The Curtiss R-36 was a new generation of monoplane fighter aircraft that entered service with the US Army Air Corps. It was quite comparable with the Spitfire Supermarine, Hurricane and Messerschmitt Bf.109 fighters, which first flew in the middle of the 30-s, at intervals of several months. And although the P-36 is almost nothing left of the Curtiss biplanes, he retained the nickname "Hawk", characteristic of the company's aircraft.
The prototype of the P-36 fighter was the “Model 75” project, which was developed by order of the army to participate in the competition for a new fighter, the start of which was planned for May 1935. Although Curtiss lost the first place in the competition, it really turned out to be the winner, winning the contract for 227 aircraft for the army air corps and putting the 753 fighter for export. In addition, at least 25 aircraft were built under license in other countries.
The 75 model really had little to do with previous Curtiss aircraft. The chief designer of the project was Donovan Berlin, who switched to Curtiss from Northrop and brought many new ideas from the last job. Experienced aircraft received civil registration X-17Y. It was an all-metal monoplane with fabric covering only on the steering surfaces. The cabin was closed with a backward-moving lantern, turning into a tall gargrot. The main landing gear and tail wheel were removed. The main pillars were retracted back into the wing with a twist of the 90 °. This cleaning mechanism was originally developed by Boeing, which retained its copyright on it, receiving a license payment from each aircraft equipped with such a landing gear kinematics. The wing was made of two consoles connected on the line of symmetry of the aircraft. The consoles were sealed caissons to provide a forced landing on the water. The flaps were split with a hydraulic control system. Initially, the weapons met the American standards of the time - 12,7-mm and 7,62-mm synchronous machine guns (one by one). Neither the pilot’s armor or the tanks were designed.
The assembly of the prototype machine began in November 1934. Initially, the aircraft was equipped with a Wright XR-1670-5 air-cooled engine with a power of 900 hp, which turned out to be unsuccessful. The first flight of the "75 model" took place in May 1935. During the subsequent tests, the test aircraft showed a speed of up to 3050 km / h at an altitude of 450 m, a ceiling of 9150 m and a range of 860 km.
27 May 1935, the Curtiss offered a "75 model" for the competition, organized by the Army Air Corps Supply Division. However, the “75 model” turned out to be the only flight competitor at the time of the planned test start date. The main competitor, a double fighter Seversky SEV-2HR, was "heavily damaged" during the distillation at Wright-field, and not staying on time. The SEV-2XP was returned to the company, where it was converted into a single-seat fighter with retractable landing gear. As a result, the competition was suspended until the readiness of SEV-1ХР. Finally, the 15 August fighter Seversky appeared on Wright Field under a new designation. Another competitor, the Northrop 2A, immediately after the first take-off of July 30 fell into the ocean.
Curtiss tried to protest, since the delay in the start of the competition clearly played into the hands of Seversky, and persuaded the army to postpone the final decision on choosing the winner until April 1936. During the first tests, the "Model 75" with the XR-1670-5 engine proved to be unsatisfactory. So Don Berlin took advantage of the delay in the tender to install the 1535hp Pratt & Whitney R-700 engine. Since this 9-cylinder in-line engine no longer had any development prospects, it was also quickly replaced by the Wright HR-1820-39 (G5) Cyclone, with a takeoff power of 950 hp. With this engine, the prototype aircraft received the designation Model 75B (the designation Model 75A was reserved for the export version of the Hawk). The final version of the "Model 75B" was distinguished by a reinforced canopy and glazed "ears" in the gargrotto behind the cockpit, which slightly improved the view back.
The new Cyclone engine turned out to be almost as unsuccessful as its predecessor R-1670, and also did not deliver the declared power. During the tests at Wright Field had to change four engines. In addition, there were problems with the compatibility of the new engine and airframe. On the "75В model" it was possible to reach speeds of only 456 km / h instead of 470 km / h guaranteed by the company. And although the Seversky firm also did not keep its promises, the fighter presented by it was more expensive than the Curtiss option, the “75В model” lost the competition, and the order for the 77 aircraft was received by the Seversky P-35.
