| SGS 1-34 | |
|---|---|
 SGS 1-34 with air brakes deployed | |
| General information | |
| Type | Standard-class sailplane |
| National origin | United States |
| Manufacturer | Schweizer Aircraft Corporation |
| Designer | |
| Number built | 93 |
| History | |
| First flight | 1969 |
| Variant | Martin Marietta Model 845 |
TheSchweizer SGS 1-34 is a United States StandardClass, single-seat, high-wing glider built bySchweizer Aircraft ofElmira, New York.[1]
The 1-34 was designed over a number of years in the mid-1960s and first flew in 1969.[2]
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.[1][3]
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 withterminal 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.[3]
The SGS 1-34 is of all metalaluminum semi-monocoque construction. All surfaces are aluminum covered, with the exception of the rudder which is covered in aircraft fabric.[1]
The 1-34 has air brakes capable of limiting theterminal 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.[3]
The 1-34 was the first Schweizer design to depart from using a NACA airfoil. The 1-34 has no wingwashout and instead uses aWortmann FX 61-163 airfoil at thewing root, transitioning to a Wortmann FX 61-126 airfoil at thewing tip. The tip airfoil stalls at a higher angle of attack, ensuring that the wing root stalls first.[1]
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.[1]
The 1-34 also features in-flight adjustable rudder pedals and a two-way adjustable seat to accommodate pilots of different heights.[1]
The 1-34 was flown in Standard Class competitions, but was out-performed by the newfiberglass European gliders, such as theGlasflügel H-201 Standard Libelle.[3]
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 the1-26.[3]
In service the 1-34 has proven to be a popular club aircraft and ideal for the completion ofbadge 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.[3]
The 1-34 type certificate is currently held by K & L Soaring ofCayuta, New York. K & L Soaring now provides all parts and support for the Schweizer line of sailplanes.[4][5]
At least two 1-34s have been highly modified. Bob Park's 1-34R, registered N17974, was damaged when ahurricane passed throughGeorgia and resulted in a hangar collapse. The 1-34R was rebuilt with aV-tail and ballast tanks mounted in the wings that hold 230 lbs (105 kg) of water. The aircraft was subsequently registered in theexperimentalRacing – Exhibition category.[2][6][7]
A modified SGS 1-34 airframe with tricycle landing gear and powered by aLycoming TIO-360 piston engine was used as the basis for the pilotlessMartin Marietta Model 845 prototype, an entry in the early 1970s USAF Compass Dwell enduranceUAV program.[8]
In May 2008 there were still 63 1-34s and six 1-34Rs registered in the USA[9] and 5 SGS 1-34s in Canada.[10]
TheUSAF designation for the SGS 1-34 isTG-6.
General characteristics
Performance
Aircraft of comparable role, configuration, and era
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