Flight testing and simulation of an F-15 airplane using throttles for flight control

Flight tests and simulation studies using the throttles of an F-15 airplane for emergency flight control have been conducted at the NASA Dryden Flight Research Facility. The airplane and the simulation are capable of extended up-and-away flight, using only throttles for flight path control. Initial simulation results showed that runway landings using manual throttles-only control were difficult, but possible with practice. Manual approaches flown in the airplane were much more difficult, indicating a significant discrepancy between flight and simulation. Analysis of flight data and development of improved simulation models that resolve the discrepancy are discussed. An augmented throttle-only control system that controls bank angle and flight path with appropriate feedback parameters has also been developed, evaluated in simulations, and is planned for flight in the F-15

Frank Lamson Scribner Correspondence

Entries include brief biographical information, handwritten letters on plain paper describing early employment around the Maine state capitol and the first book he borrowed from the Maine State Library, and correspondence that mentions three volumes of his work published as bulletins by the U.S.D.A., Division of Agrostology

Frank Dean Tubbs Correspondence

Entries include the brief biographical information of an anthropology professor, a typed biography, and a handwritten letter from Speck on University of Pennsylvania, Philadelphia, The College, Anthropology, stationery

Flight test of a propulsion controlled aircraft system on the NASA F-15 airplane

Flight tests of the propulsion controlled aircraft (PCA) system on the NASA F-15 airplane evolved as a result of a long series of simulation and flight tests. Initially, the simulation results were very optimistic. Early flight tests showed that manual throttles-only control was much more difficult than the simulation, and a flight investigation was flown to acquire data to resolve this discrepancy. The PCA system designed and developed by MDA evolved as these discrepancies were found and resolved, requiring redesign of the PCA software and modification of the flight test plan. Small throttle step inputs were flown to provide data for analysis, simulation update, and control logic modification. The PCA flight tests quickly revealed less than desired performance, but the extensive flexibility built into the flight PCA software allowed rapid evaluation of alternate gains, filters, and control logic, and within 2 weeks, the PCA system was functioning well. The initial objective of achieving adequate control for up-and-away flying and approaches was satisfied, and the option to continue to actual landings was achieved. After the PCA landings were accomplished, other PCA features were added, and additional maneuvers beyond those originally planned were flown. The PCA system was used to recover from extreme upset conditions, descend, and make approaches to landing. A heading mode was added, and a single engine plus rudder PCA mode was also added and flown. The PCA flight envelope was expanded far beyond that originally designed for. Guest pilots from the USAF, USN, NASA, and the contractor also flew the PCA system and were favorably impressed

Mildred Coes Wasson Correspondence

Entries include brief biographical information, a biography typed on green paper stationery describing Wasson\u27s authorship as grounded in the family history of her former husband David A. Wasson whose passing was causal to her writing of the Nancy books at the start of her writing career, typed book loan correspondence on the stationery of Frank D. Rowe, Superintendent of Schools, Warren, Maine, requesting The Big House by Wasson whom he had met on vacation with his mother, a fan, and a folded biographical letter sent to Maine state librarian Henry Ernest Dunnack that Wasson had sent to Frank D. Rowe\u27s mother in 1926 with a handwritten biographical note, a typed introductory letter to the Maine Author Collection in 1935, Wasson\u27s typed letter of regret on personal notepaper stationery concerning awarding free copies of her books to libraries, and typed correspondence from the Maine State Library on the acquisition of her books from the publisher and on receipt of the inscribed titles for the Maine Author Collection

Frank I. Dorr Correspondence

Entries include letters of correspondence from the Maine State Library, a biographical review newspaper clipping, and an illustrated book description

Simulator Evaluation of Simplified Propulsion-Only Emergency Flight Control Systems on Transport Aircraft

With the advent of digital engine control systems, considering the use of engine thrust for emergency flight control has become feasible. Many incidents have occurred in which engine thrust supplemented or replaced normal aircraft flight controls. In most of these cases, a crash has resulted, and more than 1100 lives have been lost. The NASA Dryden Flight Research Center has developed a propulsion-controlled aircraft (PCA) system in which computer-controlled engine thrust provides emergency flight control capability. Using this PCA system, an F-15 and an MD-11 airplane have been landed without using any flight controls. In simulations, C-17, B-757, and B-747 PCA systems have also been evaluated successfully. These tests used full-authority digital electronic control systems on the engines. Developing simpler PCA systems that can operate without full-authority engine control, thus allowing PCA technology to be installed on less capable airplanes or at lower cost, is also a desire. Studies have examined simplified ?PCA Ultralite? concepts in which thrust control is provided using an autothrottle system supplemented by manual differential throttle control. Some of these concepts have worked well. The PCA Ultralite study results are presented for simulation tests of MD-11, B-757, C-17, and B-747 aircraft