CONTACT: David F. Salisbury, News Service (415) 725-1944;
Everyone who has flown safely in the thin aluminum fuselages of today's commercial jetliners owes a debt of gratitude to Nicholas J. Hoff. The well-known aeronautical engineer pioneered the study of the stability of such structures in the 1940s through the '60s.
Hoff, a professor emeritus of aeronautics and astronautics at Stanford University, died at his campus home on Monday, Aug. 4, of old age.
Born on Jan. 3, 1906 in the small town of Magyarovar in western Hungary, Hoff was eight when his family moved to Budapest. There, he graduated from the same high school as three other great Hungarian scientists: physicists Eugene Wigner and Leo Szilard, and mathematician John von Neumann.
"He was one of the last of this group of great Hungarian scientists, including Wigner, Szilard, von Neumann, Teller and von Karman, who came to the United States in the period between World War I and II," said George Springer, chairman of Stanford's aeronautics and astronautics department.
As a boy, Hoff was an avid reader, especially of books on geography and history. He read widely in Hungarian and German literature. Private lessons in English and French helped him cultivate his linguistic gifts. He played the violin in the school orchestra. But it was his interest in sports that lead to his career in aeronautics.
Hoff was an enthusiastic and versatile sportsman who engaged in track, tennis, swimming, skiing, fencing and boxing. While studying mechanical engineering under Aurel Stodola, the famed professor of thermodynamics and steam turbine design, at the Polytechnic Institute of Zurich, Switzerland, Hoff discovered mountain climbing and gliding. His interest in gliding caused him to change shift to aeronautics, despite advice to the contrary that his father solicited from von Karman.
Despite this discouragement, Hoff persevered and finally obtained a position with the only Hungarian airplane company at the time, the Manfred Weiss Aeroplane and Motor Works of Budapest. He spent 10 years from 1929 to 1939 designing training planes and fighters for the clandestine Hungarian air force. When the work load was light, he carried out various research projects and became interested in analyzing aircraft structures.
After working with German aeronautical engineers on aircraft that Hungary purchased in 1935, Hoff decided that he needed more freedom than the Hungarian system provided. So he wrote to the famous mechanical engineer Stephen P. Timoshenko, who taught at Stanford, and asked if he could continue his studies of structural stability there. Timoshenko agreed, and Hoff arrived on campus in April 1939.
Hoff received his doctoral degree in 1942. The war in Europe kept him from returning to Hungary as he had intended. He was offered an instructor's position at the Polytechnic Institute in Brooklyn. There, he and his students began exploring both theoretically and experimentally the stability problems of a new type of aircraft construction technique: reinforced aluminum monocoque. They were the first to identify a serious instability in this system, called inward-bulge buckling, and come up with ways to prevent it. Hoff studied the buckling in aluminum sandwich materials that are widely used in today's aircraft. He also investigated the effects that supersonic heating had on the stability of aircraft wings and fuselages.
In 1957 Stanford Provost Frederick Terman brought Hoff to Stanford to start an independent department of aeronautical engineering. Under Hoff and his immediate successors, Professors Arthur E. Bryson and Robert H. Cannon, the department developed into one of America's leading centers of teaching and research in aeronautics and astronautics. In 1995 the National Research Council ranked Stanford's doctoral program in aeronautical engineering third in the nation.
Equally as important to his Stanford colleagues, Hoff set a tone of friendliness and collegiality that has come to characterize the department, said Walter Vincenti, professor emeritus of aeronautics and astronautics, who was a long-time friend and colleague. "He was a fine leader for the department. He could get along with just about anyone, and he was very encouraging to people who worked for him. To this day, the department is a very congenial place because of the tone that he helped set. He also worked closely with lots and lots of graduate students."
While at Stanford, Hoff continued with his basic work on the stability of thin-shelled structures. In 1965 he published a famous textbook on the subject titled "The Analysis of Structures." Although his focus was primarily on aeronautical structures, much of his work was extremely general and has been applied in a number of different fields. His pioneering advanced shell analysis method, for example, was used in designing nuclear submarines.
Hoff's entire body of work includes more than 200 papers and six books. He received virtually every major award in his field, including the Centennial Medal of the American Society of Mechanical Engineers (ASME), the Theodore von Karman Medal of ASME, the Daniel Guggenheim Medal, the von Karman Lecturership of the American Institute of Aeronautics and Astronautics, and the Wilbur Wright Memorial Lecturership of the Royal Aeronautical Society in London.
In addition to his teaching and research activities, throughout his career Hoff kept in close touch with his field by serving as a consultant to industry and government. He served on advisory boards for the U.S. Air Force, NATO, NASA and its predecessor, NACA, and the U.S. Navy. He also was active in several engineering societies.
An individual with enormous energy, Hoff operated on an international stage. Nowhere was that more evident than the period after he retired from Stanford in 1971. He served as a visiting professor at several institutionsm including Monash University in Melbourne, Australia; the Cranford Institute of Technology in England; and his alma mater, the Polytechnic Institute of Zurich. His worldwide reputation is also illustrated by his election not only to the U.S. National Academy of Engineering, but also to the Hungarian Academy of Science, the French Academy of Sciences, the French National Academy of Air and Space and the International Academy of Astronautics.
According to Vincenti, Hoff lived life with considerable gusto. He injured his hip in an accident when he was a young man. When hip replacement surgery was first developed in Europe, he traveled to Zurich for the operation. Following the operation, he was so active that he eventually wore out the first prosthesis and had it replaced. In fact, he kept up a relatively vigorous schedule until just a few months before his death: swimming every other day and dropping into the department twice a week to consult with colleagues.
Hoff is survived by his wife, Ruth Kleczewski Hoff, step-daughter Karen Brandt of Palo Alto, and brother George Hoff of Santa Barbara.
A private service will be held on Aug. 7. A public memorial is being planned on the Stanford campus after classes start in the fall.
Mrs. Hoff asks that well-wishers make contributions either to the Nicholas Hoff Graduate Student Award in the Department of Aeronautics and Astronautics at Stanford or to charities of their own choosing.
By David F. Salisbury