William B. Gazdik, 61, a U.S. Geological Survey employe since 1952, died Sunday in a helicopter crash 70 miles off the coast of New Jersey.

YMr. Gazdik had taken off from Atlantic City, N.J., and was en route to inpect an oil-drilling rig of the coast when the Petroleum Helicopters Inc. aircraft crashed, killing both Mr. Gazdik and Paul Perrino, of Ludlow, Vt., the copilot. Three other persons were rescued by the Coast Guard.

Since 1957, Mr. Gazdik had worked as a mining engineer in the survey's conservation division, where he helped supervise mineral operations on federal lands and the Outer Continental Shelf. In 1976, he became assistant conservation manager, eastern region, of the U.S. Geological Survey.

Born in Pittsburgh, Mr. Gadzik earned a bachelor's degree at the University of Pittsburgh and served in the Army in the Pacific during World War II.

He was a member of the American Institution of Mining, Metallurgical, and Petroleum Engineers and of the Association of Professional Geological Scientists.

Mr. Gazdik was a member of St. Andrew The Apostle catholic Church in Wheaton.

He is survived by his wife, Eugenie, and a son, Terrence, of the home in Silver Spring; two brothers, Edward and Eugune, both of Pittsburgh; six sisters, Alice Vinsky, of Hatfield, Pa., and Stella Haser, Emma Maraden, Margaret, Mildred Yugosic, and Frances Bertha, all of Pittsburgh; and two grandchildren.