This Messerschmitt design was an advanced development of the basic Me 262 airframe and was proposed in January 1944. The P.1099B utilized the wings and tail of the Me 262A-2a, but had an entirely new and enlarged fuselage and undercarriage. Two Jumo 004C jet engines were to be fitted and a crew of two or three sat in the redesigned cockpit. The basic armament for this variant was two FPL 151 20mm cannon (remotely controlled), two MK 103 30mm cannon and two FHL 151 20mm cannon barbettes. A large variety of more detailed proposals for the Me P.1099 were issued on March 22, 1944, including various armaments (see table below) and for remotely controlled defensive armament for the P.1099B. A night fighter development was also proposed, armed with an additional two MK 108 30mm cannon in an upward firing (Schrage Musik) configuration.

     Span: 12.58 m (41' 3.7")       Length: 12 m (39' 4.8")        Max. Speed: 825 km/h (512 mph)