Browse Topic: Flight tests

Items (160)
Find
Nonlinear Observer for Estimating Gravity Vector and Flight Path Angles of a High-Performance Aircraft01-17-01-000708/14/2023
This paper proposes a nonlinear observer for the estimation of gravity vector and angles with respect to velocity vector (flight path angle, bank angle) of a high-performance aircraft. The technique is computationally simpler than the extended Kalman filter (EKF) and hence is suitable for onboard implementations when the digital flight control computer (DFCC) has computational burdens. Flight test data of a highly maneuvering flight such as wind-up turns and full rolls have been used to validate the technique.
Chandrasekaran, Kamali, Jain, Shikha
Additive Manufacturing of Threaded Parts for Aerospace applications2022-26-117005/26/2022
Additive manufacturing also known as 3D printing and rapid prototyping is ‘the process of joining materials to make objects from 3D model data, generally layer upon layer. It is a suitable process to produce complex net shape parts, and prototypes. Additive Manufacturing empowers both design and industrial revolution, in various industrial sectors such as aerospace, energy, automotive, medical, tooling and consumer goods. In aerospace today, Additive Manufacturing is bringing lots of advantages and applications but manufacturing threaded fasteners or parts with threads is not much explored. In this study we are exploring this and trying to establish manufacturing threaded parts using additive manufacturing. This is going to give many benefits like reduced part cost, manufacturing and installation time and increased safety. The key features of such parts which makes AM as a best manufacturing method are – angled internal grove, provision for sealant for complete sealing, customized
Shetty, Dr. Kishora, Murthy, Harsha
Wave Energy Modeling for Safer Space TravelTBMG-3822212/01/2020
National Renewable Energy Laboratory US Department of Energy Golden, CO
Celebrating Women in Engineering & Science: Jasmin Moghbeli, NASA AstronautTBMG-3616603/01/2020
Jasmin Moghbeli’s astronaut class graduated in January 2020 — the first class to graduate since the agency announced the Artemis program. She holds a BS degree in aerospace engineering with information technology from the Massachusetts Institute of Technology and a MS in engineering science in aerospace engineering from the Naval Postgraduate School. Moghbeli was commissioned as a Second Lieutenant in the United States Marine Corps in 2005 upon completion of her undergraduate degree. An AH-1W Super Cobra helicopter pilot and Marine Corps test pilot, Moghbeli served in Operation Enduring Freedom in Afghanistan from 2009 to 2010. At the time of her selection as an astronaut candidate, Moghbeli was testing H-1 helicopters. She has accumulated more than 150 combat missions and 2,000 hours of flight time in more than 25 different aircraft. She is eligible for assignment to missions destined for the International Space Station, the Moon, and ultimately, Mars.
Facing the Challenges of Supercooled Large Droplet Icing: Results of a Flight Test Based Joint DLR-Embraer Research Project2019-01-198806/10/2019
Today’s airplanes are well equipped to cope with most common icing conditions. However, some atmospheric conditions consisting of supercooled large droplets (SLD) have been identified as cause of severe accidents over the last decades as existing countermeasures even on modern aircraft are not necessarily effective against SLD-ice. In 2014, the new Appendix O to the certification regulations (FAR Part 25 / CS-25) had been issued to guarantee the safe operation of future airplane when encountering SLD conditions. But as the SLD topic is quite new for the majority of aircraft manufacturers and research institutes in a same way, DLR (German Aerospace Center) and Embraer established a joint research cooperation in 2012 to obtain a better understanding of the distinct influences of SLD-ice shapes on aircraft characteristics and to evaluate proper ways for future airplane certification under App. O. Furthermore, one additional scientific goal of the cooperation was to develop and test new
Deiler, Christoph, Ohme, Per, Raab, Christian, Mendonca, Celso, Silva, Daniel
Korean Utility Helicopter KUH-1 Icing Certification Program2019-01-198906/10/2019
The KUH-1 Surion is a twin-engine utility helicopter designed and developed jointly by Korea Aerospace Industries (KAI) and Airbus Helicopters primarily for the Republic of Korea Army (ROKA). Following customer requirements, KAI launched a program aimed at the military qualification of the KUH-1 for flight in icing conditions following tailored airworthiness certification criteria based on 14 CFR Part 29 and DEF STAN 00-970. The Netherlands Aerospace Centre (NLR) became involved in the program on the eve of the first icing flight test campaign performed in the winter of 2015/2016. NLR has supported all subsequent test activities and the finding of compliance in close collaboration with KAI and certain suppliers. The test activities performed include 1) component-level development and qualification icing wind tunnel testing at Cox & Co in Long Island, NY, 2) icing qualification testing of the engine air intake ice protection system at Rail Tec Arsenal (RTA) in Vienna, Austria, 3
van 't Hoff, Stefan, Lammers, Karel, Hwang, Yoo Sang, Kim, Jik Soo, Kim, Kyung Sam
High Altitude Ice Crystal Detection with Aircraft X-band Weather Radar2019-01-202606/10/2019
During participation on EU FP7 HAIC project, Honeywell has developed methodology to detect High Altitude Ice Crystals with the Honeywell IntuVue® RDR-4000 X-band Weather Radar. The algorithm utilizes 3D weather buffer of RDR-4000 weather radar and is based on machine learning. The modified RDR-4000 Weather Radar was successfully flight tested during 2016 HAIC Validation Campaign; the technology was granted Technology Readiness Level 6 by HAIC consortium. After the end of HAIC project, the method was also evaluated with respect to newly set preliminary industry standard performance requirements1. This paper discuses technology design rationale, high level technology architecture, technology performance, and challenges associated with performance evaluation.
