilPressures were simultaneously measured in the variable-density tunnel at 54 orifices distributed over the midspan section of 5 by 30 inch rectangular model of the NACA 4412 airfoil at 17 angles of attack ranging from -20 degrees to 30 degrees at a Reynolds number of approximately 3,000,000.…NACA-TR-563
Calculated Hovering Helicopter Flight Dynamics with a Circulation Controlled RotorThe influence of the rotor blowing coefficient on the calculated roots of the longitudinal and lateral motion was examined for a range of values of the rotor lift and the blade flap frequency. The control characteristics of a helicopter with a circulation controlled rotor are discussed. The…NASA-TM-78443
Calculation of the chordwise load distribution over airfoil sections with plain, split, or serially hinged trailing-edge flapsA method is presented for the rapid calculation of the incremental chordwise normal-force distribution over an airfoil section due to the deflection of a plain flap or tab, a split flap, or a serially hinged flap. This report is intended as a supplement to NACA Report no. 631, wherein a method is…NACA-TR-634
Capabilities of the Unitary Plan Wind TunnelAn overview of the capabilities of the NASA Ames Unitary Plan Wind TunnelARC-E-DAA-TN38585
CFD Study of NACA 0018 Airfoil with Flow ControlThe abilities of two different Reynolds-Averaged Navier-Stokes codes to predict the effects of an active flow control device are evaluated. The flow control device consists of a blowing slot located on the upper surface of an NACA 0018 airfoil, near the leading edge. A second blowing slot present…NASA/TM-2017-219602
Characteristics of NACA 4400R Series Rectangular and Tapered Airfoils, Including the Effect of Split FlapsNo abstract availableNACA-WR-L-493
Cmparison of flight-measured helicopter rotor-blade chordwise pressure distributions with static two-dimensional airfoil characteristicsHelicopter rotor blade pressure distributions compared with static two-dimensional airfoil characteristics for extreme flight conditionsNASA-TN-D-3936
Cockpit Technology for Prevention of General Aviation Runway IncursionsGeneral aviation accounted for 74 percent of runway incursions but only 57 percent of the operations during the four-year period from fiscal year (FY) 2001 through FY2004. Elements of the NASA Runway Incursion Prevention System were adapted and tested for general aviation aircraft. Sixteen General…
Collaborative Experiments and Computations in Aircraft IcingThe formation of ice over lifting surfaces can affect aerodynamic performance. The ability to predict ice accumulation and the resulting degradation in vehicle performance is essential to determine the limitations of aircraft in icing encounters. The consequences of underestimating performance…GRC-E-DAA-TN56891
Commercial aviation icing research requirementsA short range and long range icing research program was proposed. A survey was made to various industry and goverment agencies to obtain their views of needs for commercial aviation ice protection. Through these responsed, other additional data, and Douglas Aircraft icing expertise; an assessment…NASA-CR-165336
Comparing 3D and 2D CFD for Mars Helicopter Ingenuity Rotor Performance PredictionSingle and coaxial rotor performance simulations for the Mars Helicopter Ingenuity rotor are performed for representative Mars atmospheric conditions. Analyses are presented using both a high-fidelity 3D CFD model of the rotor and 2D CFD models of the airfoil sections for comprehensive analyses…
Comparison of acoustic data from a 102 mm conic nozzle as measured in the RAE 24-foot wind tunnel and the NASA Ames 40- by 80-foot wind tunnelA cooperative program between the Royal Aircraft Establishment (RAE), England, and the NASA Ames Research Center was initiated to compare acoustic measurements made in the RAE 24-foot wind tunnel and in the Ames 40- by 80-foot wind tunnel. The acoustic measurements were made in both facilities…NASA-TM-81343
Comparison of Aircraft Conceptual Design Weight Estimation Methods to the Flight Optimization SystemWeight estimation is critical in the aircraft conceptual design process. The Flight Optimization System (FLOPS) is an aircraft conceptual design tool that has been the primary aircraft synthesis software used by the Systems Analysis and Concepts Directorate at NASA Langley Research Center. FLOPS…AIAA-2018-2032
Comparison of control-fixed stability derivatives for two supersonic fighter airplanes as determined from flight and wind-tunnel testsComparison of control-fixed stability derivatives for two supersonic fighters as determined from flight and wind tunnel testsNASA-MEMO-2-3-59L
Comparison of Flight Measured Helicopter Rotor Blade Chordwise Pressure Distributions and Two-Dimensional Airfoil CharacteristicsHelicopter rotor blade chordwise pressure distribution and two-dimensional airfoil characteristics
Comparison of Heat Transfer from Airfoil in Natural and Simulated Icing ConditionsAn investigation of the heat transfer from an airfoil in clear air and in simulated icing conditions was conducted in the NACA Lewis 6- by 9-foot icing-research tunnel in order to determine the validity of heat-transfer data as obtained in the tunnel. This investiation was made on the same model…NACA-TN-2480
Comparison of Methods for Efficient Static Wind Tunnel Testing Using Multiple Control SurfacesThe Integrated Adaptive Wing Technology Maturation (IAWTM) half-span wind tunnel test article was tested in the Transonic Dynamics Tunnel (TDT) at NASA's Langley Research Center in Hampton, VA. The test article has a wing aspect ratio of 13.5, wing half span length of 12.75 ft, and is configured…
Comparison of model and flight test data for an augmented jet flap STOL research aircraftAerodynamic design data for the Augmented Jet Flap STOL Research Aircraft or commonly known as the Augmentor-Wing Jet-STOL Research Aircraft was based on results of tests carried out on a large scale research model in the NASA Ames 40- by 80-Foot Wind Tunnel. Since the model differs in some…NASA-TM-X-62491
Comparison of Pitching Moments Produced by Plain Flaps and by Spoilers and Some Aerodynamic Characteristics of an NACA 23012 Airfoil with Various Types of AileronSectional characteristics of airfoil having retractable slotted flap with plain, slot-lip, or retractable ailerons are presented for a large range of aileron deflections. The analysis indicated that pitching moments produced by spoilers were less positive than those produced by plain flaps of equal…NACA-ACR-L5C24a
Comparison of RTA Vibratory Loading in the 40- by 80-Foot Wind Tunnel and 80- by 120-Foot Wind Tunnel at the National Full-Scale Aerodynamics ComplexThis paper presents data taken in the 80- by 120-Foot Wind Tunnel in 1992 to data taken in the 40- by 80-Foot Wind Tunnel in 2016 at the NFAC. In both sets of data, the RTA was equipped with an identical set of S-76 helicopter blades. These data sets were compared to determine the repeatability of…ARC-E-DAA-TN34899
Comparison of stability and control parameters for a light, single-engine, high-winged aircraft using different flight test and parameter estimation techniquesThe longitudinal and lateral stability and control parameters for a high wing, general aviation, airplane are examined. Estimations using flight data obtained at various flight conditions within the normal range of the aircraft are presented. The estimations techniques, an output error technique…NASA-TM-80163
Comparison of the CHARM Predictions of the Multirotor Test Bed with Wind Tunnel Experimental ResultsUrban air mobility as a fast transportation solution has captured the attention of private companies and government aviation departments in the 21st century. New designs of aerial vehicles are being developed to meet industry needs but often neglect the aerodynamic characteristics and the effects…
Comparison of wind tunnel and flyover noise measurements of the YOV-10A STOL aircraftThe YOV-10A Research Aircraft was flown to obtain flyover noise data that could be compared to noise data measured in the 40- by 80- foot wind tunnel at NASA Ames Research Center. The flyover noise measurements were made during the early morning hours on runway 32L at Moffett Field, California. A…NASA-TM-X-62166
