Robert William Fortnam was born on August 15, 1922. Following the onset of World War II, he enlisted in the United States Army Air Forces in 1942, initially working as an aviation mechanic before completing flight training to become a pilot.

During World War II, Second Lieutenant Fortnam served as a co-pilot aboard a B-17 Flying Fortress with the 305th Bombardment Group. On October 10, 1943, while on a bombing mission targeting enemy infrastructure in Bremen, Germany, his aircraft sustained heavy damage from enemy fighter attacks.

Despite severe damage to the aircraft and injuries among the crew, Lieutenant Fortnam managed to crash-land the bomber in occupied Holland. The crash landing successfully saved the lives of nine crew members. Following the landing, he was captured by German forces.

Fortnam was held as a prisoner of war for 19 months. He was held in German POW camps, including Stalag Luft III and Stalag VII-A, before his eventual liberation in 1945. He completed his military service in 1946.

After his military discharge, Fortnam established his civilian life in New Hampshire, living in Pembroke and Concord. He spent 71 years flying as a civilian pilot, served as a flight instructor at Boire Field in Nashua, and volunteered as a docent at the New Hampshire Aviation Museum.

Robert William Fortnam died on August 1, 2017, at the age of 94. He was interred at the New Hampshire State Veterans Cemetery in Boscawen, New Hampshire.