Design of the Polikarpov TsKB-12 single-seat fighter prototype was begun by Polikarpov s team at TsKB (Central Design Bureau) in the spring of 1933 A stubby radial-engined cantilever low wing monoplane, it had a wood monocoque fuselage and a metal wing with long-span split-type ailerons which doubled as landing flaps. The main landing gear units were manually retracted inwards into the wing. Powered by a 358-kW (480-hp) M 22 engine, this prototype made its first flight on 31 December 1933. The TsKB-12bis which had an imported 529-kW (710 hp) Wright Cyclone SR-1820 F3 radial, flew on 18 February 1934. With the M-22 a maximum speed of 359 km/h (223 mph) at sea level was attained, while the Cyclone-powered prototype reached 437 km/h (272 mph) at 3000m (9 8 4 5 f t ). The I-16 proved a very demanding aircraft but its speed and excellent rate of climb won it official support, and an evaluation batch of some 30 M-22-powered I 16s was built 10 of them participated in the flypast over Moscow on May Day 1935. Development continued with changes of engine and armament up to the end of planned production in 1939. Remarkably, the I-16 was reinstated in production in 1941-42, the ultimate version having the more powerful 820-kW (1,100-hp) M-63 engine. Overall production of all versions was 7,005 including dual-control trainers.

From 1935 series I 16 Type 4 (imported Cyclone) and Type 5 (M-25 engine) fighters were delivered to the eskadrilu of the Soviet air force. Supply of the Type 5 to the Spanish Republican air arm began in October 1936, and this model was followed by the Type 6 (M25A) and Type10 (M-25V) The Types 5 and 6 were christened ‘Mosca’ (fly) and the Type 10 became the ‘Super Mosca’. In all 278 I-16s were delivered to Spain, where licence production of the Type 10 by Hispano Suiza produced another 10 before the surrender of the Government forces in March 1939, after which another 30 were completed for the Franco regime. The I-16 gave a reasonable account of itself, but tactics adopted by its pilots, mostly Soviet volunteers, did not make the best use of the type’s speed and rate of climb.

Soviet I 16s flew in China against the invading Japanese in 1937, re equipping two eskadrilu which had previously flown the l-15bis. Early in 1938 the I 16 Type 10 began to equip Chinese units, and in 1939 Soviet I-16s were engaged in furious air battles with Japanese army fighters at Nomonhan on the Manchurian border, four fighter regiments (lAPs) ultimately being fully committed to the struggle. The I-16 took a prominent part in the Winter War with Finland 1939-40, but was obsolescent (even in its latest Type 24 version) when Germany invaded the Soviet Union m June 1941. At that time nearly two-thirds of the Soviet air force fighter arm comprised I-16s. The type bore the brunt of the invasion and suffered heavy losses on the ground and in the air during 1941. It became renowned for Taran ramming attack on German bombers and fighters, in which the Soviet pilot risked his aircraft and himself in order to defeat the enemy. Only in late 1943 was the I-16 finally with drawn from first line service. Flown by skilled pilots it had done well against German aircraft, several I-16 veterans becoming Heroes of the Soviet Union, and a number of I 16 lAPs winning the coveted ‘Guards’ title.

The type also achieved a worldwide first, being the precursor of all the cantilever low-wing monoplane fighters with retractable landing gear to go into large-scale service By the time of its greatest commitment it was obsolete, but even so its rugged construction and ability to take a great deal of punishment still endeared it to many Soviet pilots, despite the heavy calls it made on pilot skill and expertise.

Variants

I-16 Type 1: about 30 built and used for evaluation, M-22 engine, two wing mounted 7 62-mm (0 3-in) ShKAS machine-guns, sometimes designated I-16M-22.

I-16 Type 4: first main series production with imported Wright Cyclones, landing gear main wheels had fairing doors, pilot had 8-mm (0 3- m) armour back plate.

I-16 Type 5: entered production July 1935, 522-kW (700-hp) M 25 radial (developed from Cyclone) and AV-1 propeller, first model to have under wing bomb racks, more than 1,500 of this version built, one was converted as the first I-16P with armament of two ShKAS machine-guns (fuselage) and two 20-mm cannon (wings), Cyclone engine.

