Samuel E. Gates, 73, a New York lawyer and president-elect of the American College of Trial Lawyers, died Thursday at Thomas Jefferson University Hospital in Philadelphia.

He had suffered an aneurysm while driving to New York after visiting here.

Mr. Gates lived here in the 1930s and 1940s. He was international counsel for the Civil Aeronautics Board during 1938-42. He then served for four years as a colonel with the Air Transport Command of the Army Air Forces.

For his work as assistant chief of staff and chief of organizational planning and of organization and contract supervision of ATC during World War II, he received the Distinguished Service Medal.

From 1946 to 1948, when he moved to New York, Mr. Gates was a member of the Washington law firm of Douglas, Proctor, MacIntyre and Gates, legal counsel for aviation interests.

At the time of his death, he was a senior partner in the New York law firm of Debevoise, Plimpton, Lyons and Gates and was in general law practice.

Mr. Gates was born in Lagro, Ind. He was a graduate of the University of Southern California, where he later earned a law degree. He also held a degree from the University of Paris.

He taught in Long Beach, Calif., was a Carnegie Foundation fellow, and was in private law practice in Los Angeles before joining the CAB. He had been a member of American delegations to international civil aviation conferences in the 1940s.

Mr. Gates belonged to the American Law Institute, the American Judicature Society, the American Society of International Law and the Metropolitan Club in Washington.

He is survived by his wife, the former Philomene Asher, of the home in New York City; three daughters, Gilda Wray, of Paris, France, Sharon Stearns, of New York City, and Mary Kathe Williamson, of London, England, and eight grandchildren.