Tupolev I-4

Tupolev ANT-5 - přehled verzí
Tupolev I-4 (I-4)
In the second half of the 1920s, the VVS RKKA (ВВС РККА) fighter air force was still heavily reliant on aircraft supplies from abroad. A significant part of its air fleet consisted of Dutch Fokkers D.XI, Italian Ansaldo A-1 and English Martinsyde F.4 Buzzard. In order to replace them, the VVS leadership commissioned the country's design teams to design a number of fighter aircraft of various types. In the autumn of 1925, a brief for an all-metal fighter aircraft with an air-cooled engine first appeared. This task was later corrected several times and was finally approved by the NTK UVVS (НТК УВВС ) only on 7 July 1927.


The task ordered the maximum flight speed at ground level - 260 km/h, at 5000 m - 250 km/h. The fighter aircraft had to be able to climb to an altitude of 5000 m in 12 minutes. The requirements for manoeuvrability were quite high: for example, a figure of eight was to be performed in 25-28 seconds. The project envisaged, as with all Soviet aircraft of the time, two quickly interchangeable landing gear variants - wheels and skis. Interestingly, the last version of the specification called for a very powerful armament for the time, consisting of four machine guns, as well as the installation of a radio station, which was not common at the time even on fighters developed by Western countries. The following point was also a novelty: "...the possibility of mounting removable armour protecting the pilot from behind and below must be taken into account".


Several design groups responded to the assignment: first Grigorovich I-2[/b:aaaa] (Григорович И-2) was created, then Tupolev's I-4[/b:aaaa] and later Polikarpov[/b:aaaa] with new tail surfaces it can be recommended only on condition of correcting errors". And errors were revealed in abundance - 34 list items in all. Among them were some very substantial ones. For example, the non-detachable lower wing makes it impossible to remove them without removing the undercarriage. They found the connection of the upper wing halves unfortunate. Exhaust gases were leaking into the carburettor intake manifold. The cowling and the aerodynamic propeller cowling proved insufficiently strong (the latter cracked during testing). The designer used three different methods of attaching different parts of the engine cowling. Both the engine bed and the aerodynamic wheel cover proved to be insufficiently rigid. The instrument package did not match the UVVS approved types because CAGI used the ones they had available or those that fit within the outline dimension.


Only one type of radio could be put in the aircraft - an imported Marconi AD5 (under the seat). Domestic VO3I and VO3J (BO3I, VOZI) did not fit. A number of comments also came from pilots, who demanded to increase the cut-out of the upper wing, to change the design of the uncomfortable seat and headrest, to make a footrest with an edge for cleaning mud from shoes.


At that time CAGI was preparing the second example of the I-4 prototype - "Dubler". In it they planned to build a more powerful 480 HP Gnôme-Rhône 9Aq engine (analogue of the English Jupiter VI). This engine was planned to be produced in the USSR under license (the license agreement was decided in March 1928). The new Gnôme-Rhône was slightly longer than the older type (by 40 mm). It was housed in a new, reduced engine cowling, with individual aerodynamic cylinder covers. In the design of the "analogue", lessons were learned from the shortcomings of the first machines. The lower wing became a split wing with a small centroplane, the upper wing mounting was changed, the fuselage was reshaped, the pilot's seat was enlarged and the equipment components were rearranged. In doing so, space was made available for a VO3III (BO3III ) radio station in the forward cabin. Later, they intended to place a new KV-radio station KIR (КИР), created by developing the VO3I type. The propeller cowling was modified to be removable.


On 5 November 1927, a wooden faithful mock-up of the analogue was presented to the NTK UVVS (НТК УВВС) commission headed by A. V. The members of the commission expressed a number of comments on the equipment and armament of the aircraft. In particular, they did not like the forward displacement of the machine guns, the extension of the fuselage and the impaired visibility demonstrated on the mock-up. However, CAGI promised to narrow the fuselage to its former outline. The remaining comments were taken into account and on 30 November the NTK approved the deployment of weapons and equipment.


