The Chase XCG-20, also known as the XG-20 and by the company designation MS-8 Avitruc, 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.