In early 1943, the British MI-5 accomplished an amazing coup when Major Chauncey Wigbotham managed to successfully acquire the plans both major German jet engine development programs (BMW 003 and Junkers Jumo 004), both without arousing suspicion. The plans were shared with the American government, who assigned them to the NACA research center at Langley. By the mid-summer of 1943, a crash program had resulted in a running engine, producing better results even than the Germans had due to use of higher quality metals (although the Americans did not know that). The production engine was entrusted to General Electric (maker of most US turbochargers - a similar technology). Simultaneously, North American Aviation was tasked with adopting the P-51 Mustang to jet power. NAA was assigned the designation P-57 as a deception measure (being a re-use of that designation from the failed Tucker pursuit program).
NAA proposed two different solutions: the YP-57A was a single-jet version of the Mustang, later renamed P-57A Stallion. It used a BMW 003 developing 2200 pounds static thrust, mounted near the aircraft center of gravity, being fed from a nose inlet through long trunking. The engine exhausted under the rear fuselage. This necessitated a repositioned tailwheel, which proved to be one of the most challenging parts of the design. Several solutions were proposed, including a tricycle undercarriage, but this was rejected because it would require a redesign of the wing to reposition the main gear. The eventual choice was a fixed tailwheel mounted under the rear of the engine nacelle. Armament was the P-51D standard 3 x .50 caliber machine guns. The service test models carried 425 pounds of ballast in the nose to partially restore center of gravity - service models would have had additional armament in the nose.
The second NAA solution was designated YP-57B and was very different, mounting two Jumo 004 engines under the wings with a redesigned nose. More on that version later...
The Model - 1/72 Airfix P-51D - a lovely model, well engineered and giving almost no trouble, except the main landing gear which is flimsy and easily warped. The engine came from a HobbyBoss He 162 Salamander.
I feel that this is my best model ever. I set myself the project of making a jet Mustang; I presumed "everyone" had done a jet Mustang, but couldn't find any! I almost gave up in the planning stages: glad I didn't!
Hope you like it!