Despite the fact that the “75 model” was never officially acquired by the army, in some sources this aircraft is called the XP-36, which more closely follows the logic of the development of events than the real stories. Experienced aircraft "model 75" after equipping the Wright engine SCR-1670-G5 with the power 900 hp later received the brand designation "model 750". After the conversion, the aircraft was delivered to the army under the designation XP-37.
On June 16, 1936, Curtiss received an order from the Supply Department for three "Model 75B" prototypes under the official designation Y1P-36. The main reason for the renewed interest in Hawk was the inability of Seversky's firm to keep up with the delivery schedule. The brand name was Model 75E. At the request of the army, the planes were equipped with Pratt & Whitney R-1830-13 Twin Wasp aircraft engines - the same type as the P-35. "Twin Wasp" produced 3600 hp at an altitude of 900 m. at 2550 rpm, and takeoff power was raised from 950 to 1050 hp. The propeller was a Hamilton Standard, a three-blade, constant-speed automatic machine. The armament corresponded to the standards of that time - one 7,62-mm and one 12,7-mm synchronous machine gun. They differed from the first prototype Y1P-36 only in the engine and enlarged glazed "ears" in the gargrot.
The first Y1P-36 joined the army in March 1937 of the year and was tested at Wright Field in June of the same year. Test pilots met the aircraft very well, especially noted the good maneuverability of the aircraft. Control of the aircraft was easy and efficient in the entire speed range, the aircraft was stable and well controlled on the ground. The pilots did not like the curved visor of the cockpit canopy, which introduces distortion, poor cockpit ventilation, as well as the location of the controls for cleaning the chassis and flaps. Thus, the R-1830 engine version was positively received by the army, and on July 7 the 1937 was followed by an order for the X-NUMX Р-210А - the largest order for military aircraft in the USA since the First World War. For the first time, Curtiss initiative development received a well-deserved assessment.
The production aircraft differed from the Y1P-36 by additional louvers on the engine hood and "frog eyes" - fairings over the machine gun ports. The final version of the R-36A received the Pratt & Whitney R-1830-13 engine with a capacity of 1050 hp. and the Curtiss-Electric automatic propeller.
Even before readiness, one of the P-36A was converted into an experienced XP-40 ("model 75Р"), and another copy into an experienced XP-42 ("model 75S"). The first of these was the prototype for a production aircraft.
Another of the P-36s was circled in the fall of the 1938 of the year with the R-1830-25 engine, which had take-off power in the 1100 hp. The designation of the aircraft changed to P-36В. The maximum speed reached 500 km / h. Later, the aircraft was again converted into a standard P-36A.
The P-XNUMHA from its modern fighters ("Spitfire" or "Hurricane") was distinguished by relatively weak weaponry. As a result, one of the machines was experimentally equipped with an additional pair of rifle-caliber wing machine guns. The installation was considered successful and the last 36 aircraft on request were refined accordingly. At the same time, they received a new designation P-30С. The new modification also differed in the R-36-1830 engine (take-off power of the 17 hp). All these modifications of the production machines were approved by 1200 January 16 of the year. Externally, the serial P-1939C differed from the P-36A in cartridge boxes of wing machine guns, slightly protruding under the wing. Despite their additional air resistance, thanks to the installation of the new engine, the speed even increased.
The P-36 with serial number 38-174 in January 1939 was withdrawn from the combat squadron to equip with four 7,62-mm wing-powered machine guns with tape feed. Simultaneously, two large-caliber synchronous machine guns were installed on the aircraft. After revision, it received the designation XP-36D.
Another P-36A number 38-147 was equipped with new wing consoles with installation of four 7,62-m machine guns with tape feed (as on the "Spitfire" and "Hurricane") in each. The synchronous 12,7-mm machine gun was left but turned off. The aircraft received the code number XP-36E.
The designation XP-36P was assigned to the P-36А, equipped with two 23-mm guns of the system of the Danish company Madsen, in the underwing fairing. In this case, synchronous machine guns were left. The installation of additional weapons led to an increase in take-off weight to 3110 kg, and the speed dropped to 424 km / h. Therefore, the guns were removed, the aircraft was remade back to P-36, and finally it was written off in the fall of 1944.
