Schweizer cargo glider designs
Encyclopedia
The Schweizer cargo glider designs were a series of design proposals made to the United States Army Air Force by the Schweizer Aircraft Corporation of Elmira, New York
during the Second World War. None of the designs was accepted by the USAAF and no cargo gliders
were built by Schweizer during the war.
The four designs proposed are of note due to having been assigned Schweizer model numbers. Due to the lack of production of these designs, Schweizer concentrated on designing and building the TG-2
and TG-3
training gliders instead. When the training glider contracts were completed Schweizer turned to subcontract work for other aircraft manufacturers. This trend continued after the war when Schweizer would increasingly turn to subcontract work to supplement the small amount of revenue realized from designing and building gliders.
-borne attack on the Belgian
fortress of Eben-Emael
and their use in the Battle of Crete
convinced the US military that they would need glider-borne forces of their own.
The US Army had no glider pilot training program. Neither did they have any training or assault gliders when the war began. The USAAF, the US Navy and Marines all embarked on ambitious glider programs, starting in April 1941, some nine months prior to the Attack on Pearl Harbor
and US entry into the war.
Once the services had commenced procurement of training gliders, such as the Frankfort TG-1 and Schweizer TG-2
and schools were being set up, military attention turned to development of operational gliders for air assault use.
The low landing speed was intended to ensure that even if the gliders impacted trees or other hard obstacles on combat landings that troop survival would be likely. The specification required that the glider designs not include flaps
to make the gliders cheap and simple to build and also to simplify pilot training.
considered the specification flawed, as an aircraft that would land at 38 mph without flaps would require very low wing loading
. To design an aircraft with a very low wing loading, but able to carry nine or fifteen troops, would require a very large wing, rendering the resulting aircraft cumbersome on the ground, especially on windy days.
The designs that were submitted complied with the USAAF specification, but were considered by the company to be impractical. In the long run, the Schweizer's concerns with the specification were taken seriously and the requirements were later changed to allow higher landing speeds and the use of flaps, making the resulting gliders smaller and more useful.
Schweizer also developed designs for six-place and single-place cargo gliders for military use. Like the earlier designs, none were put into production.
Schweizer aircraft did not submit revised designs for the new specification, but instead concentrated on production of the army TG-2
and the navy and marine LNS-1
along with the new wooden structure TG-3
. The TG-3 was designed to avoid the use of strategic materials, such as aluminum and took a large measure of company resources to design and produce in numbers. The company also moved into subcontract work for other companies, producing assemblies and components.
After the war the specialization in subcontract work led Schweizer Aircraft to produce whole aircraft under sub-contract, such as the Grumman Ag Cat
agricultural aircraft and the Hughes 300 helicopter, for which it later purchased the rights, renaming it the Schweizer 300.
. Their design became the Waco CG-3
. Due to the limitations of the specification, the aircraft was not a success and the initial order of 300 was reduced to 100, with the intention to use them as trainers for the follow-on fifteen seat assault glider.
WACO's fifteen seat design was also chosen as the winner in the competition for the modified specification. This aircraft served with great success as the Waco CG-4
. Almost 14,000 were built and it played a role in the July 1943 Allied invasion of Sicily
, the American airborne landings in Normandy
on 6 June 1944 and in other important airborne assaults in Europe
and in the China
-Burma-India
Theater.
Elmira, New York
Elmira is a city in Chemung County, New York, USA. It is the principal city of the 'Elmira, New York Metropolitan Statistical Area' which encompasses Chemung County, New York. The population was 29,200 at the 2010 census. It is the county seat of Chemung County.The City of Elmira is located in...
during the Second World War. None of the designs was accepted by the USAAF and no cargo gliders
Military glider
Military gliders have been used by the military of various countries for carrying troops and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g...
were built by Schweizer during the war.
