Nicholas J. Hoff; Aeronautical Engineer Studied Jet Stability

Nicholas J. Hoff, 91, aeronautical engineer who pioneered the study of jet plane stability. Hoff earned the major awards in his field, including the Centennial Medal of the American Society of Mechanical Engineers and the Daniel Guggenheim Medal, for his lifelong contributions to manned flight. In 1957, Hoff started the department of aeronautical engineering at Stanford University; he taught there until 1971 and was a consultant until his death. Born in Hungary, he studied at the Polytechnic Institute of Zurich, where he discovered gliding, the sport that was to move him into aeronautics. He spent 10 years designing training planes and fighters for the clandestine Hungarian air force, and in his spare time began analyzing aircraft structures. Seeking greater intellectual freedom, he moved to California to continue his research and earn a doctorate at Stanford. Hoff then taught at the Polytechnic Institute in Brooklyn, where he studied stability of then-new aircraft construction using reinforced aluminum. He was the first to identify the problem of inward-bulge buckling, and found ways to prevent it. He also investigated the effects of supersonic heating on the stability of aircraft wings and fuselages. Modern jet planes benefit greatly from his findings, which he published in more than 200 scientific papers and six books. After his retirement from Stanford, Hoff was a visiting professor in Australia, England and Switzerland. On Monday Aug. 4 in Palo Alto.