Download or read book Flight Testing a Digital Flight Control System Issues and Results written by and published by . This book was released on 1984 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The AFTI/F-16 Advanced Development Program modified an F-16A to be a testbed for evaluating new flight control related technologies. The program has completed its first phase of flight testing. Some of the technologies being developed are: a triplex digital fly-by-wire flight control system which operates asynchronously, an analog independent backup unit (IBU), eight separate digital task-tailored control laws, and six decoupled controller options. Included among these task-tailored modes are normal operation modes, air-to-air combat and air-to-surface combat modes. One unique aspect of this program was the heavy involvement of the AFTI/F-16 Joint Test Force throughout the entire system development (pre-flight test) phase. This forced early design consideration to be given to pilot-vehicle interface issues. Through use of a General Dynamic (GD) simulator, the test pilot became an integral part of the flight control normal digital mode, seven different sensor reconfiguration digital modes, and the analog IBU. Much concern surfaced prior to first flight as to how landable these different modes were; this resulted in all the landing modes being extensively tested on the GD Simulator, the Flight Dynamics Lab LAMARS, and the NT-33 Inflight Simulator. Two of these modes, the normal mode and the IBU, have been flight tested on the AFTI/F-16 itself and the flight test results were different from any of the simulator's predicted results. This has raised several issues on the use of simulators to accurately represent today's highly augmented fighter aircraft.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Digital Flight Control Research Using Microprocessor Technology written by Robert F. Stengel and published by . This book was released on 1980 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: A digital flight control system based on microprocessor technology was designed, developed, and flight tested in Princeton's Variable-Response Research Aircraft (VRA). The microprocessor-based digital flight control system works in conjunction with the VRA's existing fly-by-wire control system, and is programmed to provide command and stability augmentation control laws formulated through modern control theory. The initial flight control computer program, CAS-1, provides direct, pitch rate, and normal acceleration command modes. The latter two closed-loop control laws are designed using sampled-data linear-quadratic regulator theory. The computer hardware and software are described and initial flight test results are presented. Flight test results are based on two longitudinal manual control tasks: tracking at altitude and approach and landing. They demonstrate the effects of varying sampling rate, computation delay, and control resolution on calibrated step response and on pilot opinion ratings. It is concluded that the pilot can provide effective control with lower sampling rates and control resolution than might have been anticipated. The limiting values are task dependent, generally lying in the range of 5 to 10 samples per sec and 4- to 8-bit resolution. Flight test results with pure time delay tend to confirm that there is rapid degradation of pilot opinion as the delay increases beyond 0.2 sec.
Download or read book Development and Flight Test Experiences with a Flight crucial Digital Control System written by Dale A. Mackall and published by . This book was released on 1988 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Information Indexes written by United States. Naval Air Systems Command and published by . This book was released on 1975 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design Implications from AFTI F 16 Flight Test written by and published by . This book was released on 1984 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cockpit Automation Flight Systems Complexity and Aircraft Certification written by Bart Elias and published by . This book was released on 2019-10-20 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing complexity and automation of flight control systems pose a challenge to federal policy regarding aircraft certification and pilot training. Despite significant commercial aviation safety improvements over the past two decades, flight control automation and aircraft complexity have been cited as contributing factors in a number of major airline accidents, including two high-profile crashes overseas involving the recently introduced Boeing 737 Max variant in 2018 and 2019. These crashes have directed attention to Federal Aviation Administration (FAA) oversight of aircraft type certification and pilot training practices for transport category aircraft, particularly as they pertain to complex automated flight control systems. As aircraft systems have evolved over the past three decades to incorporate new technologies, Congress has mandated FAA to streamline certification processes, with the primary motivation being to facilitate the development of new safety-enhancing technologies. Modern commercial aircraft rely on "fly-by-wire" flight control technologies, under which pilots' flight control inputs are sent to computers rather than through direct mechanical linkages to flight control systems. The fly-by-wire software contains flight control laws and logic that, in addition to optimizing performance efficiency, protect the aircraft from commanded actions that could put the airplane in an unsafe state. Automated flight control systems have largely been viewed as having a positive effect on safety, and accident rates have improved considerably over the past two decades. However, the increasing complexity of automated flight systems has sometimes caused confusion and uncertainty, contributing to improper pilot actions during critical phases of flight and in some cases leading pilots to unintentionally place an aircraft in an unsafe condition. Besides designing these systems in a manner that minimizes pilot errors and the consequences of those errors, aircraft designers and operators face challenges regarding maintaining piloting skills for flight crews to be able to take over and manually fly the aircraft safely if critical systems fail. They also face challenges regarding documentation and pilot training effectiveness in building accurate mental models of how these complex systems operate. The primary goals of ongoing efforts to address these challenges are to enhance pilot situation awareness when using automation and reduce the likelihood of mode errors and confusion, while at the same time not overburdening pilots with intricate systems knowledge beyond what is necessary. In the ongoing investigations of two Boeing 737 Max crashes, Lion Air flight 610 and Ethiopian Airlines flight 302, concerns have been raised about the design of an automated feature called the Maneuvering Characteristics Augmentation System (MCAS) and its reliance on a single angle-of-attack sensor even though the aircraft is equipped with two such sensors. These concerns led to the worldwide grounding of all Boeing 737 Max aircraft until the MCAS safety concerns can be resolved, significantly impacting both U.S. and foreign airlines that operate the aircraft. These recent aviation accidents have prompted reviews of the manner in which modern transport category aircraft are certified by FAA and its foreign counterparts, and in particular, the roles of regulators and manufacturers in the certification process. The challenges of certifying increasingly complex aircraft are largely being met by delegating more of FAA's certification functions to aircraft designers and manufacturers. This raises potential conflicts between safety and quality assurance on the one hand and competitive pressures to market and deliver aircraft on the other. Under Organization Designation Authorization (ODA), FAA can designate companies to carry out delegated certification functions on its behalf.
