Effects of the P-51 in World War II



 This paper deals with the contributions of the P-51 Mustang to 
the eventual victory of the Allies in Europe during World War II. It 
describes the war scene in Europe before the P-51 was introduced, 
traces the development of the fighter, its advantages, and the 
abilities it was able to contribute to the Allies' arsenal. It 
concludes with the effect that the P-51 had on German air superiority, 
and how it led the destruction of the Luftwaffe. The thesis is that: 
it was not until the advent of the North American P-51 Mustang 
fighter, and all of the improvements, benefits, and side effects
that it brought with it, that the Allies were able to achieve air
superiority over the Germans.

Table of Contents

 Reasons for the Pre-P-51 Air Situation
 The Pre-P-51 Situation
 The Allied Purpose in the Air War
 The Battle at Schweinfurt
 The Development of the P-51
 The Installation of the Merlin Engines
 Features, Advantages, and Benefits of the P-51
 The P-51's Battle Performance
 The Change in Policy on Escort Fighter Function
 P-51's Disrupt Luftwaffe Fighter Tactics
 P-51's Give Bombers Better Support
 Works Cited


 On September 1, 1939, the German military forces invaded Poland 
to begin World War II. This invasion was very successful because of 
its use of a new military strategic theory -- blitzkrieg. Blitzkrieg, 
literally "lightning war," involved the fast and deadly coordination 
of two distinct forces, the Wermacht and the Luftwaffe. The Wermacht 
advanced on the ground, while the Luftwaffe destroyed the enemy air 
force, attacked enemy ground forces, and disrupted enemy communication 
and transportation systems. This setup was responsible for the 
successful invasions of Poland, Norway, Western Europe, the Balkans 
and the initial success of the Russian invasion. For many years
after the first of September, the air war in Europe was dominated by 
the Luftwaffe. No other nation involved in the war had the experience,
technology, or numbers to challenge the Luftwaffe's superiority. It 
was not until the United States joined the war effort that any great 
harm was done to Germany and even then, German air superiority 
remained unscathed. It was not until the advent of the North American 
P-51 Mustang fighter, and all of the improvements, benefits, and side 
effects that it brought with it, that the Allies were able to achieve 
air superiority over the Germans.

Reasons for the Pre-P-51 Air Situation

 The continued domination of the European skies by the Luftwaffe 
was caused by two factors, the first of which was the difference in 
military theory between the Luftwaffe and the Royal Air Force. The 
theories concerning the purpose and function of the Luftwaffe and RAF 
were exactly opposite and were a result of their experiences in World 
War I. During WW I, Germany attempted a strategic bombing effort 
directed against England using Gothas (biplane bombers) and Zeppelins 
(slow-moving hot-air balloons) which did not give much of a result. 
This, plus the fact that German military theory at the beginning of WW 
II was based much more on fast quick results (Blitzkrieg), meant that 
Germany decided not to develop a strategic air force. The Luftwaffe 
had experienced great success when they used tactical ground-attack 
aircraft in Spain (i.e. at Guernica), and so they figured that their 
air force should mainly consist of this kind of planes. So Germany 
made the Luftwaffe a ground support force that was essentially an
extension of the army and functioned as a long- range, aerial 
artillery. The RAF, on the other hand, had experimented with 
ground-attack fighters during WW I, and had suffered grievous casualty 
rates. This, combined with the fact that the British had been deeply 
enraged and offended by the German Gotha and Zeppelin attacks on their 
home soil, made them determined to develop a strategic air force that 
would be capable of bombing German soil in the next war. Thus, at the 
beginning of WW II, the RAF was mostly a strategic force that 
consisted of heavy bombers and backup fighters, and lacked any 
tactical dive- bombers or ground-attack fighters. (Boyne 21)

The Pre-P-51 Situation

 Because of these fundamental differences, the situation that 
resulted after the air war began was: bombers in enemy territory vs. 
attack planes. The "in enemy territory" was the second reason for the 
domination of the Luftwaffe. At the beginning of WW II, and for many 
years afterward, the Allies had no long-range escort fighters, which 
meant that the bombers were forced to fly most of their long journeys 
alone. (Perret 104) Before the P-51 was brought into combat, the main 
Allied fighters were the American P-47 Thunderbolt and the British 
Spitfire, neither of which had a very long range. The rule-of-thumb 
for fighter ranges was that they could go as far as Aachen, which was 
about 250 miles from the Allied fighters' home bases in England, 
before they had to turn around. Unfortunately, most of the bombers' 
targets were between 400 and 700 miles from England. (Bailey 2-3)
This meant that bombers could only be escorted into the Benelux
countries, northern France, and the very western fringe of Germany. 
When these unescorted, ungainly, slow, unmaneuverable bombers flew 
over Germany, they were practically sitting ducks for the fast German 
fighters. On the other hand, the bombers were equipped with several 
machine guns and were able to consistently shoot down some of their 
attackers. Because of this, "U.S. strategists were not yet convinced 
of the need for long-range fighters; they continued to cling to the 
belief that their big bomber formations could defend themselves over 
Germany." (Bailey 153)

