The P-51D-20-NA Mustang is one of the many variants of the Mustang produced by North American. The P-51D variant was the most produced variant of the Mustang family featuring improved wings and was built at multiple locations. The "-NA" denotes that the aircraft was built at North American's Inglewood plant. "-NT" aircraft were built at North American's new plant in Texas. Around 1,600 D-20s were built at Inglewood meanwhile 400 were built in Texas. The D-20 series of aircraft were built with the K-14 gunsight which was the USAAF name for the Mark II gunsight. The D-20 lacked the higher manifold pressure of the D-30 variant and more closely resembles the D-5.

Introduced in Update 1.33 as a premium pack, the P-51D-20-NA is a decent aircraft but has some flaws. The D-20 is very close to the D-5 in performance and shares the lower manifold pressure (lower power). However, it does have an improved rudder design which helps with controllability at higher speeds. Although the P-51D-20-NA is fast, it suffers in climb rate and is limited in its capabilities due to the lower engine power. Players must stick to the P-51's advantages whenever possible and should avoid dogfights with more nimble enemy aircraft.