Polikarpov UTI-4 typ 15

Polikarpov UTI-4 type 15

The transition of pilots to the then-modern Polikarpov I-16 fighter was quite challenging if the pilot was transitioning from the I-15 series of biplanes, he had to get used to the high surface load and also to the completely different behaviour of the single-plane "sixteeners", even worse for young pilots who had been flying training Polikarpov Po-2. Therefore, a total of 115 two-seat trainers UTI-2 were built, based on the combat I-16 Type 4, i.e., it was powered by a nine-cylinder Svecov M-22 with 480 hp, but this engine ceased to be produced over time and so it was necessary to proceed to the production of a more modern trainer. The other reasons were that in 1935 the performance of the next versions of the "sixteen" increased and this was mainly due to the Švecov M-25 engine and in addition the new versions were equipped with flaps, thus creating a new aircraft for continued training as the UTI-3, which was powered by the M-58 engine. The prototype was tested, but engines were in short supply, and so the UTI-3 remained a single example. In the same year, another aircraft designated UTI-4 was built.


This aircraft was based on the I-16 Type 5, the prototype flew in the autumn of 1935, flying unarmed, with smaller fuel tanks, no radio equipment and no breathers, the landing gear was retractable. The aircraft was powered by a M-25A engine of 715 hp. After some time, the aircraft continued to be lightened and the UTI-4 was to be delivered with a fixed undercarriage, if you say that this is detrimental to the quality of training, it is not true in Russian terms, only the instructor could operate the undercarriage from his seat! From 1 January 1939 aircraft were delivered with fixed undercarriage, i.e. only some had fixed undercarriage, some had retractable undercarriage but fixed in the open position and the undercarriage shafts were covered with the original covers, now bolted on - the order was obeyed. The rigid chassis made it easy to swap wheels for skis.


Towards the end of production, the UTI-4s finally saw newly manufactured covers and parts that eliminated the undercarriage shafts. These last production blocks were delivered with 750 hp M-25V engines and dyno starters. Production at Moscow, Gorky and Novosibirsk was completed in 1940, the Rostov plant was evacuated to Baku and production continued there until 1942. Several dozen combat aircraft, designated UTI-4B, were also produced at this factory.
These planes were single-seaters with a flush rear cockpit, two Berezin UBK machine guns of 12.7 mm calibre in the wings, and could be fitted with six RS-82 unguided rockets or two 50-pound FAB-50 bombs. These fighters formed the armament of the 266th Air Regiment.
The training aircraft were gradually used up and so were replaced by more modern aircraft such as the Yak-7UTI. A few aircraft, however, lasted in service until the end of the war, but these were used in the role of courier aircraft. A total of 1,660 trainer aircraft were produced and approximately 130 aircraft were converted from single-seat fighters.

Sources used:
Yefim Gordon and Keith Dexter. Polikarpov's I-16 Fighter, Its Forerunners and Progeny, Red Star, Vol.3., Earl Shilton, Leicester, UK, Midland Publishing Ltd., 2002. ISBN 1-85780-131-8
Hans-Heiri Stapfer, Polikarpov Fighters in Action, Part 2, Aircraft in Action number 158., Carrollton, TX, Squadron/Signal Publications, Inc., 1996. ISBN 0-89747-355-8.
Mikhail Maslov, Istrebitel I-16, Issue No. 2: M. Armada, 1997
http://i16fighter.ru/mods/uti4/uti4.htm
http://www.airwar.ru/enc/other2/uti2.html
http://i16fighter.ru/mods/uti4/uti4.htm
author's archive

I-16 UTI


Zdroj :http://englishrussia.com/?p=2239#more-2239