Lukas, Jan, Badin, Pavel
CH148 Icing Flight Test Performance Data Correlation2019-01-199106/10/2019
This paper presents results of correlation of an empirical code to CH148 Cyclone® icing flight test performance data. Predicted icing main rotor torque penalties, generated using the Sikorsky Generalized Rotor Performance (GRP) model with the integral DELICE icing performance module, are compared to flight test results. DELICE methodology adjustments are shown that lead to CH148 test data correlation and improved correlation to previously-examined S-92A™ icing flight test performance data. Finally, a comparison of results between GRP and Sikorsky-Maryland FreeWake is shown, providing an indication of the influence of rotor wake methodology on icing model correlation.
Griffiths, Daniel
The Cloud Detectability Conundrum2019-01-193206/10/2019
Since the beginning of aviation, aircraft designers, researchers, and pilots have monitored the skies looking for clouds to determine when and where to fly as well as when to deice aircraft surfaces. Seeing a cloud has generally consisted of looking for a white / grey puffy orb floating in the sky, indicating the presence of moisture. A simple monitoring of a temperature gauge or dew point sensor was used to help determine if precipitation was likely or accumulation of ice / snow on the airframe could occur. Various instruments have been introduced over the years to identify the presence of clouds and characterize them for the purposes of air traffic control weather awareness, icing flight test measurements, and production aircraft ice detection. These instruments have included oil slides, illuminated rods, vibrating probes, hot wires, LIDAR, RADAR, and several other measurement techniques. Each technology has its own strength and weakness including the particle size range and water
Jackson, Darren Glenn
Wind Tunnel Measurements of Simulated Glaciated Cloud Conditions to Evaluate Newly Developed 2D Imaging Probes2019-01-198106/10/2019
Instrumentation that has been used for characterization of mixed-phase and glaciated conditions in the past, like the OAP probes, are subject to errors caused by variations in diffraction on the images away from the object plane and by the discrete nature of their particle detection and sizing. Correction methods are necessary to consider their measurements adequate for high ice water content (IWC) environments judged to represent a significant safety hazard to propellers and turbofan engine operability and performance. For this reason, within the frame of EU FP7 HAIC project, instrumentation characterization and validation is considered a major element need for successful execution of flight tests campaigns. Clearly, instrumentation must be sufficiently reliable to assess the reproducibility of artificial clouds with high ice water content generated in icing tunnels. Instruments are required to measure these conditions with a sufficient level of accuracy for the purposes of the
Esposito, Biagio M., Bachalo, William D., Leroy, Delphine, Schwarzenboeck, Alfons, Jurkat, Tina, Voigt, Christiane, Bansmer, Stephan
SLD and Ice Crystal Discrimination with the Optical Ice Detector2019-01-193406/10/2019
In response to new safety regulations regarding aircraft icing, Collins Aerospace has developed and tested an Optical Ice Detector (OID) capable of discriminating among icing conditions appropriate to Appendix C and Appendix O of 14 CFR Part 25 and Appendix D of Part 33. The OID is a short-range, polarimetric lidar that samples the airstream up to ten meters beyond the skin of the aircraft. The intensity and extinction of the backscatter light correlate with bulk properties of the cloud, such as water content and phase. Backscatter scintillation (combined with the outside air temperature from another probe) signals the presence of supercooled large droplets (SLD) within the cloud-a capability incorporated into the OID to meet the requirements of Appendix O. Recent laboratory and flight tests of the Optical Ice Detector have confirmed the efficacy of the OID to discriminate among the various icing conditions. Drizzle-sized droplets, mixed with a small droplet cloud in the Collins Cloud
Anderson, Kaare J., Ray, Mark D.
Radar Detection of High Concentrations of Ice Particles - Methodology and Preliminary Flight Test Results2019-01-202806/10/2019
High Ice Water Content (HIWC) has been identified as a primary causal factor in numerous engine events over the past two decades. Previous attempts to develop a remote detection process utilizing modern commercial radars have failed to produce reliable results. This paper discusses the reasons for previous failures and describes a new technique that has shown very encouraging accuracy and range performance without the need for any modifications to industry’s current radar design(s). The performance of this new process was evaluated during the joint NASA/FAA HIWC RADAR II Flight Campaign in August of 2018. Results from that evaluation are discussed, along with the potential for commercial application, and development of minimum operational performance standards for future radar products.
