Browse Topic: Fly-by-wire control systems

Items (68)
Find
SAE TOMORROW TODAY: Constant Innovation in Aviation1290108/07/2020
As the innovation center for Airbus, Acubed is bringing the Silicon Valley approach to advancement to the aerospace industry. Mark Cousin, CEO of Acubed, joins host Grayson Brulte for an in-depth conversation on the aviation innovations that Acubed is working on to improve efficiency and safety. Mark shares with us the important developments that Acubed and Airbus have made over the past 10-15 years to help the organization achieve year-over-year efficiencies; how Acubed has evolved over the past five years to become a more targeted innovation center; and some of the specific innovations, including Fly by Wire, Project Wayfinder and ATOL, that demonstrate the importance of machine learning and AI to enable autonomy that will improve safety of commercial aviation, reduce costs and address the pilot shortage. He also gives a sneak peek at some of the current and future projects in the works at Acubed that will advance Airbus' vision for innovation, including unmanned traffic management
Hineman, Marcie
Aerospace - Passive Side Stick Unit General Requirements for Fly-by Wire Transport and BusinessARP6001B (Current)04/23/2020
This SAE Aerospace Recommended Practice (ARP) provides recommendations for design and test requirements for a generic “passive” side stick that could be used for fly-by wire transport and business aircraft. It addresses the following: The functions to be implemented The geometric and mechanical characteristics The mechanical and electrical interfaces The safety and certification requirements
A-6A3 Flight Control and Vehicle Management Systems Cmt
Streamlining EMC Solutions for Avionics Interfaces19AERP02_0402/01/2019
Lightning strikes to jet airliners are common - about once every 1000 flight hours. The DO-160G standard, Environmental Conditions and Test Procedures for Airborne Equipment, is a standard for the environmental testing of avionics hardware. Many airplane manufacturers specify DO-160G Section 22, lightning induced transient susceptibility, as a requirement for critical systems like guidance, radars, communications, engine control, and heat and air controls. Aircraft fuselage, wing and tail flight controls, wing tips, fin tips, engine nacelles, and landing gear are the areas most likely to be hit by lightning strikes. Modern aircraft are designed with fly by wire systems for flight controls. Fly by wire means that inputs from either flight control computers or pilot manual inputs are transmitted electrically to a servomotor, which controls flight control actuators. Communication interfaces for these flight control systems can be implemented on an RS-485 physical layer. Communication
Streamlining EMC Solutions for Avionics InterfacesTBMG-3377302/01/2019
Lightning strikes to jet airliners are common - about once every 1000 flight hours. The DO-160G standard, Environmental Conditions and Test Procedures for Airborne Equipment, is a standard for the environmental testing of avionics hardware. Many airplane manufacturers specify DO-160G Section 22, lightning induced transient susceptibility, as a requirement for critical systems like guidance, radars, communications, engine control, and heat and air controls. Aircraft fuselage, wing and tail flight controls, wing tips, fin tips, engine nacelles, and landing gear are the areas most likely to be hit by lightning strikes.
Integrated Rudder and Brake Pedal Unit, General Requirements for Fly-By Wire Transport and Business AircraftARP6252 (Current)10/15/2018
This Aerospace Recommended Practice (ARP) provides general requirements for a generic, integrated rudder and brake pedal unit, incorporating a passive force-feel system that could be used for fixed-wing fly-by wire transport and business aircraft. This ARP addresses the following: The functions to be implemented The mechanical interconnection between captain and F/O station The geometric and mechanical characteristics The mechanical, electrical, and electronic interfaces The safety and certification requirements
A-6A3 Flight Control and Vehicle Management Systems Cmt
Aerospace - Passive Side Stick Unit General Requirements for Fly by Wire Transport and BusinessARP6001A (Historical)10/04/2018
This SAE Aerospace Recommended Practice (ARP) provides general requirements for a generic “passive” side stick that could be used for fly by wire transport and business aircraft. It addresses the following: The functions to be implemented The geometric and mechanical characteristics The mechanical and electrical interfaces The safety and certification requirements
A-6A3 Flight Control and Vehicle Management Systems Cmt
Aerospace Fluid Power Electrohydrostatic Module, Design, Performance and Test RecommendationsARP6154 (Current)03/15/2017
This Aerospace Recommended Practice provides general requirements for Electrohydrostatic Module (EHM) that is used in Electrohydrostatic Actuator (EHA) for aerospace applications. This document includes design, performance and test (production and qualification) requirements.