Comparison of wind-tunnel and flight results on a four-propeller tilt-wing configurationOver the years aerodynamicists have learned to rely heavily on wind-tunnel-model results in predicting the aerodynamic characteristics of conventional aircraft configurations. With the development of V/STOL configurations which have high slipstream deflection angles. such as the four-propeller…
Computational Icing Analysis on NASA’s SIDRM Geometry to Investigate Collection EfficiencyComputational icing analysis results were compared to experimental icing tunnel data including aerothermal (e.g. dry air) and supercooled water droplet rime-ice conditions from tests conducted in early 2022 at the NASA Icing Research Tunnel (IRT). The Simulated Intercompressor Duct Research Model…
Computational Icing Risk Analysis of the D8 "Double Bubble" AircraftA computational icing risk analysis utilizing LEWICE3D was performed for the D8 Double Bubble aircraft. A variety of discrete drop sizes spanning the Appendix C and O regimes were simulated. For computational efficiency a 50-bin global discretization was produced and projected onto the…NASA/TM-2018-220006
Computational Icing Risk Analysis of the D8 "Double Bubble" AircraftA computational icing risk analysis utilizing LEWICE3D was performed for the D8 Double Bubble aircraft. A variety of discrete drop sizes spanning the Appendix C and O regimes were simulated. For computational efficiency a 50-bin global discretization was produced and projected onto the…GRC-E-DAA-TN55986
Computational Support of 9x7 Wind Tunnel Test of Sonic Boom Models with PlumesNASA and its industry partners are performing studies of supersonic aircraft concepts with low sonic boom pressure signatures. The interaction of the nozzle jet flow with the aircrafts' aft components is typically where the greatest uncertainly in the pressure signature is observed with…ARC-E-DAA-TN40151
Computer and engine performance study of a generalized parameter fuel control for jet enginesComputer and engine performance study of jet engine generalized parameter fuel controlNASA-TN-D-5871
COMSAC: Computational Methods for Stability and ControlWork on stability and control included the following reports:Introductory Remarks; Introduction to Computational Methods for Stability and Control (COMSAC); Stability & Control Challenges for COMSAC: a NASA Langley Perspective; Emerging CFD Capabilities and Outlook A NASA Langley Perspective; The…NASA/CP-2004-213028/PT1
COMSAC: Computational Methods for Stability and ControlThe unprecedented advances being made in computational fluid dynamic (CFD) technology have demonstrated the powerful capabilities of codes in applications to civil and military aircraft. Used in conjunction with wind-tunnel and flight investigations, many codes are now routinely used by designers…NASA/CP-2004-213028/PT2
Conference on V/STOL and STOL aircraftThis compilation contains results of recent NASA research on problems associated with V/STOL and STOL aircraft. The first three sections include papers presented at the NASA Conference on V/STOL and STOL Aircraft held at the Ames Research Center, Moffett Field, California, on April 4 and 5, 1966.…NASA-SP-116
Continuous measurement of aircraft wing icingIce formation on the wings of aircraft is a problem that has plagued air travel since its inception. Several recent incidents have been attributed to ice formation on the lifting surfaces of wings. This paper describes a SBIR Phase 1 research effort on the use of small flat dielectric sensors in…
Control Architecture for a Concept Aircraft with a Series/Parallel Partial Hybrid Powertrain and Distributed Electric PropulsionTraditional aircraft propulsion control approaches are insufficient for electrified aircraft powertrains due to their increased complexity compared to current systems. New control approaches are required to manage the increased interdependency and complexity of these electrified powertrains.…
Control Architecture for a Concept Aircraft with a Series/Parallel Partial Hybrid Powertrain and Distributed Electric PropulsionTraditional aircraft propulsion control approaches are insufficient for electrified aircraft powertrains due to their increased complexity compared to current systems. New control approaches are required to manage the increased interdependency and complexity of these electrified powertrains.…AIAA-2023-1750
Control Architecture for a Concept Aircraft with a Series/Parallel Partial Hybrid Powertrain and Distributed Electric PropulsionTraditional aircraft propulsion control approaches are insufficient for electrified aircraft powertrains due to their increased complexity compared to current systems. New control approaches are required to manage the increased interdependency and complexity of these electrified powertrains.…AIAA 2023-1750
Control-system techniques for improved departure/spin resistance for fighter aircraftThis paper summarizes some fundamental information on control-system effects on controllability of highly maneuverable aircraft at high angles of attack and techniques for enhancing fighter aircraft departure/spin resistance using control-system design. The discussion includes (1) a brief review of…NASA-TP-1689
Cooling Tests of an Airplane Equipped with an NACA Cowling and a Wing-duct Cooling SystemCooling tests were made of a Northrop A-17A attack airplane successively equipped with a conventional.NACA cowling and with a wing-duct cooling system. The method of cooling the engine by admitting air from the propeller slipstream into wing ducts, passing it first through the accessory compartment…NACA-TN-813
Cooperative control theory and integrated flight and propulsion controlThis report documents the activities and research results obtained under a grant (NAG3-998) from the NASA Lewis Research Center. The focus of the research was the investigation of dynamic interactions between airframe and engines for advanced ASTOVL aircraft configurations, and the analysis of the…NASA-CR-197493
Correaltion of full-scale drag predictions with flight measurements on the C-141A aircraft. Phase 2: Wind tunnel test, analysis, and prediction techniques. Volume 1: Drag predictions, wind tunnel data analysis and correlationThe degree of cruise drag correlation on the C-141A aircraft is determined between predictions based on wind tunnel test data, and flight test results. An analysis of wind tunnel tests on a 0.0275 scale model at Reynolds number up to 3.05 x 1 million/MAC is reported. Model support interference…NASA-CR-2333
Correlation of full-scale drag predictions with flight measurements on the C-141A aircraft : Phase 2: Wind tunnel tests, analysis, and prediction techniques. Volume 2: Wind tunnel test and basic dataA research program has been conducted to determine the degree of cruise drag correlation on the C-141A aircraft between predictions based on wind tunnel test data, and flight test results. Information is presented on the wind tunnel test program and basic aerodynamic data on the C-141A wind-tunnel…NASA-CR-2334
Correlation of low speed wind tunnel and flight test data for V/STOL aircraftThe XV-5B fan-in-wing aircraft and the Y0V-10 RCF rotating cylinder flap aircraft were subjected to wind tunnel tests. These tests were conducted specifically to provide for correlation between wind tunnel and inflight aerodynamics and noise test data. Correlation between aerodynamic and noise data…NASA-TM-X-62423
Correlation of wind-tunnel and flight-test aerodynamic data for five V/STOL aircraftCorrelation of wind tunnel and flight test aerodynamic data for five V/STOL aircraftAGARD-520
Correlations Among Ice Measurements, Impingement Rates Icing Conditions, and Drag Coefficients for Unswept NACA 65A004 AirfoilAn empirical relation has been obtained by which the change in drag coefficient caused by ice formations on an unswept NACA 65AO04 airfoil section can be determined from the following icing and operating conditions: icing time, airspeed, air total temperature, liquid-water content, cloud droplet…NACA-TN-4151
