The Role of USAAF Aircraft

During World War II

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What is now known as the United States Air Force evolved drastically leading up to and during World War II. New technology made it possible to travel higher and faster than before. Bombers could carry more weapons than during the Great War and the role of air combat became increasingly important. What started as the Air Corps, later evolved into the Army Air Force or USAAF, and now the USAF. The aircraft used by the Air Force had a very important role leading up to and during World War II, and their development is part of our American history.

All metal airplanes could be mass-produced by the early 1930s due to advances in aircraft design and construction. Although there were aircraft made of all metal during the Great War, most aircraft during and before the 1920s were made of wood and fabric. Produced between 1932 and 1933, the B-9 was the Air Corps' first all metal bomber. The B-9 was surpassed by the all-metal Martin B-10 and only seven B-9s were bought. The Consolidated P-25 was the Air Corps' first all metal fighter and was built in 1933; only two were ordered. The first all-metal fighter that was ordered in quantity was the Boeing P-26. There were 139 purchased between the years 1932 and 1936.1

An event to remember in Air Force history was in March 1935 when the War Department founded the General Headquarters of the Air Force. The Air Force then shifted to serving as a central striking force for long-range assault and observation to defend United States coastal areas and islands under United States occupation from attack by sea. This went far beyond the traditional role of supporting Army ground troops on the battlefield. However, to be operative, the General Headquarters of the Air Force needed something that was not yet available, the long-range bomber. It was through this need for a strategic bomber that the Boeing B-17 Flying Fortress was developed.2

During the summer of 1935, Boeing made public its Model 299. It was an outstanding four engine, high-speed, long-range, heavy bomber, that eventually was designated the B-17. The B-17 is one of the most well known bombers of all time. It became famous during the daylight bombing raids over Europe.3 The aircraft had thirteen machine guns and appeared to be a flying "fortress in the sky."2 The first B-17s went into combat in the year 1941 when the Royal Air Force purchased several B-17s for high-altitude missions. As World War II became more intense, these bombers needed additional armament and armor. Boeing built 6,981 B-17s in various models. Most of them were scrapped at the end of the war with only a few remaining today.4

The Consolidated B-24 was designed in 1938 to attempt to improve on the performance of the B-17 Flying Fortress. The design incorporated a new wing design optimized for high-lift and low drag, and tricycle landing gear versus tail draggers like the B-17. The prototype B-24 was ordered in March of 1939 and the first flight on 29 December 1939. They had so much confidence in the new aircraft that seven, service test aircraft were ordered before the final design was complete. In addition, thirty-eight B-24As were ordered in August of 1939 before the prototype has its first flight.5

The B-24 Liberator was the most extensively built of all of the United States wartime aircraft. The aircraft served in all theaters of combat and delivered large bomb loads over long distances. The B-24s that were operating with the US Navy were known as PB4Ys, and B-24s modified as transports were designated C-87s.6

The 75mm cannon had an important role during the war. In 1939, Wright Field modified a B-18 for placement of a 75mm cannon in its underside. However, the results were less successful than anticipated. This was the first attempt to mate a 75mm weapon to an airplane. During the war, 75mm cannons were placed in B-25G Mitchell aircraft and used successfully against Japanese shipping and shore facilities.7

The North American B-25 Mitchell was a very versatile medium bomber that was used on all fronts.8 Even though the airplane was originally designed for level bombing from medium altitudes, it was used extensively in the Pacific area for bombing Japanese airfields. The United States Army Air Force was not the only service to use the B-25 Mitchell. Over 700 aircraft were sent to the U.S. Navy and Marines.9

One of the most historically famous aircraft of all-time, the B-29 Superfortress, played an important role during the war. It was the B-29 that dropped the atomic bomb on Hiroshima and Nagasaki. The Boeing B-29 was designed in 1940 as a replacement for the B-17 Flying Fortress and B-24 Liberator. The aircraft made its first flight on 21 September 1942. In December of 1943, the Army Air Force decided not to use the B-29 in the European Theater. It was sent to the Pacific area where its great range made it suited for long flights over the Pacific Ocean required to attack the Japanese mainland. In November and December of 1944, B-29s began operating against Japan from the islands of Saipan, Guam, and Tinian.10