A-6B2 Electrohydrostatic Actuation Committee
Impact of Cable Bundles and Systems' Integration Rules Dedicated to Metallic Aircraft on the Electromagnetic Immunity of Systems in Composite Aircraft2014-01-212209/16/2014
Advanced commercial aircraft increasingly use more composite or hybrid (metal and composite) materials in structural elements and, despite technological challenges to be overcome, composites remain the future of the aviation industry. Composite and hybrid aircraft today are equipped with digital systems such as fly by wire for reliable operations no matter what the flying environment is. These systems are however very sensitive to electromagnetic energy. During flight, aircraft can face High Intensity Radiated Fields (HIRF), static electricity, or lightning. The coupling of any of these threats with airframe structure induces electromagnetic energy that can impair the operation of avionics and navigation systems. This paper focuses on systems susceptibility in composite aircraft and concludes that the same electromagnetic rules dedicated to all metal aircraft for systems and wiring integration cannot be applied directly as such for composite aircraft.
Moupfouma, Fidele, Ndoye, Amadou, Jalali, Mohsen, Tse, William
Aerospace - Testing of Electromechanical Actuators, General Guidelines ForARP5724 (Current)10/04/2013
This document provides an overview of the tests, and issues related to testing, that are unique to Electromechanical Actuators (EMAs). The tests, and issues documented, are not necessarily all-inclusive. This document discusses both the tests applicable to EMAs and the test methodologies to accomplish the test objectives. EMAs may be used in a wide variety of applications such as utility, secondary flight controls and primary flight controls, in a wide variety of markets including manned and unmanned civil and military aircraft, small missile fin and thrust vector control applications up to high powered utility and flight controls. EMAs may also have either a rotary or a linear output, be servo controlled or use simple open loop point-to-point or other control topologies. As such this document covers a wide range of potential applications, the application of any given test requirement is determined by the application and the user. This document attempts to provide basic guidance on
A-6B3 Electro-Mechanical Actuation Committee
Multi-Axis Serially Redundant, Single Channel, Multi-Path FBW Flight Control System2013-01-225709/17/2013
A multi-axis serially redundant, single channel, multi-path FBW (FBW) control system comprising: serially redundant flight control computers in a single channel where only one “primary” flight control computer is active and controlling at any given time; a matrix of parallel flight control surface controllers including stabilizer motor control units (SMCU) and actuator electronics control modules (AECM) define multiple control paths within the single channel, each implemented with dissimilar hardware and which each control the movement of a distributed set of flight control surfaces on the aircraft in response to flight control surface commands from the primary flight control computer, and a set of (pilot and co-pilot) controls and aircraft surface/reference/navigation sensors and systems which provide input to a primary flight control computer and are used to generate the flight control surface commands in accordance with the control law algorithms implemented in the flight control
Lin, Shu, Smith, Tim, De Serres, Pierre
Autonomous Electrical Power System for Multi Role Transport Tanker Aircraft2012-01-219210/22/2012
Today's civil airliners integrate electrical power capability properly sized to supply the growing demands of modern aircraft systems, that are more electrical than ever. The conversion of civil aircraft into a military derivative aircraft faces the challenge of rearranging the available generation capability to feed the new power-hungry military systems while at the same time minimizing the impact on certification of the base aircraft for use on civil operations. This challenge is particularly difficult when the new military systems demand high peak power consumption, as in the case of the conversion of a civil airliner into a military Multi-Role Transport Tanker aircraft with high performance multipoint refueling capabilities. In fact the selection of the type of actuation (either electrical or hydraulic) for the refueling systems is heavily conditioned by the excess of either electrical or hydraulic power available in the base aircraft. The A330MRTT Multirole Transport Tanker from
Fernandez-Garcia, F.Javier, Valdeolmos, Javier
Evaluation of Sliding Mode Observers for Fault Reconstruction on the ADDSAFE Functional Engineering Simulator2011-01-280210/18/2011
This paper presents a preliminary evaluation of the results from using second order sliding mode observer schemes applied to an aircraft fault detection benchmark problem for a class of sensor faults. The scheme has been evaluated on the ADDSAFE Functional Engineering Simulator (FES). This is part of ongoing work on a European FP7 funded project entitled Advanced Fault Diagnosis for Sustainable Flight Guidance and Control (ADDSAFE) which aims to study advanced fault detection and isolation (FDI) methods for aircraft. The simulation and verification FES used in this evaluation incorporates a high fidelity nonlinear aircraft model from AIRBUS (which includes sensor and process noise). It is intended to provide a design tuning and assessment tool for the proposed FDI schemes developed within the ADDSAFE consortium and acts as a platform to test the robustness of the proposed schemes using a predetermined grid or sequence to cover a wide range of flight conditions and perturbations in the
Alwi, Halim, Edwards, Christopher
EMA Aileron COVADIS Development2011-01-272910/18/2011
In the frame of the COVADIS project (flight control with distributed intelligence and systems integration) supported by the DPAC and where Airbus and Sagem are partners, an electromechanical actuator (EMA) developed and produced by Sagem (SAFRAN group) flew for the first time in January 2011 as an aileron primary flight control of the Airbus A320 flight test Aircraft. With this new type of actuator, in the scope of the preparation of the future Airbus Aircraft, the perspectives of using EMA technologies for the flight control systems is an important potential enabler in the more electrical aircraft. The paper deals with the development phase of this actuator from the definition phase up to the flight tests campaign. It is focused on : COVADIS project context (flight control with distributed intelligence and systems integration), The challenges of the definition phase, Test results presentation (ground and flight).
