Holt Ashley, giant in aeronautical engineering, dies at 83

By Dawn Levy

Holt Ashley, a professor emeritus of aeronautics and astronautics and of mechanical engineering whose methods changed the design of structures from wings to wind turbines, died May 9 of natural causes at his home in Woodside. He was 83. A memorial service was held May 12 in Memorial Church.

"His contributions to aerospace were as large as he was," Professor Brian Cantwell, chair of the Department of Aeronautics and Astronautics, said at the memorial service. Ashley was 6-foot-8—a height that prevented his acceptance as a pilot during World War II. Shortly after joining Stanford in 1967, he achieved his dream by obtaining his pilot's license.

"Professor Ashley's contributions were diverse and multidisciplinary," said aeronautics and astronautics Professor Ilan Kroo, who had been a doctoral student of Ashley's. "While he is best known for his pioneering research and books in the field of aeroelasticity—the combination of aerodynamics and structures—he wrote classic textbooks in aerodynamics and aircraft engineering as well."

Ashley served on committees and advisory boards of NACA [NASA's predecessor, the National Advisory Committee for Aeronautics], NASA, the Air Force, the Navy and the National Research Council as well as of the aerospace industry. "From his work on the NACA subcommittee on vibration and flutter to a review of space-shuttle tile safety, Ashley has applied fundamental approaches to a wide array of practical engineering problems," Kroo said.

Ashley was born Jan. 10, 1923, in San Francisco. His father, Harold, had served in World War I and was a prominent businessman by the time World War II broke out. Nonetheless, he reenlisted. The younger Ashley felt intense guilt that it was his father, and not he, who was serving, and took leave from the California Institute of Technology, where he had been a sophomore, to join the Army Air Corps. He served in the war as a weather forecaster and reconnaissance officer, flying with squadrons over the North Atlantic and Europe. The experience spawned his first paper, "Icing in North West Europe," and earned him six military medals.

After earning master's (1948) and doctoral (1951) degrees in aeronautical engineering from the Massachusetts Institute of Technology, Ashley rose through the faculty ranks there to become an associate professor in 1954 and a full professor in 1960.

In 1964, he helped establish the Department of Aeronautical Engineering at the Indian Institute of Technology (IIT) in Kanpur. "He nurtured deep and sincere friendships with scientists from far, far away," Stanford Professor Sanjiva Lele, an IIT graduate, wrote in an e-mail read at the memorial. "He served as first head of the department. He taught there during the very first year of the institute, wrote a classic book and inspired a generation of young Indian engineers."

Ashley returned to his native California in 1967 to join Stanford as a professor in the Department of Aeronautics and Astronautics. His students remember him as a patient mentor whose door was always open and whose meticulous lectures were models of clarity.

"Professor Ashley encouraged us to work on hang gliders or to take a summer off to think about sailboats or to think about flapping vehicles, whatever, but to think independently and to think deeply," Kroo said. "He was the only member of the faculty to be a specialist in every discipline of the PhD qualifying examinations."

As much a father as a teacher to some of his students, Ashley "instilled in us a love for flight and the elegant mathematics that helped us understand it" as well as shared his love for Stanford, the Bay Area, basketball games, big cigars and fine wine, Kroo said. "He took us to the Faculty Club for dinners and to meetings that would make our careers."

Many recalled Ashley's sense of humor. At the end of a committee's first meeting, he would make a motion to terminate the committee to stimulate the discussion that would test its worth. With Bob Halfman, one of his co-authors, he formed a consulting company to work on aircraft design—they called it Half-Ash Aeronautical Consultants.

Ashley became emeritus in 1989. "[He] took early retirement to enable the department to hire new young faculty," former Aero/Astro Chair George Springer, the Paul Pigott Professor of Engineering, said. "He then proceeded to carry a full load of teaching and research for the [following] years without pay."

Ashley's honors include the 2003 Daniel Guggenheim Medal, which is jointly sponsored by the American Institute of Aeronautics and Astronautics (AIAA), the American Society of Mechanical Engineers and the Society of Automotive Engineers, and the 2006 Reed Aeronautics Award of the AIAA, the highest award in aeronautics and astronautics.

His work has been published in about 100 journal articles and five books: Aeroelasticity, Thickness and Boundary Layer Effects, Principles of Aeroelasticity, Aerodynamics of Wings and Bodies and Engineering Analysis of Flight Vehicles.

Since 1962, he was a member of the Bohemian Club of San Francisco. He also served on the board of the civic association for the town of Woodside.

Research Professor Richard Christensen recalled a visit to Ashley, bedridden a week before his death: "As I was leaving he said to me, 'Please tell your lovely wife hello.' I mean, think about that. At the end of his life, he had the thoughtfulness, the grace, to say that. He did not say, 'Tell your wife goodbye.' He said, 'Tell her hello.' That was Holt Ashley—never looking down, always looking up. That's the Holt Ashley I will always remember."

Survivors include his sister, Joan Ashley Ennis of Silver Spring, Md., and nephews Ashley Ennis of Silver Spring, Md., and Holt Ennis of Maynard, Mass. Ashley's wife, Frances Day Ashley, died many years ago.

Ashley was a cat lover. His cat, Jackie O, was adopted shortly after his death. In lieu of flowers, the family requests donations in Ashley's memory to the San Francisco Society for the Prevention of Cruelty to Animals, 2500 16th St., San Francisco, CA 94103-4213.

Editor Note:

A photo of Ashley is available on the web at http://newsphotos.stanford.edu/.

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