Plans were made to upgrade the wing to the Boeing B-52 Stratofortress. However, although adequate for B-47 operations, the runway at Hunter was inadequate for B-52 operations when tested in the early 1960s. In addition, during the 1950s the urban area of the City of Savannah was expanding and encroaching on the airfield, making Hunter unsuitable for heavy nuclear-equipped bomber operations over the urbanized area. A 1958 Tybee Island B-47 crash in which a Mark 15 hydrogen bomb was lost in the Atlantic Ocean just off the coast of Savannah was another reason in the decision by SAC to move the Wing to a non-urban area.