The Rubik R-07a Tücsök () and R-07b Vöcsök () were two versions of a Hungarian primary trainer, differing most obviously in the pilot's seating. First flown in the late 1930s, about 530 were built, some remaining in service into the 1960s.

Design and development

The first primary glider designed and built by the MSrE (Müegyetemi Sportrepülő Egyesület or in English the Technical University's Sports Flying Group) was the EMESE-B. It was designed to have better performance than existing examples of this class but did not prove popular. One of its designers was

Ernő Rubik Ernő Rubik (; born 13 July 1944) commonly known by his nickname, "Little Man", is a Hungarian inventor, architect and professor of architecture. He is best known for the invention of mechanical puzzles including the Rubik's Cube (1974), Rubi ...

who used this experience to produce the R-05 Vöcsök, a simpler, lower performance aircraft. Like the EMESE-B it was a typical open frame (uncovered flat girder fuselage) glider with its wing mounted on top of the girder and

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. Human anatomy Part of the functionality o ...

-braced. This prototype proved very successful. Production aircraft were designated R-07 with the name Vöcsök if the pilot's seat was enclosed within a nacelle as it had been on the EMESE-B. R-07s with the seat completely exposed had the name Tücsök. This naming convention was maintained through the R-06 Csóvöcsök, a later, one-off tube (csó) steel fuselage version. The R-07 models, whether Vöcsöks or Tücsöks, were all-wood aircraft, with a wing built around two

spars The United States Coast Guard (USCG) Women's Reserve, also known as the SPARS (SPARS was the acronym for "Semper Paratus—Always Ready"), was the women's branch of the United States Coast Guard Reserve. It was established by the United States ...

and rectangular in plan out to blunted tips. Because the nacelle increased the empty weight of the Vöcsök by (22%) it needed a longer span wing with a 13% greater area than the Tücsök. The forward spar was close to the

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

-covered

leading edge The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...

and the rest of the wing was fabric-covered. Broad chord

ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in Flight dynamics, roll (or ...

filled the outer 40% of the span. The post-war R-07D Vöcsök introduced Frise ailerons. The wing was braced with streamlined steel V-struts to the lower fuselage. A flat, wooden, diagonally-braced girder formed the fuselage of all R-07s, with a deepened, ply-covered forward lower chord,

longeron In engineering, a longeron and stringer is the load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural ...

or keel which supported the wing struts, the pilot's seat and controls and, on its underside, a rubber sprung landing skid. On Vöcsöks the keel also supported a ply nacelle which enclosed the pilot, with fabric covering behind it to the first diagonal fuselage member. The nacelle lengthened the Vöcsök by . At the rear there was a narrow

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...

mounting a deep, fabric-covered

balanced rudder Balanced rudders are used by both ships and aircraft. Both may indicate a portion of the rudder surface ahead of the hinge, placed to lower the control loads needed to turn the rudder. For aircraft the method can also be applied to elevators and ...

with a trapezoidal profile. A roughly triangular

tailplane A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplane ...

was mounted on the top of the fuselage and forward of the rudder post. It was fabric-covered apart from a ply leading edge and carried constant chord

elevators An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They are ...

separated by a small nick for rudder movement.

Operational history

Despite the large number built (c.530 including all variants), remaining in use from 1938 to the early 60s, little is recorded in English about individual examples or their distribution over Hungarian aeroclubs. A 1981 replica R-07b, ''HA-2336'', remained active until at least 2008.

Aircraft on display

* R-07b Vöcsök ''HA-2254,'' Kzlekedesi Muzeum,

Budapest Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population ...

Variants

;R-05 Vöcsök: First prototype, with nacelle. First flown 1 October 1937. ;R-06 Csóvöcsök: Steel tube fuselage. First flown in 1939. ;R-07a Tücsök: Production model with no seat enclosure. Fin area reduced by cropping to lower longeron; rudder similarly cropped with compensation extension of upper tip. First flown 20 March 1938. 178 built by Aero Ever Kft, Esztergom ;R-07b Vöcsök: Production model with nacelle, greater span and length, increasing performance. First flight 1938. About 300 built, mostly by Aero Ever Kft but also including 12 by the Transylvanian Aircraft Plant, Nagyvárad

Oradea Oradea (, , ; german: Großwardein ; hu, Nagyvárad ) is a city in Romania, located in Crișana, a sub-region of Transylvania. The county seat, seat of Bihor County, Oradea is one of the most important economic, social and cultural centers in the ...

. ;R-07D Vöcsök: 1955-6 production batch of 30 examples built by the Experimental Aircraft Plant of the Hungarian Aeronautical Association (MRSz), Dunakesziwith. Fitted with Frise ailerons. In use into early 1960s.

Specifications (R-07 Vöcsök)

References

{{DEFAULTSORT:Rubik R-07 Vocsok Aircraft first flown in 1937 1930s Hungarian sailplanes Rubik aircraft High-wing aircraft