SGM 2-37 | |
---|---|
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 |
US$$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[]
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:
- Nose, cowling and engine installation adapted from the Piper PA-38 Tomahawk[2]
- Wings adapted from the Schweizer SGS 1-36 Sprite, including extensions to bring it from the Sprite's 46.2 feet (14.1 m) to 59.5 feet (18.1 m) and leading edge cuffs to improve stall characteristics[2]
- Tail from the Schweizer SGS 2-32[2]
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[]
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[]
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 US$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[]
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.[13]
Variants[]
- 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.[14] 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.[15]
- 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.[16]
- 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.[17]
Operators[]
Specifications (SGM 2-37)[]
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: 56 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
- Never exceed speed: 135 mph (219 km/h)
- Maximum speed: 135 mph (181 km/h)
- Cruise speed: 112 mph (181 km/h)
- Stall speed: 48 mph with divebrakes closed (78 km/h)
- Range: 230 mi (372 km)
- Service ceiling: 14,000 ft (4300 m)
- Rate of climb: ft/min (m/s)
- Wing loading: 9.45 lb/ft2 (46.15 kg/m2)
- Power/mass: 16.51 lb/hp (0.100 kW/kg)
See also[]
- List of gliders
- Diamond HK36 Super Dimona
- Grob G 109
- Pipistrel Sinus
- Valentin Taifun
References[]
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Activate Media (2006). "SGS 2-37 Schweizer". http://www.sailplanedirectory.com/PlaneDetails.cfm?planeID=302. Retrieved 2008-06-03. Cite error: Invalid
<ref>
tag; name "ActivateMedia" defined multiple times with different content - ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 United States Air Force Academy (May 2008). "TG-7A". Archived from the original on 2007-04-21. http://web.archive.org/web/20070421041324/http://www.usafa.af.mil/tu/306ftg/94fts/tg-7a.cfm. Retrieved 2008-05-26.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Said, Bob: 1983 Sailplane Directory, Soaring Magazine, page 131. Soaring Society of America, November 1983. USPS 499-920
- ↑ Federal Aviation Administration (June 2008). "FAA Registry". http://registry.faa.gov/aircraftinquiry/nnumsql.asp?NNumbertxt=764AF. Retrieved 2008-06-03.
- ↑ 5.0 5.1 Schweizer Aircraft Corp (2006). "Reconnaissance Aircraft: SA 2-37B". Archived from the original on 2008-04-14. http://web.archive.org/web/20080414213216/http://www.sacusa.com/recon/sa237b.asp. Retrieved 2008-06-03.
- ↑ 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
- ↑ Smithsonian Institution (2004). "Directory of Airplanes". http://siris-thesauri.si.edu/ipac20/ipac.jsp?session=120981572FNL8.17&profile=planes&uri=link=3100020~!50828~!3100001~!3100002&aspect=subtab13&menu=search&ri=2&source=~!sithesauri&term=Schweizer+SGU+1+1+SGP+1+1&index=. Retrieved 2008-05-03.
- ↑ Federal Aviation Administration (May 2008). "FAA Registry Make/Model Inquiry Results". http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=231&mfrtxt=Schweizer&cmndfind.x=14&cmndfind.y=15&cmndfind=submit&modeltxt=2-31. Retrieved 2008-05-27.
- ↑ Savetz Publishing (2008). "SCHWEIZER 2-31 Profile". http://www.aircraftprofile.com/aircraft/schweizer-2-31-8051202.php. Retrieved 2008-05-27.
- ↑ USAF: USAF T.O. 1G-7(T)A-1 Issue C - 30 April 2002, pages 3-11 and 3-12.
- ↑ 11.0 11.1 Federal Aviation Administration (September 2007). "TYPE CERTIFICATE DATA SHEET NO. G1NE". http://www.airweb.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/3F492310AA326E6C862573B1005BB248?OpenDocument. Retrieved 2008-05-26.
- ↑ K & L Soaring (undated). "K & L Soaring, LLC". http://klsoaring.com/. Retrieved 2008-04-05.
- ↑ Federal Aviation Administration (April 2008). "Make / Model Inquiry Results". http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=SGM237&mfrtxt=&cmndfind.x=18&cmndfind.y=16&cmndfind=submit&modeltxt=SGM+2-37. Retrieved 2008-04-29.
- ↑ World Aircraft Directory (undated). "Schweizer SA 2-37A". http://www.aircraftworlddirectory.com/civil/s/schweizersa237a.htm. Retrieved 2008-06-03.
- ↑ Federal Aviation Administration (June 2008). "Make / Model Inquiry Results". http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=SA237A&mfrtxt=Schweizer&cmndfind.x=14&cmndfind.y=17&cmndfind=submit&modeltxt=SA+2-37A+. Retrieved 2008-05-03.
- ↑ Federal Aviation Administration (June 2008). "Make / Model Inquiry Results". http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=SA237B&mfrtxt=Schweizer&cmndfind.x=17&cmndfind.y=19&cmndfind=submit&modeltxt=SA+2-37B. Retrieved 2008-05-03.
- ↑ Stoll, Alex (September 2001). "Schweizer RU-38A Twin Condor". http://www.alexstoll.com/AircraftOfTheMonth/9-01.html. Retrieved 2008-06-04.
- ↑ unknown photographer (undated). "Photo of SA 2-37 in Columbian Air Force markings". http://bp0.blogger.com/_10UdUMmJSLg/RsHl84DWFnI/AAAAAAAAA9Q/f4QvGsnlxpI/s1600-h/FAC+SA2-37B+Schweizer.jpg. Retrieved 2008-11-08.
- ↑ Garcia, Sergio Echeverria (November 2005). "Picture of the Schweizer SA2-37A Condor aircraft". http://www.airliners.net/photo/Mexico---Air/Schweizer-SA2-37A-Condor/0962610/&sid=c7e96bd832944ab40e4fd5cebde3db36. Retrieved 2009-11-08.
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