| P-36 Hawk/Hawk 75/Mohawk | |
|---|---|
_(35522160474).jpg) A P-36C at the Flying Legends Airshow in 2016 | |
| General information | |
| Type | Fighter |
| National origin | United States |
| Manufacturer | Curtiss-Wright Corporation |
| Primary users | United States Army Air Corps |
| Number built | 215 (P-36) plus 900 export Hawk 75 variants |
| History | |
| Introduction date | 1938 |
| First flight | 6 May 1935 |
| Retired | 1954, Argentina |
| Developed into | Curtiss YP-37 Curtiss P-40 Warhawk Curtiss XP-42 |
TheCurtiss P-36 Hawk, also known as theCurtiss Hawk Model 75, is an American-designed and builtfighter aircraft of the 1930s and 40s. A contemporary of theHawker Hurricane andMesserschmitt Bf 109, it was one of the first of a new generation of combat aircraft—a sleek monoplane design with a retractable undercarriage making extensive use of metal in its construction.
Perhaps best known as the predecessor of theCurtiss P-40 Warhawk, the P-36 saw little combat with theUnited States Army Air Forces duringWorld War II. It was the fighter used most extensively and successfully by theFrench Air Force during theBattle of France. The P-36 was also ordered by the governments of the Netherlands and Norway but did not arrive in time to see action before both were occupied by Nazi Germany. The type was also manufactured under license in China, for theRepublic of China Air Force, as well as inBritish India, for theRoyal Air Force (RAF) andRoyal Indian Air Force (RIAF).
Axis andco-belligerent air forces also made significant use of captured P-36s. Following the fall of France and Norway in 1940, several dozen P-36s were seized by Germany and transferred to Finland; these aircraft saw extensive action with theFinnish Air Force against theSoviet Air Forces. The P-36 was also used byVichy French air forces in several minor conflicts; in one of these, theFranco-Thai War of 1940–41, P-36s were used by both sides.
From mid-1940, some P-36s en route for France and the Netherlands were diverted to Allied air forces in other parts of the world. The Hawks ordered by the Netherlands were diverted to theDutch East Indies and later saw action against Japanese forces. French orders were taken up byBritish Commonwealth air forces, and saw combat with theSouth African Air Force (SAAF) against Italian forces in East Africa, and with the RAF over Burma. Within the Commonwealth, the type was usually referred to as theCurtiss Mohawk.
With around 1,000 aircraft built by Curtiss, the P-36 was a commercial success for the company. It also became the basis of theP-40 and two unsuccessful prototypes: theP-37 and theXP-42.
The CurtissModel 75 was a private venture by the company, designed by formerNorthrop Aircraft Company engineerDon R. Berlin. The first prototype, constructed in 1934, featured all-metal construction with fabric-covered control surfaces, a Wright XR-1670-5 radial engine developing 900 hp (670 kW), and typicalUnited States Army Air Corps (USAAC) armament of one .30 in (7.62 mm) and one .50 in (12.7 mm) machine gun firing through the propeller arc. Also typical of the time was the total absence of cockpitarmor orself-sealing fuel tanks. The distinctive landing gear, which rotated 90° to fold the main wheels flat into the thin trailing portion of the wing, resting atop the lower ends of the maingear struts when retracted, was aBoeing-patented design for which Curtiss had to payroyalties.
The prototype first flew on 6 May 1935, reaching 281 mph (452 km/h) at 10,000 ft (3,000 m) during early test flights. On 27 May 1935, the prototype was flown toWright Field, Ohio, to compete in the USAAC fly-off for a new single-seat fighter, but the contest was delayed because theSeversky entry crashed on its way there. Curtiss took advantage of the delay to replace the unreliable engine with a Wright XR-1820-39 Cyclone producing 950 hp (710 kW) and to rework the fuselage, adding the distinctive scalloped rear windows to improve visibility. The new prototype was designatedModel 75B with the R-1670 version retroactively designatedModel 75D. The fly-off finally took place in April 1936. Unfortunately, the new engine failed to deliver its rated power and the aircraft only reached 285 mph (459 km/h).
