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Schweizer SGS 1-23

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SGS 1-23
Schweizer SGS 1-23D
Role Open-classandStandard-class(1-23H-15)sailplane
National origin United States
Manufacturer Schweizer Aircraft Corporation
Designer Paul A Schweizer
First flight 5 July 1948[1]
Number built 93 (all marks)

TheSchweizer SGS 1-23is a United States Open and StandardClass,single-seat, mid-winggliderbuilt bySchweizer AircraftofElmira, New York.[2]

The original "standard" 1-23 was introduced in 1948.[3]The aircraft quickly became the most numerous competition and performance sailplane in the USA. A total of 93 of all sub-models were built by the time production was completed in 1967.[2]

Design and development

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Schweizer Aircraft started construction of the 1-23 prototype in May 1948. The aircraft was completed and first flew on 5 July 1948, only nine weeks after construction had begun.[1]

The prototype had been ordered by Bill Frutchy ofElmira, New Yorkand the aircraft was available for him to fly it in the second half of the US Nationals.[1]

The first production 1-23 was ordered by E.J Reeves. The success of this aircraft led to more orders and series production was commenced. The 1-23 was initially sold on a "factory direct"basis, which allowed them to be sold at a lower price than through the dealer network.[1]

The 1-23 receivedCivil Aeronautics Administrationtype certificate1G1 on 22 November 1949.[4]

The type certificate is currently held by K & L Soaring ofCayuta, New York.K & L Soaring now provides all parts and support for the Schweizer line of sailplanes.[4][5]

Operational history

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A 1-23, flown by William Ivans, set a world altitude record for gliders on 30 December 1950, reaching a height of 42,089 ft (12,840 m).[6]

1-23Ds were flown by Paul McCready to win the 1953 US Nationals and to set a distance record of 455.5 miles (733 km) by Joe Lincoln. Lincoln was awarded theBarringer Trophyin 1960 for that distance flight.[2][3]

Paul Bikle flew the sole 1-23E to a world absolute altitude record of 46,267 feet for a record gain of 42,300 feet on 25 February 1961. The records were set in theSierra Nevadalee wavebetweenMojave, CaliforniaandInyokern, California.Bikle flew the record flights without cabin pressurization or a pressure suit. His record stood for many years.[7]

In April 2008 there were still 49 1-23s registered in the USA[8]and 5 in Canada.[9]

