In one of those rambling multi-subject discussions, military guys enjoy having the question arose, “Which was the best US fight plane of WWII?”

I knew my answer would cause an argument and it did.

I’ve answered that question before by qualifying it with, “Best under what definition?”

There are lots of ways to quantify the best US fighter of WWII, including engineering stats like service ceiling, speed, climb and turn rates.  It could also be quantified by the number produced on the reasoning that the U.S. wouldn’t pour men and pilots on a plane that wasn’t very good.  Then there is the supposed trump card of the best fighter in WWII, its air-to-air kill ratio.  This is the one that counts, right?  How many planes did fighter X shoot down versus how many fighter Xs were brought down by the enemy?

I think all of those arguments have merit but they tend to be narrowed to give the crown to the plane a person already thinks is the best anyway.

The United States produced 276,000 aircraft in WWII. 23,ooo were lost in combat and a staggering 15,000 were lost in operational accidents, mostly in the US.  The loss rate from all causes was 13% of the total of all aircraft.  Remember this, it will factor in later on.

I think the best fighter of WWII argument is missing a very important and I think decisive argument that I will make here, but first the contenders for the title.

Curtis P-36 Hawk

Honorable mention as the first US-marked aircraft to bring down a Japanese fighter in WWII.  The Army built fewer than 300 Curtis P-36 Hawks but they hold an interesting place in history.  These were the first fighter planes to engage Japanese forces at Pearl Harbor on December 7th, 1941.  Popular movies have given this distinction to the P-40 Warhawk but it rightly belongs to the P-36.  This was their only combat action in the Pacific.  We did export a version of this aircraft to France which used them against the Luftwaffe when Germany invaded them in 1940.   They were actually quite good, the radial-engined Hawk fighter made aces out of 11 French pilots. When the US landed in North Africa in 1942, the French piloted Hawks shot down 7 US aircraft.

P-40 Warhawk

The Curtis P-40 Warhawk, made famous by the shark’s mouth painted on its nose was a workhorse in the early days of the war.  While it lacked the speed at high altitudes to escort bombers, at medium and low altitudes it was very good.  It could out-turn the A6M2 Zero at speeds that would rip the wings of the light Japanese fighter and could out-dive most of the early fighters in service at the time.  It was made out of very tough stuff and could take tremendous punishment.  While it was not used as an escort for 8th Air Force bombers over Europe, it racked up a considerable combat record in Asia, Africa, and the middle-east. The US built nearly 15,000 Warhawks during WWII and they were flown by the British and Soviets.   They were also reasonably priced at $48,892. By all accounts, they were a very well-liked fighter at medium altitude and in the ground attack role.  They were good enough to shoot down 2,225 aircraft in combat. In fact, the P-40 produced the 1st US ace of the war when 1st Lt. Boyd “Buzz” Wagner, based in the Philippines flamed his fifth Japanese aircraft on Dec. 16, 1941. That’s 9 days after the attack on Pearl Harbor.

P-39 Aerocobra

This pursuit fight built by the Bell Aircraft Corporation was a staple fight in the US Army Air Corps at the start of the war while the more famous fighter were still concept drawings if they existed at all. Entering into service in 1941 it bore the brunt of the early onslaught of the Japanese drive in the Pacific.

The aircraft itself was revolutionary in design. Bell just about built the aircraft around the 37mm cannon that fired through the nose cone of the propeller. Crazy idea right? Not really, the German Bf-109 had a 20mm firing through the nose already so upping the ante with a 37mm anti-tank gun wasn’t so nuts.  Most aircraft in those days were built around the performance of an engine, but in the case of the Aerocobra, it was the Oldsmobile-built(yeah, the car maker) cannon that the engineers built the plane around.  The idea of building an aircraft around a gun capable of killing tanks will sound familiar to A-10 Warhog fans.

The Army wanted the Aerocobra to be a high-altitude fighter fast enough to chase down bombers and a 37mm cannon would mean the P-39 could engage bombers outside the range of its defensive machine guns which were .30 cal weapons for the most part.  Firing through the nose simplified targeting too, whereas guns in the wings had to be adjusted to converge at a certain range in front of the aircraft.

The aircraft at low altitude performed very well, its roll rate exceeded that of the Japanese Zeros at speeds under 300 mph and under 12,000 feet. What limited the performance of the Aerocobra was the absence of a 2-stage turbocharger.  The placement of the cannon and its ammunition in the nose, along with two more machine guns meant the engine was located in the fuselage behind the pilot who was seating forward of the leading edge of the wing.  There just wasn’t room for a 2 stage turbo after they barely wedged a single-stage unit into the fuselage along with all its intake and outflow ductwork.