The I-4 with the 9Aq engine looked decidedly more promising than the 9Ad variant, an opinion shared by then UVVS Chief Baranov (Баранов). But the fighter was required by the VVS immediately, and the NTK on November 17 "...accepted the I-4 into the armament of the VVS RKKA ", and in December at CAGI began production of working drawings for a series with the 9Ad engine bed.


The serial production of the fighter was entrusted to Plant No. 22, the only one in the country capable of producing all-metal aircraft (the former licensed Junkers plant in Fily (г. Fili)). The first order for the I-4 envisaged the assembly of 75 units. The state budget allocated 2 million 815 thousand rubles for it. The first two machines came to 60 thousand rubles, and the remaining - to 35 thousand. It was very expensive - instead of one domestic fighter plane, two could be bought abroad (at the ruble exchange rate at that time). But to these costs the command of the VVS went to free themselves from dependence on the foreign aircraft industry, and, moreover, the price of all Soviet aircraft at this time exceeded the price of imported ones. By the way, in reality, the serial I-4s were even more expensive. The complete set (aircraft, backup propeller, skis, armament) cost 36,089 rubles in 1930. The first mass-produced I-4 was scheduled to be ready by November 1, 1928. From January 15, 1928, drawings began to flow from CAGI to Plant No. 22. The plant began preparing accessories and tools, procuring the required materials. In July of the same year, the construction of "Dubler" I - 4 was completed. In the same month, it passed a short race test and was approved by the NII VVS on 1 August. The armament was not tested on the first aircraft because the machine guns were incorrectly mounted in the CAGI. The machine guns were installed on the second machine by Plant No. 25. This took over a month to complete and it was not until 21 September that the aircraft returned to VVS. Prolonged trials were initiated. Some lightening of the airframe as well as an increase in engine power made it possible to bring the performance of the I-4 almost up to the level of the technical specification: the maximum speed near the ground increased to 257 km/h, the range reached 7650 m. The requirements for horizontal manoeuvrability were even exceeded - the figure of eight was performed in 24.5 s - almost 10 s faster than on the first example. Already in the first takeoff the pilot I. F. Kozlov (И. Ф. Козлов) noted that the machine was constantly going into a climbing flight - it was raising the nose spontaneously. Problems also arose with the durability of the individual elements of the structure: on 22 November the take-off ended in a forced landing, during which part of the fuselage covering was torn off.
The exhaust pipe burst, the oil pressure in the system fluctuated, the oil cooler leaked, and bolts broke. With the onset of winter, the engine start-up deteriorated considerably.


Therefore, the second I-4 returned to CAGI for adjustment of the carburetor preheater. It did not return until 19 February 1929, and on 28 February, I. F. Kozlov also suffered an accident: a torn propeller cover damaged the propeller, the engine cover and the left ski (by this date, there were already custom skis for the I-4, produced by plant No. 28). The aircraft was transported to the CAGI development plant for repairs. There they found a very simple and effective means to combat spontaneous nose lift - they turned the stabilizer "upside down", bulging side up. Since March 14, the fighter started flying again, the tendency to lift the nose completely disappeared. During the tests at VVU, they made a number of small changes to the aircraft: they redesigned the pilot's headrest, added a new steering handle (50 mm shorter) and standard machine gun reloading handles, reinforced the aerodynamic cylinder cover and propeller cover. The tests were not completed until 25 April 1929. The NII's opinion was very positive. It was praised for good stability in all flight modes, quick and legible reaction to rudder work, easy execution of higher piloting figures, stable dive flight, good visibility, comfortable cabin. It is true that some minor vibration of the wingtips in some engine modes and delays in the exit from the corkscrew are pointed out, but this did not influence the final decision: "...the I-4 JuVI can be recommended for the VVS armament as a modern fighter".