Harrah, Steven, Strickland, Justin, Hunt, Patricia, Proctor, Fred, Switzer, George, Ratvasky, Thomas, Strapp, J. Walter, Lilie, Lyle, Dumont, Christopher
NRC Particle Detection Probe: Results and Analysis from Ground and Flight Tests2019-01-193306/10/2019
High altitude ice crystals are causing in-service events in excess of one per month for commercial aircraft. The effects include air data probes malfunctioning (pitot pressure and total air temperature in particular), and uncommanded engine power loss or flameout events. The National Research Council Canada (NRC) has developed a particle detection probe (PDP) that mounts on the fuselage of aircraft to sense and quantify the ice crystals in the environment. The probe is low-power and non-intrusive. This paper presents the results of ground and flight testing of this probe. Results are presented for ground testing in a sea level ice crystal wind tunnel and an altitude icing tunnel capable of generating both ice crystal and super-cooled liquid. The PDP was operated on several flight campaigns and the results of two will be presented. The first was on board a NRC Convair 580 aircraft in French Guiana (FG) and the second was on an Airbus operated A340 research aircraft in Darwin and Reunion
Davison, Craig, Chalmers, Jennifer, Fuleki, Dan
On-Ground Cold Soak Fuel Frost Modeling2019-01-197506/10/2019
In this paper a cold soak fuel frost modeling for an aircraft wing tank is presented. Numerical prediction is compared with experimental data and a qualitative verification for the frost formation and melting is also shown. The numerical simulation showed good agreement with experimental observations. The model was used to define, through a Monte Carlo analysis, two different frost formations whose impact on aircraft handling was evaluated by flight tests using representative grits.
Silva, Daniel Martins da, Santos, Luis, Katchborian, André, Sousa, Rodrigo
A Smart Icing Detection System for Any Location on the Outer Aircraft Surface2019-01-193106/10/2019
Given approximately one million small and light aircraft in operation worldwide, icing detection and icing quantification of in-flight icing are still an open research topic. Despite technical means are available to de-ice on ground, there is a lack of a suitable control system based on sensor data to de-ice while the aircraft is airborne. Most often, it is still task of the pilot to visually inspect the icing status of the airfoil and/or other critical parts of the aircraft such as engine air intakes, which distracts the flight crew from flying the aircraft especially in IMC conditions. Based on preliminary simulation and tests in 2014 in a collaborative research project lasting from 2015 until 2018, the technology of energy self-sustaining, wireless, self-adhesive smart sensors for industrial sensing in an aerodynamically critical environment (i.e. wind turbines) was further investigated to fulfil general aviation requirements. Prototype hardware setups have been designed and built
Schlegl, Thomas, Moser, Michael, Loss, Theresa, Unger, Thomas
Aerospace & Defense Technology: June 201919AERP0606/01/2019
Eyes in the Sky Rugged High-Speed Cameras Capture Critical Flight Test Video Data Panoramic Thermal Imaging Technology A New Concept in Naval Defense Coating Technology Enables Effective Missile Countermeasures FACE™ - Future Airborne Capability Environment Diminishing U.S. Combat Superiority Drives New Software Development Requirements Broadband 1.2- and 2.4-mm Gallium Nitride (GaN) Power Amplifier Designs Multi-Agent RF Propagation Simulator Electrical Characterization of Crystalline UO2, THO2 and U0.71TH0.29O2 Evaluating the suitability of advanced alloys for use in uranium-based neutron detectors. ONR Short Pulse Research, Evaluation and non-SWaP Demonstration for C-sUAV Study Research project is designed to map small unmanned aerial vehicle (sUAV) effects space, empirically and by simulation, as a function of high power microwave (HPM) waveform to develop effective countermeasures. Matrix-Free Assisted Laser Desorption Ionization Using Metal-Organic Frameworks Machining Titanium
Is the Future of Aerial Autonomy Up in the Air?19AVEP03_1303/01/2019
As autonomous-drone and air-taxi concepts debut, legal hurdles will need to be cleared before the skies are automated. Autonomous vehicle technology literally has nowhere to go but up. At CES '19, more than 170 exhibitors showed aerial drones of various shapes and sizes. Potential use cases for these devices appear to be limitless, but technical, legal and regulatory hurdles must first be overcome. Drones are categorized by vehicle weight. The small devices weighing between 0.55 and 55 pounds (.25 kg to 25 kg) are known as Unmanned Aircraft Systems (UAS) and are lightly regulated. Drones exceeding 55 lb are regulated as traditional aircraft. Operators must obtain proper registration, licenses and certification for airworthiness.
