Captain Graper was a veteran of World War II. In Korea, he was a the pilot of a C-46D Commando transport with the 34th Troop Carrier Squadron, 315th Troop Carrier Wing based at Brady Air Base, Kyushu, Japan. On 16 October 1952, he was flying on a courier run between Kangnung, Korea (K-18) and Pohang, Korea (K-3). The aircraft crashed into the sea killing all 25 servicemen on board. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Graper was awarded the Air Medal with Oak Leaf Cluster, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation, the Republic of Korea War Service Medal and the World War II Victory Medal.