Derrien, Jean-Claude, Tieys, Pierre, Senegas, David, Todeschi, Michel
Airbus - EMAs for Flight Controls Actuation System - An Important Step Achieved in 20112011-01-273210/18/2011
A significant step is achieved on the flight control actuation system toward the more electrical aircraft through the Airbus A380, A400M and the A350 development phase ongoing. The A380/A400M/A350 features a mixed flight control actuation power source distribution, associating electrically powered actuators with conventional FlyByWire hydraulic servocontrols. In the scope of the preparation of the future Airbus Aircraft, this paper presents the perspectives of the use of the EMA technologies for the flight control systems in the more electrical aircraft highlighting the main technical challenges need to treat: jamming susceptibility, “on board” maintenance reduction, Operational reliability increase, power electronics and power management optimization, and regarding the environmental constraints, the predicted performances; the benefits associated to the optimized utilization of on-board power sources. On the 4th of January 2011, an aileron EMA was successful flown on Airbus A320 MSN1
Todeschi, Michel
Machine tools meet new materials11AERD0629_0106/29/2011
If you're in the business of making machine tools for aerospace applications, you're probably working on improvements in cutting tough metals and composites. How's this for a challenge to makers of machine tools for aerospace applications: “95% of the new materials used in the new aircraft programs are impossible to machine with conventional CNC machines.” So says Scott Walker, President of Mitsui Seiki North America. His company and others are hard at work developing the technologies to make the impossible possible, especially as it relates to titanium.
Ponticel, Patrick
Aerospace – Test Methodology for Electrohydrostatic ActuatorsARP5879 (Historical)04/28/2010
This document provides an overview of the tests and issues related to testing that are unique to Electrohydrostatic Actuators (EHAs). An EHA incorporates a linear or rotary hydraulic actuator and a variable speed, reversible electric servomotor driving a fixed displacement hydraulic pump for actuator control, and associated power drive electronics. The tests and issues documented are not necessarily all-inclusive. This document discusses both, the tests applicable to EHAs and the test methodologies to accomplish the test objectives. This document also lists tests that are not unique to EHAs, but are still applicable to EHAs. In these instances a discussion of such tests is not contained in this document, and as applicable, the reader may reference ARP1281 (Actuators: Aircraft Flight Controls, Power Operated, Hydraulic, General Specification For), which addresses test issues applicable to electrohydraulic flight control servoactuators. In the discussion of the tests and test
A-6B2 Electrohydrostatic Actuation Committee
Aerospace Engineering & Manufacturing 2010-01-1310AEMD011301/13/2010
Well sealed in flight The introduction of fly-by-wire and electrohydraostatic actuators has changed the design of hydraulic flight controls.
A Brief Study of Conditionally Enabled Phase Compensated Rate Limiters2008-01-225608/19/2008
This paper describes how airplane control surface rate limiting can enable a ‘cliff-like’ onset of Pilot-Induced Oscillation, (P.I.O.) and how the danger can be erased by implementation of Conditionally Enabled Phase Compensated Rate Limiters, (PCRLs), in the design of the airplane's flight control system. The application is particularly important for large airplanes where control surface actuator sizing and the associated hydraulic system volumetric flow rate capability cannot be generously over-sized without large weight and cost penalties. It is shown that the PCRL can remain inactive during normal airplane operations where RMS control commands are relatively small thus avoiding adverse control surface response effects that have hindered earlier PCRL acceptance. Then, when RMS control commands are significantly increased due to P.I.O. onset, the onset of increased RMS control displacements can be used to enable the PCRL and remove the large control system phase loss that is causing
Kendall, Eric
Loss-of-Control-Inhibitor Systems for AircraftTBMG-248912/01/2007
Systems to provide improved tactile feedback to aircraft pilots are being developed to help the pilots maintain harmony between their control actions and the positions of aircraft control surfaces, thereby helping to prevent loss of control. A system of this type, denoted a loss-of-control-inhibitor system (LOCIS) can be implemented as a relatively simple addition to almost any pre-existing flight-control system. The LOCIS concept offers at least a partial solution to the problem of (1) keeping a pilot aware of the state of the control system and the aircraft and (2) maintaining sufficient control under conditions that, as described below, have been known to lead to loss of control.