AGOS CAGI was already thinking about new modifications to the I-4, primarily to increase the powerplant's performance. It was proposed to install a Jupiter VII engine on the aircraft, having better altitude characteristics, or even more "high altitude" a new Soviet M-15 engine. A. Tupolev was even eager to acquire the newly tested Gnôme-Rhône in France, giving up to 600 hp.
The "doubler" I-4 was just coming up for trials at VVS VVS when the first production aircraft was pushed out of the workshops of Plant No. 22. The production machines actually had airframes similar to the second test specimen, but with the 9Ad engine; only the carburetor was replaced with the superior Triplex (the Klodel type was on both prototypes). All instruments were now Soviet-made, except the clock. The first production I-4 from plant No. 1513 tested at VVS from 10 October to 26 November 1929. Compared to the doubler, No. 1513 proved to be 44 kg heavier. The plant tried to blame the weight increase on the paint (the prototypes were not painted), but the military acceptance committee quickly proved the absurdity of this claim. The weight growth led to a significant deterioration in flight performance, with climb rate and approach speed particularly affected. The maximum ground speed was 249.5 km/h, the practical range - 7120 m. Nevertheless, some of the previously detected defects remained uncorrected. Too little resistant aerodynamic covers on the wheels were removed, the wheel fixing proved to be weak, the oil tank leaked.


Nevertheless, the VVS stated that "the I-4 aircraft of the first series from plant No. 22 can be approved for the VVS armament".
The new fighters were intended to arm mainly the air parts of the Belarusian Military District and the Red Battalion Caucasian Army (авиачасти Белорусского военного округа и Краснознаменной Кавказской армии). By mid-1929, according to the plan, they intended to concentrate 75 I-4s in Belarus. However, by June he had practically only one serial aircraft available. In fact, it was the personal plane of the chief of the VVS of the MVO, the ace of the Civil War, I. U. Pavlov (И. У. Павлов). This I-4 was referred to as a machine undergoing operational tests. "...the aircraft and the engine will show their better sides during the month", - he wrote in the test protocol. The objections were mainly connected with the armament - the machine guns were not new and their installation not strong enough.


Pavlov made a number of remarks about the placement of instruments and control organs. After the machine had been in service for six months, it was dismantled and re-examined. The specialists found many insufficiently strong elements of the structure, showing various degrees of damage.
Parallel to this, operational tests of the "analogue" were carried out at the VVS VVS. This aircraft was also used for demonstrations to the audience of the Academy and the command of the VVS units. Pilots of the 70th Air Brigade, which was to receive the new fighters first, trained on it. However, the first test ANT-5 came to Belarus, to the 15th Air Brigade (Белоруссию, в 15-ю авиабригаду), where it is also undergoing tests.


But plans still clashed with reality. In the years 1929 - 1933 it was to be purchased, in total, 180 I-4. As of 20 September 1929, out of the planned 77 aircraft, the plant had delivered only 32, of which the military acceptance committee could take delivery of only 2. The others had various manufacturing defects. The then chairman of the 1st (aircraft construction) section of the NTK UVVS S. V. Ilyushin (chairman of the 1st (aircraft construction) section of the NTK UVVS S. В. Ilyushin ) proposed to conduct an army test with a smaller group of I-4s in one of the airborne detachments, and then, according to their results, only order a large series, but the VVS was in a hurry to have the newly acquired machines go immediately to the combat detachments.


There they were also eager to get the new fighters as soon as possible. The VVS supervisor of the Red Battalion's Caucasus Army, Nikiforov, also agreed to receive the first batch of I-4s with partially unremedied defects and incomplete (without pneumatic starters and oxygen devices), stating that the remaining deficiencies "[i:aaaa" target="_blank">are easily remedied by the troops". The first production I-4 arrives at the 70th KKA and the first production I-4. By June 1930, the RKKA VVS already had 58 I-4s. They were stationed in Baku (70th LO KKA), Peterhof (46. LO VVS Baltského moře and Jevpatorii (29. letecká eskadra VVS Černého moře) (Baku (70th ao KKA), Peterhof (46th ao VVS Baltic Sea and Evpatoria (29th air squadron VVS Black Sea).