The Allied Purpose in the Air War

 The Allies knew that they had to drive German industry into the 
ground in order to win the war. Since the factories, refineries, 
assembly-lines, and other industry-related structures were all inland, 
the only way to destroy them was by sending in bombers. The only way 
that the bombers could achieve real success was by gaining air 
superiority, which meant that nearly all of the bombers would be able 
to drop their bombs without being harassed by fighters, and return 
home to fight another day. The problem with this sequence was that the 
Allies did not have this superiority, (Bailey 28) because their 
bombers were consistently getting shot down in fairly large numbers, 
by the German fighters that kept coming. The Allies soon realized
that in order to gain this superiority, they would have to destroy 
more German fighters. In order to destroy the fighters, they would 
have to be forced into the air in greater numbers. In order to get 
more German fighters into the air, the more sensitive German 
industries would have to be attacked with more aggression. Following 
this logic, the Allies began a intensified bombing effort that 
resulted in the famous bombings of Hamburg (July 24-28, 1943) and 
Ploesti (August 1, 1943), among others. And, indeed, this did cause 
more fighters to come up to meet and engage the bombers. 
Unfortunately, the bombers were overwhelmed by the German opposition,
and their losses soon began to increase. (Copp 359) The Allied air 
forces had, in effect, pushed a stick into a hornets' nest, hoping to 
kill the hornets when they came out, and been stung by the ferocity of 
their response.

The Battle at Schweinfurt

 The culminating point of this backfiring plan was the second 
bombing raid on Schweinfurt, which occurred on October 14, 1943. 
Schweinfurt was the location of huge ball-bearing factories that 
supplied most of the ball-bearings for the entire German military. The 
U.S. Eighth Air Force had staged a fairly successful raid on the same 
city two months earlier, but the second time around, the Germans were 
ready for them. The official report afterwards said that the Luftwaffe 
"turned in a performance unprecedented in its magnitude, in the 
cleverness with which it was planned, and in the severity with which 
it was executed." Of the 229 bombers that actually made it all the way 
to Schweinfurt, 60 were shot down, and 17 more made it home, but were 
damaged beyond repair. This was a 26.5% battle loss rate for the 
Americans, while the Germans only lost 38 airplanes the whole day, 
from all causes. (Boyne 327) This battle was one of the key battles of 
the war, and undeniably proved to the Allies that the bomber offensive 
could not continue without a long-range fighter escort. (Copp 444) 
Even before October of '43, some had begun to realize the need
for this kind of fighter. In June, the Commanding General of the Army
Air Forces, General Hap Arnold, wrote a memo to his Chief of Staff, 
Major General Barney Giles, which said:

 This brings to my mind the absolute necessity for building a
 fighter airplane that can go in and out with the bombers.
 Moreover, this fighter has got to go into Germany. . . . Whether
 you use an existing type or have to start from scratch is your
 problem. Get to work on this right away because by January '44, I
 want a fighter escort for all our bombers from the U.K. into
 Germany. (Copp 413-414)

The Development of the P-51

 In April of 1940, "Dutch" Kindleberger, president of North 
American Aviation, visited Sir Henry Self, the head of the aircraft 
division of the British Purchasing Commission, asking if Britain would 
like to buy some of his B-25 bombers. Self was not interested in 
buying any more bombers, but was interested in buying a good fighter. 
He directed Kindleberger to the Curtiss company, who had a new fighter 
design, but were too busy building P-40's to do anything with it. 
Kindleberger went to Curtiss and bought their design for $56,000. He 
promised Self to have the planes ready by September of 1941. The 
prototype of the NA-73, as it was called, was ready to fly in October 
of 1940 and proved to have an excellent design. The NA-73 had a 
revolutionary wing design that allowed it to fly at high speeds
without adverse compression effects. In other planes, as they 
approached a certain speed, usually around 450 mph, the air would be 
flowing around the wing at nearly the speed of sound, putting huge 
amounts of pressure on the wings, which were unable to deal with the 
stress. The NA-73 did not have this problem, which meant it could fly 
safely at much higher speeds. Another revolutionary idea in the plane 
was the way heated air from the radiator was dealt with. The NA-73's 
engineers designed it to expel this air and boost the planes speed by 
15 or 25 mph. The engineers also worked especially hard on making the 
plane as aerodynamic as possible, and so they positioned the radiator 
in a new place, made the fuselage as narrow as possible, and set the 
cockpit low in the fuselage. (Perret 118-119) It was at this point 
that an error was made that made the Mustang useless as a long-range 
offensive fighter. When the NA-73 was mass produced as the P-51,
it was powered by a 1550 horsepower air-cooled Allison engine, which 
did not have a supercharger and lost performance above 11,800 ft. At 
high altitudes air pressure goes down, and so there is less oxygen in 
a given amount of air, which means that engines do not burn as 
cleanly, and so lose power. Superchargers compress air before it is 
pumped into the engine cylinders so that there is enough oxygen for 
the engine to function well. The early Allison-engined planes did not 
have the supercharger, and so were limited to low-altitude operations. 
Even without a high- altitude capability, the Mustang was an 
impressive plane and was bought in quantity by the RAF. It flew its 
first mission on May 10, 1942, against Berck-sur-Mer on the French 
coast. (Grant 17-18)

