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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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21 Sep 2009
TL;DR: This paper discusses TLOH recoverability as a function of conditions, and TOC landability results for a range of transport airplanes, and some key techniques for flying with throttles and making a survivable landing.
Abstract: If normal aircraft flight controls are lost, emergency flight control may be attempted using only the thrust of engines. Collective thrust is used to control flightpath, and differential thrust is used to control bank angle. One issue is whether a total loss of hydraulics (TLOH) leaves an airplane in a recoverable condition. Recoverability is a function of airspeed, altitude, flight phase, and configuration. If the airplane can be recovered, flight test and simulation results on several transport-class airplanes have shown that throttles-only control (TOC) is usually adequate to maintain up-and-away flight, but executing a safe landing is very difficult. There are favorable aircraft configurations, and also techniques that will improve recoverability and control and increase the chances of a survivable landing. The DHS and NASA have recently conducted a flight and simulator study to determine the effectivity of manual throttles-only control as a way to recover and safely land a range of transport airplanes. This paper discusses TLOH recoverability as a function of conditions, and TOC landability results for a range of transport airplanes, and some key techniques for flying with throttles and making a survivable landing. Airplanes evaluated include the B-747, B-767, B-777, B-757, A320, and B-737 airplanes.
4 citations
13 Aug 2012
TL;DR: In this article, a yaw rate to throttle feedback feedback system was designed to replace a damaged rudder for crosswind landings, which can act as a Dutch roll damper and as a means to facilitate pilot input for cross wind landings.
Abstract: This paper describes the implementation and evaluation of a yaw rate to throttle feedback system designed to replace a damaged rudder. It can act as a Dutch roll damper and as a means to facilitate pilot input for crosswind landings. Enhanced propulsion control modes were implemented to increase responsiveness and thrust level of the engine, which impact flight dynamics and performance. Piloted evaluations were performed to determine the capability of the engines to substitute for the rudder function under emergency conditions. The results showed that this type of implementation is beneficial, but the engines’ capability to replace the rudder is limited.
4 citations
TL;DR: In this paper, an H∞ loop transfer recovery (LTR) technique is applied to address the stability recovery and robustness of performance in maintaining safe flight operation of a damaged aircraft.
Abstract: Thrust-only control of a jet transportation aircraft is also referred to as propulsion-controlled aircraft (PCA). It may be adopted as an alternative to using propulsive force to provide a certain level of control capability in case of failure of the aircraft's conventional control system. Previous PCA research was mainly concerned with control surface malfunctions such as free-floating and locked-in-place situations. On the other hand, structural damage to the aircraft control surfaces makes it necessary for PCA study and results in significant challenges due to the damage-induced aerodynamic and geometric parameter deviations. This paper presents a damage-tolerant control system design for aircraft with vertical tail damage. An H∞ loop transfer recovery (LTR) technique is applied to address the stability recovery and robustness of performance in maintaining safe flight operation of a damaged aircraft. Modelling of the damaged flight dynamics and control design is presented followed by numerical...
3 citations
01 Jan 2017
TL;DR: In this paper, the authors have made use of differential engine thrust together with ailerons deflection in the control column for the design reconfiguration of an emergency yaw damper to regain the lateral/ directional stability of a transport aircraft which has undergone severe damage to its vertical tail during flight.
Abstract: In this paper, authors have made use of differential engine thrust together with ailerons deflection in the control column for the design reconfiguration of an emergency yaw damper to regain the lateral/ directional stability of a transport aircraft which has undergone severe damage to its vertical tail during flight. An earlier version of the transport aircraft Boeing-747 is chosen as a working platform. At first the damage to the vertical tail and its effects on the aerodynamics of the aircraft are modeled and then the role of thrust dynamics and its utilization as a control effector is discussed. Engine thrust dynamics are modeled as a second order system to account for real time delays and for its inclusion in the simulation process. An optimal servo LQR controller is designed to minimize the control effort for the proposed model and simulated in Matlab Simulink environment to analyze the intended fault tolerant control design for different flight conditions. The simulation results are encouraging for the use of differential engine thrust as a control effector together with residual control surfaces and help recover the aircraft from the emergency situation successfully.
2 citations
01 Oct 2016
TL;DR: In this paper, intelligent flight control system for recovering controllability of the aircraft when an unexpected problem occurs during a flight is proposed.
Abstract: In this paper, intelligent flight control system for recovering controllability of the aircraft when an unexpected problem (such as faults or failures to the actuators/sensors or structural damage) occurs during a flight is proposed.
2 citations
Cites background from "Manual Manipulation of Engine Throt..."
...Flight 232 DC–10 in Sioux City, Iowa 1989 (which suffered a tail engine failure that caused the total loss of hydraulics) [5, 6], the Kalita Air freighter in Detroit, Michigan, October 2004 (where engine No: 1 was shed but the crew managed to land safely without any casualties) and the DHL A300B4, Baghdad, November 2003 (which was hit by a missile on its left wing and lost all hydraulics, but still landed safely using only the engines) [5], represent some examples of successful landings using clever manipulation of the remaining functional redundant control surfaces (Fig....
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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