Polikarpov's I-16 types
by Massimo Tessitori

Updated on 9 March 2021

back to Sovietwarplanes Pages index
back to I-16 page index

 

TsKB-12 and Type 4

First production version of 1934, broadly similar to the first TsKB-12 first prototype:

  • equipped with M-22 engine and V-22 fixed pitch propeller, turning clockwise, no spinner;
  • NACA cowling, nearly cylindrical, a bit tapered on the rear; there were not visible exhaust pipes;
  • fin turned on the right of 2° to contrast the torque;
  • sliding forward canopy, with OP-1 telescopic gunsight;
  • pilot's door on the left side only;
  • long ailerons, with protruding hinges on the lower surface and large gap between wings and ailerons;
  • armed with two ShKAS machine guns in the wings;
  • the hinge line between fin and rudder was covered by a long thin plate;
  • during the operational service, the fin was strengthened with two fastening wires connected to the stabilizers.

58 pre-production ones were built in GAZ-39 at Khodynka in 1934; they are recognizable for a longer cowling and at least the first ones had two flares protruding backwards on the right wingtip; they were still known as TsKB-12.

A larger number (with shortened engine cowling as shown here, without flares behind the right wingtip) was delivered from GAZ-21 starting from October 1934, for a total of 400 or more built. The name 'Type 4' originated from this factory.

It was publicly shown over Red Square and Tushino, and delivered to units in mid 1935; it remained in production up to the end of 1935.

It never saw combat, but some were still serviceable as training planes at the war outbreak.

 

 

Type 5 early

A first batch of pre-production Type 5 with imported Wright-Cyclone engines, much more powerful than the M-22, were built in GAZ-39 in late 1935, on the base of the TsKB-12bis prototype as modified after an accident.

The massive production of Type 5 with M-25 engine started in early 1936 at GAZ-21 and, marginally, GAZ-153.

Compared to the Type 4, the early Type 5 featured:

  • a new engine M-25 or M-25A;
  • V-25 propeller with pitch adjustable on the ground only, turning counterclockwise, with spinner;
  • tapered engine cowling, closed on its front, with 9 frontal vents closable with a rotating shutter;
  • side openings of pointed-backward shape for individual exhaust pipes (two were coupled on the top-left opening);
  • new improved ailerons with less gaps and no protruding hinges;
  • tail fin was twisted in the left of 2° to compensate the torque of the propeller.

The Type 5 had a huge evolution during its production, particularly in early 1937:

  • the wing consoles were strenghtened on their upper surface with a longer metal skinning and the addition of 11 half ribs between the 11 full ribs; the new outer consoles could have been refitted to older planes;
  • the wheels were enlarged to 750x150 mm instead of the previous 750x100 mm;
  • an armoured backrest was introduced instead of the usual backrest; it was easily mountable/dismountable to refit older planes;

 

 

Type 5 late

  • In late 1937, the forward sliding closed canopy was replaced by a fixed windshield that allowed a better visibility to the pilot (this modification is often unproperly called Type 6); at first, the OP-1 gunsight was preserved;
  • later, the OP-1 tubular gunsight was replaced by PAK-1 reflective gunsight;
  • some final production Type 5 were equipped with M-25V engine ; they were distinguishable for the small T-shaped inlet for the oil cooler on the low part of their front, and the circular outlet under the cowling.
  • The total production of Type 5s totalized about 2200 planes up to early 1938.

Type 5s were widely utilized by the Soviet Air Force, they fought against Japaneses in the Nomonhan Incident, against Finns in the Winter War, and in the end against Germans in the GPW, often converted into ground attack planes with RS-82 rockets and protective metal skinning on the wings, and refitted with M-25V engine, curved windshield, PAK-1 or later gunsight.

Type 5s were exported in Spain, where they were called Moscas by Republicans and Rata by Nationalists, and in China, where they fought against Japaneses.