Long Range Aircraft, an Ideal Case for Fuel Cell Power2007-01-295711/28/2007
This paper shows that the analysis of factors such as costs, weights, fuel distribution logistics, etc. indicates that the replacement of internal combustion engines (ICE) by fuel cell/electric motor (FC/EM) systems, can be more attractive to aeronautical than to automotive applications. For long range airplanes especially, where the fuel represents an important fraction of the vehicle weight, the penalties from that replacement by a heavier system, can be overcome by the fuel weight reductions resulting from the higher fuel cell efficiencies. The necessity of FC/EM powered airplanes is also discussed in view of the eventual climate effects the air traffic may have, due to the injection of carbon dioxide and water vapor into the high troposphere. Some of the weight and aerodynamic issues posed by a FC/EM medium sized long range transport airplane preliminary design are discussed, and a non conventional aircraft configuration is proposed to be used in order to partially compensate the
Galvão, Francisco Leme
A Novel Tool for the Conceptual Design of Aircraft On-Board Power Systems2007-01-382909/17/2007
Schallert, Christian
Fault Detection and Isolation in Attitude and Heading Reference Systems For Fly-By-Wire Control System For General Aviation Aircraft2006-01-241508/30/2006
The article presents problems of fault detection and isolation in AHRS systems for the Fly-By-Wire control system for general aviation. The system is currently being designed at the Rzeszów University of Technology. The idea of the system is to create a general aviation pilot-friendly aircraft. The FBW control system is equipped with three AHRSs. Their diagnostics is realized on three levels. The article describes hardware redundancy and software redundancy for AHRS systems and then shows how to use it for diagnostics. The article focuses especially on estimation techniques applied in research. For simulations data from flight tests were used.
Kopecki, Grzegorz, Dolega, Boguslaw
System Immunity in HIRF/Lightning Environment and Interconnecting Cable Characterization Based on Functionality Mode2006-01-150804/03/2006
The advances in electronics and software since two decades have increased the use of digital technology in modern aircraft. Because digital electronics are powered with low level energy and are made of miniatured components, they are very sensitive to electromagnetic energy. It takes a single glitch to change the entire information. Therefore, insuring the proper protection of critical systems against Electromagnetic energy is a must during early design phase of the modern aircraft. All the onboard systems that govern aircraft functions are interconnected by hundreds of meters of wires and bundles. Moreover, the immunity of any signal on board aircraft is for at least 50% guaranteed by the cable shielding effectiveness and the shield termination. Wiring acts like an antenna: it can either radiate or collect energy. If not protected, it may pick up any electromagnetic noise in the surrounding; consequently, unwanted energy can modulate signals and cause system malfunction. The criteria
Moupfouma, Fidèle, Bae, Nami
Study of High Order Dynamics Effects on Flight Control Systems2005-01-397011/22/2005
This work presents a study of different architectures for fly by wire flight control, emphasizing the dynamic effects of time delays and data conversion processes generated by the insertion of digital computers and electronic components into the control loop. High order dynamic effects, made up of processing delays and the dynamics of sensors, converters and filters are investigated. The influence exerted by each one of these elements is assessed by means of sensitivity analyses, which are performed on the longitudinal model of a civil aircraft. Aiming at higher levels of safety, it is suggested that the control laws design processes incorporate these associated dynamics inherent to the fly by wire approach. In fact, if, on one hand, the introduction of electronic components into flight control architectures has brought a number of operational and technical advantages, on the other it has become necessary to take into account their dynamic behaviour during flight control laws
Grinits, Erick Vile, Kienitz, Karl Heinz, de Oliveira Moreira, Fernando José
A Simple Analytical Redundancy Method for Pitch and Bank Angles Estimation2005-01-336210/03/2005
The article presents the idea of Pitch and Bank Angles estimation with the use of incomplete measurement information. This idea is applied in Attitude and Heading Reference Systems used in the Fly-By-Wire control system for a general aviation aircraft. The idea of the Fly-By-Wire control system for a general aviation aircraft designed in the Department of Avionics and Control Systems is presented in brief. For estimations Lunenberger observers were used. Simulation results are based on the flight test data.
