Polikarpov I-180
Encyclopedia
The Polikarpov
I-180 was a 1938
Soviet fighter aircraft
prototype. It was the last attempt to extract performance from the basic Polikarpov I-16
design. The development cycle was plagued with problems and the death of the Soviet hero pilot Valery Chkalov
in one of the prototypes effectively ended Nikolai Nikolaevich Polikarpov
's career as an aircraft designer.
design in order to take advantage of the more powerful two-row radial engine
s. It was designed to meet a requirement of the Soviet Air Force
of January 1938 for a new interceptor aircraft
with a radial engine. It was preceded by a series of projected I-16 variants with a stronger M-88 two-row radial engine: I-161, I-162, I-163, I-164, I-165, I-166 and I-167. The I-180 was a single-engine, low-wing monoplane fighter aircraft of mixed construction with a duraluminum frame covered in plywood
and fabric. The pilot sat near the tailfin in an open cockpit with a windshield similar to I-16. Landing gear was retracted pneumatically with a retractable tail wheel. The main visual difference between I-180 and I-16 was a new wing with a perpendicular straight leading edge, and an aerodynamically refined fuselage with longer slim engine cowling. The new fighter was to be powered by an 820 kW (1,100 hp) M-88 engine, a development of the license-built Gnome-Rhône Mistral Major
(known as M-85 in USSR), and represented the next step in evolution from the 1937
I-165-11 prototype. The proposed armament consisted of four 7.62 mm (.3 in) ShKAS machine gun
s and 200 kg (440 lb) of bombs. Dmitriy Tomashevich was assigned as the lead designer.
The ill-fated development of the I-180 started early on. The only version of M-88 available at the time used reduction gear requiring a very large propeller at least 3.2 m (10 ft 6 in) in diameter – massive for an aircraft that in layout and dimensions resembled an I-16 with an elongated nose. Even before leaving the drawing board, the fighter had to be redesigned for M-88R with reduction gear and a constant speed propeller. The projected top speed fell from 572 km/h (355 mph) to 557 km/h (345 mph). The first prototype however was eventually fitted with similar M-87 950 hp engine, because M-88R was not ready. The prototype was built at Number 156 factory in Moscow.
took off and made a low altitude circuit around the airfield. For the second circuit, Chkalov flew farther away, climbing to over 2,000 m (6,560 ft) even though the flight plan specifically forbade exceeding 600 m (1,970 ft). Chkalov apparently miscalculated his landing approach and came in short of the airfield but when he attempted to correct the engine stalled. The pilot was able to avoid several buildings but crashed into a powerline. Chkalov was ejected from the cockpit, sustained injuries and died two hours later.
The official government investigation concluded that the engine stalled because it became too cold in the absence of the cowl flaps. Others hypothesized that Chkalov rapidly advanced the throttle and flooded the engine. As the result of the crash, Tomashevich and several other officials, including Arms Industry Department director S. Belyakin, who urged the first flight, were immediately arrested. Years later, fellow test pilot M.M. Gromov
blamed the designers for flawed engine cooling and Chkalov himself for deviating from the flight plan. Chkalov's son also claimed that a plan to assassinate his father had been in the works in the months preceding his death but the circumstances of the crash make foul play unlikely. Regardless, with Chkalov's death Polikarpov's reputation with Joseph Stalin
suffered a blow from which he would never recover.
Nevertheless, work on I-180 continued. The second prototype I-180-2 with a bigger wingspan of 10.09 m (33 ft 1 in) and M-87A engine flew on 27 April 1939, and participated in the May Day
parade a few days later. Later, the engine was changed to M-87B and the wing construction was strengthened. The prototype demonstrated a top speed of 540 km/h (335 mph) and was recommended for mass production with the M-88 engine. Then, on 5 September 1939, I-180-2 piloted by Tomas Suzi crashed during high altitude testing, killing the pilot. Again, the exact circumstances of the crash were unclear. According to eyewitnesses, the aircraft steeply dove (others claimed it fell in a spin) to 3,000 m (9,840 t) where it leveled out, then entered a spin again leveling out once more at 300 m (985 ft). The pilot then abandoned the aircraft but did not use his parachute. No definite explanation was ever given but hypotheses include blinding of the pilot by oil from a leaking oil cooler, a heart attack, or loss of consciousness due to failure of oxygen equipment.
