Curtiss P-40 variants

Curtiss P-40 variants
Tomahawk of No. 3 Squadron RAAF in North Africa, 23 December 1941.

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 Syria
• Chinese Air Force (American Volunteer Group; AVG; “Flying Tigers”) 1941–42: China/Burma/India (CBI)^[1]
• United States Army Air Forces (USAAF) 1941–42: Pearl Harbor,^[2] Philippines^[3] and Java^[4]
• 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. Many were destroyed on the ground at Pearl Harbor and in the Philippines in December 1941; 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 Bf 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 Is. The P-40B (Tomahawk IIa) had the same 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.

There were a variety of differences between the British Commonwealth and US variants, (starting with the guns, .303 instead of .30 caliber) so that there is not actually an exact correlation between specific US variants (P-40B etc.) and British Commonwealth export versions (i.e. 'Tomahawk')

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

Restored P-40E Warbird in Aleutian "Tiger" markings.

A P-40E-1 piloted by the ace Keith "Bluey" Truscott, September 1942.

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, CBI
• Royal Australian Air Force (RAAF) (1942–43) Kokoda Track, Battle of Milne Bay, Darwin
• Royal New Zealand Air Force (RNZAF) (1942–43) South Pacific
• DAF (1942) Desert War, principle air superiority fighter for early 1942
• VVS (late 1942–43)
• Chinese Air Force (1943–27 P-40E)^[5]

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 (DAF) in intense fighting against the Luftwaffe and Regia Aeronautica also in 1942. 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 Bf 109E and its replacement by the faster and more maneuverable Bf 109F. The top scoring DAF squadrons, including No. 3 Squadron RAAF and No. 112 Squadron RAF, transitioned from the Tomahawk to the Kittyhawk, scoring many kills against Luftwaffe and Regia Aeronautica types, helping the DAF hold on through this tough period.

P-40K/P-40M (British Commonwealth/Soviet "Kittyhawk Mk III")

Distinguishing Features

P-40K has expanded tail fin, later M models had extended tail

Time in Service

1942–43

Major Operators

• USAAF (1942–43) New Guinea, Guadalcanal, CBI
• RAAF (1942–43) Kokoda Trail, Milne Bay, Darwin
• Royal New Zealand Air Force (RNZAF) 1942–43 South Pacific
• VVS (late 1942–43)

Commentary

These were the slowest and heaviest P-40 variants. 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-40M was also an important type for the Soviets.

P-40F/P-40L (British Commonwealth/Soviet "Kittyhawk Mk II and IIa")

P-40F or L over Texas 1943

P-40Fs of the 44th Fighter Squadron USAAF, Guadalcanal

Restored Curtiss P-40N-5-CU Warbird

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 Theater; South-West Pacific Theater^[6]
• VVS (1943)
• Free French Air Force (1943) Mediterranean Theater

Commentary

This version fulfilled the longstanding wish of the British to fit the P-40 with a Merlin engine (which is what ultimately 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-40Fs 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 Bf 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-40N (British Commonwealth/Soviet "Kittyhawk Mk IV", USAAF "Warhawk")

Distinguishing Features

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

Major Operators

• USAAF: (1943–44) CBI
• DAF: (1943–44) Mediterranean Theater
• RAAF: (1943–44) South West Pacific
• RNZAF: (1943–44) South West Pacific
• VVS: (1943)

Commentary

This version (Model 87V, 87W) remained in use as an air superiority fighter in the CBI. It was the most produced of all P-40s, with 5,220 examples built. 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 model only a marginally better effective altitude than a P-40E. As with the F/L, there were both 'light' and 'heavy' versions, the lightest 'hot' fighter-configuration-with-four-guns P-40Ns achieved a top speed of up to 378 MPH. The first sub-model, P-40N-1-CU, weighted only 2,700 kg (max 4,015) and it was meant to be a high-altitude interceptor. It was the fastest of all P-40s with 608 km/h at 3,100 m (one of the best performances at such altitude), 6,7 minutes to 4,570 m, and a ceiling of 38,000 ft. Only 400 were built. Later run P-40Ns were made with a lower-power engine, specifically for training or fighter-bomber missions and had a top speed of only 345 Mph. The production led to many blocks, up to P-40N-40-CU with 1,360 hp and metal-covered ailerons. One of the most important sub-model, the P-40N-15-CU, weighed 6,200 pounds empty, 8,350 loaded, 11,400 max. Its performance dropped to 208 mph/5.000 feet, 325 mph/10,000 feet (thus almost 100 km/h slower), 343 mph/15,000 feet, at 20,000 feet in 8.8 min, service ceiling was 31,000 feet.

Specifications

A listing of specifications for major P-40 variants.