Dukarski, Jennifer
Design, Manufacturing, Testing, and Analysis of a Highly-Constrained Single-Use UAV Wing2018-01-195810/30/2018
Unmanned aerial vehicle (UAV) design aspects are as broad as the missions they are used to support. In some cases, the UAV mission scope can impose design constraints that can be difficult to achieve. This paper describes recent work performed at West Virginia University (WVU) to support repeated flight testing of a single-use UAV platform with emphasis on the highly specialized wings required to help meet the overall airframe mass properties constrained by the project sponsor. The wings were fabricated using a molded polyurethane (PU) foam as the base material which was supported by several different types of rigid and flexible substructures, skins, and matrix-infused fiber elements. Different ratios of infused fiber mass to PU foam were tested and additional tungsten masses were added to the wings to achieve the correct total mass and mass distribution of the wings. Expected accelerations were applied to the wing designs analytically and numerically to establish appropriate test
Browning, Patrick H., Hubbard, Levi S., Pennock, Philip
3D Printed Spacecraft PartsTBMG-3273008/01/2018
Stratasys Ltd. Eden Prairie, MN 952-937-3000
Establishment and Application of Aero-engine Lubricating Oil System Model Based on Flight Test Data2017-01-221510/08/2017
A lubricating system modeling method based on flight test data is proposed in this paper. ANN model based on a large number of flight test data is trained and validated, and models of 6 lubricating system parameters in all engine operation settings and whole flight envelope are established. Model results are in good agreement with flight test results, which shows feasibility and effectiveness of the presented modeling method. The model results are packaged in dynamic link library, and the coordination between calculating model and GDAS is accomplished. Comparison of model and flight test results in real-time monitoring of flight test comes true, thus on-line trend monitoring of oil parameters is implemented and applied. Additionally, input parameters are gradually decreased as new input parameter group of ANN structure. Oil parameter model is trained and validated again with the new group of parameters, until leading to unacceptable bias between model and flight test results. The main
Ma, Mingming
SEA Model Development for Cabin Noise Prediction of a Large Commercial Business Jet2017-01-176406/05/2017
The demand for quieter interior cabin spaces among business jet customers has created an increased need for more accurate prediction tools. In this paper, the authors will discuss a collaborative effort between Jet Aviation and Gulfstream Aerospace Corporation to develop a Statistical Energy Analysis (SEA) model of a large commercial business jet. To have an accurate prediction, it is critical to accurately model the structural and acoustic subsystems, critical noise transmission paths, and dominant noise sources for the aircraft. The geometry in the SEA model was developed using 3D CAD models of major airframe and interior cabin components. The noise transmission path was characterized through extensive testing of various aircraft components in the Gulfstream Acoustic Test Facility. Material definitions developed from these tests became input parameters in the SEA model. Both ground and flight tests were conducted on the aircraft with an array of microphones to measure and map Sound
Dande, Himanshu Amol, Wang, Tongan, Maxon, John, Bouriez, Joffrey
Uncertainty of In-Flight Thrust DeterminationAIR1678B (Current)10/22/2016
This document defines and illustrates the process for determination of uncertainty of turbofan and turbojet engine in-flight thrust and other measured in-flight performance parameters. The reasons for requiring this information, as specified in the E-33 Charter, are: determination of high confidence aircraft drag; problem rectification if performance is low; interpolation of measured thrust and aircraft drag over a range of flight conditions by validation and development of high confidence analytical methods; establishment of a baseline for future engine modifications. This document describes systematic and random measurement uncertainties and methods for propagating the uncertainties to the more complicated parameter, in-flight thrust. Methods for combining the uncertainties to obtain given confidence levels are also addressed. Although the primary focus of the document is in-flight thrust, the statistical methods described are applicable to any measurement process. The E-33 Committee
E-33 In Flight Propulsion Measurement Committee
Coaxial Rotor Flow Phenomena in Forward Flight2016-01-200909/20/2016
Coaxial rotors are finding use in advanced rotorcraft concepts. Combined with lift offset rotor technology, they offer a solution to the problems of dynamic stall and reverse flow that often limit single rotor forward flight speeds. In addition, coaxial rotorcraft systems do not need a tail rotor, a major boon during operation in confined areas. However, the operation of two counter-rotating rotors in close proximity generates many possible aerodynamic interactions between rotor blades, blades and vortices, and between vortices. With two rotors, the parameter design space is very large, and requires efficient computations as well as basic experiments to explore aerodynamics of a coaxial rotor and the effects on performance, loads, and acoustics. In this study, the Harrington/Dingeldein rotor forward flight test case from the 1950s is simulated using the incompressible Rotor Unstructured Navier-Stokes (RotUNS) CFD to predict performance and flow field properties using momentum source
Barbely, Natasha, Komerath, Narayanan
Aircraft Weight and Center of Mass Estimation System2016-01-202509/20/2016
Aircraft weight and center of mass are two critical design and operational parameters that have to be within a design envelope to ensure a safe and efficient operation of aircraft. Previous efforts to accurately determine aircraft weight and center of mass before takeoff using landing gear shock strut pressures have failed due to the distortion of measured pressures by shock strut seal friction. Currently, aircraft loading process is controlled with loading sheets and passenger/cargo weight estimation as there are no online measurement systems that can accurately and efficiently estimate aircraft weight and determine the center of mass location before takeoff. However, errors in loading sheets, shifting cargo and errors in weight estimation could lead to incorrect loading of aircraft and, consequently, increase the risk of accidents, particularly in cargo flights. In this paper, an online weight measurement system that can determine an aircraft weight and its center of mass before
Fazeli, Amir, Cepic, Adnan, Reber, Susanne
Flight Test System for Accurately Predicting FlutterTBMG-2493307/01/2016
Traditional methods of flight flutter testing analyze system parameters such as damping levels that vary with flight conditions to monitor aircraft stability. In the past, the actual flight envelope developed for aircraft operation was essentially determined only by flight testing. The edges of the envelope are points where either the aircraft cannot fly any faster because of engine limitations, or, with a 15% margin for error, where the damping trends indicate a flutter instability may be near. After flight testing, the envelope empirically determined is used for regular operations.