Preparations were carried out in 1940 to produce the first batch of 10 aircraft at Factory No.21 in Gorki
, engaged in manufacturing the I-16. However, their production was extremely slow, without much attention of the aviation authorities, with the first 10 aircraft taking more than eight months. One of the reasons for this was that the local OKB
led by M.M. Pashinin was designing their own I-16 based fighter, the Pashinin I-21
and factory management had devoted all of their resources to the hometown favorite, with only six brand new engineers assigned to production of the I-180. While this was being investigated, the third prototype I-180-3, powered by a more powerful M-88R engine and fitted with a stressed skin wing (replacing the I-16 type wing structure of the previous prototypes) was completed, flying on 10 February 1940. It was armed with two 12.7 mm Berezin BS and two 7.62 mm ShKAS machine guns on a common gunbed over the engine.
Finally in April 1940, three aircraft designated I-180S were completed, these being similar to the I-180-3, but reverting to an open cockpit and the I-16 type wing structure. Their test flights were favorable. The new fighter resembled I-16 in agility but was more stable. Top speed was 575 km/h (357 mph). Major criticisms included the open canopy and poor build quality. It was believed that fixing these defects would raise the top speed to 600 km/h (373 mph). However, the I-160-3 prototype crashed on 6 July 1940, when it entered an inverted spin due to pilot error. The pilot was able to safely bail out. In preparation for production, Polikarpov produced the definitive I-180-5 with several modifications and M-88A engine without reduction gear. The aircraft could also accept the new M-89 engine with 1,007 kW (1,350 hp) (up to 1,165 kW (1,560 hp) with fuel injection) which would raise its top speed to over 650 km/h (404 mph). There was also a proposal for I-180Sh with improved main landing gear.
Then, near the end of 1940, Polikarpov was suddenly informed that I-180 was being cancelled, and the factory no.21 would manufacture LaGG-3 fighters instead. The reason for this was a misconception of the Ministry of Aviation Industry, that radial engines in NACA cowling
s were poorly suited for aircraft with top speeds of over 500 km/h (310 mph) due to high drag. Former government officials later admitted that the fascination with liquid cooled engines stemmed in part from attempts to imitate the then state-of-the-art Messerschmitt Bf 109
. Stalin's dislike for Polikarpov after Chkalov's death likely also played a role.
According to some recent historians, like Mikhail Maslov, a cancellation of the I-180 was caused by personal and non content-related reasons and might be considered an error. Especially after Chkalov's death, the Soviet authorities started to promote young designers, as an opposition to Polikarpov, despite the I-180 was the best performing Soviet fighter at the time of its cancellation and it was faster than the Bf 109. One of information series I-180 developed a speed of 585 km/h, that could be improved after projected changes, like adding a closed canopy. The next best fighter, Yakovlev's I-26 (Yak-1 prototype), suffered from a troublesome and protracted development cycle, but Alexander Sergeyevich Yakovlev
was one of Stalin's favorites which most likely saved his design. In addition, the I-180 could be available much earlier than Yak-1 and LaGG-3 types, and there was a possibility to produce it with a temporary M-87 engine, until the M-88 would be improved. Crashes of I-180 prototypes were mostly accidental, and should not be regarded as disqualifying the design. Moreover, the I-180 showed much less "teething problems" than its counterparts, especially Yak-1, confirming Polikarpov's competence in aircraft designing. Another advantage was, that a construction of the I-180 was similar to the I-16, which was familiar to the Soviet industry and pilots, but handling of the I-180 was even easier and it was more stable. The same situation repeated with the next Polikarpov's design, the advanced I-185
, basing on the I-180 design.
Polikarpov
Polikarpov Design Bureau was a Soviet OKB for aircraft, led by Nikolai Nikolaevich Polikarpov. After his death on 30 July 1944 at the age of 52, his OKB was absorbed into Lavochkin, but with some of its engineers going to Mikoyan-Gurevich and its production facilities going to Sukhoi...
I-180 was a 1938
1938 in aviation
This is a list of aviation-related events from 1938:- Events :* Imperial Airways inaugurates scheduled service from London to Montreal. Pan American World Airways is banned from British airports out of fears that more advanced U.S...
