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A critical analysis is presented of the application of statistics to flight vehicle vibration problems. Analytical engineering procedures are proposed for determining statistical properties of a single vibration record, and for establishing the over-all vibration environment from a collection of vibration records. Jet aircraft and several categories of missiles are broken down into definite operating phases as regards their vibration environment. Simple statistical techniques are developed for reducing the amount of data to be gathered for later processing. Statistical tests are developed for testing fundamental assumptions of randomness, stationary, and normality. Mathematical and physical distinctions are explained between different information obtained by measuring numerous important statistical parameters, such as an instantaneous amplitude probability density function, or a mean square acceleration power spectral density function, or an autocorrelation function.

The design of nonlinear controllers has relied on the use of detailed aerodynamic and engine models that must be associated with the control law in the flight system implementation. Many of these controllers were applied to vehicle flight path control problems and have attempted to combine both inner- and outer-loop control functions in a single controller. An approach to the nonlinear trajectory control problem is presented. This approach uses linearizing transformations with measurement feedback to eliminate the need for detailed aircraft models in outer-loop control applications. By applying this approach and separating the inner-loop and outer-loop functions two things were achieved: (1) the need for incorporating detailed aerodynamic models in the controller is obviated; and (2) the controller is more easily incorporated into existing aircraft flight control systems. An implementation of the controller is discussed, and this controller is tested on a six degree-of-freedom F-15 simulation and in flight on an F-15 aircraft. Simulation data are presented which validates this approach over a large portion of the F-15 flight envelope. Proof of this concept is provided by flight-test data that closely matches simulation results. Flight-test data are also presented.

The design of nonlinear controllers has relied on the use of detailed aerodynamic and engine models that must be associated with the control law in the flight system implementation. Many of these controllers were applied to vehicle flight path control problems and have attempted to combine both inner- and outer-loop control functions in a single controller. An approach to the nonlinear trajectory control problem is presented. This approach uses linearizing transformations with measurement feedback to eliminate the need for detailed aircraft models in outer-loop control applications. By applying this approach and separating the inner-loop and outer-loop functions two things were achieved: (1) the need for incorporating detailed aerodynamic models in the controller is obviated; and (2) the controller is more easily incorporated into existing aircraft flight control systems. An implementation of the controller is discussed, and this controller is tested on a six degree-of-freedom F-15 simulation and in flight on an F-15 aircraft. Simulation data are presented which validates this approach over a large portion of the F-15 flight envelope. Proof of this concept is provided by flight-test data that closely matches simulation results. Flight-test data are also presented.

Thermodynamic problems of air breathing jet engine performance in space flight

Book digitized by Google from the library of the Library of Congress and uploaded to the Internet Archive by user tpb.

Bibliography: p. 123-125

There are many problem-solving tasks that are too complex to fully automate given the current state of technology. Nevertheless, significant improvements in overall system performance could result from the introduction of well-designed computer aids. We have been studying the development of cognitive tools for one such problem-solving task, enroute flight path planning for commercial airlines. Our goal has been two-fold. First, we have been developing specific system designs to help with this important practical problem. Second, we have been using this context to explore general design concepts to guide in the development of cooperative problem-solving systems. These design concepts are described below, along with illustrations of their application.

Previous studies by NASA Dryden have shown the use of throttles for emergency flight control to be extremely difficult, especially for landing. Flight control using only the throttles to achieve safe landing for a large jet transport airplane, the Boeing 720, is investigated using Quantitative Feedback Theory (QFT). Results are compared to an augmented control developed in a previous study. The controller corrected unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but improving the control bandwidth substantially proved very difficult. The pitch controller is robust in conditions of no or moderate turbulence. The roll controller performed well in conditions of no turbulence, but is sensitive to moderate turbulence. Handling qualities of the augmented control for approach and landing were evaluated by piloted simulation flights.

Previous studies by NASA Dryden have shown the use of throttles for emergency flight control to be extremely difficult, especially for landing. Flight control using only the throttles to achieve safe landing for a large jet transport airplane, the Boeing 720, is investigated using Quantitative Feedback Theory (QFT). Results are compared to an augmented control developed in a previous study. The controller corrected unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but improving the control bandwidth substantially proved very difficult. The pitch controller is robust in conditions of no or moderate turbulence. The roll controller performed well in conditions of no turbulence, but is sensitive to moderate turbulence. Handling qualities of the augmented control for approach and landing were evaluated by piloted simulation flights.