Although the competingSeversky P-35 also underperformed and was more expensive, it was still declared the winner and awarded a contract for 77 aircraft. However, on 16 June 1936, Curtiss received an order from USAAC for three prototypes designatedY1P-36. The USAAC was concerned about political turmoil in Europe, and about Seversky's ability to deliver P-35s in a timely manner, and therefore wanted a backup fighter. The Y1P-36 (Model 75E) was powered by a 900 hpPratt & Whitney R-1830-13 Twin Wasp engine, and the scalloped rear canopy was further enlarged. The new aircraft performed so well that it won the 1937 USAAC competition with an order for 210P-36A fighters.
The aircraft's extremely low wing loading of just 23.9 lb/ft2 gave it outstanding turning performance,[note 1] and its highpower-to-weight ratio of 0.186 hp/lb gave superb climbing performance for the time. The single speedsupercharger was a serious handicap at high altitudes. Compared to the later Allison-engined P-40, the P-36 shared the P-40's traits of excellent high-speed handling, roll rate that improved at high speed, and relatively light controls at high speed. However, it was underpowered, affecting its acceleration and top speed, and it did not accelerate in a dive as well as the P-40.[citation needed]
Argentina bought a number of the simplified, fixed landing gearHawk 75Os, (intended for rough-field operations and ease of maintenance) and purchased a manufacturing license for the type; 30 were built and delivered by Curtiss, and 20 produced locally. These aircraft used the same engine, Wright Cyclone R-1820-G5 as theMartin 139WAA's andNorthrop 8A-2s used by theArgentine Army Aviation at the time. Usually armed with one 11.35 mm (0.45 in) Madsen machine gun heavily modified for aircraft use and three 7.65 mm (0.30 in)Madsen light machine guns, there was provision for up to 10 30 lb (14 kg) bombs on underwing pylons. The last Argentinian Hawks remained in service until November 1954.[2][3]
In March 1942, 10 USAAC P-36As were transferred to Brazil.
TheRoyal Air Force (RAF) also displayed interest in the aircraft. Comparison of a borrowed FrenchHawk 75A-2 with aSupermarine Spitfire Mk I revealed that the Hawk had several advantages over the early variant of the iconic British fighter. The Hawk was found to have lighter controls than the Spitfire at speeds over 300 mph (480 km/h), especially in diving attacks, and was easier to maneuver in a dogfight (thanks to the less sensitive elevator). The Hawk also had better all-around visibilityand was easier to control on takeoff and landing. Not surprisingly, the Spitfire's superior acceleration and top speed ultimately gave it the advantage of being able to engage and leave combat at will.
Although the British decided not to purchase the aircraft, they soon came into possession of 229 Hawks by way of shipments diverted from occupied France and aircraft flown by escaping French pilots. The aircraft received the designationsMohawk I through IV, mirroring FrenchHawk 75A-1 throughA-4, and were fitted with 0.303-cal. machine guns and conventional throttles (forward to increase power).[4]
Although the Hawk was considered obsolete, a number saw service with the RAF andRoyal Indian Air Force (RIAF) in India and Burma. In April 1941, the government of British India ordered 48 Cyclone-powered Mohawk IVz (Hawk 75A) for the RIAF, to be built byHindustan Aircraft. The first such aircraft completed was test flown on 31 July 1942. Only four additional aircraft were completed before the project was abandoned. However, Chinese license production of theHawk 75A-5 was moved to India, and these aircraft were also absorbed into the RAF/RIAF as Mohawk IVs. They were supplemented by 10 Hawk 75A-9s that were captured in Iran, during theAnglo-Soviet invasion of Iran of August 1941.[5] A further 74 Mohawk IVs that had originally been ordered by France were shipped to India from the United Kingdom.[4] The only RAF units to see combat in Mohawks wereNo. 5 Squadron RAF andNo. 155 Squadron RAF, using the type mainly for bomber escort and ground attack. The type was retired by the RAF/RIAF in 1944.[6]
