Donald O. Nevinger, 74, an aerospace engineer and a volunteer at the Smithsonian Institution's National Air and Space Museum, died of pulmonary fibrosis Aug. 22 at the Capital Hospice. He lived in Alexandria.

Mr. Nevinger was born in Warsaw, N.Y., and in high school played in the band and excelled in track and basketball. He graduated from Tri-State University in Angola, Ind., with a degree in aeronautical engineering.

In 1952, Mr. Nevinger worked on the Bell Aircraft X-2, one of the first planes to break the sound barrier. His work in mass properties engineering took him to Boeing Co. for supersonic studies, Ling Temco Vaught for missile engineering properties and Teledyne Ryan and General Dynamics for cruise missile engineering. After moving to Alexandria, he worked for the Naval Air Systems Command Evaluation Division. He retired in 1965.

Mr. Nevinger served in the Army from 1954 to 1956, where he tested Nike missiles at White Sands Proving Ground and was an adviser on Army aircraft at Fort Rucker, Ala.

He was national vice president of the International Society of Allied Weight Engineers and twice was chapter president of the group. He was awarded the Navy Unit Commendation for his work for the Naval Air Systems Command.

After retiring as an aeronautical engineer, Mr. Nevinger volunteered for 10 years in the Air and Space Museum's Archives Division. He used his expertise on airplanes, rockets and other things that fly to answer technical questions for researchers.

An animal and nature lover, he built platforms to protect turtles and geese from predators and helped with other wildlife conservation efforts at Huntley Meadows Park. He also served on the board of the McLean Symphony.

He continued hiking and bicycling until three years ago.

His marriage to Evelyn Smith Nevinger ended in divorce.

He attended the Society of Friends (Quakers) meeting at Fort Belvoir.

Survivors include his wife, his high school sweetheart whom he married in 1988, Dr. Janette Sherman of Alexandria; two children from his first marriage, Kevin Nevinger of San Diego and Donna Kellogg of Blue Jay, Calif.; two stepchildren, Connie Bigelow of Seattle and Charles Bigelow of Round Hill; a grandson; and two step-grandchildren.