Coupled rotor/fuselage dynamic analysis of the AH-1G helicopter and correlation with flight vibrations dataUnder a research program designated Design Analysis Methods for VIBrationS (DAMVIBS), existing analytical methods are used for calculating coupled rotor-fuselage vibrations of the AH-1G helicopter for correlation with flight test data from an AH-1G Operational Load Survey (OLS) test program. The…NASA-CR-181723
Crew Factors in Flight Operations XV: Alertness Management in General Aviation Education ModuleRegional operations encompass a broad range of pilots and equipment. This module is intended to help all those involved in regional aviation, including pilots, schedulers, dispatchers, maintenance technicians, policy makers, and others, to understand the physiological factors underlying fatigue,…NASA/TM-2002-211394
Critical Mach Numbers of Thin Airfoil Sections with Plain FlapsCritical Mach number as function of lift coefficient is determined for certain moderately thick NACA low-drag airfoils. Results, given graphically, included calculations on same airfoil sections with plain flaps for small flap deflections. Curves indicate optimum critical conditions for airfoils…NACA-WR-W-2
Current Methods for Modeling and Simulating Icing Effects on Aircraft Performance, Stability and ControlIcing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to…NASA/TM-2008-215453
Current Methods Modeling and Simulating Icing Effects on Aircraft Performance, Stability, ControlIcing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to…AIAA Paper-44650-413
DARPA/AFRL/NASA Smart Wing Second Wind Tunnel Test ResultsTo quantify the benefits of smart materials and structures adaptive wing technology, Northrop Grumman Corp. (NGC) built and tested two 16% scale wind tunnel models (a conventional and a "smart" model) of a fighter/attack aircraft under the DARPA/AFRL/NASA Smart Materials and Structures Development…
Decoupling control synthesis for an oblique-wing aircraftInterest in oblique-wing aircraft has surfaced periodically since the 1940's. This concept offers some substantial aerodynamic performance advantages but also has significant aerodynamic and inertial cross-coupling between the aircraft longitudinal and lateral-directional axes. This paper presents…NASA-TM-86801
Defining Services, Functions, and Capabilities for an Advanced Air Mobility (AAM) In-time Aviation Safety Management System (IASMS)NASA’s vision for Advanced Air Mobility (AAM) Mission is to help emerging aviation markets to safely develop an air transportation system that moves people and cargo between places previously not served or underserved by aviation. The integration of new operational paradigms and vehicle classes in…
Design and evaluation of a robust dynamic neurocontroller for a multivariable aircraft control problemThe design of a dynamic neurocontroller with good robustness properties is presented for a multivariable aircraft control problem. The internal dynamics of the neurocontroller are synthesized by a state estimator feedback loop. The neurocontrol is generated by a multilayer feedforward neural…NASA-TM-105579
Design and Stability of an On-Orbit Attitude Control System Using Reaction Control ThrustersBasic principles for the design and stability of a spacecraft on-orbit attitude control system employing on-off Reaction Control System (RCS) thrusters are presented. Both vehicle dynamics and the control system actuators are inherently nonlinear, hence traditional linear control system design…M16-4984
Design and Testing of Drag Minimization and Maneuver Load Alleviation Control Laws for the IAWTM Wind Tunnel TestThis paper presents the design and experimental testing of drag minimization and maneuver load alleviation (MLA) controllers for high aspect ratio wing wind tunnel model. The controllers are developed for the Integrated Adaptive Wing Technology Maturation (IAWTM) wind tunnel tests at Langley…
Design and Testing of Gust Load Alleviation Control Laws for the IAWTM Wind Tunnel TestThis paper summarizes the design and testing of gust load alleviation (GLA) control laws developed for the Integrated Adaptive Wing Technology Maturation (IAWTM) wind tunnel test campaign at NASA’s Langley Research Center Transonic Dynamics Tunnel (TDT). The IAWTM program is a joint NASA and Boeing…
Design Criteria for Integrated Flight/Propulsion Control Systems for STOVL Fighter AircraftAs part of NASA's program to develop technology for short takeoff and vertical landing (STOVL) fighter aircraft, control system designs have been developed for a conceptual STOVL aircraft. This aircraft is representative of the class of mixed-flow remote-lift concepts that was identified as the…NASA-CP-3220
Design of a Slowed-Rotor Compound Helicopter for Future Joint Service MissionsA slowed-rotor compound helicopter has been synthesized using the NASA Design and Analysis of Rotorcraft (NDARC) conceptual design software. An overview of the design process and the capabilities of NDARC are presented. The benefits of trading rotor speed, wing-rotor lift share, and trim strategies…ARC-E-DAA-TN1155
Design of Combustor for Long-range Ram-jet Engine and Performance of Rectangular AnalogThe report describes the design of a piloted combustor intended for a ram-jet engine of long flight range. The unit comprises a large annular basket of V-type cross-section, the inner surface of which is slotted and bent into small V-gutters. At the trailing edge of the basket, eight V-gutters are…NACA-RM-E53K13
Design of Rail Instrumentation for Wind Tunnel Sonic Boom Measurements and Computational-Experimental ComparisonsAn innovative pressure rail concept for wind tunnel sonic boom testing of modern aircraft configurations with very low overpressures was designed with an adjoint-based solution-adapted Cartesian grid method. The computational method requires accurate free-air calculations of a test article as well…ARC-E-DAA-TN4517
Determination of Aircraft Antenna Loads Produced by Natural Icing ConditionsA flight investigation was made to determine the effect of distance flown in the icing region, antenna length, and antenna angle on the tension occurring in aircraft antennae while in regions of aircraft icing. The experimental antennas were of lengths ranging from 15 to 43 feet and were placed at…NACA-RM-E7H26a
Determination of control-surface characteristics from NACA plain-flap and tab dataThe data from previous NACA pressure-distribution investigations of plain flaps and tabs have been analyzed and are presented in this paper in a form readily applicable to the problems of control-surface design. The experimentally determined variation of aerodynamic parameters with flap chord and…NACA-TN-796
Determination of control-surface characteristics from NACA plain-flap and tab dataThe data from previous NACA pressure-distribution investigations of plain flaps and tabs with sealed gaps have been analyzed and are presented in this paper in a form readily applicable to the problems of control-surface design. The experimentally determined variation of aerodynamic parameters with…NACA-TR-721
Determination of flight characteristics of supersonic transports during the landing approach with a large jet transport in-flight simulatorFlight characteristics of supersonic transports during landing approach with large jet transport in flight simulatorNASA-TN-D-3971
Determination of Stability and Control Derivatives using Computational Fluid Dynamics and Automatic DifferentiationWith the recent interest in novel control effectors there is a need to determine the stability and control derivatives of new aircraft configurations early in the design process. These derivatives are central to most control law design methods and would allow the determination of closed-loop…AIAA Paper 99-3136
Development and Testing of a High Stability Engine Control (HISTEC) SystemFlight tests were recently completed to demonstrate an inlet-distortion-tolerant engine control system. These flight tests were part of NASA's High Stability Engine Control (HISTEC) program. The objective of the HISTEC program was to design, develop, and flight demonstrate an advanced integrated…NASA/TM-1998-206562
