Sole Prototype. Built around December 1944/January 1945 this airframe was apparantly used for aerodynamic testing of the new fuselage, and taxying tests of the new undercarriage. It is extremely unlikely that aerodynamic tests were conducted with the Walter motor. Developments being turned over to Junkers at Dessau. Once Junkers acquired the project, there was a complete revamp of the airframe and the project acquired the designation the Junkers Ju.248. It was captured by Soviets and transferred to Mikoyan OKB where I-270(Zh) rocket-interceptor was built based in original Me.263.