Perhaps the “classic” Mustang, the P-51D was the major production version. Despite the improved visibility conferred by the Malcolm hood, even more was needed, and thus North American flew a pair of P-51Bs refitted with clear “teardrop” canopies as XP-51Ds. Virtually all the production P-51Ds also had a dorsal fin to help increase lateral stability, and some earlier models gained this feature. Later block P-51Ds had additional fuel tankage added aft of the cockpit, and the capability to carry rockets underwing. The tactical reconnaissance counterpart was the F-6D (RF-51D from 1948) while the RAF designated their P-51Ds as Mustang Mk.IVs. The P-51K was the Dallas-built counterpart to the P-51D, being fitted with a propeller from Aeroproducts. The F-6K/RF-51K was the reconnaisance version.
Whereas surviving early Mustang models were rapidly retired at war’s end, the P-51D (F-51D after 1948) would be in military service for decades after WWII. Aircraft from the Air National Guard were federalized in 1950 and rapidly shipped across the Pacific to Korea; quite vulnerable in the fighter-bomber role thanks to their liquid-cooled Merlins, the Mustangs were still badly needed in the theater, as they could operate from austere strips in South Korea itself, and had more combat persistence than the fuel-thirsty F-80 Shooting Star jets. The West Virginia ANG did not retire the last US military Mustangs until 1957, and even this was a temporary end, as the US Army later acquired a few Mustangs rebuilt by Cavalier to serve as chaseplanes for the AH-56 Cheyenne program.
P-51D Bibliography:
Ken Brill “Pacific escort” Scale Modeler October 1979. Building the Monogram 1/48 scale P-51D as a 21st Fighter Group aircraft.