TheSouth African Air Force received 72 Mohawks. Its first Mohawks were delivered to East Africa in mid-1941, where they were used by3 Squadron SAAF to support operations in theEast African Campaign, taking part in theBattle of Gondar which ended the campaign, and helping to patrol the border with Vichy French heldDjibouti.[7] These Mohawks were then sent to South Africa, where, supplemented by fresh deliveries, they were used for training and for home defense.[8]
The prototype of theHawk 75H—a simplified version with fixed landing gear, like the 75O—was eventually sold to the Chinese Nationalist government who presented it toClaire L. Chennault for personal use. China also received two similar demonstrators, theHawk 75Q. They also used a number of simplifiedHawk 75Ms against the Japanese. On 11 January 1939, five Hawk 75Ms of the veteranCAF 25th Fighter Squadron led by commander Liu Yijun (劉依鈞) were flown to the new wartime capital ofChongqing in preparations for defense duties there; Liu Yijun and his four specially-trained Hawk 75 pilots all died in the crash of transport aircraft in the return flight.[9] These Hawk 75Ms were intended for the newly established 16th and 18th Fighter Squadrons that were previously light attack-bomber squadrons, but did not supersede the increasingly obsolescentPolikarpov I-15 andI-16 that formed the backbone of most of China's fighter squadrons from 1938 to 1941.[10] TheHawk 75A-5 was built under license in China, but production was later moved to India, and these aircraft were absorbed into the RAF as the Mohawk IV.
After thefall of France, Germany agreed to sell captured Curtiss Hawk fighters to Finland in October 1940. In total, 44 captured aircraft of five subtypes were sold to Finland with three deliveries from 23 June 1941 – 5 January 1944.[11] Not all were from the French stocks, 13 were initially sold to Norway and captured when the Germans conquered that country.[12] The aircraft were given serial codes CU-501 to CU-507 (A-4 submodel with Cyclone) and CU-551 to CU-587 (all other submodels with Twin Wasp).
In Finnish service, the Hawk was well liked, affectionately calledSussu ("Sweetheart").[13] The Finnish Air Force enjoyed success with the type, credited with 190⅓ kills by 58 pilots, between 16 July 1941 and 27 July 1944, for the loss of 15 of their own.[11] Finnish Hawk pilots included the type's highest-scoring ace,Altto Kalevi "Kale" Tervo, with between 14¼ and 15¾ victories in the type; another ace,Kyösti "Kössi" Karhila, scored 12¼ or 13¼ of his 32¼ victories in the Hawk.[14][15]
The Finnish Hawks were initially armed with either four or six 7.5mm machine guns. While sufficient during the early phase of theContinuation War, the increasing speeds and armor of Soviet aircraft soon showed this armament was not powerful enough. From 1942, theState Aircraft Factory replaced the fuselage machine guns with either one or two .50 in (12.7 mm) Colt orBrowning FN machine guns and installed two or four .303 in (7.7 mm) Browning machine guns in each wing. The 12.7mmBerezin UB or LKk/42 heavy machine guns were also used.[11] The installation of heavier armament did not change the very good flying characteristics of the fighter, and the armament was much more effective against Soviet aircraft. The Finnish Hawks were also equipped with Revi 3D or C/12D gunsight.
Surviving Finnish aircraft remained in service with the FAF aviation unitsHLeLv 13,HLeLv 11 andLeSK until 30 August 1948, when the last operational Finnish Hawks were put into storage. In 1953, the stored aircraft were scrapped.[11][16]
Even before the P-36A entered production, the French Air Force entered negotiations with Curtiss for delivery of 300 aircraft. The negotiating process ended up being very drawn-out because the cost of the Curtiss fighters was double that of the FrenchMorane-Saulnier M.S.406 andBloch MB.150, and the delivery schedule was deemed too slow. Since the USAAC was unhappy with the rate of domestic deliveries and believed that export aircraft would slow things down even more, it actively opposed the sale. Eventually, it took direct intervention from U.S. PresidentFranklin Roosevelt to give the French test pilotMichel Detroyat a chance to fly the Y1P-36.
