Upon the death of fellow crewman Morris Jeppson on March 30, 2010, Van Kirk became the last surviving member of the Enola Gay crew.

On 1 April 1942, he received both his commission and navigator wings and transferred to the 97th Bomb Group, the first operational Boeing B-17 Flying Fortress unit in England.

In October 1942, they flew General Mark Clark to Gibraltar for his secret North African rendezvous with the French prior to Operation Torch.

After German reinforcements began pouring into the port of Bizerte, Tunisia, posing a serious threat to Allied strategy, a new mission emerged.

As they approached the target Van Kirk worked closely with the bombardier, Tom Ferebee, to confirm the winds and aimpoint.

According to the 1995 New York Times interview by Gustav Niebuhr Mr. Van Kirk said he was often asked, "given a choice about his role in the Hiroshima bombing, would he do it again?

On Friday, April 9, 2010 Van Kirk spoke at the University of West Georgia in the Biology Building Lecture Hall.

On September 3, 2010 Major Van Kirk, accompanied by his wife, appeared at the model air show "Warbirds Over Atlanta 2010" in Ball Ground, Georgia where he signed his books and photographs as a replica of the B-29 flew overhead.

On September 15, 2013, he spoke for approximately an hour and answered questions about his military service and specifically his role as the navigator on the Enola Gay at the Cavanaugh Flight Museum in Addison, Texas.

Van Kirk, United States Army Air Forces, for gallantry in action while engaged in aerial flight against the Japanese Empire on 6 August 1945.

Captain Van Kirk was Navigator for a combat crew of the B-29 aircraft of the 393d Bombardment Squadron, 509th Composite Group, 20th Air Force, which flew from a base in the Marianas Islands to drop on the city of Hiroshima, Japan, the first atomic bomb to be used in warfare.

Flying 1500 miles over open water to the coast of Japan, they manned their assigned positions and crossed the island of Shikoku and the Inland Sea.

They constantly faced the danger of being hit by anti-aircraft fire, enemy fighters, or suffering mechanical or other failures which would intensify the risks of carrying this powerful missile.