	P-40B	P-40E	P-40F	P-40N
General characteristics
Crew	One	One	One	One
Length	31 ft 8 in (9.66 m)	31 ft 8 in (9.66 m)	31 feet 2 in, from P-40F-5-CU 33 feet 4 in (11,38 m)	33 ft 4 in (10.16 m)
Wingspan	37 ft 4 in (11.38 m)	37 ft 4 in (11.38 m)	37 ft 4 in (11.38 m)	37 ft 4 in (11.38 m)
Height	12 ft 4 in (3.76 m)	12 ft 4 in (3.76 m)	12 ft 4 in (3.76 m)	12 ft 4 in (3.76 m)
Wing area	235.94 ft² (21.92 m²)	235.94 ft² (21.92 m²)	235.94 ft² (21.92 m²)	235.94 ft² (21.92 m²)
Empty weight	5,590 lb (2,535 kg)	6,350 lb (2,880 kg)	6,590 lb (2,990 kg)	6,405 lb (2,905 kg)
Loaded weight	7,326 lb (3,323 kg)	8,280 lb (3,760 kg)	8,500 lb (3,855 kg)	7,730 lb (3,505 kg)
Maximum gross takeoff weight	7,600 lb (3,447 kg)	8,810 lb (4,000 kg)	9,350 lb (4,238 kg)	8,860 lb (4,020 kg)
Powerplant	1x Allison V-1710-33, 1,040 hp	1x Allison V-1710-39, 1,150 hp (860 kW)	1x Packard V-1650-1, 1,300 hp	1x Allison V-1710-81, 1,200 hp (895 kW) Late-series P-40N-40 had V-1710-115, 1,360 hp (1,015 kW)
Performance
Maximum speed	352 mph (566 km/h)	360 mph (580 km/h)	364 mph at 20,000 ft (585 km/h)	378 mph (608 km/h) at 5,000 m (16,400 ft)(light version)
Cruise speed	n.a.	270 mph (435 km/h)	n.a.	280 mph (455 km/h)
Range	730-1230 mi (1,173-1,977 km)	650 mi (1,050 km)	700-1500 mi with 141.5 Imp gal drop tank (1k125-2,400 km)	745 mi (1,200 km)
Service ceiling	32,400 ft (9,875 m)	29,000 ft (8,840 m)	34,400 ft (10,500 m)	31,000 ft (9,450 m)
Climb rate	2,860 ft/min (14.5 m/s)	2,100 ft/min (10.7 m/s)	to 6,100 m in 11,6 min	2,240 ft/min (11.4 m/s)
Wing loading	152.3 kg/m²	35.1 lb/ft² (171.5 kg/m²)	176 kg/m²	32.8 lb/ft² (159.9 kg/m²)
Power/mass	0.16 hp/lb	0.14 hp/lb (230 W/kg)	0.15 hp/lb	0.16 hp/lb (260 W/kg)
Armament
	2x12,7 mm and 4x 0.30-inch Browning	6x .50 cal (12.7 mm) Browning M2 machine guns, 281 rounds/gun Up to 1,500 lb (680 kg) of bombs on three hardpoints.	4 or 6 M2, 240-312 rounds/gun 2x227 kg bomb	4x .50 cal (12.7 mm) Browning M2 machine guns Up to 1,500 lb (680 kg) of bombs on three hardpoints.

References

Notes

1. ^ Rossi, J. R. "History." AVG: American Volunteer Group, The Flying Tigers, 1998. Retrieved: 5 July 2011.
2. ^ Jordan, Corey C. (1998-2000). "The Amazing George Welch: Part One - The Tiger of pearl Harbor". Planes and Pilots Of World War Two. http://www.planesandpilotsofww2.webs.com/Welch1.html. 
3. ^ L, Klemen (1999-2000). "Chronology of the Dutch East Indies, 7 December 1941 - 11 December 1941". Forgotten Campaign: The Dutch East Indies Campaign 1941-1942. http://www.dutcheastindies.webs.com/december2.html. 
4. ^ L, Klemen (1999-2000). "The conquest of Java Island, March 1942". Forgotten Campaign: The Dutch East Indies Campaign 1941-1942. http://www.dutcheastindies.webs.com/java.html. 
5. ^ Demin, Anatolii (2000). "Changing from "Donkeys" to "Mustangs" Chinese Aviation In The War With Japan, 1940-1945". Planes and Pilots Of World War Two. http://www.planesandpilotsofww2.totalh.com/ChineseAviationAgainstJapan.html. 
6. ^ "Curtiss P-40E, K, M, N Warhawk/Kittyhawk." Air Force Museum of New Zealand. Retrieved: 5 July 2011.

Bibliography

• Baugher, Joe. "Curtiss P-40 Warhawk, Tomahawk, Kittyhawk." American Military Aircraft.