 

 

Type10

The first Type 10s were tested at the very beginning of 1938. They implemented some improvements due to the experiences of the Spanish Civil War:

  • the addition of two synchronized ShKAS machine guns over the top of the engine cowling, in addition to those already on the wings;
  • the widening of the upper engine cowling panel, moving aside and downwards the junction to the side panels;
  • the reshaping of the vents for the exhausts on the sides, that were shortened not to interfere with the ammo boxes of the synchronized ShKAS; the upper vents were moved a bit downwards;
  • the shortening of the ailerons and the addition of pneumatically operated flaps (excluding few early ones without flaps and with long ailerons);
  • the restyling of the wheel bay plates, fixed with dzud locks and with smaller windows inside.

The first batch of 31 sent to Spain in March 1938 still had the M-25A engine without the inlet and outlet for the oil cooler and with two simple holes for the synchronized ShKAS. After that, Type 10s had the M-25V engine with the T-shaped inlet for the oil cooler on the front cowling, the ventral outlet and protruding blast tubes for the synchronized ShKAS. Further improvements introduced during the production were:

  • an armoured backrest and other structural strenghtenings of the fuselage;
  • provision for a ski retractable gear, and the coupling of exhaust pipes under the nose to make room for two recesses for the skis in retracted position;
  • separing the rear part of the side cowling panels to give easier access to the ammo boxes of the synchronized ShKAS.

Type 10s were widely utilized by the Soviet Air Force, they fought against Japaneses in the Nomonhan Incident, against Finns in the Winter War, and in the end against Germans in the GPW, often converted into ground attack planes with RS-82 rockets.

They were exported in Spain, where they were called Moscas by the Republicans and Rata by the Nationalists, and in China, where they fought against Japaneses. Modified I-16s remained serviceable ne l'Ejercito de l'Aire up to 1953.

Type 12

 

The Type 12 of 1937 was the first ShVAK-armed version, derived from the I-16 Type 5. Despite the number 12, it was built before the Type 10 on the base of the prototype TsKB-12P of 1936.

The pre-production Type 12 differed from Type 5 of early 1937 for:

  • having its ShKAS machine guns removed from their original position and relocated into the base of the outer wing consoles to make room to two ShVAK firing just outside the propeller's disk;
  • different outer consoles lodging the ShKAS at their base, and their feeding mechanism that was loaded through small hatches over the wingtips;
  • 8 DER-32 and 2 DER-31 bombs suspension points located to the root of the wing outer consoles;
  • reduced metal skinning on the leading edge of the outer consoles;
  • small hatch over the nose for feeding the ShVAK guns.

The production could have totalized 34 planes; of these, at least 8 were intensively tested and at least 11 were sent to operative units.

When the Type 10 entered production, it was considered a better base for a gun-armed version. Two Type 12 were converted into the prototypes of Type 17. Perhaps some other ones, built in 1937 with defective wing consoles, were converted into Type 17 in 1938-39, preserving the long ailerons and the lack of flaps.

 

 

Type17

This was a variant of the late Type 10 adapted for the ground attack role:

  • the ShKAS on the wings were replaced by 20 mm ShVAK guns, easily recognizable for the big protruding barrels;
  • the hatches for the weapons on the wings were lengthened;
  • the waste shells slots under the wings changed;
  • a square cut for an hatch for the guns ammo loading was added at the rear edge of the upper panel of the engine cowling;
  • nearly all the Type 17 had the lower part of the cowling with the coupled exhaust pipes and the recesses for the retractable ski gear, eventually partially closed by screwed plates that let an air outlet slot on their rear.

27 Type 17s were built in 1938 and further 314 in 1939; many of them were later rebuilt as Type 27 or 28.

The Type 17 was never exported, but fought in the ground attack role against Japaneses in the Nomothan incident, against Finns in the Winter War and against Germans in 1941/42, during the Great Patrioctic War.

 

 

Type 18

The Type 18 of 1939 was equipped with the engine Shvetsov M-62, a Soviet copy of the Wright-Cyclone R-1820-G-5.

Its visual characteristics were:

  • VISh-6A or AV-1 propeller with hydraulically movable pitch, visually distinguishable for the bigger and bulbuous spinner or, when this was removed, for two balance weights on the hub;
  • a small protrusion on the front plate, related to the speed regulator of the new engine;
  • some small flat oval protrusions on the front plate between the vents, barely visible;
  • a new triangular air intake for the supercharger was put on the top of the cowling;
  • the oil cooler air intake low on the front cowling was now trapezoidal with bent-in sides;
  • a fairing for the enlarged oil cover altered the profile under the nose; it was cut obliquely on its rear for the air outlet.

