The Schweizer SGM 2-37 is a two-place, side-by-side, fixed gear, low wing
motor glider
A motor glider is a fixed-wing aircraft that can be flown with or without engine power. The FAI Gliding Commission Sporting Code definition is: a fixed-wing aerodyne equipped with a means of propulsion (MoP), capable of sustained soaring flight ...
.
[Said, Bob: ''1983 Sailplane Directory, Soaring Magazine'', page 131. Soaring Society of America, November 1983. USPS 499–920]
A total of twelve were produced between 1982 and 1988, including nine for the
United States Air Force Academy
The United States Air Force Academy (USAFA) is a United States service academy in El Paso County, Colorado, immediately north of Colorado Springs. It educates cadets for service in the officer corps of the United States Air Force and U ...
, which designated it the TG-7A. The TG-7A was retired from USAFA service in April 2003.
The basic airframe was later developed into the SA 2-37A and B covert surveillance aircraft.
Development
Schweizer had flown a
Schweizer SGU 1-19
The Schweizer SGU 1-19 and Schweizer SGU 1-20 are a family of United States single-seat, high-wing, strut-braced, utility gliders built by Schweizer Aircraft of Elmira, New York.Schweizer, Paul A: ''Wings Like Eagles, The Story of Soaring in ...
as a motor glider in 1946 without putting the design into production. In 1958 the company carried out a design study of a powered aircraft using the wings and tail of the 1-26 designated as the
Schweizer SA 1-30, but after some test flying and modification it was not put into production. A two-seat version of the 1-30, the
Schweizer SA 2-31 was completed in 1960 but not put into production due to competition in the light aircraft market. Both the 1-30 and 2-31 were designed as regular light aircraft and no further motorgliders were built by the company until 1982.
[Schweizer, Paul A: ''Wings Like Eagles, The Story of Soaring in the United States'', page 120. Smithsonian Institution Press, 1988. ]
The SGM 2-37 was designed at the request of the USAF for use at USAFA, in both the powered and glider trainer role.
To save both money and development time the aircraft used a number of existing aircraft components:
* Nose, cowling, and engine installation adapted from the
Piper PA-38 Tomahawk
* Wings adapted from the
Schweizer SGS 1-36 Sprite
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 Sprit ...
, including extensions to bring it from the Sprite's to and
leading edge cuff
A leading-edge cuff is a fixed aerodynamic wing device employed on fixed-wing aircraft to improve the stall and spin characteristics. Cuffs may be either factory-designed or an after-market add-on modification.Crane, Dale: ''Dictionary of Aer ...
s to improve stall characteristics
* Tail from the
Schweizer SGS 2-32
Schweizer (German meaning 'Swiss') may refer to: People
* Eduard Schweizer (1913–2006), Swiss New Testament scholar
* Irène Schweizer (born 1941), Swiss Jazz pianist
* J. Otto Schweizer (March 27, 1863–1955) Swiss-American sculptor
* Julián ...
The design was intended to be available as a civil aircraft as well as a military aircraft. The USAF version was delivered with a
Lycoming O-235-L2C 4-cylinder aircraft engine of . The civil version offered the same engine or an option of a
Lycoming O-320
The Lycoming O-320 is a large family of naturally aspirated, air-cooled, four-cylinder, direct-drive engines produced by Lycoming Engines. They are commonly used on light aircraft such as the Cessna 172 and Piper Cherokee. Different variants ...
of or a
Lycoming O-360
The Lycoming O-360 is a family of four-cylinder, direct-drive, horizontally opposed, air-cooled, piston aircraft engines. Engines in the O-360 series produce between 145 and 225 horsepower (109 to 168 kW), with the basic O-360 producing ...
of .
The aircraft is of all-metal aluminum
monocoque
Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell".
First used for boats, ...
construction. The engine cowling is made from
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 clo ...
and plastics are employed in some of the nonstructural components.
The 2-37 features a baggage compartment behind the side-by-side seating. The aircraft does not have flaps, but instead has top-and-bottom wing-mounted balanced divebrakes, similar to other Schweizer glider designs.
Performance includes a cruise speed of 114 mph while burning 4
US gal per hour with the O-235 engine. The 17.9 aspect ratio wing provides a glide ratio of 28:1 with the propeller feathered, and a minimum sink speed of 3.16 feet/sec (0.96 m/s).
The USAF Technical Orders indicate a glide ratio of between 19.3:1 and 19.7:1.
[USAF: ''USAF T.O. 1G-7(T)A-1 Issue C – 30 April 2002'', pages 3–11 and 3–12.]
The SGS 2-37 was marketed by the company as being suitable for the following roles:
*Sailplane trainer
*Powered aircraft trainer
*Glider towplane (with larger horsepower engine option)
*Private touring aircraft
*Surveillance
*Aerial Inspection
The 2-37 was later developed into the SA 3-38, known in military service as the
Schweizer RU-38 Twin Condor.