Soviet fighter aircraft
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...
prototype. It was the last attempt to extract performance from the basic Polikarpov I-16
Polikarpov I-16
The Polikarpov I-16 was a Soviet fighter aircraft of revolutionary design; it was the world's first cantilever-winged monoplane fighter with retractable landing gear. The I-16 was introduced in the mid-1930s and formed the backbone of the Soviet Air Force at the beginning of World War II...
design. The development cycle was plagued with problems and the death of the Soviet hero pilot Valery Chkalov
Valery Chkalov
Valery Pavlovich Chkalov was a Russian aircraft test pilot and a Hero of the Soviet Union .-Early life:...
in one of the prototypes effectively ended Nikolai Nikolaevich Polikarpov
Nikolai Nikolaevich Polikarpov
Nikolai Nikolaevich Polikarpov was a Soviet aeronautical engineer and aircraft designer, known as "King of Fighters". He designed the I-15 series of fighters, and the I-16 Ishak "Little Donkey" fighter....
's career as an aircraft designer.
Design and development
The I-180 represented a further development of the basic I-16Polikarpov I-16
The Polikarpov I-16 was a Soviet fighter aircraft of revolutionary design; it was the world's first cantilever-winged monoplane fighter with retractable landing gear. The I-16 was introduced in the mid-1930s and formed the backbone of the Soviet Air Force at the beginning of World War II...
design in order to take advantage of the more powerful two-row radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
s. It was designed to meet a requirement of the Soviet Air Force
Soviet Air Force
The Soviet Air Force, officially known in Russian as Военно-воздушные силы or Voenno-Vozdushnye Sily and often abbreviated VVS was the official designation of one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces...
of January 1938 for a new interceptor aircraft
Interceptor aircraft
An interceptor aircraft is a type of fighter aircraft designed specifically to prevent missions of enemy aircraft, particularly bombers and reconnaissance aircraft. Interceptors generally rely on high speed and powerful armament in order to complete their mission as quickly as possible and set up...
with a radial engine. It was preceded by a series of projected I-16 variants with a stronger M-88 two-row radial engine: I-161, I-162, I-163, I-164, I-165, I-166 and I-167. The I-180 was a single-engine, low-wing monoplane fighter aircraft of mixed construction with a duraluminum frame covered in plywood
Plywood
Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...
and fabric. The pilot sat near the tailfin in an open cockpit with a windshield similar to I-16. Landing gear was retracted pneumatically with a retractable tail wheel. The main visual difference between I-180 and I-16 was a new wing with a perpendicular straight leading edge, and an aerodynamically refined fuselage with longer slim engine cowling. The new fighter was to be powered by an 820 kW (1,100 hp) M-88 engine, a development of the license-built Gnome-Rhône Mistral Major
Gnome-Rhône Mistral Major
|-See also:-References:* Danel, Raymond and Cuny, Jean. L'aviation française de bombardement et de renseignement 1918-1940 Docavia n°12, Editions Larivière...
(known as M-85 in USSR), and represented the next step in evolution from the 1937
1937 in aviation
This is a list of aviation-related events from 1937:- Events :* The Hawker Hurricane enters service as the Royal Air Forces first monoplane fighter....
I-165-11 prototype. The proposed armament consisted of four 7.62 mm (.3 in) ShKAS machine gun
ShKAS machine gun
The ShKAS is a 7.62 mm machine gun widely used by Soviet aircraft in the 1930s and during World War II...
s and 200 kg (440 lb) of bombs. Dmitriy Tomashevich was assigned as the lead designer.
The ill-fated development of the I-180 started early on. The only version of M-88 available at the time used reduction gear requiring a very large propeller at least 3.2 m (10 ft 6 in) in diameter – massive for an aircraft that in layout and dimensions resembled an I-16 with an elongated nose. Even before leaving the drawing board, the fighter had to be redesigned for M-88R with reduction gear and a constant speed propeller. The projected top speed fell from 572 km/h (355 mph) to 557 km/h (345 mph). The first prototype however was eventually fitted with similar M-87 950 hp engine, because M-88R was not ready. The prototype was built at Number 156 factory in Moscow.