Development of an advanced pitch active control system and a reduced area horizontal tail for a wide-body jet aircraftThe development of an advanced pitch active control system (PACS) and a reduced area horizontal tail for a wide-body jet transport (L-1011) with a flying horizontal stabilizer is discussed. The advanced PACS control law design objectives were to provide satisfactory handling qualities for aft c.g.…NASA-CR-172283
Discussion of the results of the boundary-layer tests of an airfoil fitted with a rotary cylinderThe results of the velocity measurements in the boundary layer described in NACA-TM 411 are here discussed in greater detail. The measurements made were of the velocity distribution in the vicinity of an airfoil model fitted with a rotary cylinder and were undertaken for the purpose of obtaining a…NACA-TM-424
Dry wind tunnel systemThis invention is a ground flutter testing system without a wind tunnel, called Dry Wind Tunnel (DWT) System. The DWT system consists of a Ground Vibration Test (GVT) hardware system, a multiple input multiple output (MIMO) force controller software, and a real-time unsteady aerodynamic force…Patent Number: US-Patent-8,393,206
Dynamic stall experiments on the NACA 0012 airfoilThe flow over a NACA 0012 airfoil undergoing large oscillations in pitch was experimentally studied at a Reynolds number of and over a range of frequencies and amplitudes. Hot-wire probes and surface-pressure transducers were used to clarify the role of the laminar separation bubble, to delineate…NASA-TP-1100
Dynamics and Adaptive Control for Stability Recovery of Damaged AircraftThis paper presents a recent study of a damaged generic transport model as part of a NASA research project to investigate adaptive control methods for stability recovery of damaged aircraft operating in off-nominal flight conditions under damage and or failures. Aerodynamic modeling of damage…
Effect of Compressibility on the Pressure and Forces Acting on a Modified NACA 65,3-019 Airfoil Having A 0.20-Chord FlapAn investigation has been conducted in the Langley rectangular high-speed tunnel to determine the effect of compressibility on the pressure distribution for a modified NACA 65,3-019 airfoil having a 0.20-chord flap. The investigation was made for an angle-of-attack range extending from -2 to 12 deg…NACA-WR-L-76
Effectiveness of Thermal-Pneumatic Airfoil-Ice-Protection SystemIcing and drag investigations were conducted in the NACA Lewis icing research tunnel employing a combination thermal-pneumatic de-icer mounted on a 42-inch-chord NACA 0018 airfoil. The de-icer consisted of a 3-inch-wide electrically heated strip symmetrically located about the leading edge with…NACA-RM-E50K10A
Effects of asymmetry on the dynamic stability of aircraftThe oblique wing concept for transonic aircraft was proposed to reduce drag. The dynamic stability of the aircraft was investigated by analytically determining the stability derivatives at angles of skew ranging from 0 and 45 deg and using these stability derivatives in a linear analysis of the…NASA-CR-142857
Effects of Compressibility on the Maximum Lift Characteristics and Spanwise Load Distribution of a 12-Foot-Span Fighter-Type Wing of NACA 230-Series Airfoil SectionsLift characteristics and pressure distribution for a NACA 230 wing were investigated for an angle of attack range of from -10 to +24 degrees and Mach range of from 0.2 to 0.7. Maximum lift coefficient increased up to a Mach number of 0.3, decreased rapidly to a Mach number of 0.55, and then…NACA-ACR-L5G10
Effects of control laws and relaxed static stability on vertical ride quality of flexible aircraftState variable techniques are utilized to generate the RMS vertical load factors for the B-52H and B-1 bombers at low level, mission critical, cruise conditions. A ride quality index is proposed to provide meaningful comparisons between different controls or conditions. Ride quality is shown to be…NASA-CR-143843
Effects of Induction-System Icing on Aircraft-Engine Operating CharacteristicsAn investigation was conducted on a multicylinder aircraft engine on a dynamometer stand to determine the effect of induction-system icing on engine operating characteristics and to compare the results with those of a previous laboratory investigation in which only the carburetor and the…NACA-RM-E6L24
Effects of lateral control characteristics on hovering a jet lift vtol aircraftEffect of lateral control characteristics on hovering of jet lift VTOL aircraftNASA-TN-D-2701
Effects of wing height on the stability and control characteristics at a mach number of 2.01 of a canard airplane configuration with a 70 deg delta wingWing height effect on stability and control of 70 deg delta-wing canard-aircraft configuration at Mach 2.01NASA-TM-X-328
EFFECTS OF WING VERTICAL LOCATION ON THE STABILITY AND CONTROL CHARACTERISTICS AT A MACH NUMBER OF 2.01 OF A CANARD AIRPLANE CONFIGURATION WITH A TRAPEZOIDAL ASPECT-RATIO-3 WINGEffects of wing vertical location on stability and control of canard aircraft at supersonic speedsNASA-TM-X-44
Enabling Advanced Wind-Tunnel Research Methods Using the NASA Langley 12-Foot Low Speed TunnelDesign of Experiment (DOE) testing methods were used to gather wind tunnel data characterizing the aerodynamic and propulsion forces and moments acting on a complex vehicle configuration with 10 motor-driven propellers, 9 control surfaces, a tilt wing, and a tilt tail. This paper describes the…AIAA Paper-2014-3000
Engine Yaw Augmentation for Hybrid-Wing-Body Aircraft via Optimal Control Allocation TechniquesAsymmetric engine thrust was implemented in a hybrid-wing-body non-linear simulation to reduce the amount of aerodynamic surface deflection required for yaw stability and control. Hybrid-wing-body aircraft are especially susceptible to yaw surface deflection due to their decreased bare airframe yaw…DFRC-E-DAA-TN3895
Estimation of longitudinal stability and control derivatives for an icing research aircraft from flight dataThe results of applying a modified stepwise regression algorithm and a maximum likelihood algorithm to flight data from a twin-engine commuter-class icing research aircraft are presented. The results are in the form of body-axis stability and control derivatives related to the short-period,…NASA-TM-4099
Evaluation of a wind-tunnel gust response technique including correlations with analytical and flight test resultsA wind tunnel technique for obtaining gust frequency response functions for use in predicting the response of flexible aircraft to atmospheric turbulence is evaluated. The tunnel test results for a dynamically scaled cable supported aeroelastic model are compared with analytical and flight data.…NASA-TP-1501
Evaluation of active control technology for short haul aircraftAn evaluation of the economics of short-haul aircraft designed with active controls technology and low wing-loading to achieve short field performance with good ride quality is presented. Results indicate that for such a system incorporating gust load alleviation and augmented stability the direct…NASA-CR-137634
Evaluation of Alternative Altitude Scaling Methods for Thermal Ice Protection System in NASA Icing Research TunnelA test was conducted at NASA Icing Research Tunnel to evaluate altitude scaling methods for thermal ice protection system. Two new scaling methods based on Weber number were compared against a method based on Reynolds number. The results generally agreed with the previous set of tests conducted in…GRC-E-DAA-TN42129
Evaluation of Icing Scaling on Swept NACA 0012 Airfoil ModelsIcing scaling tests in the NASA Glenn Icing Research Tunnel (IRT) were performed on swept wing models using existing recommended scaling methods that were originally developed for straight wing. Some needed modifications on the stagnation-point local collection efficiency (i.e., beta(sub 0)…NASA/CR-2012-217419
Evaluation of Response Surface Experiment Designs for Distributed Propulsion Aircraft Aero-Propulsive ModelingModern distributed hybrid and electric propulsion aircraft, including vertical, short, and conventional takeoff and landing configurations, exhibit significant aero-propulsive complexity and a large number of interacting test factors. This paper presents the development and evaluation of experiment…