Certification
The SGM 2-37 was certified by the
Federal Aviation Administration
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic ...
under type certificate G1NE on 22 March 1983. The 2-37 type certificate is currently held by K & L Soaring of
Cayuta, New York
Cayuta is a city in Schuyler County, New York, United States. As of the 2020 census, the population was 508.
The City of Cayuta occupies the southeastern corner of the county and is northeast of Elmira. It is part of the Elmira Metropolitan Sta ...
. K & L Soaring now provides all parts and support for the Schweizer line of sailplanes.
Reception
''Soaring'', the journal of the
Soaring Society of America
The Soaring Society of America (SSA) 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, 193 ...
, described the SGM 2-37 as: "Very versatile, very promising, very expensive". The publication's review noted that the $70,000 base price did not include a
feathering propeller, gyro instruments,
wheel fairings
An aircraft fairing is a structure whose primary function is to produce a smooth outline and reduce drag.Crane, Dale: ''Dictionary of Aeronautical Terms, Third Edition'', page 206. Aviation Supplies & Academics Inc, Newcastle Washington, 1997. ...
, long range fuel tanks, or other optional extras.
Operational history
Examples of the TG-7 were used by the
US Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...
from 1985 on covert surveillance duties under the ''Grisly Hunter'' project. The two aircraft were then transferred to the
US Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and maritime law enforcement, law enforcement military branch, service branch of the United States Armed Forces and one of the country's eight Uniformed services ...
by mid 1989, were modified and were re-designated RG-8A. The aircraft were used on coastal patrols from the US Coast Guard base at Miami wearing a grey low visibility color scheme, as shown in the adjacent image taken in 1989.
There were nine aircraft still registered in the US in April 2008. Current owners include the
Tuskegee Airmen National Historical Museum and designer
Leslie E. Schweizer.
Variants
![Schweizer RG-8A 85-0047 USCG Opa 11](https://upload.wikimedia.org/wikipedia/commons/0/07/Schweizer_RG-8A_85-0047_USCG_Opa_11.11.89_edited-2.jpg)
;SGM 2-37
:Motor glider for USAF and civil use, 12 completed.
;SA 2-37A
:The SA 2-37A is a two-seat special-mission surveillance aircraft built for the
Central Intelligence Agency
The Central Intelligence Agency (CIA ), known informally as the Agency and historically as the Company, is a civilian foreign intelligence service of the federal government of the United States, officially tasked with gathering, processing, ...
and
US Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...
and equipped with a
Lycoming O-540-B powerplant of and first flown in 1982.
The US aircraft register records six SA-2-37As, including four belonging to Vantage Aircraft Leasing. All are in the
experimental
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a ...
''exhibition'' category.
;SA 2-37B
:The SA 2-37B is a development of the 2-37A equipped with a
Lycoming TIO-540-AB1AD powerplant of . The aircraft is optimized for covert surveillance missions and carries
FLIR
Forward-looking infrared (FLIR) cameras, typically used on military and civilian aircraft, use a thermographic camera that senses infrared radiation.
The sensors installed in forward-looking infrared cameras, as well as those of other thermal ...
and electronic sensors. It has a 500 lb (231 kg) sensor payload in a fuselage bay. With a fuel capacity of it can remain on station for up to 12 hours. Gross weight is 4300 lb (1950 kg).
The US aircraft registry records four SA 2-37Bs, all owned by Schweizer Aircraft. All are in the
experimental
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a ...
''Research and Development'' category.
;TG-7A
:United States Air Force designation for the SGM 2-37.
;RG-8A
:In
US Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and maritime law enforcement, law enforcement military branch, service branch of the United States Armed Forces and one of the country's eight Uniformed services ...
service the SA 2-37 is designated RG-8A, indicating ''Glider, Reconnaissance''.
Operators
;
*
United States Air Force
The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...
*
United States Army
The United States Army (USA) is the land warfare, land military branch, service branch of the United States Armed Forces. It is one of the eight Uniformed services of the United States, U.S. uniformed services, and is designated as the Army o ...
*
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, mu ...
;
*
Colombian Air Force
, "We are the Force"
, colours =
, colours_label =
, march = Colombian Air Force Hymn
, mascot = Capitan Paz
, anniversaries = 8 November
, ...
;
*
Mexican Air Force
The Mexican Air Force (FAM; es, Fuerza Aérea Mexicana) is the primary aerial warfare service branch of the Mexican Armed Forces. It is a component of the Mexican Army and depends on the National Defense Secretariat ( SEDENA). The objective of ...
Specifications (SGM 2-37)
See also
References
{{DEFAULTSORT:Schweizer Sgm 2-37
1980s United States military trainer aircraft
Schweizer aircraft
Motor gliders
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1982