Variants

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1-23
The original 1-23 model is also referred to as a "standard". The aircraft had a 43.83 foot wingspan and a glide ratio of 27:1, with a minimum sink of 2.3 feet per second.[2][3]
Gross weight for serial numbers 1 to 11 was 600 lbs. Later 1-23 standards had a gross weight of 660 lbs.[4]One "standard" was retrofitted at the factory with water ballast for Kim Scribner. There were 22 "standards" completed.[2]
Many pilots like the faster roll and better circling characteristics of the "standard" over the later longer-winged versions of the 1-23.[2]
1-23A
There were no 1-23As built.[2]
1-23B
The "B" model was introduced in 1952 and incorporated a longer wing of 50 feet in span. The spars were standard 1-23 spars with a spliced section added. There was only one "B" model built. It was a custom order forPaul MacCreadyspecifically to fly in the 1952World Gliding Championshipsheld inMadrid,Spain.[2][3]
The production version of the "B" model was the "D" model.[2]The 1-23B was not certified.[4]
1-23C
The "C" model was also built in 1952 and, like the "B", incorporated a longer wing with a 50 foot span. The "C" had heavier wing skins and a heavier spar and, as a result, weighed 90 lbs more than the "B". There was only one "C" model built for the designerPaul A Schweizerspecifically to fly in the 1952World Gliding Championshipsheld inMadrid,Spain.[2][3]
The 1-23C was not certified.[4]
The "C" was subsequently sold to by Larry Gehrlein who modified it to a large degree. It was crashed and rebuilt with a set of 1-23D wings. It was later damaged again in an accident and rebuilt by the factory as a "D" model. In the mid-1980s it was owned by the Rochester Soaring Club.[2][3]
The "C" wings were also later rebuilt and used in thehomebuiltGehrlein Precursor.[2]The Precursor mounts the 1-23C wings high on aSchweizer 1-26Afuselageto produce an aircraft with a 53.5 foot wing span and a glide ratio of 32:1.[10][11]
1-23D
Schweizer 1-23D
The 1-23D was introduced in 1953[4]and incorporated the improvements tested in the "B" and "C" models at the 1952 World Championships and beyond.[2]
The "D" has a wingspan of 50 feet and a glide ratio of 30:1 at 48 mph, with a minimum sink of 2.0 feet per second at 36 mph.[2]The gross weight on the "D" and later models is 750 lbs.[4]
A total of 12 "D" models were produced.[2]The aircraft received its type certificate on 1 June 1953.[4]
1-23E
The 1-23E has 52.8 foot wings equipped with balanced dive brakes. It has a glide ratio of 31:1 at 46 mph and a minimum sink speed of 1.95 feet per second at 40 mph.[2][3]
A single 1-23E model was constructed forPaul MacCreadyto compete in the 1954World Gliding Championshipsheld inGreat Hucklow,United Kingdom. He flew the "E" to a fourth place finish. The aircraft was originally constructed without a wheel and used a skid for takeoff and landing. After the Worlds a wheel was retrofitted.[2][3]
The aircraft was subsequently sold toPaul Bikleand he used it to set two world altitude records on 25 February 1961.[1]In the mid-1980s it was owned by the Rochester Soaring Club.[2]The 1-23E was not certified.[4]
1-23F
The 1-23F was a 1-23E with the same 52.8 foot wings but was constructed with heavier gauge, butt-constructed wing skins. Only one was built.[2][3]
The 1-23F received its type certificate on 12 June 1958.[4]
1-23G
The 1-23G was the production version of the 1-23E and F. It retained the 52.8 foot wing and had the same glide ratio of 31:1 at 46 mph and a minimum sink speed of 1.95 feet per second at 40 mph. The "G" had a redesigned taller fin and top-surface spoilers only.[2][3]
A total of eight 1-23Gs were constructed.[2]The type received its type certificate on 12 June 1958.[4]
1-23H and 1-23H-15
The 1-23H was designed by adding balanced dive brakes to the "G", designing a square fin and rudder to replace the rounded ones found on earlier models, adding removable wingtips plus other minor changes.[2][3]
The "H-15" reduced the span from 52.8 feet to 49.2 feet (15.0 m) which, combined with the dive-brakes, qualified the type for the then newStandard Class.With removable wingtips the aircraft could be easily converted between the standard class and open class.[2][3]
In its Standard Class configuration the "H-15" has a 29:1 glide ratio at 50 mph and a minimum sink of 2.2 feet per second at 37 mph.
The type received its type certificate on 13 March 1961[4]and a total of 47 were built, including 39 H-15s. Production of the "H" ended in 1967, completing a 19-year production run.[2][12]
1-23HM
One production 1-23H was rebuilt as anexperimental aircraftin the "racing-exhibition" category by Sterling Starr and designated SGS 1-23HM.[13][14]
The HM was built by using a stock 1-23H fuselage and tail assembly. Starr built a new set of 54 foot (16.6 m) span wings with an aspect ratio of 23.5:1. The wings took 1500 hours to construct, but the resulting aircraft has a glide ratio of 33.2:1 which is a 7% improvement over the stock 1-23H. The HM later had retractable landing gear added.[13][15]
The 1-23HM was flown in the 1966 US nationals.[13]
The aircraft is registered as N94298 and is currently owned by Vincent Grisemer. It is on loan to theNational Soaring Museum.[14][15]

Aircraft on display

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Specifications (1-23-H)

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Data fromThe World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde Volume II[16]

