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Manual Manipulation of Engine Throttles for Emergency Flight Control
02 Aug 2013-
TL;DR: In this paper, a history of accidents or incidents in which some or all flight controls were lost, manual TOC results for a wide range of airplanes from simulation and flight, and suggested techniques for flying with throttles only and making a survivable landing.
Abstract: If normal aircraft flight controls are lost, emergency flight control may be attempted using only engines thrust. Collective thrust is used to control flightpath, and differential thrust is used to control bank angle. Flight test and simulation results on many airplanes have shown that pilot manipulation of throttles is usually adequate to maintain up-and-away flight, but is most often not capable of providing safe landings. There are techniques that will improve control and increase the chances of a survivable landing. This paper reviews the principles of throttles-only control (TOC), a history of accidents or incidents in which some or all flight controls were lost, manual TOC results for a wide range of airplanes from simulation and flight, and suggested techniques for flying with throttles only and making a survivable landing.
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15 Feb 2018
TL;DR: The first flight of a Pan American (Pan Am) World Airways Boeing 707 airliner left New York for Paris on October 26, 1958 as discussed by the authors, with the Champs-Elysees only 6 hours away, and the New York Times declared the second coming of a 'cleaner, leaner' Jet Age.
Abstract: The New York Times announced America's entry into the 'long awaited' Jet Age when a Pan American (Pan Am) World Airways Boeing 707 airliner left New York for Paris on October 26, 1958. Powered by four turbojet engines, the 707 offered speed, more nonstop flights, and a smoother and quieter travel experience compared to newly antiquated propeller airliners. With the Champs-Elysees only 6 hours away, humankind had entered into a new and exciting age in which the shrinking of the world for good was no longer a daydream. Fifty years later, the New York Times declared the second coming of a 'cleaner, leaner' Jet Age. Decades-old concerns over fuel efficiency, noise, and emissions shaped this new age as the aviation industry had the world poised for 'a revolution in jet engines'. Refined turbofans incorporating the latest innovations would ensure that aviation would continue to enable a worldwide transportation network. At the root of many of the advances over the preceding 50 years was the National Aeronautics and Space Administration (NASA). On October 1, 1958, just a few weeks before the flight of that Pan Am 707, NASA came into existence. Tasked with establishing a national space program as part of a Cold War competition between the United States and the Soviet Union, NASA is often remembered in popular memory first for putting the first human beings on the Moon in July 1969, followed by running the successful 30-year Space Shuttle Program and by landing the Rover Curiosity on Mars in August 2012. What many people do not recognize is the crucial role the first 'A' in NASA played in the development of aircraft since the Agency's inception. Innovations shaping the aerodynamic design, efficient operation, and overall safety of aircraft made NASA a vital element of the American aviation industry even though they remained unknown to the public. This is the story of one facet of NASA's many contributions to commercial, military, and general aviation: the development of aircraft propulsion technology, which provides the power for flight.
33 citations
01 Aug 2007
TL;DR: In this paper, the NASA Aviation Safety Program is conducting resilient propulsion research aimed at developing adaptive engine control methodologies to operate the engine beyond the normal domain for emergency operations to maximize the possibility of safely landing the damaged aircraft.
Abstract: Gas turbine engines are designed to provide sufficient safety margins to guarantee robust operation with an exceptionally long life. However, engine performance requirements may be drastically altered during abnormal flight conditions or emergency maneuvers. In some situations, the conservative design of the engine control system may not be in the best interest of overall aircraft safety; it may be advantageous to "sacrifice" the engine to "save" the aircraft. Motivated by this opportunity, the NASA Aviation Safety Program is conducting resilient propulsion research aimed at developing adaptive engine control methodologies to operate the engine beyond the normal domain for emergency operations to maximize the possibility of safely landing the damaged aircraft. Previous research studies and field incident reports show that the propulsion system can be an effective tool to help control and eventually land a damaged aircraft. Building upon the flight-proven Propulsion Controlled Aircraft (PCA) experience, this area of research will focus on how engine control systems can improve aircraft safe-landing probabilities under adverse conditions. This paper describes the proposed research topics in Engine System Requirements, Engine Modeling and Simulation, Engine Enhancement Research, Operational Risk Analysis and Modeling, and Integrated Flight and Propulsion Controller Designs that support the overall goal.
20 citations
Patent•
12 Oct 2006
TL;DR: In this paper, a method for controlling an aircraft when the hydraulic system of the aircraft has been compromised is described, where the method may include resealing at least one gain vector of a digital fly-by-wire, lower-order, full-state feedback control.
Abstract: A method is disclosed for controlling an aircraft when the hydraulic system of the aircraft has been compromised. The method may include resealing at least one gain vector of a digital fly-by-wire, lower-order, full-state feedback control in at least one axis. The gain(s) may then used by a digital control to modulate engine thrust. In this manner, engine thrust modulation may be used for stabilization and control of control-configured aircraft without requiring a substantial change in piloting technique.
19 citations
27 Jul 2015
TL;DR: In this paper, the authors discuss the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft, which is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40,000) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control.
Abstract: This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40,000) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.