In May of 1940, President Roosevelt called for the production of 50,000 military airplanes in a year, due to the decaying military situation in Europe. This was an incredible increase in production from the 1,800 produced in 1938. Many expansion programs were allowed, and aircraft production began to climb rapidly. The pilot training program was also accelerated due to the need for new pilots to fly these 50,000 airplanes.11

When the United States went to war in 1941, the War Department looked to the civil airlines for aid in gaining additional aircraft, developing new flight routes, and transporting cargo and passengers on contract over domestic and foreign routes. Thousands of new transport planes were ordered and pilot reserves were called to active duty. On 20 June 1942, the Ferrying Command became known as the Air Transport Command with responsibility for ferrying aircraft, transporting personnel, mail, and maintaining air route facilities outside of the United States. Near the end of the war, the command had more than 3,000 transport aircraft in use and had become the safeguard of the United States Army Air Force.12

This great expansion made it very important for better cooperation between the Air Corps and the Air Force Combat Command, formerly the General Headquarters of the Air Force. They were independent at the time; the Air Corps was responsible for material and training functions and the Air Force Combat Command was responsible for operational functions. As a result, the United States Army Air Forces was created on 20 June 1941 to unify the two. By December of 1941, the Army Air Force had grown to 354,000 men as compared to 26,000 men in September of 1939.13

There were five aircraft that took the majority of the fighter combat action during the war. Among these are the Lockheed P-38 Lightning, Bell P-39 Airacobra, Curtiss P-40 Warhawk, Republic P-47 Thunderbolt and the North American P-51 Mustang.14

In February of 1937, the Air Corps needed a long-range interceptor and escort aircraft. This aircraft needed to be able to maintain a speed of 360 mph at an altitude of 20,000 feet. Lockheed was able to meet these requirements, came up with a somewhat radical design for the time and was awarded the contract to build the P-38.15 The Lockheed P-38 first flew on 27 January 1939 and entered service in June of 1941. Late in 1942, the P-38 went into large-scale operations during the North African campaign where the German Luftwaffe named it "Der Gabelschwanz Teufel" or "The Forked-Tail Devil." When production ended in 1945, more than 9,900 P-38s had been built.16

Like the P-38, the Bell P-39 Airacobra was also one of the primary pursuit airplanes in December of 1941. The first flight was in April of 1939 at Wright Field. By the time of the attack on Pearl Harbor, almost 600 had been built.17 The Airacobra was used in many parts of the world, but specifically in the Southwest Pacific, Mediterranean and Russian theaters. It performed best below 17,000 feet in altitude, and was often used at lower altitudes such as ground strafing. When P-39 production ended in August 1944, Bell had built 9,584.18

The P-40 Warhawk was developed from the P-36 and first flew in May of 1935. P-40s engaged on Japanese aircraft during the attack on Pearl Harbor and the invasion of the Philippines in December of 1941. This extremely rugged aircraft served in many combat areas including the Aleutian Islands, Italy, the Middle East, the Far East, and the Southwest Pacific. In the end, more than 14,000 had been built.19

The P-47 first flew on 6 May 1941, but the first production aircraft was not sent to the United States Army Air Force until 18 March 1942. The aircraft flew its first combat mission on 8 April of 1943, taking off from Great Britain in a course over western Europe. Army Air Force pilots quickly learned that the Thunderbolt could out-dive any Luftwaffe airplane that it met. The P-47 also escorted Army Air Force heavy bombers into German territory.20

Furthermore, the P-47 was recognized as a low-level fighter-bomber due to its ability to absorb battle damage and keep flying. At the war's end, the Thunderbolt had been used in every war theater besides Alaska.21

