Aviation of World War II
At the end of the 30s, in the team of the Special Design Bureau-30, under the leadership of the chief designer V. Shevchenko, the IS-1 biplane, unique for that time, was developed, which was then built at plant No. 156. Before Shevchenko, none of the foreign and our designers encroached on static the entire bearing surface, did not try to completely get rid of one wing that interferes with high-speed flight. And the thing is that this biplane, after taking off from the ground, could remove not only the landing gear, but also the lower wing, folding it along the hinges. At the same time, the wheels were removed into the side niches of the fuselage, the root part of the wing was also removed here with a special lifting mechanism, and the end part fit into the recess of the lower part of the upper plane. The monoplane obtained in this way immediately changed all its characteristics: the frontal resistance was significantly reduced, and the flight speed increased. At that time, monoplanes with an increased area load, as we have already noted, had a rather high maximum speed, but reduced maneuverability and worse takeoff and landing characteristics. Biplanes, on the contrary, are famous for their excellent maneuverability and excellent takeoff and landing properties. They do not need extensive airfields, but, alas, their maximum speed was already considered clearly insufficient. So, Major Shevchenko, a test pilot at the Air Force Research Institute, came up with the idea to combine the best qualities of a mono- and biplane in one plane. And now Shevchenko submitted sketch calculations and drawings to the scientific board of the Air Force. The project was found very interesting and original, not seen before in world practice. The designer was given a room in the old building of the Moscow Aviation Institute, small funds, and a team was assigned to build the model. Having learned about the unusual work that Shevchenko is doing, the outstanding pilots Heroes of the Soviet Union Grigory Kravchenko, Stepan Suprun and Anatoly Serov warmly supported the enthusiast, helped him with advice and deed. The well-known pilot brigade commander Alexander Filin also joined in the implementation of the idea.
The IS-1 was an experimental aircraft built to study a previously unprecedented scheme and test the wing retraction mechanism and landing gear in flight. Outwardly, the IS-1 had some similarities with the I-153.
The lower wing consisted of a center section and folding consoles. By means of a lifting mechanism installed in the fuselage, the center section rotated on the hinges of the attachment to the fuselage and folded the lower wing. The lifting mechanism, in turn, consisted of a hydraulic cylinder and two rocker struts. Working pressure (60 atm) was created by a pump mounted on the motor. The console had two spars riveted from duralumin profiles with a wall. Sheathing made of sheet duralumin, reinforced with stamped ribs. The lower center section consisted of two truss welded spars and a central tube for attaching the wings of the lifting mechanism. The ribs and lining of the center section are duralumin.
The undercarriage and tail skid were removed at the same time as the wing was retracted. The aircraft provided for the installation of four machine guns ShKAS 7.62 mm, located in the center section of the upper wing.
The fuselage, welded from chromansile pipes, was a power truss with an outer duralumin frame and mixed skin. The front compartment consisted of four frames interconnected into a farm. In place of the center section, a power basket was attached. A rod for lifting and releasing the wing and landing gear is installed in its compartment. On the outer sides of the basket there were attachment points for the lower center sections. On the front frame are the attachment points of the motor mount. On the fourth - the attachment points of the rear fuselage. Between the first and second frames is the front gas tank, and between the third and fourth is the rear. The rear compartment is braced with wire crosses. The pilot's compartment had additional rods for installing the seat and floor. The outer skin of the fuselage was divided into front and rear sections. The frame of the tail section was made of light duralumin frames, and longitudinal profiled stringers and covered with ACT-100 canvas. The upper wing consisted of a gull-shaped center section and two consoles. The wing is of a two-spar design with a working duralumin skin. Truss-type spars welded from chromansile pipes. The ribs of the wing, stamped from duralumin, were attached to the spar with steel clamps. In the skin of the center section of the upper wing there were power hatches for servicing machine guns.
The stabilizer had two spars, on which stamped ribs were typed. The stabilizer was attached to the fuselage with four bolts, which made it possible to change the installation angle of the stabilizer on the ground in the range from +2 to -4 °.
The keel is a removable two-spar design, attached to the fuselage at four points.
Cantilever chassis with shock absorption and normal brake wheels measuring 700×150 mm. An aircraft-mounted crutch, unguided, orienting, lockable in neutral position. Cleaning and release of it was carried out with cables. The crutch is equipped with a pneumatic shock absorber.
Aircraft control is mixed. Elevator and ailerons - rigid, consisting of duralumin pipes and rocking chairs. Steering wheel control - cable.