It must be said that the adoption of the new technique was not without difficulties. They stemmed from both design flaws and low production culture. The units complained about the unreliability of the engine cowling clamping, rivets falling out, damage to the aerodynamic wheel covers - replacements for the destroyed ones were used covers from I-2 and R-1 (Р-1), low quality tires, dead running in the steering and much more. Many inconveniences were caused by armament. The problem was that for the first serial I-4s, old machine guns, removed during the dismantling of the decommissioned Fokkers, were shipped from VVS depots. Among them there were also corroded and damaged or jammed parts, which at the then level of interchangeability led to constant failures. There were continuing reports of propeller cowls being destroyed (they would be reinforced from the 13th production machine). Another particular problem manifested itself with the colouring of the aircraft. The thing is that all the aviation paints and varnishes used at that time were designed for wood and canvas structures. They therefore adhered very poorly to the colchugaluminum. They painted the planes with oil and nitrocellulose paints, and they clad the kolchugaluminium, but all of that did little to help. The factory brigades periodically repainted the planes at the units or took them to the plant for repainting. In April 1931, for example, 59 I-4s had to be repainted in a hurry, almost a third of all those produced!
At one time, wing body oscillation at 1200-1400 rpm of the engine was a serious concern. "The 1st section of the NTK states that the problem of vibration (shaking) in I-4 JuplV (И-4 ЮпlV ) aircraft is very serious and requires thorough analysis, both laboratory and flight". Through careful selection and adjustment of the carburetor at CAGI, the vibration of the upper spar was completely resolved, but the deflection of the lower spar remained at 15 mm. This issue was not definitively resolved by the VVS VVS until June 1930. The main reason for the oscillation on mass-produced fighters turned out to be too large tolerances in the propeller diameter and the asymmetry of its aerodynamic cover. After the tolerances were reduced, the vibrations stopped.
Throughout serial production, the I-4 has steadily improved due to operational experience. Starting with the 2nd series (early 1930s), they replaced the copper piping with duralumin, which reduced the weight of the machine somewhat. For more careful weight checks, the UVVS ordered the military acceptance committee to weigh every fifth production machine. This bore its fruit - the mass-produced fighter became a little lighter and, proportionally, its flight performance increased somewhat. In January they also tried using the Zenit carburetor. This modification, coupled with an adaptation of the fuselage skeleton, was implemented at CAGI in December 1929. In this month, they tested the installation of a Letomb-Lusar pneumatic starter on the I-4, and in February 1930 they brought this design into series production (for the sake of accuracy, it should be mentioned that a "knee-built" pneumatic starter was used on the I-4 by the I. U. Pavlov [И. У. Павлов] half a year earlier). They installed carburetor heaters (from No. 1522 onwards) from the 2nd series, and in April the factory work parties began fitting them to the 70th LO aircraft, which were built without heaters.
In March 1930, they strengthened the airframe structure somewhat: replacing the duralumin bolts with steel ones. In May, they almost doubled the aerodynamic covers of the spoke wheels - from 0.45 to 0.8 mm. From April onwards, Gnôme-Rhône 9Aq engines of 480 hp began to arrive from France and were fitted to the fighters. All 9Aq machines had only the Zenit carburetor.
In the first half of 1930 the armament of the I-4 also changed. As late as October 1928, Aviatrust's plan of operations included the processing of two versions of the armament with machine guns with the cartridge belt attached from the right, or one from the right and one from the left. The work is somewhat complicated by the fact that a version of the PV-1 (ПВ-1 ) machine gun with a belt feed from the left did not yet exist. It was not built until the end of December 1928. After that, it was tested and fine-tuned in the VVS VVS, and the new machine gun (in the "mirror-symmetrical" version) appeared on the I-4 only in December 1929. In January 1930, a test aircraft arrived at the VVS VVS VVS.
There, the installation of machine guns was refused, but the plant nevertheless began to mount the PV-1 on mass-produced machines from June (10th batch). Meanwhile, the belt-fed machine gun from the left existed in one single example, and it was moved from one fighter aircraft to another. Moreover, the belt feeds were then routed to each gun individually. It was not until November that the UVVS adopted an improved machine gun installation with two PV-1s, which entailed the redesign of a substantial number of aircraft in the units.


