Retired Navy Cdr. James A. McGill, 41, whose last assignment was with the Naval Air Systems Command here, died of cancer Thursday at the Bethesda Naval Medical Center.

He was deputy project manager for the Light Airborne Multi-Purpose System MK III program at the Air Systems Command from August, 1975, until retiring two weeks ago.

Born in Elizabeth, N.J., Cor. McGill grew up in Union, N.J. He graduated from the University of Rochester and was commissioned in the Navy in 1957. He then became a naval aviator and was with a helicopter antisubmarine squadron.

Cdr. McGill received a bachelor's degree in aeronautical engineering from the Naval Postgraduate School at Monterey, Calif., and a degree in aeronautical engineering from the California Institute of Technology in 1966.

He served with a helicopter antisubmarine squadron that participated in search and rescue operations in the coastal waters off North Vietnam. He received the Navy Commendation Medal for the rescue of two downed airman.

Before coming here, Cdr. McGill was on the staff of the commander naval air force, Pacific fleet. He also had assignments in Trenton, N.J., and Warminster, Pa.

He is survived by his wife, Dagmar, and a daughter, Alexandra, of the home in McLean; his mother, Catherine H. McGill, of Union; a sister, Joy Herrigel, of Clinton, N.J., and his grandmother, Margaret McCallum, of Phillipsburg, N.J.