The four designs proposed are of note due to having been assigned Schweizer model numbers. Due to the lack of production of these designs, Schweizer concentrated on designing and building the TG-2
Schweizer SGS 2-8
The Schweizer SGS 2-8 is a United States two-seat, mid-wing, strut-braced, training glider built by Schweizer Aircraft of Elmira, New York.The 2-8 was originally known simply as "The Schweizer Two-Place" when it first flew in June 1938...
and TG-3
Schweizer SGS 2-12
The Schweizer SGS 2-12 is a United States two-seat, low-wing, training glider built by Schweizer Aircraft of Elmira, New York.The 2-12 was a development of the Schweizer 2-8 two place training glider, with an all-wooden wing...
training gliders instead. When the training glider contracts were completed Schweizer turned to subcontract work for other aircraft manufacturers. This trend continued after the war when Schweizer would increasingly turn to subcontract work to supplement the small amount of revenue realized from designing and building gliders.
Background
The German use of gliderMilitary glider
Military gliders have been used by the military of various countries for carrying troops and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g...
-borne attack on the Belgian
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
fortress of Eben-Emael
Fort Eben-Emael
Fort Eben-Emael is an inactive Belgian fortress located between Liège and Maastricht, on the Belgian-Dutch border, near the Albert Canal, and designed to defend Belgium from a German attack across the narrow belt of Dutch territory in the region. Constructed in 1931–1935, it was reputed to be...
and their use in the Battle of Crete
Battle of Crete
The Battle of Crete was a battle during World War II on the Greek island of Crete. It began on the morning of 20 May 1941, when Nazi Germany launched an airborne invasion of Crete under the code-name Unternehmen Merkur...
convinced the US military that they would need glider-borne forces of their own.
The US Army had no glider pilot training program. Neither did they have any training or assault gliders when the war began. The USAAF, the US Navy and Marines all embarked on ambitious glider programs, starting in April 1941, some nine months prior to the Attack on Pearl Harbor
Attack on Pearl Harbor
The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...
and US entry into the war.
Once the services had commenced procurement of training gliders, such as the Frankfort TG-1 and Schweizer TG-2
Schweizer SGS 2-8
The Schweizer SGS 2-8 is a United States two-seat, mid-wing, strut-braced, training glider built by Schweizer Aircraft of Elmira, New York.The 2-8 was originally known simply as "The Schweizer Two-Place" when it first flew in June 1938...
and schools were being set up, military attention turned to development of operational gliders for air assault use.
Cargo glider specification
The USAAF developed a specification for two types of combat cargo gliders. The specifications required manufacturers to submit proposals for:- Cargo glider, nine seat, landing speed of no more than 38 mph (62 km/h) with no flaps
- Cargo glider, fifteen seat, landing speed of no more than 38 mph (62 km/h) with no flaps
The low landing speed was intended to ensure that even if the gliders impacted trees or other hard obstacles on combat landings that troop survival would be likely. The specification required that the glider designs not include flaps
Flap (aircraft)
Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...
to make the gliders cheap and simple to build and also to simplify pilot training.
Company response
Schweizer submitted one design each in response to the specification. The Schweizer brothersSchweizer brothers
Paul, William , and Ernest Schweizer were three brothers who started building gliders in 1930. In 1937, they formed the Schweizer Metal Aircraft Company. Their first commercial glider sale was an SGU 1-7 glider to Harvard University's Altosaurus Glider Club. At that time, Eliot Noyes was a...
considered the specification flawed, as an aircraft that would land at 38 mph without flaps would require very low wing loading
Wing loading
In aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing. The faster an aircraft flies, the more lift is produced by each unit area of wing, so a smaller wing can carry the same weight in level flight, operating at a higher wing loading. Correspondingly,...
. To design an aircraft with a very low wing loading, but able to carry nine or fifteen troops, would require a very large wing, rendering the resulting aircraft cumbersome on the ground, especially on windy days.
The designs that were submitted complied with the USAAF specification, but were considered by the company to be impractical. In the long run, the Schweizer's concerns with the specification were taken seriously and the requirements were later changed to allow higher landing speeds and the use of flaps, making the resulting gliders smaller and more useful.
Schweizer also developed designs for six-place and single-place cargo gliders for military use. Like the earlier designs, none were put into production.