All subsequent series of I-4s differed only in minor modifications, such as the replacement of the brass gasoline filter caps with aluminum ones starting with No. 1579. From the 18th series onwards, two sights, the optical OP-1 and the collimator KP-1 (optics OP-1 and collimator KP-1), were commonly fitted. Previously, only the former was dismantled or the KP-1 was added in a box without a mounting beam.


Only 163 I-4s were produced during 1930, so the plan was again not fulfilled. There were several reasons for this. First of all, production was constantly hampered by a lack of parts: there was a shortage of screws, PUL-9 (ПУЛ-9) synchronizers, and sighting devices. Secondly, the VVS gradually lost interest in the I-4, considering it clearly inferior to the new generation I-5 and I-7 fighters, but also to the older I-3 (И-5, И-7, И-3). Thus, the I-4 never became a mass-produced type. As of October 1931, when the last 11th fighter of this type was delivered (a total of 177 mass-produced fighters and 2 prototypes had been built), the I-4 made up about a quarter of the VVS RKKA fighter fleet, well behind the [url=https://www.valka.cz/topic/view/14000/Polikarpov-I-3]I-3
.


CAGI tried to look for new areas of application for its own machines, renewing them in various ways. Thus, as late as May 1929, Chief of the Black Sea Air Force Lavrov (начальник Воздушных сил Черного моря Лавров )offered to build I-4s on floats and arm large battleships with them, for which they would provide their own air cover. The float variant was commissioned to CAGI, and the float was even produced in August 1931. But later the NTK VVS admitted that the float version's seakeeping characteristics would not allow the I-4 to be launched from sea level, and so further work was discontinued. At the same time, a split wing was being developed for the I -4, greatly improving its takeoff and landing qualities.


This work was partly used in a new variant of the I-4, sometimes referred to as the I-4bis (И-4бис). It was a monoplane-parasol without a lower wing and with a new engine cowling, of the Townend type. The I-4bis was tested at NII VVS in September 1931. The tests showed that the speed increased slightly (about 10 km/h), the climb rate was practically unchanged, and the maneuverability deteriorated. Besides, the engine overheated in the new casing. The final statement of the commission was: "...we consider that the redesign is irrational". The CAGI did not pursue further improvements to the I-4 type.
Nevertheless, the I-4 remains in the VVS armament, mostly in the Fleet Air Arm. What's more, in 1932 they were equipped with one detachment (71st LO) in the Moscow Military District (71-й ао) в Московском военном округе. Many future famous fighters started their careers on this aircraft. For example, Ibrahim Dzusov (Ibrahim Dzusov) flew on the I-4 in 119 eskadrile (119-я эскадриля ).


The I-4 was used for a number of interesting experiments. V. S. Vachmistrov (В. С. Вахмистров ) used it in the first variant of his "aircraft-zveno" (самолёт-звено) - two I-4s stood on the wings of TB-1, with the lower wings of the biplane removed, which practically did not affect their flight characteristics. In 1931, work began on equipping the I-4 with dynamoreactive (recoilless) guns - its solid all-metal wing allowed guns of sufficient calibre to be mounted underneath. In April 1933, members of the RVS of the USSR at the main airfield were shown the I-4 with the APK-3 (динамореaktivная (безоткатная) пушка АПК-3) gun. The impression was apparently so powerful that in May a decree was issued by the RVS to equip one squadron by the end of the year with fighters with the improved APK -65 (АПК -65) gun. But practical use of the recoilless guns in a combat squadron did not occur. It is possible that the accident that occurred on the polygon tests on May 18, when the pilot T. Suzi (T. Suzi) in the right gun APK-Z6bis (АПК-З6бис) exploded a bullet. The pilot managed to land the damaged aircraft. And perhaps simply impressed by a thorough analysis of the shortcomings of the DRP - low rate of fire, low initial velocity of the projectile. The first Soviet reactive missiles were also used on the I-4 - they were launched from a tubular line over the upper wing. In 1935-36, one machine flew with an experimental powder launch accelerator of RNII design. It carried 3 rockets under each wing, each giving 450 kg thrust for 2.5 s. The standard launch time was about 20 s.


