Schweizer SGM 2-37

Infobox Aircraft
name = SGM 2-37

---

caption = USAFA TG-7A
type = Motor glider
national origin = USA
manufacturer = Schweizer Aircraft Corporation
designer = Leslie Schweizer cite web|url = http://www.sailplanedirectory.com/PlaneDetails.cfm?planeID=302|title = SGS 2-37 Schweizer |accessdate = 2008-06-03|last = Activate Media|authorlink = |year = 2006]
first flight = 1982
introduction = 1982
retired = USAF service: April 2003 cite web|url = http://www.usafa.af.mil/tu/306ftg/94fts/tg-7a.cfm|title = TG-7A|accessdate = 2008-05-26|last = United States Air Force Academy|authorlink = |year = 2008|month = May]
Still in civil use
status =
primary user = United States Air Force Academy - 9
more users =
produced = 1982-1988
number built = 12
program cost =
unit cost = USD$70,000 (1983 base price)
developed from = Schweizer SGS 1-36 and 2-32
variants with their own articles =

The Schweizer SGM 2-37 is a two-place, side-by-side, fixed gear, low wing, motorized glider. cite web|url = http://www.sailplanedirectory.com/PlaneDetails.cfm?planeID=302|title = SGM 2-37 Schweizer |accessdate = 2008-04-29|last = Activate Media|authorlink = |year = 2006] 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 the United States Air Force Academy, which designated it the TG-7A. The TG-7A was retired from USAFA service in April 2003. cite web|url = http://registry.faa.gov/aircraftinquiry/nnumsql.asp?NNumbertxt=764AF|title = FAA Registry|accessdate = 2008-06-03|last = Federal Aviation Administration|authorlink = |year = 2008|month = June]

The basic airframe was later developed into the SA 2-37A and B covert surveillance aircraft. cite web|url = http://www.sacusa.com/recon/sa237b.asp|title = Reconnaissance Aircraft: SA 2-37B |accessdate = 2008-06-03|last = Schweizer Aircraft Corp|authorlink = |year = 2006]

Background

Schweizer had flown a Schweizer SGU 1-19 as a motor glider in 1946 without putting the design into production. 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]

Later the company carried out a design study of a motorglider designated as the Schweizer 1-30, but no examples were built. A single motorglider prototype, the Schweizer 2-31 was completed, but no further motorgliders were built by the company until 1982. cite web|url = 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=|title = Directory of Airplanes|accessdate = 2008-05-03|last = Smithsonian Institution |authorlink = |year = 2004] cite web|url = http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=231&mfrtxt=Schweizer&cmndfind.x=14&cmndfind.y=15&cmndfind=submit&modeltxt=2-31|title = FAA Registry Make/Model Inquiry Results|accessdate = 2008-05-27|last = Federal Aviation Administration|authorlink = |year = 2008|month = May] cite web|url = http://www.aircraftprofile.com/aircraft/schweizer-2-31-8051202.php|title = SCHWEIZER 2-31 Profile|accessdate = 2008-05-27|last = Savetz Publishing|authorlink = |year = 2008]

Development

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, including extensions to bring it from the Sprite's 46.2 feet to 59.5 feet and leading edge cuffs to improve stall characteristics
* Tail from the Schweizer SGS 2-32

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. 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.

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.

The 2-37 features a 27 cu ft 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 29:1 and a minimum sink speed of 3.16 feet/sec (0.96 m/s).

Certification

The SGM 2-37 was certified by the Federal Aviation Administration under type certificate G1NE on March 22, 1983. cite web|url = http://www.airweb.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/3F492310AA326E6C862573B1005BB248?OpenDocument|title = TYPE CERTIFICATE DATA SHEET NO. G1NE|accessdate = 2008-05-26|last = Federal Aviation Administration|authorlink = |year = 2007|month = September]

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. cite web|url = http://klsoaring.com/|title = K & L Soaring, LLC|accessdate = 2008-04-05|last = K & L Soaring|authorlink = |year = undated]

Variants

;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 and US Army and equipped with a Lycoming O-540-B powerplant of 235hp (175kW) and first flown in 1982 and eight. cite web|url = http://www.aircraftworlddirectory.com/civil/s/schweizersa237a.htm|title = Schweizer SA 2-37A |accessdate = 2008-06-03|last = World Aircraft Directory|authorlink = |year = undated] . 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. cite web|url = http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=SA237A&mfrtxt=Schweizer&cmndfind.x=14&cmndfind.y=17&cmndfind=submit&modeltxt=SA+2-37A+|title = Make / Model Inquiry Results|accessdate = 2008-05-03|last = Federal Aviation Administration|authorlink = |year = 2008|month = June] .