eVTOL Vehicle-Agnostic Instrument Flight Procedures Test PlanNASA Advanced Air Mobility National Campaign is researching the utility of electric vertical takeoff and land (eVTOL) advanced air mobility (AAM) instrument flight procedures. The result will be dynamic and tailored procedures that align to the following modus operandi: maximize safety,…
Experimental and calculated characteristics of three wings of NACA 64-210 and 65-210 airfoil sections with and without 2 degree washoutReport presents the results of an investigation conducted to determine some of the effects of airfoil section and washout on the experimental and calculated characteristics of 10-percent-thick wings. Three wings of aspect ratio 9 and ratio of root chord to tip chord 2.5 were tested. One wing had…NACA-TN-1422
Experimental and theoretical low speed aerodynamic characteristics of the NACA 65 sub 1-213, alpha equals 0.50, airfoilLow-speed wind-tunnel tests have been conducted to determine the two-dimensional aerodynamic characteristics of the NACA 65 sub 1-213, a = 0.05, airfoil. The results were compared with data from another low-speed wind tunnel and also with theoretical predictions obtained by using a viscous subsonic…NASA-TM-X-3160
Experimental Results from the Active Aeroelastic Wing Wind Tunnel Test ProgramThe Active Aeroelastic Wing (AAW) program is a cooperative effort among NASA, the Air Force Research Laboratory and the Boeing Company, encompassing flight testing, wind tunnel testing and analyses. The objective of the AAW program is to investigate the improvements that can be realized by…AIAA Paper 2005-2234
Experimental Studies of Flow Separation of the NACA 2412 Airfoil at Low SpeedsWind tunnel tests have been conducted on an NACA 2412 airfoil section at Reynolds number of 2.2 x 10(exp 6) and Mach number of 0.13. Detailed measurements of flow fields associated with turbulent boundary layers have been obtained at angles of attack of 12.4 degrees, 14.4 degrees, and 16.4 degrees.…NASA-CR-197497
Experimental Study of Noise Shielding by a NACA 0012 AirfoilThe effects of sound source location, Mach number and angle of attack on the shielding of a laser-induced sound source by a NACA 0012 airfoil are examined. The sound source is a small plasma generated by a high energy, laser beam focused to a point. In-flow microphone measurements are acquired in…NF1676L-28551
Exploratory flight investigation and analysis of structural loads encountered by a helicopter hingeless rotor systemFlight test and analysis of structural loads in helicopter hingeless rotor systemNASA-TN-D-3676
Extraction of Lateral-Directional Stability and Control Derivatives for the Basic F-18 Aircraft at High Angles of AttackThe results of parameter identification to determine the lateral-directional stability and control derivatives of an F-18 research aircraft in its basic hardware and software configuration are presented. The derivatives are estimated from dynamic flight data using a specialized identification…NASA-TM-4786
Fatigue tests on big structure assemblies of concorde aircraftFatigue tests on structural assemblies of the Concorde supersonic transport aircraft are reported. Two main sections of the aircraft were subjected to pressure, mechanical load, and thermal static tests. The types of fatigue tests conducted and the results obtained are discussed. It was concluded…
Fighter aircraft flight control technology design requirementsThe evolution of fighter aircraft flight control technology is briefly surveyed. Systems engineering, battle damage considerations for adaptive flutter suppression, in-flight simulation, and artificial intelligence are briefly discussed.
FLEXSTAB: A computer program for the prediction of loads and stability and control of flexible aircraftCapabilities of the FLEXSTAB Computer Program System are described and illustrated. Aeroelastic analysis of a wide variety of aircraft configurations is performed. The aerodynamic theory used in FLEXSTAB is applicable to both steady and unsteady, subsonic and supersonic flow for multiple wing-body…
Flight Control of Flexible AircraftThis presentation presents an overview of flight control research for flexible high aspect wing aircraft in support of the NASA ARMD Advanced Air Transport Technology (AATT) project. It summarizes multi-objective flight control technology being developed for drag optimization, flutter suppression,…ARC-E-DAA-TN39476
Flight evaluation of the transonic stability and control characteristics of an airplane incorporating a supercritical wingA TF-8A airplane was equipped with a transport type supercritical wing and fuselage fairings to evaluate predicted performance improvements for cruise at transonic speeds. A comparison of aerodynamic derivatives extracted from flight and wind tunnel data showed that static longitudinal stability,…NASA-TP-1167
Flight evaluation results from the general-aviation advanced avionics system programA demonstration advanced avionics system (DAAS) for general-aviation aircraft was tested at NASA Ames Research Center to provide information required for the design of reliable, low-cost, advanced avionics systems which would make general-aviation operations safer and more practicable. Guest pilots…NASA-TM-84397
Flight investigation of dynamic stability and control characteristics of a 0.18-scale model of a fan-in-wing VTOL airplaneDynamic stability and control characteristics of 0.18 scale model of fan-in-wing VTOL aircraftNASA-TN-D-3412
Flight investigation of stability and control characteristics of a 0.18-scale model of a four-duct tandem V/STOL transportFlight stability and control tests of scale model of four-duct tandem V/STOL aircraftNASA-TN-D-3055
Flight investigation of stability and control characteristics of a 1/9-scale model of a four-propeller tilt-wing v/stol transportStability & control of 4-propeller, tilt-wing v/stol scale model transport aircraftNASA-TN-D-2443
Flight Investigation of the Stability and Control Characteristics of a 1/4-Scale Model of a Tilt-Wing Vertical-Take-Off-and-Landing AircraftAn experimental investigation has been conducted to determine the dynamic stability and control characteristics of a tilt-wing vertical-take-off-and-landing aircraft with the use of a remotely controlled 1/4-scale free-flight model. The model had two propellers with hinged (flapping) blades mounted…NASA-MEMO-11-4-58L
Flight Investigation of the Wing-rotor Lift-sharing Characteristics of a Hingeless Rotor Compound HelicopterFlight investigations of wing-rotor lift-sharing characteristics of XH-51 helicopterNASA-TM-X-61219
Flight measurements of stability and control derivatives of the x-15 research airplane to a mach number of 6.02 and an angle of attack of 25 degFlight test data on longitudinal, lateral, and directional stability and control derivatives of X-15 aircraftNASA-TN-D-2532
Flight Stability and Control and Performance Results from the Linear Aerospike SR-71 Experiment (LASRE)The Linear Aerospike SR-71 Experiment (LASRE) is presently being conducted to test a 20-percent-scale version of the Linear Aerospike rocket engine. This rocket engine has been chosen to power the X-33 Single Stage to Orbit Technology Demonstrator Vehicle. The rocket engine was integrated into a…NASA/TM-1998-206565
Flight Test EngineeringAlthough the scope of flight test engineering efforts may vary among organizations, all point to a common theme: flight test engineering is an interdisciplinary effort to test an asset in its operational flight environment. Upfront planning where design, implementation, and test efforts are clearly…DFRC-E-DAA-TN11035
Flight Test Results From a Supercritical Mission Adaptive Wing With Smooth Variable CamberThe mission adaptive wing (MAW) consisted of leading- and trailing-edge variable-camber surfaces that could be deflected in flight to provide a near-ideal wing camber shape for any flight condition. These surfaces featured smooth, flexible upper surfaces and fully enclosed lower surfaces,…AIAA-92-4101
Flight Test Results on the Stability and Control of the F-15 Quiet Spike(TradeMark) AircraftThe Quiet Spike F-15B flight research program investigated supersonic shock reduction using a 24-ft sub-scale telescoping nose boom on an F-15B airplane. The program primary flight test objective was to collect flight data for aerodynamic and structural models validation up to 1.8 Mach. Other…NASA/TM-2012-215978