Testing and evaluation
The constant speed propeller VISh-23Ye was delayed and early test runs were done with a different propeller with manual pitch control (VISh-3Ye). As the result, the engine was prone to overheating and to deal with this the cowing flaps restricting airflow around the engine were removed. Despite these problems, and a fact, that the prototype had not finished all ground tests, the authorities were demanding a test flight as soon as possible, according to a plan. Polikarpov himself objected to flying the prototype before it would be ready around February 1939, but he could not stop it. The series of events which took place on 15 December 1938, is not entirely clear but tragic. Neither Polikarpov nor Tomashevich approved the first flight, and no one had signed the form releasing the prototype from the factory. The famous Soviet test pilot Valery ChkalovValery Chkalov
Valery Pavlovich Chkalov was a Russian aircraft test pilot and a Hero of the Soviet Union .-Early life:...
took off and made a low altitude circuit around the airfield. For the second circuit, Chkalov flew farther away, climbing to over 2,000 m (6,560 ft) even though the flight plan specifically forbade exceeding 600 m (1,970 ft). Chkalov apparently miscalculated his landing approach and came in short of the airfield but when he attempted to correct the engine stalled. The pilot was able to avoid several buildings but crashed into a powerline. Chkalov was ejected from the cockpit, sustained injuries and died two hours later.
The official government investigation concluded that the engine stalled because it became too cold in the absence of the cowl flaps. Others hypothesized that Chkalov rapidly advanced the throttle and flooded the engine. As the result of the crash, Tomashevich and several other officials, including Arms Industry Department director S. Belyakin, who urged the first flight, were immediately arrested. Years later, fellow test pilot M.M. Gromov
Mikhail Gromov (aviator)
Mikhail Mikhaylovich Gromov was a famous Russian aviator and Hero of the Soviet Union.On 12-14 July 1937, Mikhail Gromov, A. B. Yumashev and S. A...
blamed the designers for flawed engine cooling and Chkalov himself for deviating from the flight plan. Chkalov's son also claimed that a plan to assassinate his father had been in the works in the months preceding his death but the circumstances of the crash make foul play unlikely. Regardless, with Chkalov's death Polikarpov's reputation with Joseph Stalin
Joseph Stalin
Joseph Vissarionovich Stalin was the Premier of the Soviet Union from 6 May 1941 to 5 March 1953. He was among the Bolshevik revolutionaries who brought about the October Revolution and had held the position of first General Secretary of the Communist Party of the Soviet Union's Central Committee...
suffered a blow from which he would never recover.
Nevertheless, work on I-180 continued. The second prototype I-180-2 with a bigger wingspan of 10.09 m (33 ft 1 in) and M-87A engine flew on 27 April 1939, and participated in the May Day
May Day
May Day on May 1 is an ancient northern hemisphere spring festival and usually a public holiday; it is also a traditional spring holiday in many cultures....
parade a few days later. Later, the engine was changed to M-87B and the wing construction was strengthened. The prototype demonstrated a top speed of 540 km/h (335 mph) and was recommended for mass production with the M-88 engine. Then, on 5 September 1939, I-180-2 piloted by Tomas Suzi crashed during high altitude testing, killing the pilot. Again, the exact circumstances of the crash were unclear. According to eyewitnesses, the aircraft steeply dove (others claimed it fell in a spin) to 3,000 m (9,840 t) where it leveled out, then entered a spin again leveling out once more at 300 m (985 ft). The pilot then abandoned the aircraft but did not use his parachute. No definite explanation was ever given but hypotheses include blinding of the pilot by oil from a leaking oil cooler, a heart attack, or loss of consciousness due to failure of oxygen equipment.
Preparations were carried out in 1940 to produce the first batch of 10 aircraft at Factory No.21 in Gorki
Nizhny Novgorod
Nizhny Novgorod , colloquially shortened to Nizhny, is, with the population of 1,250,615, the fifth largest city in Russia, ranking after Moscow, St. Petersburg, Novosibirsk, and Yekaterinburg...