That was a fatal blow to an aircraft built to chase down bombers at high altitudes but it was no vice in a fighter at a medium altitude.  With the exception of the European theater and high-altitude bomber escort missions, most of the dog fighting took place at medium and low altitudes. “Why was that?” you might ask.

Because above 10,000 feet, it got very cold and you needed oxygen to survive up there.  It was pretty uncomfortable to fly that high up before pressurized cabins were incorporated into aircraft like the B-29, Superfortress which was the first production military aircraft to use this technology.

So most of the war in the air was well under 20,000 ft.

The Aerocobra gets a bad rap because it was eclipsed by aircraft like the P-51, P-38 and P-47, all of which were built without the kinds of budget constraints that existed in peacetime.  The production model cost a bit over $50,000 each.

As these new aircraft came into production the US sold most of the P-39s to Russia which used them as fighters and ground attack aircraft.  A single one of those 37mm rounds would be enough to wreck any German fighter in the skies and also disable tanks when hitting them from above where their armor was thin.

In US service, the P-39 would shoot down some 320 aircraft, mostly Japanese but did much better in a ground attack role where it strafed and bombed ships, airfields, troops, and ground emplacements.  It was good enough that Bell produced nearly 10,000 Aerocobras by the end of the war.

P-38 Lightening

This was the first aircraft produced by Lockheed’s legendary Skunk Works staffed by the famed aeronautical engineers Kelly Johnson and Hall Hibbard.  In those days Lockheed was a maker of bombers like the Hudson and not fighter planes.  It was also a much smaller company making only a total of 19.000 aircraft in WWII out of a total of 276,000 built in total.

Prior to the war, the Army wanted a high-altitude, twin-engine fighter that could fly 460 mph, carry 1,000 pounds of ammunition and be able to reach 20,000 feet from takeoff in 6 minutes.  At the time, these parameters were all but impossible to meet.  but Johnson and Hibbard were not contained by any orthodoxy about how a fighter plane should look.  What they built was a twin-engine fighter with a pilot sitting in a pod with the tail attached to the long slender engine compartments.  This design allowed them to put Allison engines with two-stage turbo-supercharges needed for high-altitude performance.

The aircraft had stunning performance at altitude. It was so fast that problems of compressibility of the control surfaces limited its dive angle as it approached the speed of sound.  It also had two engines that saved the lives of many pilots on 1200-mile round trip flights over Europe and the vast expanses of the Pacific Ocean. It was preferable to lose “an” engine rather than “the” engine on these flights.  The P-38 had such a long range that it was the first American fighter plane capable of flying from the US to Europe entirely under its own power making 3 refueling stops along the 2,500-mile journey.

As with any aircraft it had to be employed correctly to be able to fight to its strength as a fighter plane.  Its tremendous speed and climbing ability gave it the ability to engage in zoom and boom attacks on enemy aircraft, diving from above and hosing them with a 20mm cannon and four .50 cal machine guns all in the nose out to ranges of 1,000 yards.  Again this was superior to wing-mounted guns that had a fixed convergence range out in front of them.  Pilots who learned the aircraft found that they could out-turn German and Japanese fighters with the much larger P-38 by advancing the throttle on the low engine in a tight turn. While the P-38 did not do well as a bomber escort, forced to fly close escort, when released to range ahead of the bomber formations and actively hunt German fighters, it was able to pick its fights and do very well against German 109s and 190s.

It was in the Pacific where the Lightning really shined through as an offensive fighter and escort.  Japanese planes like the Zero were lethargic at high altitudes where the Lightning cut them to pieces.  The two top-scoring US aces in WWII, Richard Bong and Thomas McGuire with 40 and 38 air-to-air victories were both flying P-38s.

In WWII, the P-38 joined the P-39 Aerocobra as the two longest-serving fighters in WWII both having been adopted by the army in 1941.  The army would go on to buy more than 10,000 Lightnings even though it was the most expensive fighter built at a whopping $97,000 a copy.  The aircraft was also under continuous improvement going from the P-38A to the P-38M model in just 4 years of service. As it was replaced in the bomber escort role by the P-51 Mustang the P-38 was improved from the “A” model all the way to the “M” model. Variants included a photo recon version and even a radar-equipped night fighter.