Kopecki, Grzegorz, Tomczyk, Andrzej
Study of Lightning Effects in Aircraft2004-01-323611/16/2004
Lightning is a high voltage and high current phenomenon and it originates by build up of electrical charge in the air or, more commonly, in clouds. It is constituted of an electric current peak of short duration (0,5 ms) and high intensity (200 kA), followed by a low intensity (400 A) but high duration (1s) periods. The lightning effects in aircraft can be divided in two groups: direct effects (physical effects such as melting, rupture, damage of surfaces and structures due to conduction of lightning current or high power magnetic force) and indirect effects (electromagnetic fields generating levels of transient voltage and current on interconnecting wiring and cable leads within the equipment circuits eventually damaging internal components). The objective of this work is present and discuss the lightning effects and, subsequently, possible lightning protection applied to aircrafts by establishing adequate conductive paths for lightning current to flow through the aircraft structure
Baldacim, Sandro Aparecido, Cristofani, Nivaldo, Santos, Carlos do Nascimento, Lautenschlager, José Rui
Low Cost Fault Tolerant and Redundant Multiplex Wiring System for Automotive Applications2004-01-157203/08/2004
A low cost fault tolerant and redundant multiplex wiring system specifically designed for automotive applications is described in this paper. Although there are many multiplex wiring systems are being used to simplify the car wiring harness, but very few are low cost, fault tolerant and redundant at the same time. Most of the system address mainly the protocol and software issues and neglected the reliability of the multiplex wiring system. This paper addresses the fault tolerant and redundancy of the system and use hardware based integrated circuit to convert from parallel to serial at the transmitter side and serial to parallel at the receiver side.
Shih, Kelvin
Ground Based Vehicle Health Monitoring for Lifecycle Cost Reduction2003-01-298109/08/2003
Unprecedented rates of change in the economic equations of air transport infrastructure are impacting military, NASA and civilian fleets. Military aero-asset operational lifespans are being continually assessed for extension, and younger assets are tasked to higher levels of mission dispatch reliability. NASA, post Columbia will now undergo a new round of safety and reliability assessments of structures and wiring on the space shuttle fleet to ensure a safe return to flight. New FAA regulations to improve aging airplane structural and wiring safety motivate comprehensive change in the approach to aviation maintenance. There are concerns that these challenges of improved reliability and life extension will further strain the resources of DOD/NASA and economic health of the civilian aviation industry. However it can be shown that the knowledge developed through implementation of these recommendations through a comprehensive vehicle health monitoring system can be used to actually reduce
Schaefer, Lloyd
Personal Air Transportation: An Analysis of the Transportation Research Board's Review of the Small Aircraft Transportation System and Other Recommendations2003-01-134703/03/2003
Mobility is closely related to our economy, lifestyle, and demographics. Economic opportunities are only available in areas with affordable transportation. At first, cities could only develop along seaports, because boats and sails where the early forms of affordable transportation. The introduction of steamboats allowed cities to develop inland along the rivers. The Industrial Revolution brought about smaller engines with increase horsepower, making trains and transcontinental travel possible. Economic opportunity was no longer limited to bodies of water. As engines were refined and their size reduced even more, automobiles became practical, extending transportation to small towns almost anywhere. Automobiles also changed our lifestyles. People were moving out of the cities into suburbs. The Jet Age brought high-speed air transportation, drastically shortening travel time. Indeed, jets made the world seem smaller. In order to make air service affordable and air traffic manageable
Tran, Matthew D.
The Benefits of a Wire Integrity Program2002-01-293911/05/2002
Aircraft are aging. Wiring on aircraft is mostly inspected visually with little emphasis on non-destructive testing. Current “on-condition” practices are time consuming, costly and subject to human factors. Wiring should to be considered as a system on the aircraft and analyzed on a proactive basis, similar to the engines and the structure. New technologies are available to enable a wire integrity program.
Gau, Francois
Compatibility Testing and Smart Monitoring of the Hawker Battery on the ELDEC (Boeing) Chargers2002-01-321610/29/2002
After the second World War and with the advent of the jet engine, main Aircraft Batteries for use in both military and commercial aircraft have been dominated by Nickel Cadmium (NiCd) batteries (over lead acid). This was due to life and high rate discharge capabilities, in particular at low temperatures, of the NiCd batteries. Over the last 20 years sealed lead acid battery developments has seen NiCd performances being matched and in some instances exceeded. To realise these capabilities and to allow NiCd applications to be retrofitted with lead acid batteries, “fit form and function” capabilities have to be proven. Therefore it has been necessary to evaluate compatibility of these advanced lead acid designs with the traditional “dedicated” NiCd charger. This paper describes compatibility testing of the Hawker sealed lead acid battery design with the ELDEC 2-301-3 charger for the Boeing 727 and 737 (100/200 Series) aircraft. Details of the approval activity with the UK CAA are included
Rice, Dave, Beutler, Jon
Applicability of System Safety Processes and Operational Risk Management Training for Future Pilots2001-01-263609/11/2001
System safety is taught as a discipline in some aeronautical programs. Such a course maybe designed to prepare career-minded aviation students with a solid background to face the technical intricacies of the commercial flight arena. Over the course of the past decade, the complexity of large modern transport category aircraft has grown, and along with that growth the command and control functions built into the avionics and flight control systems have become automatic. Most new pilots entering into the cockpits of these aircraft require an understanding of how to manage these new systems in light of the basic design principles used. One excellent method of providing education for students in aeronautical studies is through courses in system safety and operational risk management (ORM). The advantage of doing this is to provide an aircrew member sufficient understanding of the logic processes and analysis inherent in system safety to permit him to quickly learn how to handle issues and
Reynolds, Randolph S.