Schweizer aircraft did not submit revised designs for the new specification, but instead concentrated on production of the army TG-2
Schweizer SGS 2-8
The Schweizer SGS 2-8 is a United States two-seat, mid-wing, strut-braced, training glider built by Schweizer Aircraft of Elmira, New York.The 2-8 was originally known simply as "The Schweizer Two-Place" when it first flew in June 1938...
and the navy and marine LNS-1
Schweizer SGS 2-8
The Schweizer SGS 2-8 is a United States two-seat, mid-wing, strut-braced, training glider built by Schweizer Aircraft of Elmira, New York.The 2-8 was originally known simply as "The Schweizer Two-Place" when it first flew in June 1938...
along with the new wooden structure TG-3
Schweizer SGS 2-12
The Schweizer SGS 2-12 is a United States two-seat, low-wing, training glider built by Schweizer Aircraft of Elmira, New York.The 2-12 was a development of the Schweizer 2-8 two place training glider, with an all-wooden wing...
. The TG-3 was designed to avoid the use of strategic materials, such as aluminum and took a large measure of company resources to design and produce in numbers. The company also moved into subcontract work for other companies, producing assemblies and components.
After the war the specialization in subcontract work led Schweizer Aircraft to produce whole aircraft under sub-contract, such as the Grumman Ag Cat
Grumman Ag Cat
-See also:-References:* Michell, Simon. Jane's Civil and Military Aircraft Upgrades 1994-95. Coulsdon, UK:Jane's Information Group, 1994. ISBN 0 7106 1208 7.-External links:*...
agricultural aircraft and the Hughes 300 helicopter, for which it later purchased the rights, renaming it the Schweizer 300.
SGC 9-10
- In keeping with Schweizer's normal glider model nomenclature the troop glider designed to the nine-place specification was the SGC 9-10, or Schweizer Glider, Cargo, 9 seat, model 10. Some sources call it the SGC 8-10, indicating eight seats.
SGC 15-11
- The Schweizer Glider, Cargo, 15 seat, model 11 was submitted in response to the USAAF specification for a fifteen seat cargo glider.
SGC 6-14
- The Schweizer Glider, Cargo, 6 seat, model 14 was a design for a six seat cargo glider.
SGC 1-15
- The Schweizer Glider, Cargo, 1 seat, model 15 was a design for a single seat cargo glider.
Contract Results
The winning contender for the original contract for the nine-seat glider was the Waco Aircraft CompanyWaco Aircraft Company
The Waco Aircraft Company was an aircraft manufacturer located in Troy, Ohio, USA. Between 1919 and 1947, the company produced a wide range of civilian biplanes....
. Their design became the Waco CG-3
Waco CG-3
-References:...
. Due to the limitations of the specification, the aircraft was not a success and the initial order of 300 was reduced to 100, with the intention to use them as trainers for the follow-on fifteen seat assault glider.
WACO's fifteen seat design was also chosen as the winner in the competition for the modified specification. This aircraft served with great success as the Waco CG-4
Waco CG-4
The Waco CG-4 was the most widely used United States troop/cargo military glider of World War II. It was designated the CG-4 by the United States Army Air Forces, and named Hadrian in British military service....
. Almost 14,000 were built and it played a role in the July 1943 Allied invasion of Sicily
Allied invasion of Sicily
The Allied invasion of Sicily, codenamed Operation Husky, was a major World War II campaign, in which the Allies took Sicily from the Axis . It was a large scale amphibious and airborne operation, followed by six weeks of land combat. It launched the Italian Campaign.Husky began on the night of...
, the American airborne landings in Normandy
American airborne landings in Normandy
The American airborne landings in Normandy were the first United States combat operations during Operation Overlord, the invasion of Normandy by the Western Allies on June 6, 1944. Around 13,100 paratroopers of the U.S. 82nd Airborne and 101st Airborne Divisions made night parachute drops early on...
on 6 June 1944 and in other important airborne assaults in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and in the China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
-Burma-India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
Theater.