The Messerschmitt P.1101 was a single-seat, single-jet fighter project of World War II, developed as part of the 15 July 1944 Emergency Fighter Program which sought a second generation of jet fighters for the Third Reich. A prominent feature of the P.1101 prototype was that the sweep angle of the wings could be changed before flight, a feature further developed in later variable-sweep aircraft such as the Bell X-5 and Grumman XF10F Jaguar. Design and development Within nine days of the 15 July 1944 issuance of design specifications for the Emergency Fighter, the Messerschmitt design bureau, under Dr. Woldemar Voigt, had formed a preliminary paper design for the P.1101. The aircraft which was developed initially had a short and wide fuselage, tricycle landing gear, and mid-mounted wings with an inner sweep of 40° near the fuselage, and a shallower 26° outboard. The single HeS 011 jet engine was to be mounted internally within the fuselage, being aspirated by two rounded intakes located on either side of the cockpit. The high tail was of a V configuration, and mounted on a tapered boom which extended over and past the jet exhaust, while the cockpit was forward-mounted, with the canopy integrated into the fuselage and forming part of the rounded nose of the aircraft. By late August 1944, the design, still in paper form, had evolved into a sleeker incarnation, with the previously stout fuselage lengthened and narrowed with a conical nose section, added in front of the cockpit. The compound sweep wing was also abandoned, with the outer wing of the Me 262 instead being adapted. Proposals for a pulsejet and rocket combination, the P.1101L, were also put forth. The design was further developed, including a longer nose, and after wind tunnel testing of a number of wing and fuselage profiles, the decision was made to undertake the construction of a full-scale test aircraft. This finalized design and associated test data were submitted to the Construction Bureau on 10 November 1944 and the selection of production materials was begun on 4 December 1944. On 28 February 1945, the RLM settled on a competing design, the Focke-Wulf Ta 183, as the winner of the Emergency Fighter program. This decision was based in part on the considerable design difficulties being encountered by the Messerschmitt P.1101 design team. For example, the cannon installation was proving too crowded, the mainwheel retraction and door mechanisms were