During World War II, the U.S. Army made good use of a couple of Bob Henneberg's strong suits -- his understanding of conversational German learned while growing up in Long Island, N.Y., in close proximity to his immigrant grandparents, and his mechanical and electrical prowess.

The Army first assigned him to guard German prisoners of war at a camp in Louisiana, then shipped him to Calcutta, India, to a repair center where he fixed everything from battlefield medical equipment to Jeeps.

Years later, at the urging of his family, who never tired of his retelling his Army experiences, Mr. Henneberg spent two years compiling them from memory in a 100-page manuscript.

His son, Mark Henneberg of Lilburn, had his manuscript reproduced in book form last year as a surprise birthday present for his father. The title: "A First Class Private (Oops, I Mean a Private First Class)".

Molly Henneberg, a Fox News Channel correspondent in Washington, said her grandfather wrote that he thought the German POWs he guarded were just conscripts like many American soldiers, not hardened Nazis.

Many prisoners spoke some English; and like Mr. Henneberg, many guards had learned enough German from relatives that they communicated with each other reasonably well.

One incident he wrote about, she said, involved her grandfather and another U.S. soldier driving two prisoners to another camp. The drive was long enough that the two U.S. soldiers thought they should stop for lunch at a roadside diner. Before stopping, they instructed their prisoners to refrain from speaking German so as not to alarm the clerks or customers.

Just the same, commentator Walter Winchell mentioned the diner incident on his nationwide broadcast the very next day, criticizing the guards (who went unnamed) for coddling German captives.

"How Winchell ever got wind of the diner story, my grandfather never knew," Ms. Henneberg said.

Mr. Henneberg had never been on a horse in his life, yet his superiors once ordered him to mount one to watch over prisoners working in a cornfield, said his son, Dan Henneberg of Falls Church, Va. "No prisoners tried to escape while Dad struggled with his horse," he said. "They were too busy laughing."

Robert Edwin Henneberg, 86, of Atlanta died March 29 of cancer complications at Budd Terrace at Wesley Woods. Two memorial services are planned, one at 3 p.m. Wednesday at Wesley Woods Towers and another at 2 p.m. June 20 at Holy Trinity Episcopal Church, Decatur. A.S. Turner & Sons funeral home is in charge of arrangements.

After his Army discharge, Mr. Henneberg returned to Louisiana to court Kathryn "Barne" Ferguson, whom he had met during his prior duty there. They wed a month later, and he attended Louisiana Tech, earning a degree in mathematics.

After a brief teaching stint, he went to work for Western Electric, then BellSouth, as a design engineer.

"Dad's formal training was in math," his son said. "What he knew about engineering was all self-taught. And that was plenty. For instance, I learned years later he designed electrical circuits for spy satellites."

Mr. Henneberg devoted much of his free time to Holy Trinity church, singing in the choir, serving as the senior warden and a leader of the Brotherhood of St. Andrew chapter, and training acolytes.

A resident of the Druid Hills neighborhood for many years, he moved to Wesley Woods Towers after his wife died in 2007. There, his son said, he became a popular figure, circulating a weekly newsletter that included life stories of other residents.

Also surviving are two daughters, Anne Watson of Gainesville and Jane Berry of Hampton Roads, Va.; and 10 other grandchildren.