18 citations
TL;DR: The handling qualities results of a piloted flight simulator assessment with a damaged aircraft model showed that an online physical model identification approach contributed to improved pilot performance following potentially catastrophic structural and flight critical system failures.
Abstract: Recent developments in the field of loss-of-control recovery and prevention included improved pilot training, cockpit automation, and fault-tolerant control. The Flight Mechanics Action Group on Fault-Tolerant Control of the Group for Aeronautical Research and Technology in Europe demonstrated the advantages of fault-tolerant “intelligent,” flight control systems. The research enabled the improvement of the technology readiness level of these systems by evaluating one of them in realistic operational scenarios. The handling qualities results of a piloted flight simulator assessment with a damaged aircraft model showed that an online physical model identification approach contributed to improved pilot performance following potentially catastrophic structural and flight critical system failures. After the failures and subsequent control reconfiguration by the intelligent flight control system, airline and engineering test pilots experienced no difficulties in conducting a safe approach and landing.
16 citations
Cites background from "Manual Manipulation of Engine Throt..."
...In response to the 1989 Sioux City incident, a research programwas initiated at theNASADrydenFlight Research Center on “propulsion-controlled aircraft” (PCA) [12]....
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...The PCA system provided a safe landing capability using just engine thrust....
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References
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TL;DR: In contrast, the authors argue that there are many everyday contexts in which we hold agents responsible for their acts even though considerations unrelated to determinism strongly suggest that they cannot help performing them.
Abstract: Incompatibilists affirm, while compatibilists deny, that the truth of determinism would mean that we lack control over, and so are not responsible for, any of our actions. Though defined as opposites, compatibilism and incompatibilism both treat determinism as the main threat to our having enough control over our actions to be morally responsible for them. Here, by contrast, I want to call attention to another, less exotic threat to our having that much control. There are, I will argue, many everyday contexts in which we hold agents responsible for their acts even though considerations unrelated to determinism strongly suggest that they cannot help performing them. These contexts may not prevent us from specifying a conception of control that preserves our standard judgments of responsibility, but they do make that task even more difficult than is generally appreciated.
190 citations
01 Sep 1996
TL;DR: Results from a 36-flight evaluation showed that the PCA system can be used to safety land an airplane that has suffered a major flight control system failure and was used to recover from a severe upset condition, descend, and land.
Abstract: A propulsion-controlled aircraft (PCA) system for emergency flight control of aircraft with no flight controls was developed and flight tested on an F-15 aircraft at the NASA Dryden Flight Research Center. The airplane has been flown in a throttles-only manual mode and with an augmented system called PCA in which pilot thumbwheel commands and aircraft feedback parameters were used to drive the throttles. Results from a 36-flight evaluation showed that the PCA system can be used to safety land an airplane that has suffered a major flight control system failure. The PCA system was used to recover from a severe upset condition, descend, and land. Guest pilots have also evaluated the PCA system. This paper describes the principles of throttles-only flight control; a history of loss-of-control accidents; a description of the F-15 aircraft; the PCA system operation, simulation, and flight testing; and the pilot comments.
49 citations
01 Jun 1991
TL;DR: The use of throttle control laws to provide adequate flying qualities for flight path control in the event of a total loss of conventional flight control surface use was evaluated in this paper, where the results were based on a simulation evaluation by transport research pilots of a B-720 transport with visual display.
Abstract: The use of throttle control laws to provide adequate flying qualities for flight path control in the event of a total loss of conventional flight control surface use was evaluated. The results are based on a simulation evaluation by transport research pilots of a B-720 transport with visual display. Throttle augmentation control laws can provide flight path control capable of landing a transport-type aircraft with up to moderate levels of turbulence. The throttle augmentation mode dramatically improves the pilots' ability to control flight path for the approach and landing flight condition using only throttle modulation. For light turbulence, the average Cooper-Harper pilot rating improved from unacceptable to acceptable (a pilot rating improvement of 4.5) in going from manual to augmented control. The low frequency response characteristics of the engines require a considerably different piloting technique. The various techniques used by the pilot resulted in considerable scatter in data. Many pilots readily adapted to a good piloting technique while some had difficulty. A new viable approach is shown to provide independent means of redundancy of transport aircraft flight path control.
45 citations
01 Oct 1997
TL;DR: An emergency flight control system that uses only engine thrust, called the propulsion-controlled aircraft (PCA) system, was developed and flight tested on an MD-11 airplane as discussed by the authors.
Abstract: An emergency flight control system that uses only engine thrust, called the propulsion-controlled aircraft (PCA) system, was developed and flight tested on an MD-11 airplane. The PCA system is a thrust-only control system, which augments pilot flightpath and track commands with aircraft feedback parameters to control engine thrust. The PCA system was implemented on the MD-11 airplane using only software modifications to existing computers. Results of a 25-hr flight test show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds, altitudes, and configurations. PCA approaches, go-arounds, and three landings without the use of any normal flight controls were demonstrated, including ILS-coupled hands-off landings. PCA operation was used to recover from an upset condition. The PCA system was also tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control, a history of accidents or incidents in which some or all flight controls were lost, the MD-11 airplane and its systems, PCA system development, operation, flight testing, and pilot comments.
39 citations