Flight Test Maneuvers for Efficient Aerodynamic ModelingTBMG-2423604/01/2016
Flight testing is expensive. It is therefore important that necessary flight data be collected in the most efficient manner possible. Inputs traditionally used for flight test maneuvers to collect aircraft stability and control data include doublets, impulses (stick raps), multisteps, and frequency sweeps. All of these input types are designed for single-axis response, although often the inputs are applied sequentially to different controls to collect multi-axis data.
Fortifying Computer Chips for Space TravelTBMG-2318810/16/2015
Space is cold, dark, and lonely. Deadly, too, if any one of a million things goes wrong on your spaceship. It’s certainly no place for a computer chip to fail, which can happen due to the abundance of radiation bombarding a craft. Worse, ever-shrinking components on microprocessors make computers more prone to damage from high-energy radiation like protons from the sun or cosmic rays from beyond our galaxy. It’s a good thing, then, that engineers know how to make a spaceship’s microprocessors more robust. To start, they hit them with high-energy ions from particle accelerators here on Earth. It’s a radiation- testing process that finds a chip’s weak spots, highlighting when, where, and how engineers need to make the microprocessor tougher.
Autonomous Aerial RefuelingTBMG-2313910/01/2015
Northrop Grumman Corp. Falls Church, VA 703-280-2900
One Approach to the Aircraft Brake Control System Numeric Identification Method2015-01-269309/27/2015
Aircraft anti-skid brake control system is considered one of the most complex aircraft systems whose performance depends not only on subsystem parameters but rather on many other external conditions and physical parameters which are difficult to control and predict. Over the years aircraft brake control system performance and fault diagnostics have been simulated and analyzed from various aspects. Based on the task to enhance aircraft brake control system diagnostic methods, this article presents one approach to mathematical modeling and a numeric identification method of the hydro-mechanical brake control components. For any complex system behavioral or performance analysis approach, system modeling and simulation are the most common tools. Most often, the complete system model is unknown, and only simple segments of the unknown system or a small number of subsystem components may be known in a form of transfer function with static and dynamic characteristics. For that reason
Novakovic, Neno
Cessna Citation X Engine Model Identification from Flight Tests2015-01-239009/15/2015
During aircraft development, mathematical models are elaborated from our knowledge of fundamental physical laws. Those models are used to gain knowledge in order to make decisions in all development stages. Since engine model is one of the most important items in aircraft simulation, the aviation industry has recently developed a high interest on them. With the power capacities development in the last years, numerical simulations have been widely used for predicting engine response. In this paper, a methodology to identify an engine model from flight tests is presented. A Cessna Citation X Level D Flight Simulator designed and manufactured by CAE Inc. was used to sample the engine thrust force data. More than 500 flight tests were made for different flight conditions expressed in Mach numbers (M = 0 to M = 0.9), altitudes (h = 0 ft to h = 50,000 ft) and different throttle positions (idle to maximum). The engine mathematical model was developed from analysis and comparison of several
Ghazi, Georges, Botez, Ruxandra, Messi Achigui, Joseph
A Multifaceted Investigation and Intervention into the Process of Flight Clearance for UAS Experimental Flight Test2015-01-238509/15/2015
Unmanned aviation systems (UAS) acquired for US Navy for military roles are developed in the context of NAVAIR's rigorous and well-established policies, procedures and processes employed in the acquisition and development of manned aircraft. A key process is the preparation and approval of interim flight clearances (IFC) prior to flight test to ensure the aircraft is airworthy and thus safe to operate. Due to the perceived risks of UAS experimental flight test, the use of this process has been mandated for all Navy organizations, including use of commercially available UAS in research projects. This policy has proved to be a challenge, impeding and discouraging the use of UAS in research and experimental projects. Currently, the cost of compliance is unaffordable and IFC preparation and approval time are inconsistent with research cycle time expectations. The research reported here investigated the difficulties and advocates solutions devised through the application of systems
Millar, Richard C.
