After graduating from high school, Johnson enlisted in the United States Army Air Forces as an aviation cadet. On completing his training, he was commissioned a second lieutenant. He flew 44 combat missions in the Pacific Theater during World War II as a bombardier in B-25 twin-engine medium bombers.
On March 4, 1945, while flying as a navigator in a B-25 with the 100th Bombardment Squadron, 42nd Bombardment Group, 13th Air Force, his B-25 and two others were shot down during a low-level bombing and strafing run against Japanese military targets in the Philippine Islands. The B-25s encountered heavy anti-aircraft fire and all three had to ditch in the sea off Zamboanga. Johnson broke both ankles in the landing, and the radioman seated next to him was killed. Johnson received a Purple Heart for his injuries. He was also awarded the Air Medal, the Asiatic-Pacific Campaign Medal with three campaign stars, the Philippine Liberation Ribbon with one campaign star, and the World War II Victory Medal.
After Japan's surrender, Johnson was honorably discharged as a first lieutenant on November 22, 1945. He joined the United States Air Force Reserve and used the G.I. Bill to pay for his acting studies at the Actors' Lab in Hollywood. While there, he met actress Kay Cousins (1923-1980), whom he married in 1949.
Lt. Johnson, rest in peace and thank you for your service.