The Installation of the Merlin Engines

 So, for the next eighteen months, the P-51A's continued to fly 
with the RAF, doing their unexceptional jobs well. After the plane 
began to go into combat, some people began looking into the idea of 
fitting the Mustang with a more powerful engine. As the RAF said, it 
was "a bloody good airplane, only it needs a bit more poke." (Grant 
22) One day, an RAF test pilot was flying a P-51A and the thought 
occurred to him that the plane could be fitted with a Rolls-Royce 
Merlin engine, which had about 300 more horsepower and included a 
supercharger. He suggested it to Rolls-Royce's Chief Aerodynamic 
Engineer and "both men realized that the combination of this sort of 
performance with the aerodynamically efficient airframe of the
Mustang would revolutionize its potential." (Grant 22) This plan was
duly carried out and in November 1943, the first group of P-51B's 
arrived in England.

Features, Advantages, and Benefits of the P-51

 This final Mustang design was superior to anything else that 
flew at the time. The P-51B had a huge internal gasoline tank capacity 
(around 425 gallons) and its engine was very economical, using about 
half the gasoline of other American fighters. This meant its range was 
1080 miles and could be extended to 2600 miles when extra drop-tanks 
were attached to the wings. This made its range far more than any 
Allied or German fighter's. As far as performance went, it was 
superior to all others as well. Neither of the other two main American 
fighters could compete; the P-47 was too heavy and the P-38 had too 
many technical problems. The British fighters, the Spitfire and the 
Hurricane did not have the range, speed, or power. But most important 
was its superiority over the German fighters, the most important of 
which were the FW-190 and the Me-109. The Mustang was 50 mph faster 
than the Germans up to 28,000 ft beyond which it was much faster than 
the FW-190 and still substantially faster than the Me-109. The
Mustang had between 3000 and 4000 lbs more weight, and so was able to 
outdive either German plane. The tightness of its turns was much 
better than the Me-109 and slightly better than the FW-190. (Grant 31, 
Boyne 389-390, Bailey 153) The result of all of this was that the 
Allies now had a plane that could go with the bombers all the way to 
and from their targets, fight and defeat the bombers' German 
attackers, and not run out of fuel.

The P-51's Battle Performance

 So, at the end of 1943 and the beginning of 1944, the new 
American P-51B's began arriving in England in force. (Dupuy 34) For 
the first few months of the year, the Mustangs were settling in and 
having their systems perfected. But by March, the Mustangs had 
decisively taken control. The arrival and subsequent heavy use of the 
P-51's had several effects. The first effect that the Mustangs had was 
in the running air battles over Europe. Before the beginning of 1944, 
the bombers had been alone as they approached their faraway targets. 
But the P-51 changed this, and quickly made an impression on all 
concerned, enemy and ally alike. For example, on January 11, 1944, the 
Eighth Air Force launched its first deep penetration of Germany with 
P-51 coverage. The bombers' targets were the cities of Oschersleben 
and Halberstadt, where many German planes were being constructed. When 
they arrived, there were 49 Mustangs covering a force of around 220 
bombers. Even though the bombers suffered heavy casualties, they
were able to inflict substantial damage on their target factories. But
the most significant thing about the battle was the shining 
performance of the P-51's. Since the bombers were attacking two 
different cities, the Mustang force had to divide into two groups, to 
support the different attacks. Because of the sensitive nature of the 
bombers' targets, the Luftwaffe came out in force to defend their 
factories. During the ensuing melee, the 49 P-51's shot down 15 enemy 
planes without suffering a single loss. Major Howard, the group's 
leader, was credited with four kills within minutes. (Bailey 155) In 
the grand scheme of things, this battle was insignificant, but it goes 
to show how much of advantage the P-51's had over their German
counterparts. Considering that these were essentially first-time 
pilots in the Mustangs' first big battle, this is very impressive.