Flight Testing and Simulation of an F-15 Airplane Using Throttles for Flight ControlFlight tests and simulation studies using the throttles of an F-15 airplane for emergency flight control have been conducted at the NASA Dryden Flight Research Facility. The airplane and the simulation are capable of extended up-and-away flight, using only throttles for flightpath control. Initial…AIAA-92-4109
Flight-determined stability and control derivatives for the F-111 Tact research aircraftA flight investigation was conducted to provide a stability and control derivative data base for the F-111 transonic aircraft technology research aircraft. Longitudinal and lateral-directional data were obtained as functions of Mach number, angle of attack, and wing sweep. For selected derivatives,…NASA-TP-1350
FLIGHT-DETERMINED STABILITY AND CONTROL DERIVATIVES OF A SUPERSONIC AIRPLANE WITH A LOW-ASPECT-RATIO UNSWEPT WING AND A TEE-TAILFlight-determined stability & control derivatives of supersonic aircraft with low aspect ratio unswept wing & t-tailNASA-MEMO-2-2-59H
Flying qualities and control system characteristics for superaugmented aircraftAircraft-alone dynamics and superaugmented control system fundamental regulatory properties including stability and regulatory responses of the basic closed-loop systems; fundamental high and low frequency margins and governing factors; and sensitivity to aircraft and controller parameters are…NASA-CR-170419
Forced Oscillation Wind Tunnel Testing for FASER Flight Research AircraftAs unmanned air vehicles (UAVs) continue to expand their flight envelopes into areas of high angular rate and high angle of attack, modeling the complex unsteady aerodynamics for simulation in these regimes has become more difficult using traditional methods. The goal of this experiment was to…NF1676L-14053
Frostwing Co-Operation in Aircraft Icing Researche aerodynamic effects of Cold Soaked Fuel Frost have become increasingly significant as airworthiness authorities have been asked to allow it during aircraft take-off. The Federal Aviation Administration and the Finnish Transport Safety Agency signed a Research Agreement in aircraft icing research…GRC-E-DAA-TN66819
Full scale subsonic wind tunnel requirements and design studiesThe justification and requirements are summarized for a large subsonic wind tunnel capable of testing full-scale aircraft, rotor systems, and advanced V/STOL aircraft propulsion systems. The design considerations and constraints for such a facility are reviewed, and the trades between facility test…NASA-TM-X-62184
FULL-SCALE WIND-TUNNEL INVESTIGATION OF A FLEXIBLE-WING MANNED TEST VEHICLEWind tunnel stability and control tests of flexible wing manned aircraft - parawingNASA-TN-D-1946
Full-scale wind-tunnel investigation of a VTOL aircraft with a jet-ejector system for lift augmentationFull scale wind tunnel investigation of VTOL AIRCRAFT with jet ejector system for lift augmentationNASA-TN-D-3725
Full-scale wind-tunnel tests of a small unpowered jet aircraft with a T-tailThe aerodynamic characteristics of a full scale executive type jet transport aircraft with a T-tail were investigated in a 40 x 80 ft (12.2 by 24.4 meter) wind tunnel (subsonic). Static, longitudinal, and lateral stability, and control characteristics were determined at angles of attack from -2 deg…NASA-TN-D-6573
Fuzzy Model-based Pitch Stabilization and Wing Vibration Suppression of Flexible Wing Aircraft.This paper presents a fuzzy nonlinear controller to regulate the longitudinal dynamics of an aircraft and suppress the bending and torsional vibrations of its flexible wings. The fuzzy controller utilizes full-state feedback with input constraint. First, the Takagi-Sugeno fuzzy linear model is…ARC-E-DAA-TN13844
Gaps Analysis for the Development of an IASMS for Commercial Aviation OperationsAn In-time Aviation Safety Management System (IASMS) [1,2] is a set of services, functions, and capabilities (SFCs) necessary for monitoring known hazards and emergent risks, assessing safety data for anomalies, precursors, and trends, mitigating hazards that reach safety thresholds, and assuring…NASA/TM-20240012528
General aviation air traffic pattern safety analysisA concept is described for evaluating the general aviation mid-air collision hazard in uncontrolled terminal airspace. Three-dimensional traffic pattern measurements were conducted at uncontrolled and controlled airports. Computer programs for data reduction, storage retrieval and statistical…NASA-TM-X-69455
General Aviation Aircraft Reliability StudyThis reliability study was performed in order to provide the aviation community with an estimate of Complex General Aviation (GA) Aircraft System reliability. To successfully improve the safety and reliability for the next generation of GA aircraft, a study of current GA aircraft attributes was…NASA/CR-2001-210647
General aviation approach and landing practicesThe characteristics of air traffic patterns at uncontrolled airports and techniques used by a group of general aviation pilots in landing light airplanes are documented. The results of some 1,600 radar tracks taken at four uncontrolled airports and some 600 landings made by 22 pilots in two, four…
General aviation crash safety program at Langley Research CenterThe purpose of the crash safety program is to support development of the technology to define and demonstrate new structural concepts for improved crash safety and occupant survivability in general aviation aircraft. The program involves three basic areas of research: full-scale crash simulation…
General Aviation Pilots' Perceived Usage and Valuation of Aviation Weather Information SourcesAviation suffers many accidents due to the lack of good weather information in flight. Existing aviation weather information is difficult to obtain when it is most needed and is not well formatted for in-flight use. Because it is generally presented aurally, aviation weather information is…NASA/TM-2002-211443
General aviation technology assessmentThe existing problem areas in general aviation were investigated in order to identify those which can benefit from technological payoffs. The emphasis was placed on acceptance by the pilot/passenger in areas such as performance, safety, handling qualities, ride quality, etc. Inputs were obtained…NASA-CR-145979
Generation of Mars Helicopter Rotor Model for Comprehensive AnalysesThe present research is aimed at providing a performance model for the Mars Helicopter (MH), to understand the complexity of the flow, and identify future regions of improvement. The low density of the Martian atmosphere and the relatively small MH rotor, result in very low chord-based Reynolds…ARC-E-DAA-TN50660
Hamiltonian Gust Load Alleviation Control with Adaptive Gust Estimation: Analysis and Wind Tunnel Test CorrelationThis paper presents the design and experimental validation of a Hamiltonian controller for gust load alleviation (GLA) on a flexible wing wind tunnel model. The control design incorporates practical implementation considerations, including low-pass filtering to prevent excitation of high-frequency…
Handling qualities and structural characteristics of the hingeless-rotor helicopterSeveral advantages and potential problem areas associated with the hingeless-rotor helicopter are discussed. The extent to which two of the advantages - increased control and damping moments - can be obtained with the hingeless-rotor helicopter is established. The upper limit on the available…
Helicopter main-rotor speed effects on far-field acoustic levelsThe design of a helicopter is based on an understanding of many parameters and their interactions. For example, in the design stage of a helicopter, the weight, engine, and rotor speed must be considered along with the rotor geometry when considering helicopter operations. However, the relationship…NASA-TM-100512
Helicopter noise regulations: An industry perspectiveA review of helicopter noise measurement programs and noise reduction/economic studies of FAA is given along with a critique of a study which addresses the economic impact of noise reduction on helicopter noise. Modification of several helicopters to reduce noise and demonstrate the economic impact…
