While still a student he earned his pilot's license and then organized the Boston Airport Corporation, which played a leading part in establishing this country's first commercial airline run, between New York and Boston. He served as instructor and assistant professor at M.I.T. from 1927 to 1933. During the last two years, he conducted an extensive investigation of American air masses. The data he and his associates gathered during almost daily flights, at altitudes from 16,000 to 18,000 feet in an instrument-laden plane, proved of great value in the development of commercial and military aviation. They frequently encountered difficult atmospheric conditions. On one flight visibility was so poor that, coming down through a cloud layer for a landing, Sayre found he had drifted some 150 miles out to sea. With a rapidly dwindling fuel supply, he barely managed to get back, landing on a golf course near the coast. The newspapers played up the mishap, and, as Sayre liked to recall, more than one New England editor was unable to resist headlining the story: ``Professor Lost in Fog.''
Sayre was later on the editorial staff of the magazine Aviation, then, aviation editor of Newsweek, director of Statistics and Information for the Civil Aeronautics Authority, chief of the Safety Division of the Civil Aeronautics Board. In 1941 he was called to Princeton to organize an aeronautical engineering department to help meet the nation's critical needs in this field. He recruited some of the ablest aeronautical scientists in the country and secured the necessary support for their work from outside sources as well as from the University. As a result, the department rose in a very few years to a position of national leadership, evidenced in 1949 when the Guggenheim Foundation selected Princeton and the California Institute of Technology as the places for the two Guggenheim Jet Propulsion Centers.
In 1951, when the University was given the opportunity to acquire new laboratory facilities for the natural and engineering sciences from the Rockefeller Institute for Medical Research, Sayre played a leading role -- ``indeed,'' President Goheen later said, ``he was the catalyst for the efforts of all others'' -- in the establishment of the James Forrestal Research Center, later renamed the Forrestal Campus. A man of wide interests, Sayre also contributed his judgment and enthusiasm to the development of the Firestone Library and the Council of the Humanities. He died at the age of fifty-three after a five-year struggle with cancer ``gratefully remembered,'' President Dodds said, ``for his many constructive contributions to the growth of the modern Princeton and by his colleagues for his cheerfulness, his contagious wit, and his very great courage throughout his long illness.''
A short time after his death, one of the original buildings of the Forrestal Campus was named Sayre Hall in his memory.