One of the most well known historical fighters, the North American P-51 Mustang was originally designed for Great Britain in 1940. The United States Army Air Force liked the design and began purchasing them in 1941 for photo reconnaissance and ground support use because it had limited high-altitude performance.22 In 1942, a different engine revealed much improved speed and high-altitude performance. Consequently, in December of 1943, these improved P-51s entered combat over Europe. Supplying high-altitude escort to B-17 Flying Fortresses and B-24 Liberators, they worked wonderfully over German interceptors. By the end of the war, P-51s had destroyed over 4,500 enemy aircraft in the air, more than any other fighter in Europe. P-51 Mustangs served in almost every combat theater, including the Pacific where they escorted B-29 Superfortresses to Japan from Iwo Jima. Between 1941 and 1945, the Army Air Force ordered 14,855 P-51 Mustangs.23

Many conditions set the war against Japan apart from that conducted in Europe and North Africa. The most significant was an agreement between the United States and Great Britain giving priority to defeating Germany and Italy after meeting the requirements in men and materials to maintain enough defense against Japan. This agreement and the immense distances from the United States to the combat areas created major problems in supplying forces in the Pacific. The war against the Japanese was also depicted by many health and morale problems.24

Army Air Force units worked under some of the worst conditions with crews sleeping next to their aircraft and having to maintain their aircraft themselves. Disease caused many casualties in the tropics. Boredom and exhaustion produced morale problems among units stationed in remote areas.25

In conclusion, the Air Force and its aircraft played an important role during World War II. Whether it was small and known as the Air Corps, or when it became larger and was called the Army Air Force, the goal was the same. It was not long after the war before the Air Force was officially established as the USAF. The National Security Act of 1947 established the Department of Defense and a separate Air Force, which defends our skies today.26

End Notes

1 "USAF Museum History Gallery." USAF Museum Web Site [Online].

2 "GHQ Air Force." USAF Museum Web Site [Online].

3 "American Aircraft of World War II." [Online].

4 "Boeing B-17G Flying Fortress." USAF Museum Web Site [Online].

5 "Consolidated B-24D Liberator." USAF Museum Web Site [Online].

6 "American Aircraft of World War II." [Online].

7 "USAF Museum History Gallery." USAF Museum Web Site [Online].

8 "American Aircraft of World War II." [Online].

9 "North American B-25B Mitchell." USAF Museum Web Site [Online].

10 "Boeing B-29 Superfortress." USAF Museum Web Site [Online].

11 "USAF Museum History Gallery." USAF Museum Web Site [Online].

12 "Air Transport Command Created." USAF Museum Web Site [Online].

13 "The Air Corps Expands." USAF Museum Web Site [Online].

14 David A. Anderton, American Fighters of World War II (New York: Crescent Books, 1982) 17.

15 Bill Guston, Allied Fighters of World War II (New York: Arco Publishing, 1981) 128-130.

16 "Lockheed P-38 Lightning." USAF Museum Web Site [Online].

17 Anderton 26

18 "Bell P-39Q." USAF Museum Web Site [Online].

19 Gunston 132-136

20 Gunston 142-145

21 "Republic P-47D Thunderbolt." USAF Museum Web Site [Online].

22 Anderton 35-39

23 "North American P-51D." USAF Museum Web Site [Online].

24 "Combat in the Pacific." USAF Museum Web Site [Online].

25 "WWII Combat Pacific." USAF Museum Web Site [Online].

26 Colonel C.V. Glines, The Compact History of the United States Air Force (New York: Hawthorn Books, 1963) 289-290


"American Aircraft of World War II." [Online].

Anderton, David A. American Fighters of World War II. New York: Crescent Books, 1982.

"Boeing: History -- Beginnings." [Online].

Glines, Colonel C.V. The Compact History of the United States Air Force. New York: Hawthorn Books, 1963.

Gunston, Bill. Allied Fighters of World War II. New York: Arco Publishing, 1981.

"USAF Museum Display Index." USAF Museum Web Site [Online].

"USAF Museum History Gallery." USAF Museum Web Site [Online].