Detroyat's enthusiasm, problems with the MB.150, and the pressure of continuing German rearmament finally forced France to purchase 100 aircraft and 173 engines. The firstHawk 75A-1 (orH75A-1 n°1) arrived in France in December 1938 and began entering service in March 1939. A few months later, this aircraft was part of "Groupe de Chasse II/5 La Fayette" (heir of theEscadrille Lafayette that fought in France during World War I), wearing the famous Sioux Head on its fuselage side. After the first few examples, aircraft were delivered in pieces and assembled in France by theSociété Nationale de Constructions Aéronautiques du Centre.
Officially designated as theCurtiss H75-C1 (the "Hawk" name was not used in France), the aircraft were powered by Pratt & Whitney R-1830-SC-G engines of 900 hp and had instruments calibrated for the metric system, a seat for French dorsal parachutes, a French-style throttle which operated in reverse from U.S. and British aircraft (full throttle was to the rear rather than to the front) and armament of four (later models had six with two firing through the prop and four in the wings)7.5 mmFN-Browning machine guns, aimed with a French-supplied Baille-Lemaire gun sight. The aircraft evolved through several modifications, the most significant being the installation of the Wright R-1820 Cyclone engine. The H75-C1 variant saw little operational use due to its late delivery and reliability problems with the Wright radial engine. A total of 316 H75s were delivered to France before the German occupation.[17]
On 20 September, SergeantAndré-Armand Legrand, pilot of the H75A-1 n°1 in theGroupe de Chasse II/5 La Fayette was credited of the first Allied air victory ofWorld War II on the Western front with shooting down aMesserschmitt Bf 109E of theLuftwaffe3/JG 53, overÜberherrn. During 1939–1940, French H75 pilots claimed 230 air-to-air kills (of a total of 1,009 air-to-air kills by the French Air Force during 1939–1940) and 81 probable victories in H75s against only 29 aircraft lost in aerial combat.[18] While making up only 12.6 per cent of the French Air Force single-seater fighter force, the H75 accounted for almost a third of the air-to-air kills during the 1940 Battle of France.[17]
Of the 11 Frenchaces of the early part of the war, seven flew H75s. The leading ace of the time was LieutenantEdmond Marin la Meslée with 15 confirmed and five probable victories in the type. H75-equipped squadrons were evacuated toFrench North Africa before theArmistice to avoid capture by the Germans. While under theVichy government, these units clashed with British aircraft during theBattle of Mers El-Kebir and theBattle of Dakar. DuringOperation Torch in North Africa, French H75s fought against U.S. NavyF4F Wildcats, losing 15 aircraft while shooting down seven American aircraft. From late 1942, the Allies started re-equipping the formerly Vichy-controlled French H75 units with P-40s andP-39s; despite this they still saw limited service with theFree French Air Forces.[19]
TheHawk 75A-9 variant was also ordered by theImperial State of Iran (previously Persia). In or before mid-1941, 10 of these aircraft arrived in Iran, partly-assembled and in crates. They had not been assembled by the time of theAllied invasion of Iran. Seized by Commonwealth forces, these Hawk 75s were shipped to India, where they were assembled and used by the RAF/RIAF, as theMohawk Mk. IV.
In October 1939, the Netherlands ordered 24 Hawk 75A-7s for their colonies of theDutch East Indies (Oost Indië). These planes were powered by 1,200 hp Cyclones. Factory armament was one .50 inch and one .303 inch machine gun in the cowl with two .303 machine guns in the wings. After delivery, the .50 weapons were replaced to standardize parts and ammunition. The plane could carry six 23 kg (51 lb) bombs. The fighters were shipped in 1940 and almost rerouted to the Netherlands when Germany invaded. But as the mainland surrendered, the aircraft continued to the colonies where they were used extensively against the Japanese attack on the Far Eastern part of the kingdom. By that time, the aircraft had flown so many hours that the engines were showing serious wear and tear.
