Schweizer SGS 1-34
Encyclopedia
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
Standard Class
Glider Competition Classes
Competition classes in gliding, as in other sports, mainly exist to ensure fairness in competition. However the classes have not been targeted at fostering technological development as in other sports...
, single-seat, high-wing glider built by Schweizer Aircraft
Schweizer Aircraft
The Schweizer Aircraft Corporation is a manufacturer of sailplanes, agricultural aircraft and helicopters located in Horseheads, New York. It was incorporated in 1939 by three Schweizer brothers , who built their first glider in 1930...
of Elmira, New York
Elmira, New York
Elmira is a city in Chemung County, New York, USA. It is the principal city of the 'Elmira, New York Metropolitan Statistical Area' which encompasses Chemung County, New York. The population was 29,200 at the 2010 census. It is the county seat of Chemung County.The City of Elmira is located in...
.
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.
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 velocityTerminal velocity
In fluid dynamics an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the fluid through which it is moving....
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 semi-monocoque
Monocoque
Monocoque is a construction technique that supports structural load by using an object's external skin, as opposed to using an internal frame or truss that is then covered with a non-load-bearing skin or coachwork...
construction. All surfaces are aluminum covered, with the exception of the rudder which is covered in aircraft fabric.
The 1-34 has the originally specified terminal velocity dive brakes, that limit the glider to below redline speeds in a vertical dive. 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
Washout (aviation)
Washout refers to a feature of wing design to deliberately reduce the lift distribution across the span of the wing of an aircraft. The wing is designed so that angle of incidence is higher at the wing roots and decreases across the span, becoming lowest at the wing tip...
and instead uses a Wortmann FX 61-163 airfoil at the wing root
Wing root
The wing root is the part of the wing on a fixed-wing aircraft that is closest to the fuselage. On a simple monoplane configuration, this is usually easy to identify...
transitioning to a Wortmann FX 61-126 airfoil at the wing tip
Wing tip
A wing tip is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft.Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of shapes, including:* Squared-off...
. 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
Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...
European gliders, such as the Glasflügel H-201 Standard Libelle
Glasflügel H-201
|-References:*Thomas F, Fundamentals of Sailplane Design, College Park Press, 1999*Simons M, Segelflugzeuge 1965-2000, Eqip, 2004*...
.
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
Schweizer SGS 1-26
The Schweizer SGS 1-26 is a United States One-Design, single-seat, mid-wing glider built by Schweizer Aircraft of Elmira, New York.The SGS 1-26 enjoyed a very long production run from its first flight in 1954 until 1979, when production was ended. The 1-26 was replaced in production by the...
.
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
Cayuta, New York
Cayuta is a town in Schuyler County, New York, United States. The population was 545 at the 2000 census.The Town of Cayuta occupies the southeast corner of the county and is northeast of Elmira, New York.- History :...
. 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 hurricane passed through GeorgiaGeorgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
and resulted in a hangar collapse. The 1-34R was rebuilt with a V-tail
V-tail
In aircraft, a V-tail is an unconventional arrangement of the tail control surfaces that replaces the traditional fin and horizontal surfaces with two surfaces set in a V-shaped configuration when viewed from the front or rear of the aircraft...
and ballast tanks mounted in the wings that hold 230 lbs (105 kg) of water. The aircraft was subsequently registered in the experimental
Experimental aircraft
An experimental aircraft is an aircraft that has not yet been fully proven in flight. Often, this implies that new aerospace technologies are being tested on the aircraft, though the label is more broad....
Racing - Exhibition category.
A modified SGS 1-34 airframe with tricycle landing gear and powered by an Lycoming TIO-360 piston engine was used as the basis for the pilotless Martin Marietta Model 845
Martin Marietta Model 845
-References:This article contains material that originally came from the web article by Greg Goebel, which exists in the Public Domain.-External links:* at Designation-Systems.Net...
prototype, an entry in the early 1970s USAF Compass Dwell endurance UAV
Unmanned aerial vehicle
An unmanned aerial vehicle , also known as a unmanned aircraft system , remotely piloted aircraft or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously, that is, as a self-directing entity...
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
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
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-tailV-tailIn aircraft, a V-tail is an unconventional arrangement of the tail control surfaces that replaces the traditional fin and horizontal surfaces with two surfaces set in a V-shaped configuration when viewed from the front or rear of the aircraft...
and 230 lb (104 kg) of water ballast. The new tail allowed 18 lb (8 kg) of lead nose ballast to be removed. The aircraft flew three diamond goal and gold distance flights in August 1983.