Schweizer SGM 2-37

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SGM 2-37
Tg-7aNum1.jpg
USAFA TG-7A
Role Motor glider
National origin USA
Manufacturer Schweizer Aircraft Corporation
Designer Leslie Schweizer[1]
First flight 1982
Introduction 1982
Retired USAF service: April 2003[2]
Still in civil use
Primary user United States Air Force Academy - 9
Produced 1982-1988
Number built 12[1]
Unit cost
USD$70,000 (1983 base price)
Developed from Schweizer SGS 1-36 and 2-32
Variants RU-38 Twin Condor

The Schweizer SGM 2-37 is a two-place, side-by-side, fixed gear, low wing motor glider.[1][3]

A total of twelve were produced between 1982 and 1988, including nine for the United States Air Force Academy, which designated it the TG-7A. The TG-7A was retired from USAFA service in April 2003.[1][2][4]

The basic airframe was later developed into the SA 2-37A and B covert surveillance aircraft.[5]

Development[edit]

Schweizer had flown a Schweizer SGU 1-19 as a motor glider in 1946 without putting the design into production. Later in 1958 the company carried out a design study of a motorglider based on the 1-26 designated as the Schweizer SA 1-30, but after some test flying and modification it was not put into production. A single motorglider prototype, the Schweizer 2-31 was completed, but no further motorgliders were built by the company until 1982.[6][7][8][9]

The SGM 2-37 was designed at the request of the USAF for use at USAFA, in both the powered and glider trainer role.[3]

To save both money and development time the aircraft used a number of existing aircraft components:

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 112 hp (84 kW). The civil version offered the same engine or an option of a Lycoming O-320 of 150 hp or a Lycoming O-360 of 180 hp.[2][3]

The aircraft is of all-metal aluminum monocoque construction. The engine cowling is made from fiberglass and plastics are employed in some of the nonstructural components.[2]

The 2-37 features a 27 cu ft (760 L) 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.[3]

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).[1][3] The USAF Technical Orders indicate a glide ratio of between 19.3:1 and 19.7:1.[10]

The SGS 2-37 was marketed by the company as being suitable for the following roles:[1][3]

  • 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 RU-38 Twin Condor.

Certification[edit]

The SGM 2-37 was certified by the Federal Aviation Administration under type certificate G1NE on March 22, 1983. The 2-37 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.[11][12]

Reception[edit]

Soaring, the journal of the Soaring Society of America, described the SGM 2-37 as: "Very versatile, very promising, very expensive". The publication's review noted that the USD$70,000 base price did not include a feathering propeller, gyro instruments, wheel fairings, long range fuel tanks or other optional extras.[3]

Operational history[edit]

Examples of the TG-7 were used by the US Army from 1985 on covert surveillance duties under the Grisly Hunter project. The two aircraft were then transferred to the US Coast Guard 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.[13]

There were nine aircraft still registered in the USA in April 2008. Current owners include the Tuskegee Airmen National Historical Museum and designer Leslie E. Schweizer.[14]

Variants[edit]

SA2-37B of the Aerial Surveillance Squadron, 3rd Air Group, Mexican Air Force at Santa Lucia Air Force Base
RG-8A surveillance aircraft of the US Coast Guard at Opa Locka, Miami, in 1989, wearing low visibility paintwork.
SGM 2-37
Motor glider for USAF and civil use, 12 completed.[1][3]
SA 2-37A
The SA 2-37A is a two-seat special-mission surveillance aircraft built for the Central Intelligence Agency and US Army and equipped with a Lycoming O-540-B powerplant of 235 hp (175kW) and first flown in 1982 and eight.[15] The US aircraft register records six SA-2-37As, including four belonging to Vantage Aircraft Leasing with serial numbers as high as 8. All are in the experimental exhibition category.[16]
SA 2-37B
The SA 2-37B is a development of the 2-37A equipped with a Lycoming TIO-540-AB1AD powerplant of 250 hp. The aircraft is optimized for covert surveillance missions and carries FLIR and electronic sensors. It has a 500 pound (231 kg) sensor payload in a 70-cubic-foot (2,000 L) fuselage bay. With a fuel capacity of 99 US gallons (370 L) it can remain on station for up to 12 hours. Gross weight is 4300 lbs (1950 kg).[5] The US aircraft registry records four SA 2-37Bs, all owned by Schweizer Aircraft. All are in the experimental Research and Development category.[17]
TG-7A
United States Air Force designation for the SGM 2-37.
RG-8A
In US Coast Guard service the SA 2-37 is designated RG-8A, indicating Glider, Reconnaissance.[18]

