The Schweizer SGS 1-34 is a United States Standard

Class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...

, single-seat, high-wing glider built by

Schweizer Aircraft The Schweizer Aircraft Corporation was an American manufacturer of sailplanes, agricultural aircraft and helicopters located in Horseheads, New York. It was incorporated in 1939 by three Schweizer brothers (Paul, William, and Ernest), who bui ...

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.Said, Bob: ''1983 Sailplane Directory, Soaring Magazine'', page 32. Soaring Society of America, November 1983. USPS 499-920 The 1-34 was designed over a number of years in the mid-1960s and first flew in 1969. By the time the 1-34 was introduced it was no longer competitive in the Standard Class, but has proven very successful as a club aircraft, being a great "step-up" sailplane for post-solo students and accomplished pilots.Schweizer, Paul A: ''Wings Like Eagles, The Story of Soaring in the United States'', page 241. Smithsonian Institution Press, 1988.

Design and development

The 1-34 was designed over several years to spread out the development costs. At the time the design work on the aircraft was started the Standard Class was new and described a very simple aircraft with terminal velocity dive brakes, fixed landing gear and no water ballast. By the time the 1-34 had flown in 1969 the Standard Class rules had changed to allow essentially unrestricted sailplanes with a 15-metre (49.2 feet) wingspan. The SGS 1-34 is of all metal

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

semi- monocoque construction. All surfaces are aluminum covered, with the exception of the rudder which is covered in aircraft fabric. The 1-34 has air brakes capable of limiting the terminal velocity in a vertical dive to the maximum safe speed as specified in the original Standard Class rules. Developing and testing these proved expensive and time-consuming and this also extended the aircraft's development time. The 1-34 was the first Schweizer design to depart from using a NACA airfoil. The 1-34 has no wing washout and instead uses a

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FX 61-163 airfoil at the wing root, transitioning to a Wortmann FX 61-126 airfoil at the wing tip. The tip airfoil stalls at a higher angle of attack, ensuring that the wing root stalls first. The one company concession to the changing Standard Class rules was the development of a retractable landing gear version of the 1-34, designated as the SGS 1-34R. The 1-34 also features in-flight adjustable rudder pedals and a two-way adjustable seat to accommodate pilots of different heights. The 1-34 was flown in Standard Class competitions, but was out-performed by the new

fiberglass Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...

European gliders, such as the

Glasflügel H-201 Standard Libelle The firm Glasflügel (german: glass wings) was founded by Eugen Hänle in 1962 and was located in Schlattstall, south of Kirchheim unter Teck. It was the first firm to manufacture a glass-fibre sailplane in large numbers. It was also responsible ...

. During the protracted development process, Schweizer Aircraft was aware that the 1-34 would be overtaken by the changes in class rules and also by the performance of the newer European fiberglass sailplanes, but continued development of the SGS 1-34 anyway. The company identified that there was demand from private owners and especially clubs and commercial operations for a simple, rugged single seat glider with greater performance than the 1-26. In service the 1-34 has proven to be a popular club aircraft and ideal for the completion of badge flights. If a greater number of 1-34s had been built, Schweizer indicated that it would have become another one-design class, similar to the 1-26. The 1-34 type certificate is currently held by K & L Soaring of Cayuta, New York. K & L Soaring now provides all parts and support for the Schweizer line of sailplanes.

Operational history

At least two 1-34s have been highly modified. Bob Park's 1-34R, registered N17974, was damaged when a

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passed through Georgia and resulted in a hangar collapse. The 1-34R was rebuilt with a V-tail and ballast tanks mounted in the wings that hold 230 lbs (105 kg) of water. The aircraft was subsequently registered in the experimental ''Racing – Exhibition'' category.Said, Bob: ''1983 Sailplane Directory, Soaring Magazine'', page 63. Soaring Society of America, November 1983. USPS 499-920 A modified SGS 1-34 airframe with tricycle landing gear and powered by a Lycoming TIO-360 piston engine was used as the basis for the pilotless

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prototype, an entry in the early 1970s USAF Compass Dwell endurance

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program. In May 2008 there were still 63 1-34s and six 1-34Rs registered in the USA and 5 SGS 1-34s in Canada. The USAF designation for the SGS 1-34 is TG-6.

Variants

;1-34 :The original fixed landing gear 1-34 model was certified under type certificate G3EA on 16 October 1969. ;1-34R :The retractable gear 1-34R was added to type certificate G3EA on 15 June 1971. ;Park 1-34R Modified :After a hangar collapsed on Bob Park's 1-34R and destroyed the aft part of the aircraft he rebuilt it in the ''Experimental – Racing/Exhibition'' category with a V-tail and of water ballast. The new tail allowed of lead nose ballast to be removed. The aircraft flew three diamond goal and gold distance flights in August 1983.

Aircraft on display

* US Southwest Soaring Museum

Specifications

References

External links

Soaring Society of Boulder - 1-34 data and photos

SGS 1-34 Flight, Erection and Inspection Manual
{{US glider aircraft 1960s United States sailplanes Schweizer aircraft Glider aircraft High-wing aircraft Aircraft first flown in 1969