Modern-Aviation

During the first year of American participation in World War II, the Curtiss P-40 Warhawk (Kittyhawk or Tomahawk to the British) came to symbolize the United States Army Air Corps as it fought a desperate war to hold the Japanese in check. This was thanks in large measure to the highly publicized exploits of the American Volunteer Group during the first six months of the war and of their successors in the 23rd Fighter Group in China. Although the P-40 lacked the performance of the twin-engine Lockheed P-38 Lightning and Republic’s radial engine P-47 Thunderbolt, it—along with the Bell P-39 Airacobra—was one of two types of pursuit planes that were available in large numbers at the outbreak of war and the only ones immediately available for service in the Pacific.

Curtiss Aircraft Company developed the P-40 as part of its Hawk line of fighters, which began with retractable-gear biplane pursuit ships that served in Army Air Corps squadrons in the 1930s. Its immediate predecessor was the P-36, a monoplane that featured the R-1830 radial engine. To create the Warhawk, Curtiss adapted the Allison V-1710 liquid-cooled in-line engine to the P-36 fuselage. The narrow frontage presented by the Allison significantly reduced drag and greatly improved the original design’s performance.

The P-40, as it was originally designed, was poorly armed, with only two machine guns mounted on top of the nose, but the armament was increased with subsequent versions and most combat models of the P-40 carried six .50-caliber machine guns. Hard points were added under the wings for bombs and rockets, turning the Warhawk into a potent ground attack airplane.

Both the P-40 and the smaller P-39 were products of 1930s U.S. military policy, which called for defending the coasts. Consequently, both designs were intended primarily to support ground troops. Little consideration had been given to interception of enemy aircraft, since the Atlantic and Pacific Oceans provided the best defenses against attack from either Europe or Asia. There were no aircraft in existence in the 1930s with the range to make a transoceanic attack on the United States. Although naval aviation was coming into prominence, neither Germany nor Japan was considered capable of mounting a carrier-borne attack on the United States or even Hawaii.

The threat the Army sought to defend against was an amphibious assault from the sea, and both fighters were designed with that in mind. It was not until war broke out in Europe and the bomber became a preeminent weapon that aerial interception came to be seen as an important Air Corps mission.

The low altitude operations required for ground support placed aircraft in range of everything from small arms to heavy antiaircraft fire, so the P-39 and P-40 were designed to absorb ground fire and keep on flying. These qualities would prove beneficial in the ground attack role, but both airplanes were severely lacking as interceptors due to their lack of high-altitude performance capabilities.

The P-39 was a nimble aircraft that could hold its own with Japanese fighters at lower altitudes, but the heavier P-40 was considerably less maneuverable. But, while they were lacking in climb and high-altitude performance, both types were rugged airplanes and would prompt the admiration of those who flew them into combat in the Pacific. General George C. Kenney would report that both designs could “slug it out, absorb gunfire, and fly home.”

In the spring of 1941, the United States began a buildup of forces in the Philippine Islands as the War Department modified its Rainbow No. 5 war plan. Previous military plans had called for U.S. forces to withdraw to a line from Alaska to Hawaii, but Japanese aggression in Asia dictated modifications. Under the new plan, the Philippines would serve as a strategic base for attacks on Japanese positions threatening the oil fields in the Netherlands East Indies. In the event of an invasion of the islands, the defending U.S. and Filipino forces were to withdraw to the Bataan Peninsula and wait for reinforcements to arrive from the United States.

Modernization of the Air Corps in the Philippines was crucial to defense of the islands, and in May the first P-40Bs arrived in the islands and were assigned to the 20th Pursuit Squadron, replacing older types. The 3rd Pursuit Squadron was also equipped with P-40s, while the 17th Pursuit Squadron continued flying de Seversky P-35s for the time being. The Philippines Air Force received the antiquated Boeing P-26s that had previously served with U.S. Army Air Corps squadrons in the islands.

The three Army Air Corps fighter squadrons, the first in the Philippines, were organized into the 24th Pursuit Group in August 1941. They were joined by two squadrons of the 35th Pursuit Group, the 21st and 34th Pursuit Squadrons, in November. The 35th Group headquarters was still at sea when the Japanese attack came and never reached Manila; the ship carrying the headquarters was diverted to Australia, where the 35th would reform.

The two later squadrons were equipped with more modern P-40Es, but the 34th Squadron’s airplanes were given to the 17th Pursuit; the 34th received the P-35s the 17th Pursuit Squadron had been flying. Additional P-40s were en route to the islands by sea to replace the P-35s. The 20th Pursuit had received P-40Es by the end of November. The Hawaiian Air Force on Oahu also included several P-40 squadrons. The 15th Pursuit Group at Wheeler Field was equipped with P-40s, as was the 18th Pursuit at Hickam Field. Other P-40 squadrons were deployed to Alaska and the Panama Canal Zone.

A stroke of luck put four squadrons of P-40s with experienced and well-trained American pilots in China before war broke out. Captain Claire Chennault had gone to China in 1937 after his retirement from the Army to take a position as a civilian advisor to Generalissimio Chaing Kai-Shek’s Nationalist Chinese government. At the time of his retirement, Chennault was not only one of the most experienced and skilled fighter pilots in the Air Corps, but he was an outstanding tactician who knew how to use the best qualities of the aircraft under his command.

Although British Hawker Hurricanes and Supermarine Spitfires would eventually be sent to Australia, the P-40 would become the primary RAAF fighter. Australian P-40s played a significant role in the Battle of Milne Bay, a decisive battle that forced the Japanese to abandon plans to capture Port Moreseby. A squadron of RAAF P-40s operated out of the airfield at Milne Bay, attacking the Japanese landing party with bombs and machine-gun fire. Australian squadrons continued flying P-40s until late in the war.

By 1945, the role of the P-40 had diminished, but veterans of the Pacific War knew that without them, it was unlikely that the Allies would have been able to hold back the Japanese during the dark early days of the war.