Stabilizing and Improving the Active Vibration Damping by a New S-Z Mapping for Digital Control2000-01-329712/01/2000
This paper presents an analytical and simulation study of the stabilization and improvement of the active vibration damping of a system modeled by a simple analog harmonic oscillator driven by discrete time control. Initially, this control is the Bilinear (or Tustin) s-z mapping equivalent of a continuous-time asymptotically stable Proportional plus Derivative (PD) control. It is tested with high values of the sampling period. It is shown that all classical mappings (Tustin, Schneider, etc.) tested may instabilize the system. To circumvent this, we propose and use a new (ST1) mapping that behaves better than the classical ones tested under the same conditions. We also model an active discrete control of a suspension of a vehicle, and compare the performance between the PD controllers designed by Bilinear and by the new (ST1) S-Z mappings, for this example.
da Costa Tredinnick, Marcelo Ricardo Alves, de Oliveira e Souza, Marcelo Lopes
Aerospace Hydraulics and Actuation Lessons LearnedAIR4543A (Historical)06/01/2000
This SAE Aerospace Information Report (AIR) contains technical information on aerospace hydraulic, actuation and support equipment technologies lessons learned. The lessons learned were prepared by system designers and hydraulic engineers from the aerospace industry and government services as part of SAE Committee A-6, Aerospace Fluid Power, Actuation, and Control Technologies, and were presented at eight Lessons Learned Symposia from 1989 through 1999 held during A-6 Committee meetings. The technical topics represent many years of design experience in hydraulics and actuation, which it is felt is a resource for learning that should be documented and made available to current and future aerospace hydraulic engineers and designers. The document is organized into two sections: systems and components with further categories within the components section. The information topics are presented in a concise format of problem, issue, and solution, with accompanying descriptive diagrams and
A-6 Aerospace Actuation, Control and Fluid Power Systems
Intelligent Damage Adaptive Control for Commercial Air Transports1999-01-143604/13/1999
In situations of unanticipated maneuvers of an aircraft, information must be immediately received by the aircrew for correcting the aircraft flight path to a safe trajectory for continued flight and landing. These maneuvers may be due to failures in the control system, wind gust upsets, or other off-nominal conditions. Also critical are situations of control maneuvers that exceed the normal flight envelope of the aircraft, and providing information to the pilot and control system that will result in safe return to controllable flight. The Intelligent Damage Adaptive Control System (IDACS) operates during flight to detect dangerous conditions of the aircraft and to provide the crew with assistance to restore and to maintain safe control. This system is being developed by Boeing for NASA.
Urnes, James M.
Development of a Maintenance Free Self-Lubricating Ball Joint1999-01-003603/01/1999
Vehicular suspension ball joints can be categorized in the family of tribological systems which can reduce useful service or working capacity through malfunction or breakdown. Detailed metallurgical analysis of the friction and wear mechanisms on typical ball joint bearing surfaces point to a Teflon-based woven fabric, self-lubricating liner as the best bearing material for the joint. Laboratory functional testing was conducted on modern, 4-axis test equipment simulating the applicable loading and motion conditions typically encountered in use. The self-lubricated bearing liner woven with Teflon thread demonstrated higher sustained load capacity, less rotating friction, excellent torque retention qualities and extended life in comparison to existing components utilizing greased metal-on-metal and/or “plastic” bearing materials. This paper describes how the advanced Fiberglide® liner technology and redesigned suspension ball joint provides superior performance and maintenance-free
Arnold, R., Shuster, M., Maughan, G.
Flight Testing a Modern Flight Control System97552010/01/1997
With the increasing complexity of modern combat aircraft flight control systems, the flight trials phase of an aircraft development programme has become much more of an aircraft and systems model validaition exercise. This requires a highly integrated ground and flight test programme with accurate models of the aircraft and its systems and new analysis techniques to enable rapid and effective validation of these models. This paper describes recent experience at British Aerospace Warton on a number of aircraft programmes which has resulted in the development of effective real lime analysis techniques. These techniques provide the ability to perform in-flight model validation and are currently being used in the EF2000 development programme at Warton.
