United States of America
NASA Vertical Flight Controls Expert
Dr. James A. “Jack” Franklin passed away on Jan. 22, 2020, at the age of 81. He was internationally known through his theoretical and experimental work on vertical and/or short takeoff and landing (V/STOL) control and flying qualities during his research activities at NASA Ames Research Center from 1970 through his retirement in 2002.
Throughout his career, Franklin contributed extensively to the understanding of flying qualities and flight control system design for powered-lift aircraft. His interest in this area began with his research that led to a PhD in Aerospace and Mechanical Sciences from Princeton University. His research at NASA in the 1970s and early 1980s on short takeoff and landing (STOL) transports produced a fundamental understanding of the flying qualities of this class of aircraft and defined a new form of control augmentation system that explicitly accounted for their unique thrust and aerodynamic interactions.
He carried his ideas through simulation and two major flight programs where he demonstrated that the resulting control augmentation system provided excellent flying qualities for precision instrument operations. His published research from flight and simulation programs was used by the Air Force to define specifications for the Advanced Medium STOL Transport and eventually the C-17 tactical transport and also by the Federal Aviation Administration (FAA) to develop airworthiness criteria for powered-lift aircraft.
In 1975, he was promoted to chief of the NASA Flight Dynamics and Controls Branch, a position he held until his request to return solely to research at the end of 1984. During this time, he led the branch in an expansion of research to include helicopter dynamics and control, which included transferring a CH-47 research fly-by-wire helicopter to Ames. At the same time, he also continued his personal research, now focused on flying qualities issues with V/STOL aircraft. The Vertical Motion Simulator at Ames was completed during this time frame (1980) to further such research for both helicopters and V/STOL aircraft, and Franklin undertook an examination of V/STOL control laws, using the new, non-linear, inverse design scheme that was pioneered in the Flight Dynamics and Controls Branch. Concurrently, he began the process of acquiring a YAV-8B Harrier aircraft for flight verification at Ames of simulator results.
In the mid-1980s, he turned his attention to control system design for V/STOL aircraft, and short takeoff and vertical landing (STOVL) aircraft. A major challenge was the design of a control system capable of accounting for the large changes in the dynamics of this class of aircraft as it transitions from takeoff to cruise to approach and landing. He was the first to recognize the power offered by the emerging, non-linear, inverse control theory for meeting this challenge. He turned these theoretical concepts into a mature technology and demonstrated this technology through simulation and flight evaluations on both STOL and V/STOL aircraft. He transmitted the results of this technology development and demonstration to industry where they have been incorporated in modern aircraft control system designs.
He later focused his research on developing the basic understanding for effective integration of the displays, controls and propulsion system for powered-lift vehicles. He identified gaps in the criteria for the design of their flight and propulsion control systems and his research led to a new set of guidelines that were employed by the US Defense Department’s Joint Strike Fighter (JSF) program, now the STOVL F-35B Lightning II.
Franklin served as a national resource in the areas of flying qualities and dynamics and control of powered-lift vehicles. While part of the JSF Program, he was appointed the NASA representative for integrated controls. During this assignment, he established the criteria for control system sizing, vehicle dynamic performance and propulsion system sizing for the STOVL aircraft and led the NASA simulation evaluations of the industry's designs.
Previously, he represented NASA on the Defense Advanced Research Project Agency (DARPA) ASTOVL program. There, he led the design of candidate control systems and tested these designs in simulation and on the NASA experimental Harrier aircraft. Prior to that, he was the member of the US team responsible for integrated controls in a joint program between the DOD, NASA, and the UK Ministry of Defence. During the course of this program he planned and led the research across agencies on integrated flight/propulsion controls that produced advanced designs by NASA and industry in the US and UK.
Franklin’s contributions are widely recognized. In 1992, he was awarded an Ames Research Center Associate Fellowship for his contributions to V/STOL technology. In 1985, he received the NASA Exceptional Service Medal for 10 years of leadership and technical direction of Ames Research Center's program in flight dynamics and control. In 1984, he was invited to prepare a special paper on V/STOL Controls as part of an AGARD Lecture Series presented at the Von Karman Institute.
In 1994 and 1996, he received the American Helicopter Society San Francisco Bay Area Chapter's annual VTOL Research Award. In his honor, this annual award was renamed as the Franklin Award for Outstanding Contributions to the Powered-Lift Field. In 2000, the Vertical Flight Society presented him with the Paul E. Haueter Award for “outstanding technical contributions to the field of vertical takeoff and landing aircraft development other than a helicopter or an operational vertical flight aircraft.” Franklin was awarded the AIAA’s F.E. Newbold V/STOL Award in 2010, presented by future VFS Executive Director Mike Hirschberg at that year’s VFS-lead International Powered Lift Conference (IPLC).
VFS Updates: In Memoriams: Vertiflite May/June 2020