, engaged in manufacturing the I-16. However, their production was extremely slow, without much attention of the aviation authorities, with the first 10 aircraft taking more than eight months. One of the reasons for this was that the local OKB
OKB
OKB is a transliteration of the Russian acronym for "Опытное конструкторское бюро" - Opytnoe Konstructorskoe Byuro, meaning Experimental Design Bureau...
led by M.M. Pashinin was designing their own I-16 based fighter, the Pashinin I-21
Pashinin I-21
-References:* Green, William and Gordon Swanborough. The Complete Book of Fighters: An Illustrated Encyclopedia of Every Fighter Aircraft Built and Flown. London: Salamander Books Ltd, 2002. ISBN 1-840-65269-1....
and factory management had devoted all of their resources to the hometown favorite, with only six brand new engineers assigned to production of the I-180. While this was being investigated, the third prototype I-180-3, powered by a more powerful M-88R engine and fitted with a stressed skin wing (replacing the I-16 type wing structure of the previous prototypes) was completed, flying on 10 February 1940. It was armed with two 12.7 mm Berezin BS and two 7.62 mm ShKAS machine guns on a common gunbed over the engine.
Finally in April 1940, three aircraft designated I-180S were completed, these being similar to the I-180-3, but reverting to an open cockpit and the I-16 type wing structure. Their test flights were favorable. The new fighter resembled I-16 in agility but was more stable. Top speed was 575 km/h (357 mph). Major criticisms included the open canopy and poor build quality. It was believed that fixing these defects would raise the top speed to 600 km/h (373 mph). However, the I-160-3 prototype crashed on 6 July 1940, when it entered an inverted spin due to pilot error. The pilot was able to safely bail out. In preparation for production, Polikarpov produced the definitive I-180-5 with several modifications and M-88A engine without reduction gear. The aircraft could also accept the new M-89 engine with 1,007 kW (1,350 hp) (up to 1,165 kW (1,560 hp) with fuel injection) which would raise its top speed to over 650 km/h (404 mph). There was also a proposal for I-180Sh with improved main landing gear.
Then, near the end of 1940, Polikarpov was suddenly informed that I-180 was being cancelled, and the factory no.21 would manufacture LaGG-3 fighters instead. The reason for this was a misconception of the Ministry of Aviation Industry, that radial engines in NACA cowling
NACA cowling
The NACA cowling is a type of aerodynamic fairing used to streamline radial engines for use on airplanes and developed by the National Advisory Committee for Aeronautics in 1927...
s were poorly suited for aircraft with top speeds of over 500 km/h (310 mph) due to high drag. Former government officials later admitted that the fascination with liquid cooled engines stemmed in part from attempts to imitate the then state-of-the-art Messerschmitt Bf 109
Messerschmitt Bf 109
The Messerschmitt Bf 109, often called Me 109, was a German World War II fighter aircraft designed by Willy Messerschmitt and Robert Lusser during the early to mid 1930s...
. Stalin's dislike for Polikarpov after Chkalov's death likely also played a role.
According to some recent historians, like Mikhail Maslov, a cancellation of the I-180 was caused by personal and non content-related reasons and might be considered an error. Especially after Chkalov's death, the Soviet authorities started to promote young designers, as an opposition to Polikarpov, despite the I-180 was the best performing Soviet fighter at the time of its cancellation and it was faster than the Bf 109. One of information series I-180 developed a speed of 585 km/h, that could be improved after projected changes, like adding a closed canopy. The next best fighter, Yakovlev's I-26 (Yak-1 prototype), suffered from a troublesome and protracted development cycle, but Alexander Sergeyevich Yakovlev
Alexander Sergeyevich Yakovlev
Alexander Sergeyevich Yakovlev was a Soviet aeronautical engineer. He designed the Yakovlev military aircraft and founded the Yakovlev Design Bureau. -Biography:...
was one of Stalin's favorites which most likely saved his design. In addition, the I-180 could be available much earlier than Yak-1 and LaGG-3 types, and there was a possibility to produce it with a temporary M-87 engine, until the M-88 would be improved. Crashes of I-180 prototypes were mostly accidental, and should not be regarded as disqualifying the design. Moreover, the I-180 showed much less "teething problems" than its counterparts, especially Yak-1, confirming Polikarpov's competence in aircraft designing. Another advantage was, that a construction of the I-180 was similar to the I-16, which was familiar to the Soviet industry and pilots, but handling of the I-180 was even easier and it was more stable. The same situation repeated with the next Polikarpov's design, the advanced I-185
Polikarpov I-185
|-See also:-Bibliography:* Abanshin, Michael E. and Gut, Nina. Fighting Polikarpov, Eagles of the East No. 2. Lynnwood, WA: Aviation International, 1994. ISBN 1-884909-01-9....
, basing on the I-180 design.