Smith, Terry D.
Analysis of Tiltwing Aircraft Configuration Potential96229011/18/1996
This paper outlines work performed by the Aeronautical Systems Division of the Aerospace and Transportation Laboratory at the Georgia Tech Research Institute (GTRI). The paper provides limited, but pertinent information relative to the technical viability of a tiltwing configurations as civil powered-lift aircraft. Emphasis has been placed on identifying the complexity differences with tiltrotor and helicopter configurations. Complexity differences normally impact both acquisition and/or operating and support costs, although specific cost estimates are not presented.
Crawford, Charles C., Heiges, Michael W., Wasikowski, Mark
The Have Blue Technology Demonstrator and Radar Cross Section Reduction96553810/01/1996
During the mid-1970s, the US embarked on a modest but highly focused effort to demonstrate an aircraft possessing a very low radar signature and sufficient performance to have operational utility. Known as Have Blue, the project was highly successful and led to the F-117 A. This paper discusses issues associated with reducing radar signature to very low levels (levels that are “tactically meaningful,” e.g., capable of defeating realistic threat systems). Radar phenomena and the concept of radar cross section (RCS) are briefly summarized and RCS reduction techniques as they were applied to Have Blue are described. RCS reduction considerations and techniques pioneered by Have Blue have become an integral component of the combat aircraft design process over the past two decades.
Piccirillo, Albert C.
Issues Associated with Operator Use of Automation95198509/01/1995
Automation is currently a topic of great interest. Part of the reason for this may be that problems associated with operator use of automation can be relatively subtle yet severe. When designing an automated system, it may not be obvious how the interactions between the operator, the system, and the environment may lead to errors. Consequently, those who design and certify flight deck systems should be aware of some of the issues associated with pilot use of automation. These include the potential for over reliance or under reliance on automation and the factors that can contribute to them, issues of pilot and automation authority, automation complexity, feedback, and transitions between automated and manual control. In this paper, we concentrate on how pilots make decisions to use or not use automation and the factors that can influence these decisions.
Riley, Victor
Mixed Voltage, Microprocessor Based Avionic Systems95202809/01/1995
Avionic systems based on next generation microprocessors will be mixed voltage designs. Next generation microprocessors have a low voltage power supply and interface, but most of the avionics-grade support logic will remain standard voltage devices in the near term. The mixture of integrated circuit voltage technologies poses some unique problems to the avionics designer. The paper will present some fundamental techniques for designing mixed voltage, microprocessor-based avionics systems. Included will be techniques for interfacing devices of different voltage technologies and the creation of an accurate low voltage power supply.
Casazza, Jeffrey
A Millimeter Wave, Wireless, LAN for Use Inside an Aircraft94255411/01/1994
A Millimeter Wave, Wireless, Local Area Network has been built for use in distributing digital data inside an aircraft. To avoid interference with existing VHF and Microwave transmitters and receivers, the transmitters operate at 60.60 Ghz and 60.54 Ghz. This region of the Millimeter Wave Spectrum has high attenuation being the resonant frequency of local oxygen atoms. This isolates the wireless links from most interference. The transceivers employ V-Band Gunn Diode Voltage-Controlled Oscillators. The maximum range is 150 meters. The network boards have been optimized for Mil-Spec-1553 type digital messages. A wide variety of other digital formats can be supported from 200 Khz up to video rates, but analog video sent through the system was too noisy for conventional television receivers. This paper describes the rationale, the system requirements, the development, the final design, and the test results.
Ulbrich, Erwin A.
AEROSPACE - FLIGHT CONTROL ACTUATOR DISPLACEMENT - METHOD FOR COLLECTION OF DUTY CYCLE DATAARP4895 (Historical)05/01/1994
The scope of this SAE Aerospace Recommended Practice (ARP) covers acquisition of flight test data for use in developing a statistical data base of aerospace vehicle flight control surface actuator duty cycle. The statistical data base is intended for use in establishing industry guidelines and procurement specification requirements for actuator displacement duty cycle. The objective of this ARP is to provide a uniform method for the aerospace industry to collect flight control displacement type duty cycle data during demonstration and full scale development of new aircraft or during development testing of new models of existing aircraft.
A-6A3 Flight Control and Vehicle Management Systems Cmt
Trends in Air Turbine Starters for Large Turbofan Engines92197510/01/1992
Methodology development from analysis using both starter parameter trends and auxiliary system features can be applied to focus future starter development efforts. This analysis method can be used to devise improvements to the starter system and its supporting systems and equipment. Results of historic development trends of air turbine starter characteristics, parameters and features are examined for basic trends and for state-of-the art limits. This analysis of parameter relationships and of current examples breaks-down paradigms to realize previously unseen component and system advances. The data from analysis provides a new platform for starter development that can bring maximum overall value to the customer.