Download or read book Digital Flight Control System Validation Technology Assessment written by and published by . This book was released on 1982 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1991 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flight Test Experience with Pilot induced oscillation Suppression Filters written by and published by . This book was released on 1984 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flight testing of the Self repairing Flight Control System Using the F 15 Highly Integrated Digital Electronic Control Flight Research Facility written by James F. Stewart and published by . This book was released on 1990 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applications of Flight Control System Methods to an Advanced Combat Rotorcraft written by and published by . This book was released on 1989 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced flight control system design, analysis, and testing methods are applied in an analytical and flight test evaluation of the Advanced Digital Optical Control System (ADOCS) demonstrator. This paper describes the knowledge gained about the implications of digital flight control system design for rotorcraft, and illustrates. The analysis of the resulting handling-qualities in the context of the proposed new handling-qualities specification for rotorcraft. Topics included are digital flight control design and analysis methods, flight testing techniques, ADOCS handling-qualities evaluation results, and correlation of flight test results with analytical models and the proposed handling- qualities specification. Evaluation of the ADOCS demonstrator indicated desirable response characteristics based on equivalent damping and frequency, but undesirably large effective time-delays. Piloted handling-qualities are desirable or adequate for all low, medium, and high pilot gain tasks; but handling-qualities are inadequate for ultra-high gain tasks such as slope and running landings. Correlation of these results with the proposed handling- qualities specification indicates good agreement for the bandwidth boundaries, but suggests the need for more stringent limits on allowable phase-delay. Analytical models based on emulation (s-plane) techniques compare favorably with flight extracted frequency-domain characteristics of the overall (end-to-end) ADOCS responses. Direct digital analysis procedures are necessary to characterize the intersample behavior of the actuator rate response.
Download or read book Applications of Flight Control System Methods to an Advanced Combat Rotorcraft written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-08 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced flight control system design, analysis, and testing methodologies developed at the Ames Research Center are applied in an analytical and flight test evaluation of the Advanced Digital Optical Control System (ADOCS) demonstrator. The primary objectives are to describe the knowledge gained about the implications of digital flight control system design for rotorcraft, and to illustrate the analysis of the resulting handling-qualities in the context of the proposed new handling-qualities specification for rotorcraft. Topics covered in-depth are digital flight control design and analysis methods, flight testing techniques, ADOCS handling-qualities evaluation results, and correlation of flight test results with analytical models and the proposed handling-qualities specification. The evaluation of the ADOCS demonstrator indicates desirable response characteristics based on equivalent damping and frequency, but undersirably large effective time-delays (exceeding 240 m sec in all axes). Piloted handling-qualities are found to be desirable or adequate for all low, medium, and high pilot gain tasks; but handling-qualities are inadequate for ultra-high gain tasks such as slope and running landings. Tischler, Mark B. and Fletcher, Jay W. and Morris, Patrick M. and Tucker, George T. Ames Research Center...
Download or read book Flight Test Results from the NF 15B Intelligent Flight Control System IFCS Project with Adaptation to a Simulated Stabilator Failure written by National Aeronaut Administration (Nasa) and published by . This book was released on 2020-08-05 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive flight control systems have the potential to be more resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane and subjected to an inflight simulation of a failed (frozen) (unmovable) stabilator. Formation flight handling qualities evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to decouple the roll and pitch response and reestablish good onboard model tracking. Flight evaluation with the simulated stabilator failure and adaptation engaged showed that there was generally improvement in the pitch response; however, a tendency for roll pilot-induced oscillation was experienced. A detailed discussion of the cause of the mixed results is presented. Bosworth, John T. and Williams-Hayes, Peggy S. Armstrong Flight Research Center NASA/TM-2007-214629, H-2751, AIAA-2007-2818 ADAPTIVE CONTROL; FLIGHT CONTROL; NEURAL NETS; FORMATION FLYING; AIRCRAFT STABILITY; STABILITY TESTS; ADAPTATION; ROLL; SYSTEM FAILURES; FLIGHT SIMULATION; STABILIZERS; FLIGHT TEST VEHICLES
Download or read book Flight Control Systems written by Roger Pratt and published by IET. This book was released on 2000 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Bridging the gap between academic research and real-world applications, this reference on modern flight control methods for fixed-wing aircraft deals with fundamentals of flight control systems design, then concentrates on applications based on the modern control methods used in the latest aircraft. The book is written for practicing engineers who are new to the aviation industry, postgraduate students in strategic or applied research, and advanced undergraduates. Some knowledge of classical control is assumed. Pratt is a member of IEEE and is UK Member for AIAA's Technical Committee on Guidance, Navigation and Control. Annotation c. Book News, Inc., Portland, OR (booknews.com)
Download or read book Research and Technology Objectives and Plans Summary written by and published by . This book was released on with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A compilation of the summary portions of each of the RTOPs used for management review and control of research currently in progress throughout NASA"--P. i.