P-51 Mustang

What is probably the most iconic American fighter plane of WWII wasn’t even built for the US, it was built for Great Brittain. in 1941, the UK government went to North American Aviation wanting to purchase several hundred Curtis P-40 Warhawks for the war in Europe which had started in 1939 for the Brits.  The UK government had a license to make them from Curtis Aircraft. The British were cranking out all the Hurricanes and Spitfires they could from their own factories and had turned to the US to tap the unused production capacity of US aircraft makers. The people at North American didn’t like the idea of making an airplane designed by a competitor and proposed instead to make a new fighter for the Royal Air Force themselves. The problem was North American was known for making training aircraft and not fighters.  It had won a contract to build a medium bomber for the army, the B-25 Mitchell, but it had no experience with high-performance fighters.

The Brits were pretty desperate though and in less than 3 months, the first Mustang prototype was ready to test with an Allison engine like the P-38 and P-39 had but with the single-stage turbo-supercharger that limited the performance of the P-39 Aerocobra. The aircraft performed to specifications but when it was tested in Brittain there was a suggestion to change the engine to the Rolls Merlin being fitted into the Spitfires. The reason was that it gave better performance at high altitude than the Allison, raising its top speed to 440 mph at 28,000 feet.

At the time of its production the US was officially neutral and did not want to sell or give its best military technology to any country that might cross swords with the US someday, and that included Great Brittain, but since the Mustang was not made for the US military but was a custom design made just for the UK, permission was granted for export of what would become the best air superiority fighter of WWII and fitted with a British engine.  It almost seemed to have happened all by accident.

Initially, the RAF used the Mustang for long-range recon because its fuel capacity gave it very long range even at wave top altitude. It was fast enough to outrun anything the Germans could send after it.  The US had not entered the war yet so strategic bombing of Germany by hundreds of bombers had not yet begun.  RAF bombing raids into Germany were conducted at night, removing the need for escort fighters.  In hit-and-run raids on ground targets, the Mustang could dash in and out very quickly but the fighter had clay feet.  The Merlin engine was a water-cooled V-12 instead of a radial, air-cooled engine.  As such, the innards of the Mustang was crammed with hoses and two radiators to cool the oil and engine coolant, a single bullet could puncture a hose or radiator, the coolant would leak out and the engine would overheat and seize within 2 minutes.

The speed and maneuverability of the Mustang were a saving grace, but one thing nobody ever credited to the fighter was the ability to absorb damage in combat.

When the bombing campaign to soften up Germany prior to the D-Day landings began in 1944, the Mustang had the speed and range at high altitudes to take the bombers there and back.  P-38s and P-47s had been used and were reasonably effective, but they lacked the range and maneuverability to dogfight German fighters trying to mix it up the B-17 Flying Fortresses now pushing into the Third Reich in raids of ever-increasing size.  While the Mustang had a mixed record in the ground attack role, it excelled in the bomber escort role and found the best mission for its capabilities.

The Mustang would go on to claim fully half of the air-to-air victories by the Army Air Forces in Europe during WWII, with 4,950 victories in the air and another 4,131 destroyed on the ground. Late in the war, the Mustangs were also released from close escort missions and Mustang fighter groups conducted fighter sweeps of German airfields in advance of the bombers arriving.  In effect, they destroyed the Luftwaffe on the ground before it could even get in the air.  Both of General Chuck Yeager’s kills of Me-262 jet fighters were aircraft he caught low on fuel and trying to land, slow, and gear down.

Not without losses though, nearly 2,500 Mustangs were lost in combat.

After the war in Europe ended, Mustang groups were transferred to the Pacific Theater to escort B-29 Super Fortresses on raids over the Japanese home islands. By this time, the aircraft of the Japanese army and navy had been mauled pretty badly, its best pilots long dead.  In the thin, frigid air at 25,000 feet, the Zero was no longer nimble or quick and were easy pickings for the Mustangs very much in their element.

The army would go on to build 15,875 Mustangs during the war, making it the most widely produced army fighter at the economical price of $51,572, nearly half of the cost of a P-38.

P-47 Thunderbolt

It was huge, it was ugly, and it went by nicknames like “The Beast,” “Razorback” and “The Jug.” The story of the P-47 Thunderbolt by Republic Aviation is really the story of its engine, the Pratt & Whitney, R-2800 18-cylinder radial engine.  This is what made the Thunderbolt what it became, the workhorse of American fighters in WWII.