Operators[edit]

 United States
 Colombia
 Mexico

Specifications (SGM 2-37)[edit]

Data from Sailplane Directory,[1] USAFA,[2] Soaring magazine November, 1983[3] & FAA Aircraft Type Certificate G1NE[11]

General characteristics

  • Crew: two in side-by-side seating
  • Length: 27 ft 6 in (8.5 m)
  • Wingspan: 59 ft 6 in (18.14 m)
  • Height: 7 ft 8 in (2.4 m)
  • Wing area: 195.7 ft2 (18.18 m2)
  • Airfoil: Wortmann Fx 61-163
  • Empty weight: 1200 lb (544 kg)
  • Loaded weight: 1850 lb (839 kg)
  • Useful load: 650 lb (295 kg)
  • Max. takeoff weight: 1850 lb (839 kg)
  • Powerplant: 1 × Lycoming O-235-L2C aluminum fixed pitch, 112 hp (84 kW)

Performance

See also[edit]

Aircraft of comparable role, configuration and era

References[edit]

  1. ^ a b c d e f g h Activate Media (2006). "SGS 2-37 Schweizer". Retrieved 2008-06-03. 
  2. ^ a b c d e f g h United States Air Force Academy (May 2008). "TG-7A". Retrieved 2008-05-26. 
  3. ^ a b c d e f g h i Said, Bob: 1983 Sailplane Directory, Soaring Magazine, page 131. Soaring Society of America, November 1983. USPS 499-920
  4. ^ Federal Aviation Administration (June 2008). "FAA Registry". Retrieved 2008-06-03. 
  5. ^ a b Schweizer Aircraft Corp (2006). "Reconnaissance Aircraft: SA 2-37B". Archived from the original on 2008-04-14. Retrieved 2008-06-03. 
  6. ^ Schweizer, Paul A: Wings Like Eagles, The Story of Soaring in the United States, page 120. Smithsonian Institution Press, 1988. ISBN 0-87474-828-3
  7. ^ Smithsonian Institution (2004). "Directory of Airplanes". Retrieved 2008-05-03. 
  8. ^ Federal Aviation Administration (May 2008). "FAA Registry Make/Model Inquiry Results". Retrieved 2008-05-27. 
  9. ^ Savetz Publishing (2008). "SCHWEIZER 2-31 Profile". Retrieved 2008-05-27. 
  10. ^ USAF: USAF T.O. 1G-7(T)A-1 Issue C - 30 April 2002, pages 3-11 and 3-12.
  11. ^ a b Federal Aviation Administration (September 2007). "Type certificate data sheet no. g1ne". Retrieved 2008-05-26. 
  12. ^ K & L Soaring (n.d.). "K & L Soaring, LLC". Retrieved 2008-04-05. 
  13. ^ "1985 USAF Serial Numbers". Joebaugher.com. Retrieved 2014-05-08. 
  14. ^ Federal Aviation Administration (April 2008). "Make / Model Inquiry Results". Retrieved 2008-04-29. 
  15. ^ World Aircraft Directory (n.d.). "Schweizer SA 2-37A". Retrieved 2008-06-03. 
  16. ^ Federal Aviation Administration (June 2008). "Make / Model Inquiry Results". Retrieved 2008-05-03. 
  17. ^ Federal Aviation Administration (June 2008). "Make / Model Inquiry Results". Retrieved 2008-05-03. 
  18. ^ Stoll, Alex (September 2001). "Schweizer RU-38A Twin Condor". Retrieved 2008-06-04. 
  19. ^ unknown photographer (n.d.). "Photo of SA 2-37 in Columbian Air Force markings". Retrieved 2008-11-08. 
  20. ^ Garcia, Sergio Echeverria (November 2005). "Picture of the Schweizer SA2-37A Condor aircraft". Retrieved 2009-11-08.