Schweizer SGS 1-36 Sprite
Encyclopedia
The Schweizer SGS 1-36 Sprite is a United States
, single-seat, mid-wing glider
built by Schweizer Aircraft
of Elmira, New York
.
The 1-36 was first flown in 1979 and a total of 43 were built by the time production was completed in 1982. The Sprite was reportedly still available to customers in 1987, but none were built after 1982.
The 1-36 was conceived as a replacement for the One-design
competition Schweizer SGS 1-26
, when production of that model ended in 1979.
The 1-36 was also the last glider model that the company would manufacture. The completion of production of the 1-36 in 1982 marked the end of an era that started in 1930 with the Schweizer SGP 1-1
.
The SGS 1-36 Sprite was the only glider produced by Schweizer that was given an official marketing name.
The prototype SGS 1-36 first flew in August 1979 and the Sprite was certified under type certificate
G5EA on 15 October 1980.
The first customer delivery was made on 16 October 1980 to Al Freedy of Hinckley Soaring, Schweizer's dealer in Chicago
, where it was employed as a rental aircraft. In late 1980 Schweizer had 32 dealers listed and each one was required to order an SGS 1-36.
The 1-36 is an all-metal aircraft with a monocoque
fuselage. The wing is covered in aluminum sheet and the aircraft's elevator and rudder are fabric covered. The Sprite's wing has balanced top and bottom divebrakes set well aft near the trailing edge
. The 1-36 is not equipped for water ballast.
The SGS is equipped with a 13 inches (330.2 mm) diameter X 5 inches (127 mm) main wheel. The wheel has a hydraulic brake that is actuated by full application of the spoilers.
The pitot tube
is installed in the nose air intake, which gives it good protection during ground handling. The static ports are located 14 inches (35.6 cm) aft of the nose and the fuselage sides. Their location provides accurate indicated airspeed above 56 knots (64 mph, 104 km/h) but provide increasing errors below that speed, up to 4.5 knots (5.2 mph, 8.3 km/h) at the stall.
Assembly of the 1-36 is accomplished by inserting the wings and installing the main spar pins and fore and aft drag pins. The T-tail has a fixed section and the two horizontal stabilizer and elevator sections are inserted in that and retained with one pin. The elevators and divebrakes hook up automatically on assembly, but the ailerons require the manual insertion of pins.
The Sprite was built in two different versions, differing only in main wheel placement.
The 1-36 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.
and the Dallas Gliding Association and published in the Soaring Society of America
's journal, Soaring, in March 1982.
The evaluation flights showed that the aircraft has a glide ratio of 31:1 at 42 knots (82.3 km/h) calibrated airspeed
(48 mph, 78 km/h), the same glide ratio claimed by the factory. Measured minimum sink rate was 130 ft/min (2.17 ft/s) at 39 knots (45 mph, 73 km/h). The roll rate at 40 knots (78.4 km/h) was 6 seconds from 45 degrees to 45 degrees. Flight testing did note that the 1-36 has a tendency to oscillate in pitch while on aero-tow, but this was easily controlled by the pilot with practice.
Johnson's flight test evaluation indicated that the 1-36 out-performed the 1-26E by a margin of 45%.
The flight test evaluation concluded:
In May 2008 there were still 33 1-36s registered in the USA and one registered in Canada.
prototype, registered N502NA, was acquired by NASA
's Dryden Flight Research Center
at Edwards, California
and used for research into controlled, deep-stall conditions at an angle of attack
of more than 30 degrees. The Sprite was used for the test program because of its slow speed and the simple aerodynamics of its long unswept wing.
Schweizer Aircraft modified the Sprite's horizontal stabilizer to allow it to produce an elevator angle of up to 70 degrees. NASA also modified the Sprite to permit better pilot entry and exit. Radio-controlled-model, ground tests and simulator tests were conducted before manned flight.
During September and October 1983 NASA flew the test program with the SGS 1-36, to demonstrate whether a piloted aircraft could be controlled in flight at very high angles of attack. The 1-36 was usually aero-towed to 8500 feet (2,590.8 m) to conduct these test flights.
The program results showed that the Sprite could be safely controlled at angles of attack of 30 to 72 degrees and at high rates of descent.
1-36 version 36903-3
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, single-seat, mid-wing glider
Glider (sailplane)
A glider or sailplane is a type of glider aircraft used in the sport of gliding. Some gliders, known as motor gliders are used for gliding and soaring as well, but have engines which can, in some cases, be used for take-off or for extending a flight...
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 1-36 was first flown in 1979 and a total of 43 were built by the time production was completed in 1982. The Sprite was reportedly still available to customers in 1987, but none were built after 1982.
The 1-36 was conceived as a replacement for the One-design
One-design
One-Design is a racing method where all vehicles or boats have identical or very similar designs or models. It is also known as Spec series. It is heavily used in sailboat racing. All competitors in a race are then judged based on a single start time...
competition Schweizer SGS 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...
, when production of that model ended in 1979.
The 1-36 was also the last glider model that the company would manufacture. The completion of production of the 1-36 in 1982 marked the end of an era that started in 1930 with the Schweizer SGP 1-1
Schweizer SGP 1-1
|-See also:-External links:**...
.
The SGS 1-36 Sprite was the only glider produced by Schweizer that was given an official marketing name.
Design and development
By the end of the 1970s the company decided to end manufacture of the SGS 1-26 one-design class sailplane, which had been in production since 1954. The 1-26 had proven the concept and popularity of one-design soaring competition and the company felt that a similar aircraft, but with more performance, would be popular.The prototype SGS 1-36 first flew in August 1979 and the Sprite was certified under type certificate
Type certificate
A Type Certificate, is awarded by aviation regulating bodies to aerospace manufacturers after it has been established that the particular design of a civil aircraft, engine, or propeller has fulfilled the regulating bodies' current prevailing airworthiness requirements for the safe conduct of...
