The Chase XCG-20, also known as the XG-20 and by the company designation MS-8 Avitruc,[1] was a large assault glider developed immediately after World War II by the Chase Aircraft Company for the United States Air Force, and was the largest glider ever built in the United States.

The XG-20 did not see production due to a change in USAF requirements, however, it was modified into the successful Fairchild C-123 Provider twin-engined transport aircraft which saw extensive service in the Vietnam War.

[1] Following the end of World War II, the United States Army Air Forces, which became the United States Air Force (USAF) in 1947, developed a requirement for a new, large assault glider type to replace smaller types that were then in service, all existing gliders having been declared obsolete.

[2] As part of a five-year development program,[2] a contract was awarded to the Chase Aircraft Company of Trenton, New Jersey, in August 1946 for the construction of two types of gliders.

[3] The nose section was reinforced to provide optimal protection to the pilots in the event of a crash on landing, and to allow for the strongest possible towing connection.