I-16 Type 6: built 1936, M-25A engine of 544 kW (730 hp) and strengthened airframe.

I-16 Type 10: built from 1937, four 7 62-mm (0 3-m) ShKAS, second pair synchronised and mounted over engine cowling, major production version fitted with retractable skis for winter operations, 559-kW (750-hp) M-25V engine.

I-16 Type 17: 1938 production version, structural strengthening for operation at higher gross weight, tailskid replaced by rubber tail wheel, had six RS-82 rockets as alternative to bombs, and two wing-mounted ShVAK 20-mm cannon in place of wing machine-guns.

I-16 Type 18: introduced on production lines 1939, had 686-kW (920 hp) M-62 radial with two-stage supercharger, provisions for pair of auxiliary fuel drop tanks, four ShKAS machine-guns.

I-16 Type 24: entered service late 1939, early examples with M-62 engine, later had 820-kW (1,100-hp) M-63, wings strengthened, larger drop tanks, and most had RSI-1 or RSI-3 radio and oxygen equipment.

I-16 Type 28 and Type 30: reinstated in production 1941 42, total 450 of each version built and powered by the M-63 engine I-16P: second use of designation for prototype TsKB-12P of 1938, had two wing mounted 20-mm ShVAK cannon in Type 10 airframe, small number built before being superseded by Type 17.

I-16Sh: TsKB-18: prototype with additional armour for ground-attack role and four ShKAS machine-guns, no quantity production.

I-16SPB: I-16s had taken part m V S Vakhmistrov’s ‘Zveno’ parasite experiments since Zveno 6, a TB-3 bomber with two I 16 Type 1 under its wings for air-launching, Zveno 7 in 1935 comprised a TB-3 with two I 5 biplanes on wings, a Gngorovich I Z monoplane on trapeze between landing gear legs, plus two l-16s under wings Vakhmistrov then reverted to Zveno 6 SBP, TB-3 carrying two modified Type 5 fighters each with two 250-kg (551-Ib) bombs and redesignated as TsKB-29 I-16SPB dive-bombers these parasite fighter dive-bombers were flown by the Black Sea naval air force from 1938, one unit operating in the Ukraine near Odessa against targets in Romania and the Chernovodsky bridge over the Danube in 1941, and against other pinpoint targets into 1942.

I-16TK: Type 10 with two TslAM TK-1 turbochargers, altitude performance much improved but only a few built UTI-4: some 1,600 two seat dual control trainers built, at peak of production every fourth aircraft was a UTI-4 (or I-16UTI) trainer, with two open cockpits in tandem and based on Type 5 with M-25 engine, most with fixed gear, but some reported with standard retractable main units, blind flying version had special sliding canopy over rear cockpit, earlier versions were the UTI-1 (version of Type 1) and UTI-2 revised variant of UTI-1 with fixed landing gear.

Specifications (I-16 Type 24)

General characteristics

  • Crew: one pilot
  • Length: 6.13 m (20.1 ft)
  • Wingspan: 9.00 m (29.5 ft)
  • Height: 2.25 m (7.38 ft)
  • Wing area: 14.54 m² (156.5 ft²)
  • Empty weight: 1,383 kg (3,049 lb)
  • Loaded weight: 1,882 kg (4,149 lb)
  • Max takeoff weight: 2,050 kg (4,520 lb)
  • Powerplant: 1× Shvetsov M-63 air-cooled radial engine, 670 kW (900 hp) driving a two-blade propeller

Performance

  • Maximum speed: 460 km/h (290 mph)
  • Range: 440 km (275 mi)
  • Service ceiling: 9,700 m (31,800 ft)
  • Rate of climb: 14.7 m/s (2,900 ft/min)
  • Wing loading: 129 kg/m² (26 lb/ft²)
  • Power/mass: 0.36 kW/kg (0.22 hp/lb)



Armament: four 7.62-mm (0.3-in) ShKAS machine-guns, two synchronised in forward fuselage and two in wings, wing machine-guns replaced on some aircraft by two 20-mm Sh VAK cannon, a 12.7-mm (0. 5-in) UB machine gun was sometimes added to fuselage-mounted armament, plus a bomb load of up to 200 kg (441 lb) on under wing racks, with alternative of six RS-82 rockets.