Most Dutch Hawks were assigned to the1ste JachtVliegAfdeling - VliegtuigGroep IV (1ste JaVA - 1-VlG IV; "1st Fighter Squadron - Flying Group IV") of theRoyal Netherlands East Indies Army Air Force (ML-KNIL), although some flew with 1-VlG V. These aircraft saw action over Malacca, Sumatra and Java, successfully bombing the railroad and intercepting bombers and participated in the extensive dogfights over Soerabaja, where USAAF, RAF and ML aircraft fought Japanese bombers and fighters together.
Norway ordered 24 Twin Wasp-poweredHawk 75A-6s, of which 19 were delivered and seven assembled at the time of the German invasion. None of the aircraft were combat-ready. The disassembled aircraft were disabled by a single customs employee who smashed the instruments and cut all the wires he could reach.[citation needed] Thirteen Norwegian Hawks captured by the Germans were part of the first batch of 29 P-36s sent to Finland.[12] Norway also ordered 36 Cyclone-poweredHawk 75A-8s. Most of this batch (a total of 30) were delivered as advanced trainers to "Little Norway" near Toronto, Ontario, Canada, a Norwegian training base established by the London-based government-in-exile.[20] Still later, they were resold to the U.S. and redesignated the P-36G model.[21]
In 1943, the U.S. sent 28 Hawks to Peru under theLend-Lease agreement. These were ex-Norwegian P-36Gs that had served in Canada.
Portugal was officially neutral during World War II, although the Allies were allowed to use or establish ports and airfields on various Portuguese territories. One result of these friendly relations was the transfer by the British government of 12 Hawk 75A variants to thePortuguese Air Force, orForça Aérea Portuguesa (FAP), which assigned them to air defense duties in theAzores.
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A few Hawk 75Ns were used by Thailand during theFrench-Thai War. They also fought at theBattle of Prachuab Khirikhan against Japanese forces during theJapanese Invasion of Thailand. On 28 January 1941, theRoyal Thai Air Force (RTAF) dispatched nine Ki-30 Nagoyas, escorted by three Hawk 75s, to bomb Pailin and Sisophon in French Indochina. Thailand was perhaps the only country operating both Japanese and American aircraft just before World War II.[22]
The first production P-36As were delivered to the20th Pursuit Group atBarksdale Field inLouisiana in April 1938. The aircraft's service history was marred by numerous teething problems with the engine exhaust, skin buckling over landing gear, and weak points in the airframe, severely restricting the performance envelope. By the time these issues were resolved, the P-36 was considered obsolete and was relegated to training units and overseas detachments atAlbrook Field in thePanama Canal Zone,Elmendorf Field inAlaska, andWheeler Field inHawaii.
The P-36s had been delivered to Hawaii in February 1941 by being loaded on the aircraft carrier USSEnterprise in California, then in a first for the USAAC, flown off the carrier's deck by the P-36's U.S. Army Air Corps pilots when theEnterprise neared the coast of Hawaii. This saved considerable time over the traditional shipping method of having the fighters first disassembled, crated and then loaded by crane in the hold of a freighter, then unloaded and reassembled in Hawaii.[23]
The only combat by U.S.-operated P-36s took place during the Japanese attack onPearl Harbor. Five of the 39 P-36A Hawks at Pearl Harbor, delivered previously by the USSEnterprise, were able to take off during the attack and were credited with shooting down two JapaneseMitsubishi A6M2 Zeros for the loss of one P-36, thereby scoring U.S. aerial victories that were among the first of the Second World War.[24]
Data from Curtiss Fighter Aircraft: A Photographic History 1917–1948[36][37]
General characteristics
Performance
Armament
Related development
Aircraft of comparable role, configuration, and era
Related lists