G5EA on 15 October 1980.
The first customer delivery was made on 16 October 1980 to Al Freedy of Hinckley Soaring, Schweizer's dealer in Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
, where it was employed as a rental aircraft. In late 1980 Schweizer had 32 dealers listed and each one was required to order an SGS 1-36.
The 1-36 is an all-metal aircraft with a 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...
fuselage. The wing is covered in aluminum sheet and the aircraft's elevator and rudder are fabric covered. The Sprite's wing has balanced top and bottom divebrakes set well aft near the trailing edge
Trailing edge
The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge rejoins. Essential control surfaces are attached here to redirect the air flow and exert a controlling force by changing its momentum...
. The 1-36 is not equipped for water ballast.
The SGS is equipped with a 13 inches (330.2 mm) diameter X 5 inches (127 mm) main wheel. The wheel has a hydraulic brake that is actuated by full application of the spoilers.
The pitot tube
Pitot tube
A pitot tube is a pressure measurement instrument used to measure fluid flow velocity. The pitot tube was invented by the French engineer Henri Pitot Ulo in the early 18th century and was modified to its modern form in the mid-19th century by French scientist Henry Darcy...
is installed in the nose air intake, which gives it good protection during ground handling. The static ports are located 14 inches (35.6 cm) aft of the nose and the fuselage sides. Their location provides accurate indicated airspeed above 56 knots (64 mph, 104 km/h) but provide increasing errors below that speed, up to 4.5 knots (5.2 mph, 8.3 km/h) at the stall.
Assembly of the 1-36 is accomplished by inserting the wings and installing the main spar pins and fore and aft drag pins. The T-tail has a fixed section and the two horizontal stabilizer and elevator sections are inserted in that and retained with one pin. The elevators and divebrakes hook up automatically on assembly, but the ailerons require the manual insertion of pins.
The Sprite was built in two different versions, differing only in main wheel placement.
The 1-36 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.
Independent flight testing
Independent flight testing of the SGS 1-36 was carried out in January 1982 by Dick JohnsonDick Johnson (glider pilot)
Richard H. Johnson was a glider pilot, aeronautical engineer and prolific writer of articles for gliding magazines. He was an 11-time U.S. National Champion glider pilot, 9-time US Soaring Team pilot at the Soaring World Championships, held two World Gliding Records and is a member of the US...
and the Dallas Gliding Association and published in the Soaring Society of America
Soaring Society of America
The Soaring Society of America was founded at the instigation of Warren E. Eaton to promote the sport of soaring in the USA and internationally. The first meeting was held in New York City in the McGraw-Hill building on February 20, 1932. Its first objective was to hold a national soaring...
's journal, Soaring, in March 1982.
The evaluation flights showed that the aircraft has a glide ratio of 31:1 at 42 knots (82.3 km/h) calibrated airspeed
Calibrated airspeed
Calibrated airspeed is the speed shown by a conventional airspeed indicator after correction for instrument error and position error. Most civilian EFIS displays also show CAS...
(48 mph, 78 km/h), the same glide ratio claimed by the factory. Measured minimum sink rate was 130 ft/min (2.17 ft/s) at 39 knots (45 mph, 73 km/h). The roll rate at 40 knots (78.4 km/h) was 6 seconds from 45 degrees to 45 degrees. Flight testing did note that the 1-36 has a tendency to oscillate in pitch while on aero-tow, but this was easily controlled by the pilot with practice.
Johnson's flight test evaluation indicated that the 1-36 out-performed the 1-26E by a margin of 45%.
The flight test evaluation concluded:
Operational history
As a result of the low numbers produced, the 1-36 did not find a following as a one-design competition class, but it remains popular as a club, rental and personal glider.In May 2008 there were still 33 1-36s registered in the USA and one registered in Canada.
NASA Research Project
The Schweizer SGS 1-36 Sprite experimentalExperimental 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....
prototype, registered N502NA, was acquired by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Dryden Flight Research Center
Dryden Flight Research Center
The Dryden Flight Research Center , located inside Edwards Air Force Base, is an aeronautical research center operated by NASA. On March 26, 1976 it was named in honor of the late Hugh L. Dryden, a prominent aeronautical engineer who at the time of his death in 1965 was NASA's deputy administrator...
at Edwards, California
Edwards, California
Edwards is an unincorporated community in Kern County, California.It is located east-southeast of Mojave, at an elevation of 2356 feet ....
and used for research into controlled, deep-stall conditions at an angle of attack
Angle of attack
Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...
of more than 30 degrees. The Sprite was used for the test program because of its slow speed and the simple aerodynamics of its long unswept wing.
Schweizer Aircraft modified the Sprite's horizontal stabilizer to allow it to produce an elevator angle of up to 70 degrees. NASA also modified the Sprite to permit better pilot entry and exit. Radio-controlled-model, ground tests and simulator tests were conducted before manned flight.
During September and October 1983 NASA flew the test program with the SGS 1-36, to demonstrate whether a piloted aircraft could be controlled in flight at very high angles of attack. The 1-36 was usually aero-towed to 8500 feet (2,590.8 m) to conduct these test flights.
The program results showed that the Sprite could be safely controlled at angles of attack of 30 to 72 degrees and at high rates of descent.
Variants
1-36 version 36903-1- This model has a forward-position main wheel, a sprung tailwheel and no nose skid. It was intended for the private ownership market.
1-36 version 36903-3
- This model has an aft-position main wheel, a non-sprung tailwheel and an aluminum nose skid. It was intended for purchase by schools and clubs.
