The Mong MS1 Sport is a 1950s American homebuilt biplane design with over 400 sets of plans for the aircraft have been sold.

[1] The first Mong Sport was built as a personal aircraft by the designer Ralph Mong, Jr. Plans for homebuilding were provided afterward in collaboration with Frank Powell, an Aerospace Engineer and draftsman for Aero Commander at the time, due to demand.

The Mong Sport met the basic qualifications, and has been extensively modified over the years by builders to be used as a biplane racer.

A highly modified Mong Phantom with carbon fiber wings won in 2006 with a speed of 251.958 mph,[6] and has recently raised the record to 284.454mph.

[1] A Mong MS1 Sport is on display at the Planes of Fame Air Museum, Chino, California.