;SA 2-37B:The SA 2-7B 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 fuselage bay. With a fuel capacity of 99 Gallons (374.8 litres) it can remain on station for up to 12 hours. Gross weight is 4300 lbs (1950 kg). The US aircraft registry records four SA 2-37Bs, all owned by Schweizer Aircraft. All are in the experimental "Research and Development" category. cite web|url = http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=SA237B&mfrtxt=Schweizer&cmndfind.x=17&cmndfind.y=19&cmndfind=submit&modeltxt=SA+2-37B|title = Make / Model Inquiry Results|accessdate = 2008-05-03|last = Federal Aviation Administration|authorlink = |year = 2008|month = June] ;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". cite web|url = http://www.alexstoll.com/AircraftOfTheMonth/9-01.html|title = Schweizer RU-38A Twin Condor |accessdate = 2008-06-04|last = Stoll, Alex|authorlink = |year = 2001|month = September]

Marketing

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

Reception

"Soaring", the journal of the Soaring Society of America, described the SGM 2-37 as:

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.

In use

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. cite web|url = http://registry.faa.gov/aircraftinquiry/acftinqSQL.asp?striptxt=SGM237&mfrtxt=&cmndfind.x=18&cmndfind.y=16&cmndfind=submit&modeltxt=SGM+2-37|title = Make / Model Inquiry Results|accessdate = 2008-04-29|last = Federal Aviation Administration|authorlink = |year = 2008|month = April]

Operators

;USA
*United States Air Force
*United States Coast Guard

pecifications (SGM 2-37)

aircraft specifications

plane or copter?=plane
jet or prop?=prop

ref=Sailplane Directory, USAFA, Soaring magazine November, 1983 & FAA Aircraft Type Certificate G1NE

crew=two in side-by-side seating
capacity=
length main= 27 ft 6 in
length alt= 8.5 m
span main= 56 ft 6 in
span alt= 18.14 m
height main= 7 ft 8 in
height alt= 2.4 m
area main= 195.7 ft²
area alt= 18.18 m²
airfoil=Wortmann Fx 61-163
empty weight main= 1200 lb
empty weight alt= 544 kg
loaded weight main= 1850 lb
loaded weight alt= 839 kg
useful load main= 650 lb
useful load alt= 295 kg
max takeoff weight main= 1850 lb
max takeoff weight alt= 839 kg

engine (jet)=
type of jet=
number of jets=
thrust main= lbf
thrust alt= kN
engine (prop)= Lycoming O-235-L2C
type of prop=aluminum fixed pitch
number of props=1
power main= 112 hp
power alt= 84 kW
max speed main= 135 mph
max speed alt= 181 km/h
cruise speed main= 112 mph
cruise speed alt= 181 km/h
never exceed speed main= 135 mph
never exceed speed alt= 219 km/h
stall speed main= 48 mph with divebrakes closed
stall speed alt= 78 km/h
range main= 230 mi
range alt= 372 km
ceiling main= 14,000 ft
ceiling alt= 4300 m
climb rate main= ft/min
climb rate alt= m/s
loading main= 9.45 lb/ft²
loading alt= 46.15 kg/m²
more performance=

Power/mass: 16.51 lb/hp (0.100 kW/kg)

References

External links

* [http://www.usafa.af.mil/tu/306ftg/94fts/Atlas%20Site/DOSWebsite/tg-7aNum3.jpgPhoto of a USAFA TG-7A (SGM 2-37) motor glider]
* [http://www.usafa.af.mil/tu/306ftg/94fts/Atlas%20Site/DOSWebsite/tg-7aNum2.jpgPhoto of a USAFA TG-7A (SGM 2-37) motor glider]
* [http://www.aircraftworlddirectory.com/civil/s/schwei5.jpgPhoto of SA 2-37A reconnaissance aircraft]
* [http://www.sacusa.com/products/samain2.asp Photo of SA 2-37B reconnaissance aircraft]