The initial P-40 order was finally completed with 193 P-40Cs (company designation H81-B). Serials were 41-13328/13520 (c/n 16104/16296). The first flight of a P-40C was made on April 10, 1941.
The P-40C retained the 1150 hp Allison V-1710-33 engine, but was fitted with a new fuel system with 134 gallons in new tanks with improved self sealing. In addition, provisions were made for a 52-gallon drop tank carried below the fuselage. The P-40C had a SCR-247N radio instead of the SCR-283.
These additions produced yet another upward crawl in the weight--the weights for the P-40C were 5812 pounds empty, 7459 pounds gross, and 8058 pounds maximum loaded. Consequently, the performance continued to degrade. Maximum speed was 345 mph at 15,000 feet. Normal and maximum ranges were 730 and 945 miles respectively. Service ceiling was 29,500 feet, and initial climb rate was 2650 feet per minute. Dimensions were wingspan 27 feet 3 1/2 inches, length 31 feet 8 1/2 inches, height 10 feet 7 inches, wing area 236 square feet.
During 1941, a substantial number of P-40Bs and Cs were shipped to USAAC bases overseas, including the 15th and 18th Pursuit Groups at Wheeler Field, Hawaii and the 20th Pursuit Squadron of the 24th Pursuit Group at Clark Field in the Philippines. In addition, a dozen P-40Cs had been delivered to the 18th Pursuit Group's 44th Pursuit Squadron at Bellows Field, Hawaii. Over 60 P-40Cs were destroyed on the ground at Wheeler during the Pearl Harbor attack on December 7, 1941. Only a few were able to get airborne, and were quickly shot down by Zeros. A few others from Haleiwa airfield and four planes from the 47th Pursuit Group managed to make some attacks on the Japanese formation, claiming 5 kills. However, at the end of the Pearl Harbor attack, only 25 P-40s remained airworthy.
A similar scenario took place in he Philippines, where many P-40s were destroyed on the ground.
The export equivalent of the P-40C was the Tomahawk IIB (Model H81-A2). A total of 930 were built. RAF serials were AH991/999 (all to USSR), AK100/570 (36 to China), AM370/519 (64 to China), and AN218/517.
23 of these Tomahawk IIBs went to the USSR, and unspecified numbers went to Turkey and Egypt. The rest were used extensively by the RAF and South African Air Force in the North African theatre.