North American P-51 Mustang
The North American P-51 Mustang was perhaps the only airplane to seriously rival the Spitfire for the title of most beautiful and aesthetically pleasing fighter of WWII. When it came to performance, however, the Mustang had no serious rival for the title of best fighter of the war, embodying as it did the pinnacle of propeller-driven fighter technology, and proving itself a credible match against even the revolutionary Messerschmitt Me 262 jet fighter.
The Mustang was initially designed for the RAF, and the plane that was manufactured in accordance with the British buyers’ specifications, and delivered in October of 1941, was mediocre. Equipped with an underpowered engine, those early Mustangs could not compete on an equal footing with German fighters at high altitudes. As such, the RAF’s Fighter Command saw no use for the plane, and it was relegated to tactical reconnaissance and ground attack duties.
It was not until 1943, after the US Eighth Air Force joined the bombing campaign against Germany and suffered horrendous losses during raids deep into Reich territory beyond the range of fighter escorts, that the Mustang got a second look. The front-line American fighters at the time, the P-38s and P-47s, had shortcomings as bomber escorts – most important of which was the lack of sufficient range to accompany the bombers all the way to targets deep into Germany. After evaluation, it was determined that the Mustang, if modified to carry additional fuel internally and fitted with external fuel tanks, would have the necessary range to escort the bombers anywhere in the European Theater of Operations.
That fixed half of the problem: transforming the Mustang into a fighter capable of escorting American bombers all the way to targets deep inside Germany. Fixing the other half of the problem – improving the Mustang’s performance so it could beat back German fighters and actually protect the bombers it would now escort – transformed the Mustang into a legend.
What had kept the Mustang mediocre was a mediocre engine that performed poorly at high altitudes. Equipped with that stock engine, the initial Mustangs had a top speed of 390 miles per hour, and an effective ceiling of 15,000 feet – any higher, and their performance suffered. Then a British test pilot had the bright idea of replacing the Mustang’s stock engine with the Rolls Royce engine used in the Spitfire IX, and the results were immediate and dramatic, allowing the Mustang to realize its potential, and transforming it from mediocrity to the war’s best fighter. From a 390 m.p.h. top speed, the Rolls Royce engined Mustang zoomed to 440 m.p.h. (with later models reaching 490 m.p.h.), and from an effective ceiling of 15,000 feet, the improved Mustang soared to 42,000 feet.
The test results were passed on to the Americans, and converted Mustangs, equipped with the Rolls Royce engine and now designated the P-51B, began rolling out of factories in June of 1943, and by late 1943, P-51s were in place and ready for action in Europe. When they entered action in 1944, the P-51s broke the Luftwaffe’s back.
The Bf 109s had good engines, capable of performing well at the high altitudes in which the bombers flew. But to actually down the rugged B-17 and B-24 heavy bombers, the 109s needed to be fitted with heavy armaments. The problem was that putting heavy armaments on the Bf 109s’ light airframe negatively impacted their performance, making them that much more vulnerable to the bombers’ escorting P-51s, which were unencumbered by heavy armaments, and armed and optimized instead for the task of killing fighters.
The FW-190s had it even worse than the 109s when they tried to penetrate the protective screen of P-51s in order to get at the bombers. While the 109s at least had engines that were suited for high altitude dogfighting, the FW-190s did not have even that, and their radial engines were no match for the Mustangs’ Rolls Royce engines at high altitudes. Between that, and the dilemma of needing heavy armaments in order to shoot down heavy bombers, even as those heavy armaments reduced their ability to take on enemy fighters not similarly encumbered, the FW-190s found themselves at a severe disadvantage against the P-51s.
After months of heavy losses to the Mustangs, and unsustainable attrition that bled the German fighter arm white, the Luftwaffe effectively ceded the skies over Germany to the P-51 escorted bombers, shadowing the formations but mostly shying away from contact, pouncing instead on stragglers suffering mechanical malfunctions or damaged by flak.
The P-51s begrudged the Germans even that, and would not allow the once-proud Luftwaffe to skulk and scavenge in peace. If the German fighters would not come up to fight them, then they would go down to find and fight the German fighters.
Appointed to command of the Eighth Air Force, Jimmy Doolittle, of Tokyo raid fame, was not content with simply protecting the bombers. Instead, he sought to achieve aerial supremacy over German skies. To do that, he changed the orders that had required escorting fighters to stick with the bombers at all times, and freed them to sweep far ahead of the formations to engage any Germans they could find.
Additionally, once the bombers had hit their targets and began their return trip, the P-51s were free to leave the formations and “hit the deck” on their way back home, descending from their high altitudes and engaging any planes they came across, strafing German airfields, attacking trains or road traffic, engaging any targets of opportunity they spotted, and otherwise provoking and daring the Luftwaffe to come out and do something about it. In the runup to the D-Day landings, some P-51 groups were released from bomber escort duties altogether and unleashed on German airfields instead. Such aggressive tactics finally crippled the Luftwaffe.
The P-51s proved such a success, and were such a marked improvement over the P-38s and P-47s, that by the end of 1944, 14 out of the Eighth Air Force’s 15 fighter groups had switched from Lightning and Thunderbolts to Mustangs. Perhaps the greatest compliment to the Mustangs came from the Luftwaffe’s chief, Hermann Goering, who reportedly said “I knew the jig was up” when he saw P-51s over Berlin.
Even the arrival of futuristic German airplanes late in the war failed to wrest aerial supremacy from the P-51s. The most formidable of those planes, the Messerschmitt Me 262, was kept in check by a shortage of both fuel and experienced pilots, as well as by the expedients of attacking their airfields and strafing them on the ground, or keeping fighter air patrols near their airfields, and catching them at their most vulnerable when they were taking off or landing.