Validation and Update of Aerodynamic Database at Extreme Flight Regimes2015-01-256709/15/2015
Aerodynamic database update from the flight tests using system identification techniques is a crucial tool for the development of control laws and high fidelity simulators. For the certification of aircraft under test, aero-database needs to be validated from flight tests throughout the flight envelope and also to certain levels beyond the envelope boundaries. Validation of aero-database close to envelope boundaries entails additional complexities which necessitates careful handling of flight data identification and update process. This paper discusses the approach adopted for aero-database update and flight clearance, followed by a discussion on the issues relevant in the extreme flight test regimes, such as, flow angle accuracy at higher angles-of-attack, center-of-gravity variation with fuel pitch angle for high-g maneuvering conditions and inaccuracies in Mach number at transonic speeds. Results from flight data identification of a high performance aircraft with relaxed static
Kaliyari, Dushyant, Nusrath TK, Khadeeja, Singh, Jatinder
Design, Construction, and Operation of a Pneumatic Test Launch Apparatus for sUAS Prototypes2015-01-245409/15/2015
The design and testing of small unmanned aerial vehicle (sUAV) prototypes can provide numerous difficulties when compared to the same process applied to larger aircraft. In most cases, it is desirable to have a better understanding of the low Reynolds number aerodynamics and stability characteristics prior to completion of the final sUAV design. This paper describes the design, construction, and operational performance of a pneumatic launch apparatus that has been used at West Virginia University (WVU) for the development and early flight testing of transforming sUAV platforms. Although other launch platforms exist that can provide the safe launch of such prototypes, the particular launch apparatus constructed at WVU exhibits unmatched launch efficiency, and is far less expensive to operate per shot than any other launch system available. The launch system, called the Pneumatic Actuated Universal Launch Apparatus (PAULA), can launch sUAV prototypes with fuselage diameters up to 120 mm
Browning, Patrick H., Huebsch, Wade
Passive Heat Exchange System for Aircraft Equipment Cooling Applications2015-01-241809/15/2015
Due to the increasing power density of onboard electric and electronic equipment and heat dissipation in civil and military aircraft, more efficient ways of transferring heat and new cooling techniques are necessary. A passive heat transfer prototype was developed and experimentally evaluated in laboratory and on ground and flight tests in an Embraer test aircraft. The passive heat transfer device consists of a loop-thermosyphon with two condensers and a common evaporator, using water as the heat transfer working fluid. An electric resistance and a variable power source were used to dissipate heat inside the evaporator simulating heat transfer from an onboard electronics bay. The fuselage/external air stream and the air flow inside an air conditioning system duct were used as heat sinks. Prior to flight test, laboratory tests were conducted simulating ground and flight operations. During flight test, the fuselage/external air stream was responsible for dissipating over 80% of the heat
Gandolfi, Ricardo, Ribeiro, Luiz, Oliveira, Jorge, Paiva, Kleber, Mantelli, Marcia
Laboratory Test Means Scalable to the Test2015-01-254609/15/2015
To perform a complete aircraft certification plan, civil aviation test centres use specific flight test installations and ground test means. In this scope tests specialists operate ground test means which have a generic name Laboratory Tests Means (LTM) to validate aircraft functions. Today these functions are becoming more and more complex, moreover certification deadlines and tests campaign costs are becoming increasingly challenging and demand LTM use optimization. In this context current LTM development approach is no longer suitable to cover these new constraints. Currently LTMs start to be designed when testing strategy for a new aircraft is defined and design is quite specific. Drawbacks of such an approach are: tunnel effect for LTM development, no simple sharing of testing resources, LTM reuse is not easy, LTM upgrade requires re-engineering and many LTMs have to be maintained even if only partially used. As a result future LTMs shall be scalable to the tests and tests shall
Delrieu, Sylvain
Automatic Wildfire Detection and Simulation using Optical Information from Unmanned Aerial Systems2015-01-247409/15/2015
In many parts of the world, uncontrolled fires in sparsely populated areas are a major concern as they can quickly grow into large and destructive conflagrations in short time spans. Detecting these fires has traditionally been a job for trained humans on the ground, or in the air. In many cases, these manned solutions are simply not able to survey the amount of area necessary to maintain sufficient vigilance and coverage. This paper investigates the use of unmanned aerial systems (UAS) for automated wildfire detection. The proposed system uses low-cost, consumer-grade electronics and sensors combined with various airframes to create a system suitable for automatic detection of wildfires. The system employs automatic image processing techniques to analyze captured images and autonomously detect fire-related features such as fire lines, burnt regions, and flammable material. This image recognition algorithm is designed to cope with environmental occlusions such as shadows, smoke and
