The Warhawk was used by most Allied powers during World War II and remained in front line service until the end of the war.
It was the third most-produced American fighter, after the P-51 and P-47; by November 1944, when production of the P-40 ceased, 13,738 had been built.
The British Commonwealth and Soviet air forces used the name Tomahawk for models equivalent to the P-40B and P-40C, and the name Kittyhawk for models equivalent to the P-40D and all later variants.
The P-40 was originally conceived as a pursuit aircraft and was very agile at low and medium altitudes but suffered due to lack of power at higher altitudes
Allison V-1710 engines produced about 1,040 hp at sea level and 14,000 ft: not powerful by the standards of the time and the early P-40 variants’ top speeds were only average. Also, the Single-stage, single-speed supercharger meant that the P-40 could not compete with contemporary designs as a high-altitude fighter.
The P-40C Tomahawk’s was armed with two .50 in Browning AN/M2 “light-barrel” dorsal nose-mount synchronized machine guns and two .303 Browning machine guns in each wing.
The P-40D abandoned the synchronized gun mounts and instead had two .50 in guns in each wing.
P-40s first saw combat with the British Commonwealth squadrons of the Desert Air Force in the Middle East and North African campaigns, during June 1941.
Between 1941 and 1944, the P-40 played a critical role with Allied air forces in three major theaters: North Africa, the Southwest Pacific, and China.
No. 112 Squadron Royal Air Force, was among the first to operate Tomahawks in North Africa and the unit was the first Allied military aviation unit to feature the “shark mouth” logo. They bore the brunt of Luftwaffe and Regia Aeronautica fighter attacks during the North African campaign.
The P-40 was generally considered roughly equal or slightly superior to the Bf 109 at low altitude, but inferior at high altitude, particularly against the Bf 109F. Most air combat in North Africa took place well below 16,000 ft (4,900 m), thus negating much of the Bf 109’s superiority.
In the first major battles, at Pearl Harbor, and in the Philippines, USAAF P-40 squadrons suffered crippling losses on the ground and in the air to Japanese fighters such as the Ki-43 Oscar and A6M Zero. During the attack on Pearl Harbor, a few P-40s managed to shoot down several Japanese planes, most notably by George Welch and Kenneth Taylor.
In the Dutch East Indies (1942) campaign, the 17th Pursuit Squadron, formed from USAAF pilots evacuated from the Philippines, claimed 49 Japanese aircraft destroyed, for the loss of 17 P-40s.
On 11 May 2012, a crashed P-40 was found in the Sahara desert. No trace of the pilot has been found to date. Due to the extreme arid conditions, little corrosion of the metal surfaces occurred. The conditions in which it was found are similar to those preferred for aircraft boneyard. Plans are being made to move the aircraft to a British museum.
Of the 13,738 P-40s built, only 28 P-40s remain airworthy, with three of them being converted to dual-controls/dual-seat configuration. Approximately 13 aircraft are on static display and another 36 airframes are under restoration for either display or flight.