The Lippisch P.13b was a World War IIGermanramjet powered fighter aircraft designed by Alexander Lippisch. Designed in December 1944, the P.13b was a further development of the similarly delta-winged Lippisch P.13a, which was also a ramjet fighter. The cockpit was located in the nose of the fuselage, and was mounted forward of the delta wing, which featured downturned wing tips. Main landing gear comprised a retractable skid, while the rear of the aircraft would rest on the reinforced wing tips.
Air intakes were sited on either side of the cockpit in the leading edges of the wings. Due to the increasing shortages of fuel by the latter stages of the war, it was proposed to use coal (or paraffin-coated lignite dust) as a fuel. A central mounted round or hexagonal shaped combustion chamber constructed from ceramic materials was to be mounted in the wing's interior, designed to be refuellable from above. The aircraft was accelerated to ramjet speeds by rockets attached to the wings and speeds of 1200+km/h were attained
Work ceased on the concept before armament was planned, and officially no tests were ever carried out either of the airframe design or the unique power source. Flight data pertaining to this aircraft is on record[where?] and also a P13b is listed on the American forces manifest of aircraft shipped to the USA as war booty at the end of WWII.