Lum, Christopher W., Summers, Alexander, Carpenter, Brian, Rodriguez, Angel, Dunbabin, Matthew
Aerodynamic Load Maps of Vehicle Shapes at Arbitrary Attitude2015-01-257409/15/2015
The interest in flying cars comes with the question of characterizing aerodynamic loads on shapes that go beyond traditional aircraft shapes. When carried as slung loads under aircraft, vehicles can encounter severe aerodynamic loads, which may also cause them to go into divergent oscillations that can threaten the vehicle and aircraft. Slung loads can encounter the wind at arbitrary attitudes. Flight test certification for every vehicle-aircraft combination is prohibitive. Characterizing the aerodynamic loads with sufficient resolution for use in dynamic simulation, has in the past been extremely arduous. Sharp changes that drive instabilities arise over small ranges of yaw and pitch. With the Continuous Rotation technique developed by our group, aerodynamic load characterization is viable and efficient. With two well-chosen attitude sweeps and appropriate transformations, the entire 6-DOF load map can be obtained, for several rates. The paper describes application of the method to
Motahari, Nicholas R., Turbeville, Franklin, Hiremath, Nandeesh, Komerath, Narayanan
Ice Crystal Icing Engine Testing in the NASA Glenn Research Center's Propulsion Systems Laboratory: Altitude Investigation2015-01-215606/15/2015
The National Aeronautics and Space Administration (NASA) conducted a full scale ice crystal icing turbofan engine test using an obsolete Allied Signal ALF502-R5 engine in the Propulsion Systems Laboratory (PSL) at NASA Glenn Research Center. The test article used was the exact engine that experienced a loss of power event after the ingestion of ice crystals while operating at high altitude during a 1997 Honeywell flight test campaign investigating the turbofan engine ice crystal icing phenomena. The test plan included test points conducted at the known flight test campaign field event pressure altitude and at various pressure altitudes ranging from low to high throughout the engine operating envelope. The test article experienced a loss of power event at each of the altitudes tested. For each pressure altitude test point conducted the ambient static temperature was predicted using a NASA engine icing risk computer model for the given ambient static pressure while maintaining the engine
Oliver, Michael
Analysis of Flight Test Results of the Optical Ice Detector2015-01-210606/15/2015
Cloud phase discrimination, coupled with measurements of liquid water content (LWC) and ice water content (IWC) as well as the detection and discrimination of supercooled large droplets (SLD), are of primary importance in aviation safety due to several high-profile incidents over the past two decades. The UTC Aerospace Systems Optical Ice Detector (OID) is a prototype laser sensor intended to discriminate cloud phase, to quantify LWC and IWC, and to detect SLD and differentiate SLD conditions from those of Appendix C. Phase discrimination is achieved through depolarization scattering measurements of a circularly polarized laser beam transmitted into the cloud. Optical extinction measurements indicate the liquid and ice water contents, while the differential backscatter from two distinct probe laser wavelengths implies an effective droplet size. The OID is designed to be flush-mounted with the aircraft skin and to sample the air stream beyond the boundary layer of the aircraft. The
Ray, Mark, Anderson, Kaare
Certification Flight Tests in Natural Icing of the PZL Mielec M28 Commuter Turboprop Airplane2015-01-211006/15/2015
In 2014 PZL Mielec obtained an EASA Type Certificate extension for the PZL M28 05 airplane for flight into icing conditions and this has been validated by the FAA. Thus, a project that lasted four years was finished successfully. During this period, activities consisted of icing analyses, wind tunnel tests in the NASA Glenn Research Center Icing Research Tunnel, and natural icing flight tests, artificial icing flight tests, flight tests with simulated ice shapes, and calibration tests. Flights in measured natural icing conditions began during the spring of 2009 and certification flight tests were performed in 2012. The natural icing test flights, apart one flight in the USA, were performed in Poland in the Mielec area. The final test campaign can be divided into two phases: (1) March -April flight tests campaign; and (2) November - December flight test campaign, the latter after introducing some design changes in airframe ice protection system.
Brzeczek, Jozef, Pietruszka, Janusz, Flemming, Robert J., Bernstein, Ben C.
Use of HISS Test Results for Rotorcraft Civil Certification2015-01-212806/15/2015
This paper describes the AgustaWestland (AW) experience in the use of the results obtained with the HISS flight tests to support the civil ice clearance for rotorcraft. The use of the HISS, a US Army CH-47D Chinook fitted with a spray bar system providing a cloud where the helicopter can fly in icing conditions, allows stable and prolonged flight data, conditions extremely difficult to encounter during natural ice flights. The paper analyses the definition of the HISS test matrix, to optimize the points needed for system development and the points possibly usable during certification, in both normal and failure mode conditions. It is also shown how the HISS ice campaigns results can be assessed, and how they can be compared to the natural ice flights to validate them. Finally it is explained how the HISS results can be used, in addition to natural ice flights results, to support the certification.
