James Earl Helsel, 56, a manufacturers' sales representative for automobile equipment and other firms, died Saturday at Montgomery General Hospital in Olney following a heart attack. He was stricken at his home in Silver Spring.

Mr. Helsel was born in Altoona, Pa. He moved to the Washington area in 1941 and went to work for the Johns Hopkins Applied Physics Laboratory where he helped test rockets and fuses. He served briefly in the Navy during World War II, but was discharged because of heart condition.

He returned to the Applied Physics Laboratory and remained there until 1949. In that year he became vice president of Automotive Equipment Co. In 1954 he joined Wheelabrator-Fryel Balcrank, an automobile equipment firm. He remained with that firm until 1968 when he became a representative for that firm and other companies. He continued in this work until his death.

During the 1950's Mr. Helsel also ran a general contracting business.

Mr. Halsel was a member of the National Potomac Yacht Club, of the Capital Yacht Club, the Landmark Acht Club and the Potomac River Yacht Club Association. He was an Elk and a member of Lodge No. 1677.

Survivors include his wife, the former Polly Clark, of Silver Spring; four children James Earl III, of Silver Spring. Janice H. Suit of Rockville and John P. and Jay G., both of Silver Spring; his mother Theresa Helsel Spalding of Silver Spring, and a sister, LaGretta Hensel Glowacki of Silver Spring.