NASA CONNECT is an annual series of integrated mathematics, science, and technology instructional distance learning programs for students in grades 6-8. This program is designed for students to learn about the evolution of flight. The program has three components--television broadcast, Web activity, and lesson guide--which are designed as an integrated instructional package. Students learn how the Wright Brothers became the first human beings to successfully design, construct, and fly an airplane and which method the Wright Brothers used in designing their airplane. Students also observe NASA engineers and researchers using problem-solving skills to design wings that will change their shape during flight. By conducting hands-on and Web activities, students make connections between NASA research and the mathematics, science, and technology they learn in the classroom. The educator guide features: (1) program overview; (2) hands-on activity; (3) student worksheets; (4) teacher materials; (5) interactive kite modeler; and (6) resources. (KHR)

NASA CONNECT is an annual series of integrated mathematics, science, and technology instructional distance learning programs for students in grades 6-8. This program is designed for students to learn about the evolution of flight. The program has three components--television broadcast, Web activity, and lesson guide--which are designed as an integrated instructional package. Students learn how the Wright Brothers became the first human beings to successfully design, construct, and fly an airplane and which method the Wright Brothers used in designing their airplane. Students also observe NASA engineers and researchers using problem-solving skills to design wings that will change their shape during flight. By conducting hands-on and Web activities, students make connections between NASA research and the mathematics, science, and technology they learn in the classroom. The educator guide features: (1) program overview; (2) hands-on activity; (3) student worksheets; (4) teacher materials; (5) interactive kite modeler; and (6) resources. (KHR)

NASA CONNECT is an annual series of integrated mathematics, science, and technology instructional distance learning programs for students in grades 6-8. This program is designed for students to learn about the evolution of flight. The program has three components--television broadcast, Web activity, and lesson guide--which are designed as an integrated instructional package. Students learn how the Wright Brothers became the first human beings to successfully design, construct, and fly an airplane and which method the Wright Brothers used in designing their airplane. Students also observe NASA engineers and researchers using problem-solving skills to design wings that will change their shape during flight. By conducting hands-on and Web activities, students make connections between NASA research and the mathematics, science, and technology they learn in the classroom. The educator guide features: (1) program overview; (2) hands-on activity; (3) student worksheets; (4) teacher materials; (5) interactive kite modeler; and (6) resources. (KHR)

"The Problem of Mechanical Flight" is an article from Science, Volume 36 . View more articles from Science . View this article on JSTOR . View this article's JSTOR metadata . You may also retrieve all of this items metadata in JSON at the following URL: https://archive.org/metadata/jstor-1638549

A modification of the Newton method for solving boundary problems for ordinary differential equations is applied to the problem of optimal motion of a point of variable mass M(t) in a central gravitational field with a limited expenditure of power.

OPERATIONAL RELIABILITY OF FLIGHT CONTROL SYSTEMS AND AUTOMATIC PILOTING OF AIRCRAFT

There are many problem-solving tasks that are too complex to fully automate given the current state of technology. Nevertheless, significant improvements in overall system performance could result from the introduction of well-designed computer aids. We have been studying the development of cognitive tools for one such problem-solving task, enroute flight path planning for commercial airlines. Our goal has been two-fold. First, we have been developing specific system designs to help with this important practical problem. Second, we have been using this context to explore general design concepts to guide in the development of cooperative problem-solving systems. These design concepts are described below, along with illustrations of their application.

There are many problem-solving tasks that are too complex to fully automate given the current state of technology. Nevertheless, significant improvements in overall system performance could result from the introduction of well-designed computer aids. We have been studying the development of cognitive tools for one such problem-solving task, enroute flight path planning for commercial airlines. Our goal has been two-fold. First, we have been developing specific system designs to help with this important practical problem. Second, we have been using this context to explore general design concepts to guide in the development of cooperative problem-solving systems. These design concepts are described below, along with illustrations of their application.

The goals of this research were to develop design concepts to support the task of enroute flight planning. And within this context, to explore and evaluate general design concepts and principles to guide the development of cooperative problem solving systems. A detailed model is to be developed of the cognitive processes involved in flight planning. Included in this model will be the identification of individual differences of subjects. Of particular interest will be differences between pilots and dispatchers. The effect will be studied of the effect on performance of tools that support planning at different levels of abstraction. In order to conduct this research, the Flight Planning Testbed (FPT) was developed, a fully functional testbed environment for studying advanced design concepts for tools to aid in flight planning.

The goals of this research were to develop design concepts to support the task of enroute flight planning. And within this context, to explore and evaluate general design concepts and principles to guide the development of cooperative problem solving systems. A detailed model is to be developed of the cognitive processes involved in flight planning. Included in this model will be the identification of individual differences of subjects. Of particular interest will be differences between pilots and dispatchers. The effect will be studied of the effect on performance of tools that support planning at different levels of abstraction. In order to conduct this research, the Flight Planning Testbed (FPT) was developed, a fully functional testbed environment for studying advanced design concepts for tools to aid in flight planning.

The goals of this research were to develop design concepts to support the task of enroute flight planning. And within this context, to explore and evaluate general design concepts and principles to guide the development of cooperative problem solving systems. A detailed model is to be developed of the cognitive processes involved in flight planning. Included in this model will be the identification of individual differences of subjects. Of particular interest will be differences between pilots and dispatchers. The effect will be studied of the effect on performance of tools that support planning at different levels of abstraction. In order to conduct this research, the Flight Planning Testbed (FPT) was developed, a fully functional testbed environment for studying advanced design concepts for tools to aid in flight planning.

This paper is in the public domain in USA. Metadata comes from the CrossRef API, see full record in the source URL below.

This paper is in the public domain in USA. Metadata comes from the CrossRef API, see full record in the source URL below.