The R-2800 was the most powerful engine the US produced in WWII and was used in the F4U Corsair, the F6F Hellcat, and both the B-26 and A-26 bombers.  Originally rated at 1850 hp, improved models ended up in the Thunderbolt which produced an incredible 2,800 horsepower that could be overboosted north of 3,000hp.  This resulted in the Thunderbolt being the fastest piston-driven fighter plane of any air force in the war.  The P-47N model at the end of the war could bore holes in the sky at 467mph at 32,000 feet.  Modification to the wing to add additional fuel even displaced the Mustang as the longest-range single-engine fighter as well, with a range of 1980 miles with a reserve of 380 miles.  This intended range was even more incredible when you consider that the P-47 weighed more than 10 tons when fully fueled.

The aircraft also featured self-sealing fuel tanks, and armor plating for the pilot and was ridiculously overbuilt in terms of the toughness of the airframe and wings.  Thunderbolts survived mid-air collisions with German fighters and even trees at low altitudes.  They came home with holes in them you could stick your head through.  German pilots could expend all their ammunition on a P-47 in a dogfight without being able to bring it down.  The 18-cylinder engine could be hit by flak or gunfire and lose several cylinders and most of the oil without overheating and seizing. One came back missing 4 feet off one of its wings after it hit a factory chimney at 460mph.

The first P-47s were delivered in December 1941 just as the war began and would go on to fight the Luftwaffe in Africa, Italy, France, and Germany until Germany surrendered. It also flew in the Pacific across the entire theater as well, in even far-flung areas like Burma.

It did not climb as fast as the Mustang or Lightning, but it could certainly dive with them.  It could not turn as quickly either.  It did not initially have the range to escort the bombers all the way to Germany and back to England.

In a war where the winning side was often determined by who saw the other guy first and gained the advantageous position, the Beast was a huge airplane, and would be spotted first.

Nevertheless, it was there for all of it, fighting in the early days of the war when the best pilots of both Germany and Japan were still alive and flying.  And the pilots of the Thunderbolt shot them to pieces, so when the Mustangs did arrive in 1944 the Luftwaffe was a husk of what it had been in 1942. The P-47 would finish the war with 3,661 air-to-air victories and two of its pilots among the top ten US aces of all time. The ungainly beast that was the P-47 racked up a 4.61-to-1 kill ratio against enemy aircraft.

As the long-range Mustang came into the skies over Europe to escort the bombers they didn’t retire the Thunderbolt or pull it from service.  It took on the role that the vulnerable Mustang could not, the air-to-ground job of a tactical fighter bomber.  It carried thousand-pound bombs under its wings and five inches rockets as well as eight .50 cal machineguns and destroyed hundreds of locomotives, tanks, guns, barges, and rail cars. It did so while being fired at by heavy caliber guns from the ground and flying through the explosions of its own bombs.

You will note that I have mentioned the cost of aircraft to Uncle Sam in that war because economy matters in these things.  When it comes to weapons, you can have a lot of inexpensive weapons or fewer weapons that are better but cost a lot more and the Thunderbolt wasn’t a bargain. Each P-47 cost $85,587, about four grand less than the twin-engined P-38s and almost 60% more than a Mustang.

Despite the cost, the P-47 was the most widely produced US fighter plane of the war with 15,686 being built.  That gives you a clue about how valuable to the war effort the Thunderbolt was.

But that isn’t what made the P-47 Thunderbolt the best fighter plane of the Army Air Corps in WWII.

Imagine if I could take one hundred fighter pilots into a hanger that contained a P-39 Aerocobra, a P-40 Warhawk, a P-38 Lightning, a P-51 Mustang, and a P-47 Thunderbolt and offered them their choice of which one they wanted to take into combat. I could go over the flight characteristics of each aircraft, its speed, combat radius, roll rate, turn rate, and armaments.  They would probably slobber all over the Mustang which is a truly beautiful airplane to behold.  They would be very impressed with the 37mm cannon in the P-39.  They would love the big roomy cockpit of the P-38 on a 12-hour mission.  They might look right past that big ugly beast in one corner.

Then I would tell them this, the combat loss rate of that ugly Thunderbolt was just .07% per mission, the lowest of any US fighter plane in WWII, including the navy’s fighters like the Hellcat and Corsair. You were almost twice as likely to die in a Lightning, and you stood a 40% higher chance of burning up in a Mustang.

If you wanted to survive aerial combat, the Thunderbolt gave you the best chance of living to fight another day. In WWII the Army Air Corps lost 60,000 airmen in combat and training accidents.

Which one do you think they would pick then?

Which one would you pick?