The P-51 Mustang fighter plane was a truly remarkable aircraft that changed the nature of the air war over Europe in WWII. Before the advent of the P-51 Mustang, bombers on long range missions had to fly unescorted. Since the fighter planes early in the war had a range of only about 250 miles, this meant that they could not escort the bombers further than Aachen, near the western border of German. For any penetration deeper into the Third Reich, the bombers were on their own.
The unescorted missions had disastrous results for the bombers. During a bombing mission over Schweinfurt, Germany, on October 14, 1943, to bomb the large ball-bearing factories so crucial to the German war effort, the U.S. Eighth Air Force was attacked by a large number of Luftwaffe fighter aircraft. Out of 229 bombers over Scheinfurt, 60 were shot down, and 17 more were irreparably damaged. This loss rate was unacceptable and proved that the Allied bombing campaign over Germany could not continue unless the bombers could be accompanied by fighter aircraft.
The Genesis of the P-51 Mustang
Fortunately for the Allies, help was at hand. In April 1940, Sir Henry Self, head of the British Purchasing Commission aircraft division, was visited by Dutch Kindleberger, president of North American Aviation. The purpose of Kindleberger’s trip was to see if the British were interested in buying some of North America’s B-25 bombers. However, Self was more interested in buying long-range fighters, so he let Kindleberger know that the Curtiss Aircraft company had a great design for a new kind of fighter but was too busy producing P-40s to work on the new aircraft. As a result, Kindleberger purchased the design for the new fighter plane from Curtiss.
By October 1940, this new plane, then called the NA-73, was ready to fly. Flight tests proved this new fighter to be quite remarkable. It was able to fly at high speeds because its wing design was built to withstand high air compression. In addition, the heated air from the radiator was used to boost the plane’s speed an additional 15 to 25 mph. The narrow fuselage and low cockpit made the NA-73 highly aerodynamic.
Perhaps the only flaw in the design of this fighter was that its Allison V-1710 engine did not have a supercharger and lost much of its power at an altitude above 12,000 feet. Superchargers are necessary for high-altitude flight because they compress air before going into the engine cylinders, which is extremely important in thin air.
Despite this flaw in the engine, the P-51A aircraft, as the first mass-produced NA-73 aircraft was called, delivered good results despite being confined to lower altitudes. This Royal Air Force P-51A fighter remained in combat from May 1942 until early 1944. Finally, an RAF test pilot came up with the idea of replacing the P-51A engine with a Rolls-Royce Merlin engine. This engine had more horsepower plus the supercharger necessary for high-altitude flight. When this new aircraft, the P-51B Mustang, arrived in England, the pilots discovered that they had a fighter aircraft with amazing capabilities.
With a combination of a 425 gallon fuel tank capacity and an engine that used about half as much fuel as other fighters, the P-51B had a range of 1080 miles. With drop-tanks attached to the wings this range was more than doubled to 2600 miles. This meant that the P-51 now had the ability to accompany bombers on long range missions. On top of the added range, the P-51 was superior in performance to the Luftwaffe fighters, particularly in speed.
Impact on the Air War Over Europe
From their first long-range missions accompanying bombers in January 1944, the P-51 Mustangs tipped the balance of the air war over Europe in favor of the Allies. No longer could Luftwaffe fighters easily shoot down Allied bombers.
From this point, and through the rest of the war, the German fighter aircraft were on the defensive. In addition to protecting the bombers at high altitudes, the P-51 Mustangs were given the added assignment of destroying the Luftwaffe aircraft on the ground along with their support facilities during low-altitude strafing missions.
A little over 15,000 P-51 Mustangs were produced during WWII. They accounted for almost half of the German aerial losses. However, much more important than the losses inflicted on the enemy were the many lives of Allied bomber crews that were saved by the P-51 Mustang escorts. No longer were the Allied bombers sitting ducks after the P-51 Mustangs took to the air to accompany them on long-range missions over Europe.