By 1935, the I-4 was definitely obsolete. It was easily overtaken not only by fighters but also by bombers. It didn't even take part in any fights, if we don't count one machine that took part in the fights against the Basmachi (anti-Bolshevik rebels) in Central Asia. The last aircraft of this type were scrapped from the 119th Squadron in Baku (119-ая эскадриля, г. Баку) in connection with the acquisition of the I-16. The obsolete fighters were handed over to flight schools or dismantled for spare parts, as ordered. More than three dozen machines were handed over to the schools and served there for about two years before being displaced by the I-5s, which became the basic training fighters of the 1930s era.


Even after their official retirement from service, the I-4s briefly reappeared in the Baltic Fleet's VVS (ВВС Балтийского флота). They were removed from storage and used to equip three new squadrons. In December 1935, the 4. OIE (оиэ = опытно истребительная эскадриля) in Peterhof, and in February of the following year to 3. and 8. OIE there. But the I-4s there served only as training aircraft until the arrival of the new I-16s in the summer of 1936. This was the last case of application of these obsolete aircraft in combat units.


The I-4 could boast neither high performance nor an illustrious combat career. Nevertheless, it remained in memory as the ancestor of all future all-metal fighters in the USSR. The aircraft was in service from 1928 to 1933. A total of 369 machines + 2 prototypes were built.


Versions produced:
ANT-5 - prototype
ANT-5 dubler - second prototype
I-4- single-seat fighter aircraft
I-4bis - monoplane version (1 prototype)
I-4P - seaplane version (1 prototype)
I-4 Zvěno - version carried by TB-1 bomber



TTD
Prototypes:
ANT-5 (year 1927)
Crew - 1
Engine - 1 x Gnôme-Rhône Jupiter VI 1 420 hp.
Length - 7.28 m
Height - 2,82 m
Wingspan - 11.42 m
Carrying area - 23.8 m2
Weight (empty) - 921 kg
Weight (take-off) - 1 343 kg
Area load - 56.5 kg/m2
Maximum speed (near ground) - 246 km/h
Maximum speed (h = 3 km) - 250 km/h
Take-off length - 70 m / 6 s
Landing length - 140 m / 17 s
Flight endurance - 2 h 18 min
Climb time to 5 km - 11.4 min
Range - 8 200 m
Armament - 2 7.62 mm machine guns


I-4 "Dubler" (1928)
Crew - 1
Engine - 1 x Gnôme-Rhône Jupiter VI with 525 hp.
Length - 7.28 m
Height - 2.82 m
Wingspan - 11.42 m
Carrying area - 23.8 m2
Weight (empty) - 941 kg
Weight (take-off) - 1 363 kg
Area load - 57.3 kg/m2
Maximum speed (near ground) - 257 km/h
Maximum speed (h = 3 km) - 250 km/h
Take-off length - 70 m / 6 s
Landing length - 140 m 17 s
Range - 840 km
Flight endurance - 2 h 18 min
Range - 7 650 m
Climb time to 5 km - 11 min
Armament - 2 7.62 mm machine guns


pre-series I-4 (1928)
Crew - 1
Engine - 1 x Mikulin M-22 with 480 hp.
Length - 7.28 m
Height - 2,82 m
Wingspan - 11.42 m
Carrying area - 23,8 m2
Weight (empty) - 974 kg
Weight (take-off) - 1 426 kg
Surface load - 60 kg/m2
Maximum speed (ground speed) - 247 km/h
Maximum speed (h = 3 km) - 250 km/h
Length of take-off - 8 s
Length of landing - 19 s
Range - 840 km
Flight endurance - 2 h 18 min
Range - 7 650 m
Climb time to 1 km - 1.8 min
Climb time to 2 km - 4.1 min
Climb time to 3 km - 6.7 min
Climb time up to 5 km - 12.4 min
Armament - 2 7.62 mm machine guns