Helicopter rotor trailing edge noiseA two dimensional section of a helicopter main rotor blade was tested in an acoustic wind tunnel at close to full-scale Reynolds numbers to obtain boundary layer data and acoustic data for use in developing an acoustic scaling law and testing a first principles trailing edge noise theory. Results…NASA-CR-3470
Helicopter tail rotor blade-vortex interaction noiseA study is made of helicopter tail rotor noise, particularly that due to the interactions with main rotor tip vortices. Summarized here are present analysis, the computer codes, and the results of several test cases. Amiet's unsteady thin airfoil theory is used to calculate the acoustics of…NASA-CR-183178
Helicopter tail rotor noise analysesA study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex. The…NASA-CR-176829
Helicopter testing in a wind tunnelWind tunnel testing of helicopters, and test program for Polish helicopter industry
High angle-of-attack stability-and-control analysisMethods of linear systems analysis were applied to mathematical models of aircraft flying at high angle of attack and maneuver rate. First order longitudinal and lateral directional coupling is obtained by linearizing the complete nonlinear equations of motion about a generalized (quasi steady)…
High Reynolds number test of a NACA 651-213, a equals 0.5 airfoil at transonic speedsWind-Tunnel tests were conducted in the Lockheed-Georgia Company's compressible flow facility to determine the transonic two-dimensional aerodynamic characteristics of a NACA 65 sub 1-213 a = 0.50 airfoil. The results are correlated with data obtained in the NASA-Langley 8-foot transonic pressure…NASA-CR-2499
High Stability Engine Control (HISTEC) Flight Test ResultsThe High Stability Engine Control (HISTEC) Program, managed and funded by the NASA Lewis Research Center, is a cooperative effort between NASA and Pratt & Whitney (P&W). The program objective is to develop and flight demonstrate an advanced high stability integrated engine control system that uses…NASA/TM-1998-208481
High-Speed Wind Tunnel Tests of a Full-Scale Proprotor on the Tiltrotor Test RigThe Tiltrotor Test Rig (TTR) is a NASA project, joint with the U.S. Army and Air Force, to develop a new, large scale proprotor test system for the National Full-Scale Aerodynamics Complex (NFAC). The first wind-tunnel entry was completed in November 2018 with a modern, 26-ft diameter proprotor.…ARC-E-DAA-TN67822
Hingeless helicopter rotor with improved stabilityImproved stability was provided in a hingeless helicopter rotor by inclining the principal elastic flexural axes and coupling pitching of the rotor blade with the lead-lag bending of the blade. The primary elastic flex axes were inclined by constructing the blade of materials that display…Patent Application Number: US-PATENT-APPL-SN-513612
Historical Overview and Recent Improvements at the NASA Glenn Research Center 8x6 9x15 Wind Tunnel ComplexA brief history of the 8x6 Supersonic Wind Tunnel (SWT) and 9x15 Low Speed Wind Tunnel (LSWT) at NASA Glenn Research Center, Cleveland, Ohio is presented along with current capabilities and plans for future upgrades within the facility.GRC-E-DAA-TN20102
HOVERING CHARACTERISTICS OF A ROTOR HAVING AN AIRFOIL SECTION DESIGNED FOR AUTILITY TYPE OF HELICOPTERHovering characteristics of rotor having airfoil section designed for utility type helicopterNASA-TN-D-1517
Hovering performance characteristics of a rotor with and without blade-pitch servo-control flapsPhotographic performance evaluation of hovering helicopter rotor with and without blade pitch servocontrol flapsNASA-TN-D-3786
Ice Accretion Test Results for Three Large-Scale Swept-Wing Models in the NASA Icing Research TunnelThe design and certification of modern transport airplanes for flight in icing conditions increasing relies on three-dimensional numerical simulation tools for ice accretion prediction. There is currently no publically available, high-quality, ice accretion database upon which to evaluate the…GRC-E-DAA-TN32827
Ice Accretions and Full-Scale Iced Aerodynamic Performance Data for a Two-Dimensional NACA 23012 AirfoilThis report documents the data collected during the large wind tunnel campaigns conducted as part of the SUNSET project (StUdies oN Scaling EffecTs due to ice) also known as the Ice-Accretion Aerodynamics Simulation study; a joint effort by NASA, ONERA, and the University of Illinois. These data…NASA/TP-2016-218348
Ice Crystal Icing Research at NASAIce crystals found at high altitude near convective clouds are known to cause jet engine power-loss events. These events occur due to ice crystals entering a propulsion systems core flowpath and accreting ice resulting in events such as uncommanded loss of thrust (rollback), engine stall, surge,…GRC-E-DAA-TN42705
Ice Crystal Icing Research at NASAIce crystals found at high altitude near convective clouds are known to cause jet engine power-loss events. These events occur due to ice crystals entering a propulsion systems core flowpath and accreting ice resulting in events such as uncommanded loss of thrust (rollback), engine stall, surge,…GRC-E-DAA-TN43061
Ice Roughness and Thickness Evolution on a Swept NACA 0012 AirfoilSeveral recent studies have been performed in the Icing Research Tunnel (IRT) at NASA Glenn Research Center focusing on the evolution, spatial variations, and proper scaling of ice roughness on airfoils without sweep exposed to icing conditions employed in classical roughness studies. For this…GRC-E-DAA-TN42660
Ice Shape Analysis of an eVTOL Propeller in Forward Flight at the NASA Glenn Icing Research TunnelAdvanced Air Mobility (AAM) introduces many novel electric vertical takeoff and landing (eVTOL) aircraft configurations for which the effect of icing is not well understood. While icing computational tools have often aided in the design and certification of conventional aircraft, experimental data…
Ice Shape Analysis of an eVTOL Propeller in Forward Flight at the NASA Glenn Icing Research TunnelAdvanced Air Mobility (AAM) introduces many novel electric vertical takeoff and landing (eVTOL) aircraft configurations for which the effect of icing is not well understood. While icing computational tools have often aided in the design and certification of conventional aircraft, experimental data…
Ice-Accretion Test Results for Three Large-Scale Swept-Wing Models in the NASA Icing Research TunnelIcing simulation tools and computational fluid dynamics codes are reaching levels of maturity such that they are being proposed by manufacturers for use in certification of aircraft for flight in icing conditions with increasingly less reliance on natural-icing flight testing and icing-wind-tunnel…GRC-E-DAA-TN31804
Ice-Accretion Test Results for Three Large-Scale Swept-Wing Models in the NASA Icing Research TunnelIcing simulation tools and computational fluid dynamics codes are reaching levels of maturity such that they are being proposed by manufacturers for use in certification of aircraft for flight in icing conditions with increasingly less reliance on natural-icing flight testing and icing-wind-tunnel…NASA/TM-2016-219137
Ice-Crystal Icing Accretion Studies at the NASA Propulsion Systems LaboratoryThis paper describes an ice-crystal icing experiment conducted at the NASA Propulsion System Laboratory during June 2018. This test produced ice shape data on an airfoil for different test conditions similar to those inside the compressor region of a turbo-fan jet engine. Mixed-phase icing…GRC-E-DAA-TN66895
Icing Analysis of a Swept NACA 0012 Wing Using LEWICE3D Version 3.48Icing calculations were performed for a NACA 0012 swept wing tip using LEWICE3D Version 3.48 coupled with the ANSYS CFX flow solver. The calculated ice shapes were compared to experimental data generated in the NASA Glenn Icing Research Tunnel (IRT). The IRT tests were designed to test the…GRC-E-DAA-TN15312
