After these facilities were upgraded, wing headquarters were stood up 1 January 1949 at Chatham. The 2d Bomb Wing assumed the assets of the 307th Bombardment Group, which had been deployed to the base from MacDill Air Force Base, Florida; and the 2d Bombardment Group, which had returned from a deployment to RAF Lakenheath, England. Equipped with B-29 Superfortresses, the wing's primary mission was training for strategic bombardment operations. In early 1949, the B-29s began to be replaced by the B-50 Superfortress, a B-29 derivative designed for atomic warfare with more powerful engines, a higher top speed, and a higher ceiling.