THE SU-26M, SKY ACROBAT

Sports acrobatic planes with the same index in our country yet was not. We all somehow got used to the fact that the concept of “sport plane” completely adjacent to the designation Yak. In fact, until recently, flying clubs of the country were equipped with only “acrobats”, created in OKB A. S. Yakovlev.

 

In the summer of 1984 it rose in the sky the new Soviet aerobatic aircraft, on Board of which was elegantly written — the su-26. It was the first development of the youth divisions of OKB imeni P. O. Sukhoi, created by the tactical and technical requirements build a team of the USSR on aerobatics and designed for participation in world and European Championships and other major competitions.

 

When the question about the creation of the new KB design division, was supposed to solve a complex problem. As you know, the lack of creative competition leads to stagnation, and in the technical equipment of our sport aviation, the situation evolved that way. Therefore the design of alternative sport aircraft made it possible to realize — and highly successful — a design concept that dramatically improve aerobatic performance acrobatic aircraft.

 

It should be noted that a group of sport aircraft were organized here as a learning and development centre. It is known that in “large” aircraft the way from the project of the new car before its departure takes sometimes a decade. While engineering experience is typed in slowly — in fact he usually shaped in the process of development, manufacturing, flight test, analysis of results and accounting of the received data at the next design stage. When creating a sports car one such cycle is rather short, which allows young builders to pass through these stages at an accelerated pace. Especially effective this technique for the education development reserve for KB. The fact that the big help on the design of new machines was provided by the students of the Moscow aviation Institute. But KB helped students to define their place in the complex structure of modern experimental design Bureau. The returns are not immediate. Many graduate students, undergraduates and even younger students who participated in the creation of the su-26, later became permanent employees of CB or at least solid candidates for engineering positions “the firm.”

 

Aerobatic aircraft su-26 was designed and built in the shortest possible time — less than a year. The first test flight took place in June 1984. We drove the car a young test pilot, former member of the USSR national team in aerobatics Yevgeny Frolov. And next month, the athletes of the USSR team has started systematic training on a new plane.

 

Sports acrobatic plane, the su-26M:

1 — louvered hood power plant, 2 — grid for the outlet of the cooling air from under the hood, 3 — Cutlery tank oil system, 4 — tank, 5 — benzinger, 6 — hydraulic brake valve, 7 — panel, 8 — antenna, 9 — farm of the fuselage, 10 — rudder trim and Aileron, 11 — control system of Elevator, 12 — cable runs to the helm of direction, 13 — expendable tank ventsistemy, 14 — cooler, 15 — engine M-14P, 16 — propeller IN-530ТА-D35, 17 — external fuel tank, 18 — propeller-type “Hoffman”, 19 — external aerodynamic compensator Aileron, 20 cover engine bonnet, 21 — tail wheel, 22 — braking device of a wheel, 23 — Aileron su-26M-5, 24 — dashboard, 25 — right panel, 26 g — AM-10, 27 — middle panel, 28 slots ACP-1 to turn off the magneto, a 29 — button engine start, 30 — left panel, 31 — handle emergency release of the flashlight, 32 — clock Achs-1K, 33 — altimeter VD-10K, 34 pointer speed DC-450К (KUS-730/1100), 35 — transceiver of the radio station “the breeze”, a 36 — thermometer cylinder engine TCT-13K, 37 — cardholder, 38 — a mixture thermometer TUE-48, 39 — compass KI-13K, 40 — pointer-slip, 41 — tachometer ITE-1K, 42 — pressure-vacuum gauge, 43 indicator, EMI-3K, 44 — alarm “chip in oil”, 45 — voltmeter-1, 46 — priming a syringe ventsistemy.

 

A few words about the basic design concepts that distinguish the su-26 among other devices of this type. Thus, improving the aerodynamics of the car was achieved primarily due to the choice of optimal geometric parameters. Su-26 is less than all of the “Yak”, including the same type of acrobatic Yak-55. This greatly improved maneuverability and handling innovations have increased the speed of her flight allowed her ka complex of aerobatics in a good, dynamic pace and more harmonious than others.

 

It should be noted that the design of the aircraft is mostly fiberglass and preorganisation. Focusing on modern composite materials, the creators of the su-26 to a certain extent risk — because no one in the world built aerobatic machines out of plastic. And at first the attitude to the strength of the su-26 is highly loaded aerobatic plane was pretty careful. At first, the designers even went a little overboard: the first version of the su-26 got a few peretyagina due to the excessive margin of safety, however, the accumulation of experience in the design and operation of aircraft made of composite materials, this disadvantage was eliminated.

 

The first sports car received index su-26, had a one-piece two-spar wing spars, molded of carbon fiber, without the traditional cross set of ribs, a sheathing of fiberglass sandwich panels with foam filler. All connections have been the glue. The same scheme had the fin and stabilizer.

The fuel tanks on the aircraft as such was not just in the wing provided two of the sealed compartment that served as fuel tanks.

 

In the future, when working on the next modification — su-26M, has returned to the traditional ribs in the wing structure. The fact that the first cars wing was although simple, sophisticated and durable, but somewhat heavier than required for a perfect aerobatic airplane.

 

Su-26M well as permanent, direct, two-spar wing composite structure with sixteen ribs: side — of the material D16T, end — of preorganisation, the rest of the truss, of titanium.

 

The front spar is of I-section, with shelves of unidirectional carbon and fiberglass. Between the shelves and glued the foam blocks and placeholders. The rear spar — channel, preorganisation. Of the same material with the honeycomb upper and lower skin panels of the wing. Two fuel tanks with a capacity of 82 l are placed at the root of the sock of the wing. To increase the autonomy of the aircraft, for example when driving to a new location, the fuel system is complemented by an outboard tank with a capacity of 100 L.

 

The first machines the ailerons were solid foam filler, fiberglass hull and box-shaped spar with shelves made of CFRP. The su-26M, however, abandoned this design in favor of the Aileron, which consists of metal ribs and spar with a shell of five glued layers of fiberglass. Fasteners such plating is one-sided.

 

The fuselage of the su-26, raano as the su-26M, truss, welded from high strength stainless steel pipes. This allowed the glaze almost all of its middle part around the cockpit. It should be noted that this gives the athlete an important tactical advantage, allowing him in any position of the plane to see the boundaries of the aerobatic zone marked on the ground with a white cloth: output from this area faces substantial penalty points.