2nd Lt. Johnson flew his first combat mission on April 18, 1943, which was the second mission of the 56th FG. The mission, a fighter sweep over the coast of the Netherlands, proved entirely uneventful. On his return from his first combat sortie, Johnson and four other pilots were sent to RAF Goxhill to complete gunnery training, but because he could not hit the target sleeve until his final day of training, he wrote, he failed to achieve the minimum required percentage of hits and did not officially qualify as a combat pilot.