P-51D Mustang

“The most important thing to a fighter pilot is speed; the faster an aircraft is moving when he spots an enemy aircraft, the sooner he will be able to take the bounce and get to the Hun. If you have any advantage on him, keep it and use it. When attacking, plan to overshoot him if possible, hold fire until within range, then shoot and clobber him down to the last instant before breaking away. It’s like sneaking up behind someone and hitting them with a baseball bat.”

— Duane W. Beeson, P-51 pilot, 4th Fighter Group.

 

Strengths:


Speed – With a top speed of over 435 mph, the P-51D is one of the fastest planes in the game.
Guns – The standard six-gun armament of US Fighters is sufficient to knock down all but heavy bombers.
Ground Attack – The Mustang can carry up to 2000 lbs of ordnance, giving it the hitting power of many “medium” bombers.
Energy Retention – The laminar flow wing gives the Mustang possibly the best “E-retention” of any plane in the game.

Weaknesses:


Low-Speed Handling – The handling at speeds approaching stall was unpredictable, and included violent snap-rolls due to the great power-to-weight ratio.
Directional Stability – The high power-to-weight ratio made the Mustang a difficult plane to keep flying straight and level.

With their backs to the wall and in desperate need of combat aircraft, the British government turned its eye westward in 1940 to the vast manufacturing capacity of the United States. They wanted to buy Curtiss’ latest “Hawk” but the U.S. Army needed every P-40 that Curtiss could produce.

However they did succeed in gaining permission to purchase license-built P-40s, providing they could find someone to build them. With this in mind, they approached North American engineering and asked them if they would build the Curtiss fighter under license. Instead of accepting outright, the company offered to design and produce a new fighter in less time than it would take to tool their factory for P-40 production. Having been impressed with North American’s professionalism from previous contracts, the British agreed and dubbed the new design the Mustang.

A scant 127 days after the first piece of metal was cut, the Mustang airframe was rolled out of the factory and twenty days later the new Allison V-1710 engine had been installed. After several weeks of ground and engine testing, on October 26, 1940, the Mustang took to the air and flew for the first time.

Less than a year after getting the go-ahead, the first Mustang I rolled off the production line and, after acceptance testing, arrived in England and was assembled by the end of October 1941. Used primarily as a ground attack fighter, the Mustang I didn’t draw its first blood until August 19, 1942, when an American volunteer, Pilot Officer Hollis Hills of Pasadena, California shot down an FW-190 during the failed invasion at Dieppe.

The U.S. Army eventually showed an interest and purchased 55 modified Mustang Is, which they designated the P-51 Apache. The P-51 differed from the Mustang I primarily in having the machine-gun armament replaced with two 20mm cannon in each wing. However, these were shipped to photo recon units in the Mediterranean and the fighter was again lost to the Army.

Impressed with the early success of the Stuka in Europe, the Army flirted with the North American design once again, this time fitted with dive brakes as the A-36 Apache. Armed with six .50 caliber machine guns (two in the nose under the engine and two in each wing) and shackles for a pair of 500 lb. bombs under the wings the A-36 saw action in Sicily and Italy in the summer of 1943 and was used in the defense of the Burma Road that autumn.

During this time, the “dive bomber” had accounted for over 84 enemy planes in the air in addition to its bombing duties, and the potential as a fighter was obvious. Fitted with an improved supercharged Allison V-1710-81, the new P-51A retained the same armament as the A-36, minus the nose guns. Equipped with 150-gallon drop tanks, the new Mustang could now be ferried over 2700 miles in a single leg. The P-51A was used primarily in the China-Burma-India Theater, performing fighter and ground-attack duties against the Japanese.

The one weakness of the Mustang was that it had a service ceiling considerably lower than that of contemporary European fighters, like the Spitfire and Bf-109. This was due entirely to the Allison engine’s poor high-altitude performance without the bulky turbo-superchargers used on the Lightning. Convinced that the sleek airframe of the Mustang would be a winner if only it had more power, Rolls-Royce engineers began modifying a Mustang I to accept a Merlin 65 engine in place of the Allison.

The first flight tests revealed that what had once been a pleasant and easy aircraft to fly was now a spitting, kicking, bucking bronco of a plane that required constant control adjustments to keep trimmed. But the trade-off was a plane that traveled 50 mph faster and had a service ceiling 10,000 feet higher than the Allison-powered variant. Fitted for production with a Packard-built version of the Merlin, the new Mustang was designated P-51B by the U.S. Army and over 2,000 were ordered by the Army and the RAF.

Being unable to meet the production load with only their Los Angeles factory, North American retooled their Dallas, Texas factory from production of the B-24 Liberator and started producing P-51s. Although identical to the P-51B being built in California, the Texas-built planes were designated P-51Cs.

But the best was still yet to come! Looking to improve the visibility out of the cockpit, North American engineers devised a plexiglas “bubble” canopy for use on the “D” model, which gave the pilot an all-around view unobstructed by any canopy “ironwork”. The ammunition feed problem under heavy G-loading, which plagued the P-51B/C, was fixed by changing the mount angle of the guns, and another pair of .50s was added to the wing armament, giving the P-51D a total of six .50 caliber machine guns. Finally, the wings and wing hard-points were strengthened to allow loads of up to 1000 lbs. per wing to be carried.

With additional internal fuel capacity and larger drop tanks, the Mustang could now reach deep into Germany and escort bombers all the way to their targets and back. The addition of zero-length rocket launchers allowed the Mustang to carry six air-to-ground rockets for ground attack duties. Over 9600 P-51Ds were built and over 45 squadrons in the 8th Air Force were equipped to fly Mustangs by the end of the war in Europe.

 

Sources:
Green, William; War Planes Of The Second World War: Fighters Volume Four; Macdonald & Co., London; 1961.
Davis, Larry; P-51 Mustang In Action, Aircraft No. 45; Squadron/Signal Publications, Carrollton, Texas; 1981.
Freeman, Roger A.; Mustang At War, Doubleday and Company, Garden City, New York; 1974.

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