The designation “model 75A” was worn by an aircraft that remained at the firm as a demonstration and had civil registration NX22028. On it, the company conducted a number of different experiments. At first, the aircraft was equipped with a mechanically driven supercharger placed under the engine and wore the designation “model 75J. Later, the aircraft was equipped with an R-1830-SC2-G engine with a turbocharger. The turbocharger was placed below the nose of the fuselage, immediately behind the engine hood. ". Empty weight was 75 kg, take-off-2303 kg. During the tests at the beginning of 2798, the speed 1939 km / h was achieved. However, the low reliability and complexity of the turbocharger forced the army air corps to abandon its mustache Installing the P-528, ordering a Seversky (Republic of) XP-36 turbo-compressor equipped instead, representing the development of the P-41. as a demo.
The first serial P-36A was delivered to Wright Field in mid-April 1938. The first to receive them was the 20-I Fighter Group, which had previously been armed with a Boeing Р-26. However, once in the front, the Curtiss fighters demonstrated a whole “bunch” of innumerable flaws and failures. In the area of landing gear swelling of the wing skin, which caused the need to mount reinforcing plates. Delivered problems exhaust manifold, and the fuselage was not strong enough. Despite the ongoing improvements, the P-36A stayed on the ground for a longer time after the next flight ban. There was a time when there were only six P-20Аs in the flying state in the 36-I fighter group, and those flying only with a multitude of restrictions in speed, flight and overload.
The 1 th fighter group in Sel-fridge-Field, Michigan, also planned to rearm R-1938A in 36. However, this group was forced to wait for the results of the hard work on fine-tuning the fighter in Buffalo. In the end, in 1938, P-36А received only 94-I squadron, which used them together with Seversky P-35.
In 1939, three more squadrons of the 36 fighter group were reequipped on the P-8. By the beginning of the 1941, the P-36 was obviously outdated and had already been replaced in the combat units of the army Air Force (as the army air corps had come to be called), and the remaining vehicles were handed over to the training units. By the time the Japanese attacked Pearl Harbor, the P-36 was used in the 35 training group in Muffett Field, California, and in the 36 training group in Langley Field, Virginia. P-36 was used there as a transitional training aircraft for new types of fighters. The remaining P-36 were sent overseas. So, they received the 16-I and 32-I fighter groups in the area of the Panama Canal. Moreover, these groups continued to use the already archaic Boeing P-26. In February, the 1941 of the year, the 20 of the dismantled P-36, were sent to Alaska, where they entered into service with the 23-th squadron at Elmendorf-field. Simultaneously, the 31 P-36 was sent to Hawaii aboard the aircraft carrier Enterprise.
During the raid on Pearl Harbor, his anti-aircraft defense was provided by 14 Р-26А, 39 Р-36А and 99 Р-40. Most of these vehicles were destroyed or damaged on the ground during the first minutes of the raid. But four P-36s from the 46 squadron were able to rise into the air before the raid of the second wave of Japanese aircraft and attack the nine Nakajima B5М1 bombers. Two Japanese aircraft were shot down - these were the first victories of the US Army Air Forces during the war in the Pacific.
After Pearl Harbor fighter is no longer used by the US Air Force. P-36 were quickly removed from the weapons of combat units and handed over to training units. Ten P-36 were transferred to Brazil in March 1942.
Shortly before the Nazis occupied Norway, the Norwegian government planned to order the 36 Hawk-75-8, the export version of the P-36. As a result, after the readiness of these machines, they were acquired by the US government. In February, six 1941 aircraft were transferred to the armed forces of Free Norway in Canada, where they were used to train fighter pilots in the so-called “Little Norway” near Toronto. The remaining A-8 were adopted by the US Army under the designation P-36C. The aircraft were equipped with Wright R-1820-G205 "Cyclone" engines with take-off power 1200 hp, which in the arsenal of the US Army were called R-1820-95. Since the aircraft was of dubious combat value, and also due to the fact that the rest of the P-36 were equipped with other engines, they were transferred to Lend-Lease Peru in 1943 g. One of them is now stored in the museum of the Peruvian Air Force.
Although the P-36 was not actually used in the battles by the Americans themselves, he had to fight quite a bit as part of the air forces of other countries. Moreover, it was one of the few American planes that had a chance to fight on the other side. But about it in the following part of article.
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