Grušin Gr-1

Grušin Gr.-1
One of the least known of heavy fighter aircraft, developed in the USSR in the eve of the 2. world war, was the so-called doprovodé fighter aircraft long-range IDS (истребитель дальнего сопровождения - ИДС) created under the leadership of Peter Dmitrieviče Grušina (Пётр Дмитриевич Грушин).

The basic task set before the designer was to create a heavy fighter aircraft with long-range. The plane was supposed to provide fighter escort for heavy long-range bombers, such as Petljakow Pe-8 or Kalinin K-7 etc., whose development before the war in the USSR successfully was getting.
The design work took place relatively quickly. In December 1940 it was still nepostavenému the aircraft given the designation Gr-1, or Grušin-first (Гр-1, Грушин-первый).

Unlike in the OKB also built a heavy twin-engined fighter plane's EYE-6 - future The-1 - Vsevoloda Konstantinoviče Tairovand, was the machine IDS P. D. Grušina designed for two liquid cooled engines AM-37 the design And. And. Mikulina with the performance of the approx 1200 PCS. Due to its aerodynamic scheme of the plane very resembling in that time already a well-known German multi-role fighter the Messerschmitt Bf. 110 and it also made him very similar to the outline dimensions. In particular, when viewed in plan view, both machines were very similar. True ,the Gr-1 was, in contrast to the Messerschmitt, one-seater, and the radiator of the engine cooling system were located under the centroplánem wings and were made retractable. Collector exhausts of the engines were brought out on the upper surface of the wing, as it was how the aeroplane DIS(ДИС) Mikojana - Gurjeviče and aircraft TIS(ТИС) polikarpov-type construction.
The flight deck was armored. It is interesting to note that this factor was taken into account in the balance sheet definition the number of crew members - whether single pilot or two. When the weight ratio of the two-seater version of the cabin with the equipment for the gunner-radio operator did not rely in any way harder than the armoured cab, welded from sheet steel and completely protects the pilot. However Grušin gave his co-workers entering analyze both variants, so from them he received information, that a fully armoured single-seat cabin of the pilot version will be about 18 kg lighter than the cabin of the two-seaters. This led to the decision that the new aircraft will be designed as a single seater. Perhaps this decision was somewhat hasty, but of a similar groping was in pre-war times fairly frequent. Consider e.g. the case of Iljušinova attack aircraft Il-2, conceived first as a double, then in the serial production produced as a single seater. And only war experience has demonstrated the need for the presence of a second member of the crew. It can be assumed that a similar development would be met and Gr-1. In a plane similar category.

It should also be noted that the armament of the IDS has been extremely powerful and even a little bit falls behind his expected primary opponent - a messerschmitt coming Bf.110. In příďovém section of the fuselage were placed two machine guns ŠKAS, and above them two 20-mm cannon ŠVAK. The next two machine guns ŠKAS were installed in the wind crossing the hull of the wing. All machine guns had a supply of ammunition after 1250 rounds on each barrel. Combat supply of cannon formed after 300 grenades on the barrel. It was assumed one of the lower podtrupové range with two 37-mm cannon with a supply of ammunition, 200 grenades at the cannon.

Under the wing of the aircraft meant it was to install four beamed holders for hanging eight 100-kg air bombs or four rocket projectiles large-caliber RS-82 or RS-132. Besides, instead of podtrupového kanónového the container can be in the internal bomb bay to place up to 500 kg of bombs.

Regardless of the apparent similarity with the German messerschmitt coming Bf.110, was Grušinův IDS design fundamentally from him different. The wing spars should cabinet cross-section. Their uprights and trusses were made of the narrowing with steel strips, welded into a closed shape. The nodes dividing the beam wings should the original konstrukcíi with cross-comb.

The plane was designed and built only for nine months. Static strength tests took a couple of days and into the early spring of 1941 r, the aircraft was ready for flight tests. After long delays and the elimination of a large amount of minor flaws, but someone remembered that the aircraft has not passed the ofukovacími tests in TSAGI. The machine had to be dismantled and sent to Moscow. After the end of this phase of the tests the aircraft was again taken to the race no 135 for the removal of the comments. Closer to the date of the first flight. But in that war broke out. In the preparation of the withdrawal of the race to the east on the way from Kharkov military train got under an enemy air raid. The plane was heavily damaged and all the project documentation was burned. Of course, work on the plane were no longer renewable.

Note:
It is not certain whether the plane ever got into the air. Springs here differ, the most likely is but an indication, that the aircraft fly wasn't.

Sources:
http://www.airwar.ru/enc/fww2/gr1.html
http://www.airwar.ru/image/idop/fww2/gr1/gr1-1.gif třípohled
vsekommentarii.com
usssrtanks.ru
http://www.ctrl-c.liu.se/misc/ram/gr-1.html
http://fandavion.free.fr/GrushinGr1.htm
usssrtanks.ru.