The Change in Policy on Escort Fighter Function

 Another thing happened at the same time as the arrival of the 
P-51 that greatly aided the Allies and fully utilized the great 
capabilities of the Mustang. Before the beginning of 1944, the bomber 
escort's primary function was to fly alongside the bombers, repel any 
attacks made on the bombers, and generally make sure the bombers 
stayed safe. Indeed, the motto of the Eighth Air Force Fighter Command 
was "Our Mission is to Bring the Bombers Back Alive." One day at the 
beginning of the year, Jimmy Doolittle, who was the commander of the 
Eighth Air Force, saw a plaque on the wall with this motto on it and 
said, "That's not so. Your mission is to destroy the German Air Force. 
. .Take that damned thing down." (Copp 456) And just days before, in 
his New Year's Day address to the Eighth Air Force command, General 
Arnold had said, "My personal message to you-this is a MUST- is
to destroy the enemy air force wherever you find them, in the air, on 
the ground and in the factories." (Copp 456) What this meant was that 
the escort fighters were not tied to the bombers anymore, and were 
free to roam over the countryside and through the towns and cities, 
destroying at will. The sweeping Mustangs were released to ravage 
German convoys, trains, antiaircraft gun emplacements, warehouses, 
airfields, factories, radar installations, and other important things 
that would be impractical to be attacked by bombers. The fighters were 
also able to attack German fighters when they were least prepared for 
it, like when they were taking off or forming up in the air. What made 
this possible was the increase in the number of American planes 
present in Europe. This increase in the number of Allied planes 
compared to the number of German planes continued to the point that, 
on D-Day, the Allies used 12,873 aircraft while the Germans were only 
able to muster a mere 300. (Overy 77) By using this overwhelming
numerical advantage, the Allied fighters were able to swamp their
opponents in an unstoppable flood of planes.

P-51's Disrupt Luftwaffe Fighter Tactics

 This increase in the number of fighters plus the change in 
fighter philosophy allowed the escorts to cover the bombers while 
simultaneously ranging far from the bomber stream and destroying all 
that they could find. This caused the disruption of several effective 
German fighter tactics that had been used successfully in the past. 
One of these tactics was the deployment of slow, ungainly German 
planes that would fly around the bomber formations, out of gun range, 
and report back on where the bombers were and where their weak spots 
were. The free-ranging P-51's soon wiped out these planes. Another 
popular tactic was to mount rocket launchers on the wings of some of 
these slower craft, have them linger just out of range of the bombers' 
guns, and send rockets flying into the bomber formations. These rocket 
attacks were terrifying to the bomber crews, and often broke up
formations, sending some planes to the ground. Obviously, these 
attacks also came to a halt. Most importantly, the fast German 
fighters had to change their attack tactics. Beforehand, they would 
fly alongside the formations and wait for the right moment to swoop in 
and attack a bomber. Now, they were forced to group together several 
miles away from the bombers, and then turn and made a mad rush at the 
bombers, hoping to inflict sufficient damage on one pass to shoot down 
some number of enemy bombers. They could not afford to stay with the 
bombers for very long for fear of being attacked by the Mustangs. 
(Perret 293) Indeed, soon after the P-51's entered onto the scene, 
Hermann Goering, the commander of the Luftwaffe, recommended that the 
German defensive fighters avoid combat with the P-51, and only attack 
bomber formations when there were no fighters around. The result of 
all of this is that the American fighters, led by the P-51's, soon 
began to gain air superiority. Not long after Goering's 
recommendation, a sarcastic Luftwaffe officer commented that the 
safest flying in the world was to be an American fighter over Germany. 
(Dupuy 35-36) It is obvious that the P-51, once it was supplied to the 
Eighth Air Force in great quantities, and unleashed by Doolittle and 
Arnold's new fighter policies, soon took a heavy toll on German air 

P-51's Give Bombers Better Support

 Another profound effect that the increased fighter coverage had 
was on the most important people, the bombers. After the entrance of 
the P-51, and the virtual elimination of the German fighter threat, 
the bombers were in much less danger from German fighters. The result 
of the decreased danger to the bombers is subtle, but obvious when 
thought about. Imagine a bomber crew sitting in their cramped plane, 
unable to move around or evade attack during their bombing run while 
numerous German fighters speed past their plane firing at them. Second 
lieutenant William Brick, the bombardier of a B-17 bomber, tells about 
the day he flew to Linz, Austria on a bombing run:

 . . . The remainder of the run must be perfectly straight and
 level, without the slightest deviation, or our five-
 thousand-pound bomb load will fall wide of the target. No evasive
 action is possible. . . Then comes the sickening rattle of
 machine-gun bullets and cannon fire hitting our ship; ignoring
 the flak from the antiaircraft batteries, German fighter planes
 zoom in so close that it seems they will ram us. . . Even at the
 sub-zero temperatures of this altitude, salty sweat pours down my
 face and burns my eyeballs. Cursing and praying, I am gripped by
 the same brand of helpless fear that fliers experience during
 every bomb run. I feel the terror in my hands, in my stomach,
 even in my feet. Long after returning from the mission, its
 effects will remain etched indelibly on my face. . . . (Brick 61)

This kind of terror experienced by the entire crew of the bombers was
sure to affect their concentration and their carefulness. Indeed, "it 
is an undeniable, if unquantifiable, fact that it is easier to bomb 
precisely when you know you will probably not be shot out of the sky." 
(Boyne 341)


 In the end, the way that the Allied air forces gained air 
superiority was by destroying its opposition. The ways in which the 
fighters were able to destroy German fighters were diverse. The 
fighters utilized their high speed and maneuverability to fly 
low-level strafing missions that ranged over large expanses of 
territory and destroyed many Luftwaffe craft on the ground. This 
tactic was responsible for the destruction of many dozens of fighters 
that were unable to go on and fight in the air. Another way that the 
Allied fighters destroyed their opposition, and the most important
way, was by luring them into the air. Going back to the hornets' nest
analogy, the Allies stopped pushing the stick and decided to bide 
their time until the moment was right. When they did start pushing the 
stick into the nest again, they were armed with a metaphoric 
insecticide. In real life, this "insecticide" was the P-51. 
Beforehand, the Allies had nothing that could stop the "hornets" and 
so were helpless to stop their attack. But after they had developed an 
"insecticide" capable of killing the "hornets," they proceeded to lure 
the hornets into the open where they could be destroyed. In real life, 
the bombers were the lure that brought the Luftwaffe into the air. 
Using the long-range Mustangs, the Allies were able to make their
bombing raids more effective and more deadly to Germany. The 
approaching end of the Third Reich was enough to get the German 
fighters into the air to try to stop the bombers from wrecking their 
war effort. "Air superiority had been won not by bombing the enemy's 
factories into oblivion; instead, it was won by the long-range 
fighter, using the bomber formations as bait to entice the Luftwaffe 
to fight." (Boyne 338) With the advent of great numbers of the highly 
superior P-51 Mustang, the German fighters that came up to attack the 
bombers quickly met their match and were easily repelled by the 

Works Cited

Bailey, Ronald H. The Air War in Europe. Alexandria, Virginia: 
Time-Life Books, 1979. A simple, straight-forward book that includes 
much background on the development of military aviation, and includes 
many pictures that chronicle the air war.

Boyne, Walter J. Clash of Wings: World War II in the Air. New York:
Simon & Schuster, 1994. A very informative and user- friendly book 
that dealt with the air aspect of all fronts and theaters of WWII. It 
includes much data on numerous planes in its appendices.

Brick, William. "Bombardier." American History, April 1995, pp. 60-65. 
A short magazine article following the story of how a U.S. airman was 
shot down over Austria, and his subsequent imprisonment by the Nazis.

Copp, DeWitt S. Forged in Fire: Strategy and Decisions in the Airwar
over Europe, 1940-1945. Garden City, New York: Doubleday & Company, 
1982. A book dealing mostly with the U.S. involvement in the War, with 
particular emphasis on the politics of the military officials, and how 
the major strategic decisions were made.

Dupuy, Trevor Nevitt. The Air War in the West: June 1941 to April 
1945. New York: Franklin Watts, Inc., 1963. A short, very basic book 
that did not go into depth, but did cover its material well.

Grant, William Newby. P-51 Mustang. London: Bison Books Limited, 1980. 
A relatively short book, but one that dealt solely with the P-51, and 
went into considerable depth concerning its construction and use 
during WWII and in later conflicts.

Overy, R.J. The Air War: 1939-1945. New York: Stein and Day 
Publishers, 1980. A fairly dry book that dealt mostly with the 
economics and generalities of the air war, without dealing too much 
with the actual fighting.

Perret, Geoffrey. Winged Victory: The Army Air Forces in World War II.
New York: Random House, 1993. A good book that covered its topic well,
although in-depth discussion of the contributions of the other allies' 
forces is not dealt with.


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