It was an interim version before the introduction of the more powerful M-63 engine, so only 177 were built in 1939 by GAZ-21 and GAZ-153, plus some in 1940 in parallel with the Type 24, according to the available engines; so, late production Type 18 had the same airframe of Type 24.

It was never exported, but saw combat in the Nomothan incident and in the Winter War before fighting in the Great Patrioctic War.

 

 

Type 24

This version was equipped with the M-63 engine and MV-1 propeller, and was visually similar to Type 18.

Apart for the engine, it was different for:

  • a second pilot's door and an inspection hatch on the right side of the fuselage;
  • tail wheel instead of a skid;
  • scissor-type mail legs of the landing gear instead of splined ones, with a stroke of 96 mm instead of 36mm;
  • extension of the leg bays and of the leg covers rearwards for the scissors; at least two different shapes of the bays and covers were possible;
  • optional support (often installed) for camera gun (rarely installed) behind the headrest.

Late Type 24 had further characteristics:

  • front vent at 1 o'clock of reduced size;
  • predisposition for auxiliary fuel tanks under the wings (Type 24P and R) and relative hatches over the wing consoles for access to the system;
  • predisposition (Type 24R) for 6 rocket rails for RS-82 rockets, and metal plates on the wings to protect them from the fire;
  • optional extractable landing flares under the right wing, whose skin was protected by a metal plate (on some Type 24P and probably all Type 24R);
  • predisposition for a radio mast on the right side of the nose (rarely installed).

155 Type 24 were built in late 1939, 760 (including 24P and 24R and some late Type 18 with M-62 engine) in 1940 and 19 (probably 24R) in 1941, for a total of 934.

 

 

Type 27

This can be seen as a variant of the Type 18 adapted for the ground attack role with the wing-mounted ShKAS machine guns replaced by ShVAK guns, or as a ShVAK-armed Type 17 updated with M-62 engine and MV-1 propeller as Type 18.

The 20 mm ShVAK guns were easily recognizable for the big protruding barrels and some modifications to their ports.

The landing gear was usually with splined shock adsorbers as on Type 10-18.

Some late production Type 27 could have had the same airframe of Type 28 (but M-62 engine) and be visually undistinguishable from it.

59 were built in 1939, plus a total of 277 Type 27 and Type 28 in 1940.

The type was never exported, but fought in the ground attack role during the Nomothan incident, during the Winter War (when one was captured by Finns and rearmed) and during the Great Patrioctic War.

 

 

Type 28

This variant can be seen as a Type 27 with M-63 engine and other updates (scissor type landing gear and modified bays and doors, pilot's door and radio hatch on the right side, tail wheel), or as a Type 24 adapted for the ground attack role with the wing-mounted ShKAS machine guns replaced by ShVAK guns.

Some planes (1 each 4) received the predisposition for auxiliary fuel tanks under the wings, and plates over the wing consoles for access to the system.

They could have plates for extractable landing torches under the right wing console.

16 Type 28 were built in 1939, plus a total of 277 Type 27 and Type 28 in 1940.

Type 28 was never exported, but it was used during the GPW.

 

 

Type 29

The final version of the I-16 was a ground attack plane; it had much in common with the Type 24R but:

  • armed with the new Berezin BS 12,7 mm machine gun in the lower central part of the nose; its fairing characterized the profile of the lower part of the fuselage;
  • oil cooler relocated on the right side; on earlier planes, it had a protruding trapezoidal intake on the low-right front and a tubular outlet behind it; on later machines it had only a visible oval intake vent in the front plate and one on the shutter, and a slightly different outlet;
  • modified lower cowling with exhaust pipes still paired on the left side, but separed on the right side; one exhaust pipe came out from a small vent in nearly central position;
  • the cowling still had slots for cooling air outlet in its lower part, but they were not usable for any retractable ski gear, that was not provided;
  • to make space for the BS between the landing gear bays, each bay was moved 20 mm outside;
  • shorter landing gear legs by 38 mm, with reduced stroke of the shock adsorber;
  • shorter MV-1 prop diameter, from 2.8 m to 2.7 m; the blades were a bit wider to mantain their thrust;
  • the ShKAS on the wings were suppressed, while the synchronized ones on the nose were preserved;
  • 6 rocket rails for RS-82 rockets, and metal plates under the wings to protect them from the fire (not on all planes);
  • extractable landing flares under the right wing, whose skin was protected by a metal plate;
  • underwing tanks predisposition (and the access plates over the wings) as standard;
  • optional RSI-3 radio equipment with mast on the right side of the nose and wire aerials;
  • optional support for camera gun behind the headrest.