Kasak, A. John
Continuing the Etops Debate A Philosophy of Safety Overview90202109/01/1990
Five years ago, a new experiment in passenger air transportation for Atlantic Ocean crossings was introduced. It was given the acronym known as ETOPS and involves the development of passenger aircraft having only two-engines utilized for flights over such critical routes. The essence of the concern generated in this study is summarized by the safety analysis of Dr. Robert Besco, who states, “ETOPS is troublesome because the failure of only one system on an aircraft [In this case an engine] should not cause that aircraft to have to operate under emergency conditions.” Previously, a major cornerstone of civil aviation safety was the concept of providing multiple engine redundancy with a minimum of three-engines required for such critical flights. The accepted safety premise was that many unfavorable factors such as engine failures could jeopardize such flights and therefore the fail-safe method of providing three- or four-engine redundancy for these transports was prudent as well as
Sprogis, Hal
The Ergonomie Integrated Flight Deck89261212/01/1989
A coordinated flight deck design concept is presented, which takes into account human capabilities and limitations such as fit and function, seating, internal and external vision, reach, and safety. In addition to incorporating operational requirements, the concept covers amenities such as coffee cup holders, footrests, provisions for food service, storage of personal items such as suitcases and clothing, and maps, flight manuals, and charts. The design is brought together with computer-aided drafting procedures as well as sophisticated human modeling techniques, enabling a step-by-step assessment of the resulting configuration.
Stone, Gerald
Flight Test and Evaluation of Fluidic Flight Control87186410/01/1987
This paper presents the results of a multi-year project by the Naval Air Development Center to design, fabricate, evaluate, and flight test a fluidic flight control system in a Navy T-2C, a twin-jet carrier aircraft. The work leading to this flight test began with component design to the aircraft installation constraints and to flight requirements, continued through fabrication, laboratory testing and system installation, and culminated with man-in-the-loop evaluation of the system installed in the aircraft, ground tests, and flight. The results of these tests demonstrate the successful integration of three advanced technologies: 8000-psi actuation controlled both by fluidics and fly-by-wire which the Naval Air Development Center has brought to fruition.
Keyser, David R.
Fly-by-Wire Sidestick Controller Evaluation87176110/01/1987
A simulation study was conducted to investigate operational issues associated with advanced flight deck configurations of transport aircraft employing sidestick controllers and fly-by-wire control modes. The advanced concepts flight simulator in the Man-Vehicle Systems Research Facility at NASA Ames Research Center was used for this evaluation. Sixty-two pilots from Douglas Aircraft, NASA, and commercial airlines participated in the study. The primary objective was to evaluate the requirement for coupling the pilot's and copilot's sidestick controllers. Other issues addressed were the sidestick controller characteristics, the control mode handling qualities, and the requirement for coupling the autopilot to the sidestick. Three tests were conducted: (1) a handling qualities evaluation of the sidestick characteristics and the control modes, (2) an evaluation of alternative configurations for sidestick coupling, and (3) an evaluation of alternative configurations for autopilot coupling
Summers, L. G., Shannon, J. H.
Airline Requirements on a Fly-By-Wire Aircraft – A Pilot's View86180410/01/1986
The next important milestone in the development of transport aircraft will be marked by the first full FBW jetliner, possibly with only partial mechanical backup. Airline pilots may question what FBW will do good for them. What they don't want, is technology for it's own sake. Asking what we can gain with FBW, here are the answers: Improved handling characteristics: Consistent handling qualities enhance common type ratings for a family of airplanes. Added safety features: Quick and positive access to full performance envelope. Automatic recovery from performance limited conditions. More flexibility in flight deck arrangement, Reduction of training costs. How these features match our operational requirements will be discussed.
Heldt, Peter H.
Airbus A320 Side Stick and Fly By Wire — An Update86180110/01/1986
This paper discusses the side stick and fly by wire elements of the Airbus Industrie A320. After discussion of the cockpit and the effect on it of the side sticks, the arrangements of the side sticks themselves is discussed, travel, forces and electronic coupling. The control laws form the body of the paper with some emphasis on the new things that become possible with fly by wire that Airbus Industrie has vested in A320. Pitch roll and yaw control are discussed in detail and so to are the protection systems that will contain the flight path within safe limits. Some illustrations of the functioning of the protection system in flight on a test A300 equiped with the A320 control laws will be presented.
Corps, S. G.
Items per page:
1 – 50 of 68