Thomas S. Amlie, 85, an electrical engineer who retired in 1991 from the Air Force Department’s office that monitors the cost-effectiveness of weapons programs, died Jan. 2 at his home in Bethesda. He had congestive heart failure, according to his son, Thomas T. Amlie.

From 1952 to 1970, Dr. Amlie worked on Navy Department missile programs, including the Sidewinder. He was a former director of what is now the Naval Air Warfare Center Weapons Division at China Lake, Calif.

He settled in the Washington area in 1970 and spent a decade with the Federal Aviation Administration working on collision avoidance systems, radar and micro­wave landing systems.

Dr. Amlie later worked at the Air Force Department with A. Ernest Fitzgerald, the celebrated Pentagon whistleblower of the 1960s who exposed massive cost overruns.

Thomas Strong Amlie was a native of Elkhorn, Wis., and a 1946 mechanical engineering graduate of the University of Wisconsin at Madison, where he also received a doctorate in electrical engineering in 1952.

He served in the Navy V-12 officer training program during World War II .

In 1956, he married June Townsend. In 1991, she died in a commuter plane crash in Georgia that killed 23 people, including former senator John G. Tower (R-Tex.).

Dr. Amlie’s survivors include three children, Thomas T. Amlie of Mount Joy, Pa., Laura M. Amlie of Baltimore and Marcella J. Amlie of Takoma Park; two brothers; a sister; and a granddaughter.

— Adam Bernstein