About 800 Type 29s were built between the mid of 1940 and the mid of 1941.

 

 

UT-2, UTI-2 and UTI-3

The UT-2 was the first two seater training version based on the Type 4 equipped with the M-22 engine, with long enclosed canopy and doors on the left side, and a machine gun on the right wing only. Only 3 were built. As all M-22 equipped I-16s, the fin was turned rightwards;

The UTI-2 (illustrated aside) was the first serially produced version; it was simplified, with open cockpits, flat topped back and unarmed. Their serials started by 8, so it should be Type 8, but it was also known as Type 14.

The prototype flew in early 1935, 57 were built in 1935 and 1936, and about 40 in 1937 by GAZ-21.

Probably the planes built in 1935 had the same tail of the Type 4, with long plate over the rudder's hinges and fastening wires between fin and stabilizers.

Final production planes had ailerons as on Type 5 instead of Type 4, recognizable for non-protruding hinges on the lower wing surface and less gap between wings and ailerons.

The UTI-3 was a prototype of twoseater training version visually similar to the UT-2, with closed canopy, doors, machine gun on the right wing, equipped with the expermental M-58 engine. It was not serially produced because it was decided to standardize all versions of I-16 on the M-25.

 

 

 

UTI-4 (Type-15) M-25/25A

It was based on the airframe of the UTI-2 and the engine of Type 5, equipped with M-25/25A engine and unarmed. As all M-25/62/63 engined I-16, the fin was turned on the left. It was produced in 1937 and 1938.

Its serials started by 15, adding 1 before 5 to design a trainer version of Type 5; so it was called Type 15 even if it appeared before the Type 10.

  • Very early production UTI-4 had the same outer wing consoles of early Type 5 with 11 ribs each; they were soon replaced by the stronger consoles as on late Type 5, with 11+11 ribs;
  • Early production planes had the same rear windscreen and flat-topped back as on UTI-2;
  • later, a conical rear windshield was introducted, usually still with the flat-topped back fuselage; late production ones (1938?) had a rounded back as fighter versions;
  • the wheel bays plates were as on Type 5, with kidney-shaped windows, single rib and without dzud locks;
  • all UTI-4s always preserved long ailerons, and never received flaps.

 

 

UTI-4 (Type-15) M-25V

Evolution of the early UTI-4 with M-25V engine introduced around late 1938. It progressively introduced changes similar to those of late I-16s, well visible on the landing gear and lower side of cowling.

  • T-shaped oil cooler inlet, and a circular outlet under the cowling;
  • conical rear windshield and rounded back section;
  • short slots on the cowling sides as for Type 10 and later;
  • coupled exhausts as on later versions, and air outlet slots (but not usable for retractable ski gear, that wasn't provided);
  • early planes (1938-39?) had landing gears with splined shock adsorbers, covers, bays and tail skid as on Type 10;
  • later planes(1940-43?) had landing gears with scissor type shock adsorbers, covers,bays and tail wheel as Type 24;
  • the wheel bays plates were as on Type 10 and later, with small windows, twin ribs and fixed with dzud locks;
  • all UTI-4s always preserved long ailerons, and never received flaps.

The production figures of UTI-4s vary from 843 planes to 3189 planes, according to the sources; the most likely number looks around 1900.

The Type was produced in GAZ-21, GAZ-153 in Novosibirsk and GAZ-458 in Rostov On Don up to 1943.

Some UTI-4s were exported to Spain (4) China (were it was produced as Jung-28A) and Poland (2).