Bellussi, Enrico
A350XWB Icing Certification Overview2015-01-211106/15/2015
The intent of this paper is to provide a general overview of the main engineering and test activities conducted in order to support A350XWB Ice and Rain Protection Systems certification. Several means of compliance have been used to demonstrate compliance with applicable Certification Basis (CS 25 at Amendment 8 + CS 25.795 at Amendment 9, FAR 25 up to Amendment 129) and Environmental protection requirements. The EASA Type Certificate for the A350XWB was received the 30th September 2014 after 7 years of development and verification that the design performs as required, with five A350XWB test aircraft accumulating more than 2600 flight test hours and over 600 flights. The flight tests were performed in dry air and measured natural icing conditions to demonstrate the performance of all ice and rain protection systems and to support the compliance demonstration with CS 25.1419 and CS25.21g. Prior to the flight test campaign, extensive engineering analyses, laboratory tests and system
Toulouse, Marie-Laure, Lewis, Richard
Studies of Cloud Characteristics Related to Jet Engine Ice Crystal Icing Utilizing Infrared Satellite Imagery2015-01-208606/15/2015
The significant problem of engine power-loss and damage associated with ice crystal icing (ICI) was first formally recognized by the industry in a 2006 publication [1]. Engine events described by the study included: engine surge, stall, flameout, rollback, and compressor damage; which were triggered by the ingestion of ice crystals in high concentrations generated by deep, moist convection. Since 2003, when ICI engine events were first identified, Boeing has carefully analyzed event conditions documenting detailed pilot reports and compiling weather analyses into a database. The database provides valuable information to characterize environments associated with engine events. It provides boundary conditions, exposure times, and severity to researchers investigating the ICI phenomenon. Ultimately, this research will aid in the development of engine tests and ICI detection/avoidance devices or techniques. This paper first provides a detailed examination of the ICI engine event database
Grzych, Matthew, Tritz, Terrance, Mason, Jeanne, Bravin, Melissa, Sharpsten, Anna
Innovative Jet Pump Ice Protection System for A400M2015-01-213606/15/2015
A system has been designed for the A400M wherein engine air intake ice protection is provided by hot air bled from the engine cooled by air from inside the nacelle with a jet pump. Two variants of the system were developed. The first had an active temperature and pressure control downstream of the jet pump, and the second was without temperature control. Maximum temperature was a constraint for the design of the system since the engine air intake is manufactured in aluminum. In addition, several other constraints appeared during the detailed design of the system; the tight space allocation inside the nacelle limited the length of the jet pump, the low temperature provided by the engine bleed in flight idle limited the secondary flow used to cool the engine bleed, and the complex air distribution needed to supply air to the intake areas. The design, validation and verification of the system went through several stages; analyses, hot air mass flow validation testing of the intake in
Redondo, Francisco José
Microprocessor-Controlled Prostheses Are a Step in the Right DirectionTBMG-2182904/01/2015
It’s not always easy to walk in someone else’s shoes. It’s even more difficult if those shoes belong to a person with an artificial leg. However, that’s exactly what a group of scientists, engineers, and clinicians at Orthocare Innovations are doing to help engineer prostheses that respond better to the physical needs of amputees.
Data Recorders Prepare Orion for Splashdown TestTBMG-2166003/01/2015
Data recorders and software Diversified Technical Systems (DTS) Seal Beach, CA 562-493-0158
Peak-Seeking Control MethodTBMG-2107712/01/2014
Peak-seeking algorithms optimize physical processes in real time and are widely used throughout a variety of industries. However, measuring associated parameters in changing conditions, and responding to them appropriately, is difficult because the measurements are typically distorted by noise. This technology addresses that problem by employing a time-varying Kalman filter. The filter is an algorithm previously developed to estimate unknown parameters within systems that are intrinsically random and uncertain. The Kalman filter is excellent at finding estimates when it encounters noisy signals. As a minimal-variant filter, it inherently produces the best estimates of a function with the smallest amount of variation from the true value. Thus, the filter can help accurately determine the optimal coordinates of the peak- seeking function as conditions in the environment change.
Jason Moore, Fiber Optic Sensors Engineer, NASA Langley Research Center, Hampton, VATBMG-2087310/23/2014
Jason Moore has worked at NASA Langley since 1995. He currently tests and develops fiber optic technologies, including multicore fibers. He is actively organizing ground and flight tests to demonstrate the multicore fiber’s ability to sense structural shape changes in flight.
Flight Path Reconstruction and Wind Estimation Using Flight Test Data from Crash Data Recorder (CDR)2014-01-216809/16/2014
This paper presents the implementation of flight path reconstruction (FPR) and wind estimation techniques applied to a high performance fighter aircraft. The analysis is carried out for the flight test data gathered and stored in a Crash Data Recorder (CDR). The data signals obtained from CDR are generally highly noisy, with frequent data drop outs and also with low sampling rate. The estimation technique applied for data reconstruction is the extended Kalman filtering (EKF). The reconstructed trajectories can be compared with the actual flight trajectories such that, in case of unavailability of data from other sources (e.g., digital flight control computer), the algorithm should be able to reconstruct the trajectories with the minimum set of data available from the CDR. Wind estimation along with the trajectory reconstruction can give better accuracy in airspeed as well as flow angles. The algorithm also aims at determining the bias/systematic instrument errors and generating
Nusrath, Khadeeja, Sarmah, Ankur, Singh, Jatinder
Cessna Citation X Airplane Grey-Box Model Identification without Preliminary Data2014-01-215309/16/2014
An airplane model is usually obtained from preliminary wind tunnel experiments and CFD analysis. These models are then tuned from flight test measurements using system identification, and are used for airplane stability assessment and control design. However, sometimes no or little preliminary data and documentation are available and flight test identification is the main mean to obtain the model needed for control system design. If so, the purpose of this paper is to identify the grey-box model of an airplane without initial data using a combination of the least square and output error estimation methods. A grey-box model identification is preferred because it gives aerodynamic parameter estimations of the airplane. Before flight test data are available, this method was applied to the Cessna Citation X business airplane's high fidelity simulations and carried out with human-in-the-loop on a professional level D flight dynamics simulator designed and manufactured by CAE Inc. More than
Hamel, Clément, Botez, Ruxandra, Ruby, Margaux
Items per page:
1 – 50 of 160