Icing Analysis of a Swept NACA 0012 Wing Using LEWICE3D Version 3.48Icing calculations were performed for a NACA 0012 swept wing tip using LEWICE3D Version 3.48 coupled with the ANSYS CFX flow solver. The calculated ice shapes were compared to experimental data generated in the NASA Glenn Icing Research Tunnel (IRT). The IRT tests were designed to test the…GRC-E-DAA-TN15558
Icing effects on aircraft stability and control determined from flight data: Preliminary resultsThe effects of airframe icing on the stability and control characteristics of the NASA DH-6 Twin Otter icing research aircraft were investigated by flight test. The flight program was developed to obtain the stability and control parameters of the DH-6 in a baseline ('uniced') configuration and an…NASA-TM-105977
Icing Frequencies Experienced During Climb and Descent by Fighter-Interceptor AircraftData and analyses are presented on the relative frequencies of occurrence and severity of icing cloud layers encountered by jet aircraft in the climb and descent phases of flights to high altitudes. Fighter-interceptor aircraft operated by the Air Defense Command (USAF) at bases in the Duluth and…NACA-TN-4314
Icing Physics Studies Using the 3D SIDRM Test Article: 2023 Icing Tests AnalysisIn-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation capability. Experimental data are required for the development of icing physics models and…NASA/CR-20260000820
Icing Physics Studies Using the 3D SIDRM Test Article: Aerodynamic and Supercooled Liquid Icing AnalysisIn-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation capability. Experimental data is required for development of icing physics models and simulation…
Icing Physics Studies Using the 3D SIDRM Test Article: Aerodynamic and Supercooled Liquid Icing AnalysisIn-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation capability. Experimental data is required for development of icing physics models and simulation…
Icing Physics Studies Using the 3D SIDRM Test Article: Ice Crystal Icing AnalysisIn-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation capability. Experimental data is required for the development of icing physics models and…
Icing Physics Studies Using the 3D SIDRM Test Article: Ice Crystal Icing AnalysisIn-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation capability. Experimental data is required for the development of icing physics models and…
Icing: Accretion, Detection, ProtectionThe global aircraft industry and its regulatory agencies are currently involved in three major icing efforts: ground icing; advanced technologies for in-flight icing; and tailplane icing. These three major icing topics correspondingly support the three major segments of any aircraft flight profile:…E-9139
Impact of General Aviation Operations on Airport Performance Through Fast-Time Simulations at Charlotte Douglas International AirportNASA, in partnership with the Federal Aviation Administration and commercial airlines, deployed the Integrated Arrival, Departure, and Surface (IADS) traffic management system at Charlotte Douglas International Airport (CLT) in 2017 for field evaluation. The system features new capabilities of data…
Impingement of Water Droplets on an NACA 65(sub 1) -212 Airfoil at an Angle of Attack of 4 DegThe trajectories of droplets in the air flowing past an NACA 651-212 airfoil at an angle of attack of 40 were determined. The collection efficiency, the area of droplet impingement, and the rate of droplet impingement were calculated from the trajectories and are presented herein.NACA-RM-E52B12
Impingement of water droplets on NACA 65(1)-208 and 65(1)-212 airfoils at 4 degrees angle of attackThe trajectories of droplets in the air flowing past NACA 65(1)-208 airfoil and an NACA 65(1)-212 airfoil, both at an angle of attack of 4 degrees, were determined. The amount of water in droplet form impinging on the airfoils, the area of droplet impingement, and the rate of droplet impingement…NACA-TN-2952
Impingement of Water Droplets on NACA 65A004 Airfoil and Effect of Change in Airfoil Thickness from 12 to 4 Percent at 4 deg Angle of AttackThe trajectories of droplets in the air flowing past an NACA 65A004 a irfoil at an angle of attack of 4 deg were determined. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were…NACA-TN-3047
Impingement of Water Droplets on NACA 65A004 Airfoil at 0 Deg Angle of AttackThe trajectories of water droplets in the air flowing past an NACA 6511004 airfoil at a n angle of attack of 0 deg were determined. The amount of water in droplet form impinging on the airfoil , the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil…NACA-TN-3586
Impingement of Water Droplets on NACA 65A004 Airfoil at 8 deg Angle of AttackThe trajectories of droplets in the air flowing past an NACA 65AO04 airfoil at an angle of attack of 8 deg were determined.. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were…NACA-TN-3155
Implications of Contingency Planning Support for Weather and Icing InformationA human-centered systems analysis was applied to the adverse aircraft weather encounter problem in order to identify desirable functions of weather and icing information. The importance of contingency planning was identified as emerging from a system safety design methodology as well as from…SAE-2003-01-2089
Implications of control technology on aircraft designNew controls technologies are now available for implementation with aircraft systems. Many aircraft with state of the art technology in the fields of aerodynamics, structures, and propulsion require extensive augmentation merely for safety of flight considerations in addition to potential…
Improved Mars Helicopter Aerodynamic Rotor Model for Comprehensive AnalysesThe Mars Helicopter is part of the NASA Mars 2020 rover mission scheduled to launch in July of 2020. Its goal is to demonstrate the viability and potential of heavier-than-air vehicles in the Martian atmosphere. Ultimately, it aims to bridge the resolution gap between orbiters and the rover as well…ERF Paper No. 2018-28
In-Flight Stability Analysis of the X-48B AircraftThis report presents the system description, methods, and sample results of the in-flight stability analysis for the X-48B, Blended Wing Body Low-Speed Vehicle. The X-48B vehicle is a dynamically scaled, remotely piloted vehicle developed to investigate the low-speed control characteristics of a…DFRC-775
Initial Results from Radiometer and Polarized Radar-Based Icing Algorithms Compared to In-Situ DataIn early 2015, a field campaign was conducted at the NASA Glenn Research Center in Cleveland, Ohio, USA. The purpose of the campaign is to test several prototype algorithms meant to detect the location and severity of in-flight icing (or icing aloft, as opposed to ground icing) within the terminal…GRC-E-DAA-TN22909
Inlet Performance of the NFAC 1/50th-scale 80- by 120- Foot Wind TunnelThe National Full-Scale Aerodynamics Complex 80- by 120-Foot Wind Tunnel (80x120) was dedicated in 1987 and rated at 100 knots for full-scale aircraft testing at NASA Ames Research Center. The 80x120 is the world’s largest wind tunnel, designed as an open circuit tunnel with a large aerodynamically…
Input design for identification of aircraft stability and control derivativesAn approach for designing inputs to identify stability and control derivatives from flight test data is presented. This approach is based on finding inputs which provide the maximum possible accuracy of derivative estimates. Two techniques of input specification are implemented for this objective -…NASA-CR-2493
Integrated Aerodynamic and Control System Design of Oblique Wing AircraftAn efficient high speed aircraft design must achieve a high lift to drag ratio at transonic and supersonic speeds. In 1952 Dr. R. T. Jones proved that for any flight Mach number minimum drag at a fixed lift is achieved by an elliptic wing planform with an appropriate oblique sweep angle. Since…NASA-CR-192614
Integrated Flight Propulsion Control Research Results Using the NASA F-15 HIDEC Flight Research FacilityOver the last two decades, NASA has conducted several flight research experiments in integrated flight-propulsion control. Benefits have included increased thrust, range, and survivability; reduced fuel consumption; and reduced maintenance. These flight programs were flown at NASA Dryden Flight…AIAA-92-4106