During the preparations for the license production of the RCF-3, it became clear that the new power plant could not be as easily produced as had been initially assumed. As a result, it was not until October of 1935, that the new engine, designated the M-25, was finally accepted and cleared for production. As a result, the first pre-series and production I-16 Type 5s were powered by imported Wright-Cyclone SGR-1820-F-3 power plants.

Once the first M-25 power plants became available, production of a batch of M-25 powered pre-serics I-16 Type 5s was undertaken at GAZ-39 in Khodinka. The M-25 was rated at 700 hp for take off and was equipped with a Stromberg NA-F-7C carburetor and a Soviet copy of the "Scintilla" ignition system.

These pre-series aircraft differed from the TsKB-12bis prototype in having the exhaust port slightly modified. Instead of a rounded rear portion, the port was given a tear drop shape. In addition, the small propeller spinner used on the TskB-12bis was replaced by a larger spinner on all production I-16 Type 5s.

While the TsKB-12bis prototype lacked landing gear strut covers and had no main wheel cover, the I-16 Type 5 adopted the same landing gear covers that had been introduced on the production I-16 Type 4. In addition, the tailskid of the TsKB-12bis was replaced by a tailwheel on some pre-production I-16 Type 5s.

A number of pre-series aircraft were test flown by the NII-VVS. On the рге-series aircraft, take off weight had risen from 3.152 pounds (1,430 kg) to 3,384 pounds (1,535 kg), but due to other improvements, the aircraft turned in a top speed of 283 mph (457 km/h) without losing any of its maneuverability. This speed was some fifty mph faster than the latest contemporary American fighter in service, the Boeing P-26A.

The Soviet government had made no effort to conceal the development of the I-16 and had, in fact, exhibited a pre-production example of the I-16 Type 5 at the International Aeronautical Salon at Milan, Italy, held between 12 and 28 October 1935. At the Milan Fair, the I-16 drew considerable attention due to its retractable landing gear and glazed canopy.

Production of the new type started in early 1936 at both GAZ-21 and GAZ-153. By the time production of the I-16 Type 5 and Type 6 was phased out in late 1937, some 2,200 aircraft had rolled off the production line.

The standard production I-16 Type 5 differed from the pre-series aircraft in having the tail-wheel replaced by a tailskid. The firepower was augmented by replacing the two standard PV-1 machine guns with the new ShKAS 7.62mm weapon. The two ShKAS were placed in the wings, outside of the propeller arc and had a rate of fire of 1,800 round per minute, with a ammunition supply of 900 rounds per gun. There was also a provision for carrying a 440 pound (200 kg) bomb load. All I-16 Type 5s were equipped with the OP-1 telescopic gun-sight, which was also used on the earlier I-15 and I-152 biplane fighters.

The cockpit itself was decidedly snug for all but the smallest of pilots. The seat could only be adjusted vertically and equipment was spartan. The rudimentary instrumentation included altimeter, rate of climb, turn-and bank and oil temperature indicators. These instruments were, for the most part, license-manufactured American Pioneer-Bendix gauges. The cockpit, as well as the pilot's seat, was painted at the factory a Greenish Gray, while the instalment panel was Dark Green. The back and headrest were generally upholstered in Black leather.

The I-16 Type 5 was less suited to close in high G maneuvering combat than its biplane contemporaries, although it possessed the advantages of superior speed and climb. Its ailerons were feather-light and it had an exceptional rate of roll. It also had an outstanding zoom climb capability.

The I-16 Type 5, however, was no aircraft for a novice. It was overly sensitive to control movements and longitudinal stability was marginal. The fighter also tended to stall out in a glide. Instability in a climb and in turns demanded the highest concentration on the part of the pilot and the rigidly-mounted engine produced an annoyingly high vibration level.

Unless extreme care was exercised, use of the split ailerons as flaps on landing approach could result in the nose of the tighter pitching up and the aircraft entering a stall. When the undercarriage was lowered, the aircraft immediately became sluggish, buffeting was severe and power had to be kept up. since there was a marked tendency to drop a wing. The I-16 had to be literally flown onto the ground, stalling at anything up to 93 mph (150 km/h), and as only one of the three legs of each main main landing gear member incorporated an oleo shock absorber, the damping of the landing impact was inadequate and the aircraft tended to bounce, often resulting in a dangerous nose-up attitude.

Because of these handling problems, the service introduction of the I-16 Type 5 was to prove difficult and the high accident rate it experienced during its initial stages brought near-rebellion in the ranks of the Red Air Force fighter pilots.

Another shortcoming, in the opinion of many average pilots, was the enclosed cockpit. Before the introduction of the I-16. all Soviet fighters had open cockpits. Pilots believed that the sliding canopy would restrict movement and they would be unable to move their heads from side to side to check the rear. Most pilots did not believe that the wind shield always worked efficiently, especially if they had to bail out.

To convince average service pilots, test pilots P. Stefanovskij, S. Suprun, V. Yevseyev, Y. Preman and V. Rakhov began touring the Red Air Force fighter units to demonstrate the advantages of the I-16 in November of 1937. Soon the doubts and fears of I-16 Type 5 pilots were dissolved. During their tour through various Fighter Aviation Regiments, the test pilots performed not less than 3,318 acrobatic demonstration flights with their I-16 Type 5s.

During operational service, the main wheel cover was sometimes removed as a field modification, since the covers were quite often damaged during operations from unprepared fields. When the gun camera pod became available, the I-16 Type 5 was retrofitted with the gun camera on the dorsal spine behind the pilot's scat.

Only a few I-16 Type 5s were retrofitted with a short wave RSI-3 (RSI - Radiostancija dlja Istrebitelei/Radio for fighter), identifiable by the installation of a small mast on top of the vertical fin. The RSI-3 consisted a receiver and a transmitter. Usually, only the lead plane in a formation was equipped with both, sender and receiver equipment, while the remaining planes had either only a receiver or no radio at all. Both the RSI-3 receiver and transmitter were powered by the RUN-30 accumulator. Sender and transmitter had five fixed frequencies which had to be selected on the ground before a mission.

Some I-16 Type 5s were fitted with a small trim tab on the flap as a field modification. This trim tab in the inboard flap became standard on late production I-16s.

The I-16 Type 5 was still in active front-line service when the Germans invaded Russia on 22 June 1941. A number of I-16 Type 5s fell into enemy hands during the early stage of the war, when the Germans occupied airfields in Belorussia, the Ukraine, Lithuania and Latvia.

Photo	Description
	Drawing I-16 type 5
	The I-16 Nr. 1021582 equipped with TC-1 turbocharger.
	Polikarpov I-16 type 5 with RSIU-3 radio transmitter.

Bibliography

• "The history of designs of planes in USSR 1938-1950" /Vadim Shavrov/
• "The planes of Stalin falcons" /Konstantin Kosminkov and Dmitriy Grinyuk/
• "Fighter I-16" /Mikhail Maslov/
• "The Soviet planes" /Alexander Yakovlev/