 The USAAF sent instructions to its Army Air Forces Materiel Command at Wright Field, Ohio, on 30 November 1943, for a highly classified B-29 modification project. The Manhattan Project would deliver full-sized mockups of the weapons shapes to Wright Field by mid-December, where Army Air Forces Materiel Command would modify an aircraft and deliver it for use in bomb flight testing at Muroc Army Air Field in California. B-29-5-BW 42-6259 (referred to as the "Pullman airplane" from an internal code name assigned it by the Engineering Division of Army Air Forces Materiel Command) was delivered to the 468th Bombardment Group at Smoky Hill AAB, Kansas, on 30 November 1943, and flown to Wright Field, Ohio, on 2 December.
