Comparison of P-40 variants

The P-40 went through four significant transformations, comprising 10 official variants, in its international military service.

Hawk 81A-1/P-40B/P-40C (British Commonwealth/Soviet "Tomahawk Mk I" and "Tomahawk Mk IIA and IIB")

Distinguishing Features: Twin nose guns, smaller engine cowling

Time in Service:

1941-43

Major Operators:Desert Air Force (DAF) 1941–43: North Africa and SyriaChinese Air Force (American Volunteer Group; AVG; “Flying Tigers”) 1941–42: China/Burma/India (CBI)United States Army Air Forces (USAAF) 1941–42: Pearl Harbor and Philippines Voenno-Vozdushnye Sily (Soviet Air Forces; VVS) 1942–43: Eastern Front (World War II) and Continuation War

Commentary: This was a very important type for the allies in the early part of the war. Slaughtered mostly on the ground at Pearl Harbor and in the Philippines, it did well with the AVG in China and Burma, and was the most effective fighter available to the RAF in the early months of the Desert War. It was also a small but important part of the Soviet arsenal in 1942, being one of the few types available to them which could take on the Me 109. The earliest version (P-40) had only four guns and lacked armor plate or self sealing tanks, but the British pressed these into service into North Africa anyway as Tomahawk I. The P-40B (Tomahawk IIa) had the some armor, armored windscreen and partially protected fuel tanks, the P-40C (Tomahawk IIb) had a fully protected fuel system and became heavier, reducing speed to under 350 mph. The Soviets reportedly stripped the wing guns from some of their Tomahawks to improve performance.

It's important to note that there were a variety of differences between the British Commonwealth and US variants, (starting with the guns, .303 instead of .30 caliber) so that it's not actually an exact correlation between specific US variants (P-40B etc.) and their rough British Commonwealth export equivalents (i.e. 'Tomahawk')

P-40D/E/K (British Commonwealth/Soviet "Kittyhawk Mk 1", "Kittyhawk Mk Ia" and "Kittyhawk Mk III")

Distinguishing Features: Deeper engine cowling, ('definitive' P-40 "Look") Six Gun armament, P-40K has expanded tail fin

Time in Service:

1942–43

Major Operators: USAAF (1942–43) New Guinea, Guadalcanal, CBIRAAF (1942–43) Kokoda Trail, Milne Trail, Darwin
Royal New Zealand Air Force (RNZAF) 1942–43 South PacificDAF (1942) Desert War, principle air superiority fighter for early 1942 VVS (late 1942–43)

Commentary: This was the first version armed with six .50 caliber machine guns. More powerful than the P-40B/C in terms of both armor, armament and performance, this was the type which fought as a fighter during the most crucial period in both the Pacific and North African campaigns. The P-40E played a major role in the defense of Australia and New Guinea in 1942, and with the Desert Air Force in intense fighting against the Luftwaffe and Regia Aeronautica also in 1942. The P-40K was the primary type used by the 10th Air Force to establish air superiority in the China/Burma theater, achieving dominance over Japanese Army types in that theater. The P-40E was also an important type for the Soviets.

In the Desert War the arrival of the Kittyhawk led to the early retirement of the Me 109E and it's replacement by the faster and more maneuverable Me 109F. The top scoring RAF squadrons including No's 3 and 112 squadron transitioned from the Tomahawk to the Kittyhawk, scoring many kills against Luftwaffe and Reggia Aeronautica types, helping the Desert Air Force hold on through this tough period.

P40 F/L (British Commonwealth/Soviet "Kittyhawk Mk II and IIa")

Distinguishing Features: Packard-Merlin engine, no intake on top of engine, some models were lengthened, some had deleted wing guns.

Major Operators:

USAAF (1943) Operation Torch, Mediterranean TheaterVVS (1943)
Free French Air Force (1943) Mediterranean Theater

Commentary:

This version fulfilled the longstanding wish of the British to put a Merlin engine in a P-40 (which is what led to the development of the P-51), but it arrived in combat relatively late and ironically, few of this type made it to Commonwealth units. It was however the variant with which the USAAF faced the Luftwaffe and Regia Aeronautica in the Med. The Packard Merlin engine improved performance, but the single stage, two-speed supercharger still limited the effective ceiling to about 20,000 feet. Many P-40F types were lightened in the field by US squadrons to make them 'hot' by removing some armor and wing guns. The P-40L was an official light version nicknamed "Gypsy Rose Lee". Some had four guns some only had two, top speed for this type was 368 mph, climb and acceleration were better as well. This fighter could cope with the Me 109F and G within its effective performance ceiling, it was the variant used by the successful 324th, 325th and 57th fighter groups, and also by the Tuskegee Airmen's 99th FS in Italy for a short time.

P-40F/L variants were supplied to Free French squadrons flying in North Africa.

Some of the later run P-40F/L types were lengthened like the later P-40N, a measure to cope with the increased torque of more powerful engines.

P-40 M/N (British Commonwealth/Soviet "Kittyhawk Mk III and IV", USAAF "Warhawk")

Distinguishing Features: Modified rear cockpit with expanded view, lengthened fuselage, some models had deleted wing guns

Major Operators:

USAAF: (1943–44) CBIDAF: (1943–44) Mediterranean TheaterRAAF: (1943–44) South West Pacific RNZAF: (1943–44) South West PacificVVS: (1943)

Commentary:

This version remained in use as an air superiority fighter in the CBI. In other theaters it was principally used as a fighter/bomber. It featured a lengthened fuselage and a more powerful 1300 hp Allison engine but the use of a single speed, single stage supercharger gave the planes just a marginally better effective altitude than a P-40E/K. As with the F/L, there were both 'light' and 'heavy' versions, the lightest 'hot' fighter configuration P-40Ns achieved a top speed of up to 378 Mph. Most P-40M types were actually heavier and made just 345 Mph. Later run P-40Ns were made with a smaller engine, specifically for training or fighter-bomber missions.

This table compares the specifications of one early- and one late-model P-40 variant.