North American P-51 Mustang History Part II - Variants

Mustang MkI
The first production Mustang aircraft delivered to the RAF. Two of this type were delivered to the USAAF as XP-51s. Most of this type was powered by the 1150 hp Allison engine and was armed with four .50 cal and four .30 cal machine guns.

A36

The dive bomber version of the Mustang, the A36 was powered by the Allison engine and entered service in 1942. It was armed with six .50 cal machine guns or four 20mm cannons, had provisions to carry two 500-lb bombs and was equipped with dive brakes, though many of this variant had the dive brakes disabled due to stress problems. Confusion surrounds the name designation of this aircraft. Some sources refer to it as the "Apache", "Invader" or both before it adopted the name "Mustang".


P-51A

Originally ordered as Mustang IIs for the RAF, most of this type were diverted to US units in the China-Burma-India theatre as P-51As. Armament consisted of four .50 cal machine guns and provisions for two 500-lb bombs. The P-51A was powered by the Allison V-1710-81 engine.

P-51B
The P-51B was the first production Mustang fitted with the Rolls-Royce Merlin engine (manufactured under license by Packard). Other features included a 75 gallon rear fuel tank, bulged canopy and strengthened hard points for 1000-lb bombs. Armament consisted of four .50 cal machine guns. Limited numbers were sent to the RAF as Mustang Mk IIIs.

P-51D
The P-51D was the major production version of the Mustang. Features included a full bubble canopy, a dorsal fin to help stability (primarily to counter the effects of the new canopy), increased ammunition and improved instrumentation. Armament consisted of six .50 cal machine guns. Some of this variant were sent to the RAF as Mustang Mk IVs.