General characteristics

  • Crew:1
  • Length:20 ft 5.4 in (6.232 m)
  • Wingspan:52 ft 8.0 in (16.052 m)
  • Height:3 ft 6.7 in (1.085 m)
  • Wing area:164.94 sq ft (15.323 m2)
  • Aspect ratio:16.9
  • Airfoil:Root–NACA 43 012A,Mid–NACA 43 012A,Tip–NACA 23 009
  • Empty weight:481 lb (218 kg)
  • Gross weight:750 lb (340 kg)

Performance

  • Never exceed speed:140 mph (225 km/h, 121 kn)
  • Rough air speed max:140 mph; 121 kn (225 km/h)
  • Aerotow speed:110 mph; 96 kn (177 km/h)
  • Winch launch speed:67.7 mph; 58.9 kn (109 km/h)
  • Terminal velocity:with full air-brakes at max all-up weight 140 mph; 121 kn (225 km/h)
  • g limits:+6 -4 at 125.3 kn (232 km/h)
  • Maximum glide ratio:30.8:1 at 50.3 mph; 43.7 kn (81 km/h)
  • Rate of sink:123.0 ft/min (0.625 m/s) at 37.3 mph; 32.4 kn (60 km/h)
  • Wing loading:4.5 lb/sq ft (22.2 kg/m2)

See also

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Aircraft of comparable role, configuration, and era

Related lists

References

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  1. ^abcdeSchweizer, Paul A (1988).Wings Like Eagles, The Story of Soaring in the United States.Washington, D.C.: Smithsonian Institution Press. p.111.ISBN0-87474-828-3.
  2. ^abcdefghijklmnopqrstuvwxSaid, Bob (November 1983). "1983 Sailplane Directory".Soaring Magazine.Soaring Society of America: 28–30.
  3. ^abcdefghijklmActivate Media (2006)."SGS 1-23 Schweizer".Archived fromthe originalon 2007-08-08.Retrieved2008-04-15.
  4. ^abcdefghijklFederal Aviation Administration(September 2007)."GLIDER SPECIFICATION NO. 1G1".Retrieved2008-04-15.
  5. ^K & L Soaring (n.d.)."K & L Soaring, LLC".Retrieved2008-04-05.{{cite web}}:CS1 maint: year (link)
  6. ^Bridgman 1951, p. 6b.
  7. ^Schweizer, Paul A:Wings Like Eagles, The Story of Soaring in the United States,page 183. Smithsonian Institution Press, 1988.ISBN0-87474-828-3
  8. ^Federal Aviation Administration(April 2008)."FAA Registry".Retrieved2008-04-19.
  9. ^Transport Canada(April 2008)."Canadian Civil Aircraft Register".Archived fromthe originalon 2008-05-03.Retrieved2008-04-19.
  10. ^Said, Bob (November 1983). "1983 Sailplane Directory, Soaring Magazine".Soaring Magazine.Hobbs, New Mexico: Soaring Society of America: 43.
  11. ^Federal Aviation Administration(May 2008)."FAA Registry".Retrieved2008-05-31.
  12. ^Federal Aviation Administration(April 2008)."FAA Registry N94298".Retrieved2008-04-19.
  13. ^abcSaid, Bob (November 1983). "1983 Sailplane Directory, Soaring Magazine".Soaring Magazine.Hobbs, New Mexico: Soaring Society of America: 64.
  14. ^abFederal Aviation Administration(May 2008)."FAA Registry N-Number Inquiry Results N94298".Retrieved2008-05-29.
  15. ^abcMunson, J. (n.d.)."Sailplanes in Our Collection".Archived fromthe originalon 2011-05-16.Retrieved2008-04-15.{{cite web}}:CS1 maint: year (link)
  16. ^Shenstone, B.S.; K.G. Wilkinson (1963).The World's Sailplanes:Die Segelflugzeuge der Welt:Les Planeurs du Monde Volume II(in English, French, and German) (1st ed.). Zurich: Organisation Scientifique et Technique Internationale du Vol a Voile (OSTIV) and Schweizer Aero-Revue. pp. 234–237.
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