I-4 (year 1928)
Crew - 1
Engine - 1 x Mikulin M-22 with 480 hp.
Length - 7.28 m
Height - 2,82 m
Wingspan - 11.42 m
Carrying area - 23,8 m2
Weight (empty) - 978 kg
Weight (take-off) - 1 430 kg
Area load - 60 kg/m2
Maximum speed (ground speed) - 220 km/h
Maximum speed (h = 3 km) - 231 km/h
Take-off length - 90 m 7 s
Landing length - 210 m 19 s
Range - 840 km
Flight endurance - 2 h 18 min
Range - 7 000 m
Climb time to 5 km - 14.3 min
Armament - 2 7.62 mm machine guns


I-4 "Dubler" (1928)
Crew - 1
Engine - 1 x Mikulin M-22 with 480 hp.
Length - 7.28 m
Height - 2,82 m
Wingspan - 11.42 m
Carrying area - 23,8 m2
Weight (empty) - 978 kg
Weight (take-off) - 1 430 kg
Area load - 60 kg/m2
Maximum speed (ground speed) - 257 km/h
Maximum speed (h = 3 km) - 250 km/h
Take-off length - 70 m / 6 s
Landing length - 140 m 17 s
Range - 840 km
Flight endurance - 2 h 18 min
Range - 7 650 m
Climb time to 5 km - 11 min
Armament - 2 7.62 mm machine guns


I-4 'Zveno' (1930)- parasitic fighter of the Zveno project
Crew - 1
Engine - 1 x 420/525hp Gnôme-Rhône Jupiter-VI
Length - 7.28 m
Height - 2.82 m
Wingspan - 11.42 m
Carrying area - 19.8 m2
Weight (empty) - 940 kg
Weight (take-off) - 1 362 kg
Surface load - 69 kg/m2
Maximum speed (ground speed) - 253 km/h
Maximum speed (h = 3 km) - 245 km/h
Range - 686 km
Flight endurance - 2 h 18 min
Range - 7 650 m
Climb time to 5 km - 10.9 min
Armament - 2 7.62 mm machine guns + 4 x small bombs


I-4bis (1931)
Crew - 1
Engine - 1 x Mikulin M-22 with 480 hp.
Length - 7,28 m
Height - 2,82 m
Wingspan - 11.42 m
Carrying area - 19.8 m2
Weight (empty) - 973 kg
Weight (take-off) - 1 385 kg
Surface load - 70 kg/m2
Maximum speed (ground speed) - 268 km/h
Range - 686 km
Flight endurance - 2 h 18 min
Range - 7 000 m
Climb time to 1 km - 14 min
Armament - 2 7.62 mm machine guns


All versions carried the same 236 kg of fuel + 25 kg of oil
Springs:
www.tupolev.ru
http://rus.air.ru/airplanes/I-4.htm
http://www.biograph.ru/goldfund/okb_suhogo.htm
http://www.cofe.ru/avia/T/T-24.htm
http://www.ctrl-c.liu.se/misc/ram/i-4bis.html
http://www.ctrl-c.liu.se/misc/ram/i-4.html
http://www.aviastar.org/air/russia/ant-5.php
http://en.wikipedia.org/wiki/Tupolev_I-4
Duffy, Paul & Kandalov, Andrei: The Tupolev-Man and His Aircraft
URL : https://www.valka.cz/Tupolev-I-4-t9022#254158 Version : 0
A few more drawings. The source is mentioned in the previous post.
Tupolev I-4 - pramen v předchozím příspěvku

pramen v předchozím příspěvku
Tupolev I-4 - pramen v předchozím příspěvku

pramen v předchozím příspěvku
Tupolev I-4 - pramen v předchozím příspěvku

pramen v předchozím příspěvku
URL : https://www.valka.cz/Tupolev-I-4-t9022#254159 Version : 0
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