Although early P-40s were equipped with one of the most powerful inline engines available to the American aircraft industry at the time, it quickly became apparent that even that wasn’t enough. Due to its advanced and robust design, it’s no secret that the P-40 was a relatively heavy aircraft for its type, resulting in power-to-weight issues which would never be fully solved. Nonetheless, Curtiss engineers continued tweaking and improving the design in all aspects, trying to lessen the drawbacks of a high weight and insufficient power.

In 1940, the American Packard Motor Car Company acquired a licence to manufacture the Rolls-Royce Merlin engine, in an effort to satisfy the growing demand of the British aviation industry. Additionally, the licence gave American engineers access to a more powerful engine at a time where similar U.S. engines were not available. Naturally, Curtiss engineers didn’t waste any time outfitting the P-40 with the brand new licence-built Merlin engine, resulting in the creation of the P-40F. Besides the internal engine upgrade, some external changes were also applied to the aircraft. For instance, the tail section of the fuselage was lengthened in an effort to counter the negative effects of strong engine torque on take-off and landing experienced on earlier modifications. With the changes applied, serial production of the new P-40F was scheduled to begin in 1942. As the British and Commonwealth air forces were particularly keen on a Merlin-engined P-40 variant, they were also the first ones to receive the new P-40Fs as early as summer of the same year.

Despite the British and Commonwealth forces receiving the P-40Fs first, the majority of the 1,300 manufactured machines served with units of the USAAF in the Mediterranean theatre. By the end of the Mediterranean campaign in late 1943, the P-40F had successfully proven the value of the applied changes by presenting itself as a more than capable air superiority fighter, when matched up against previously superior Axis counterparts such as the Bf 109F/G and M.C. 202/205. During its service in the Mediterranean, experienced pilots, applying the right tactics showed that the Warhawk could no longer be considered the underdog, but instead an equal at very least.

Interesting: The Soviet Union received P-40 fighters under the lend-lease program; they were considered to be aircraft with medium efficiency but were quite durable. Lieutenant Alexei Khlobystov in one battle conducted two successful rams and after that encounter, the pilot and his “Kittyhawk” returned to the airfield!