Sh-Tandem (Russian: Ш-Тандем, other designations include Sh-MAI and MAI-Tandem) was a Soviet experimental ground attack aircraft of the 1930s. Designed by Peter Grushin at the Moscow Aviation Institute (hence the MAI designation), the aeroplane featured an unusual tandem wing, with the tail planes as large as 45% of the wing area. Elevators served as ailerons at the same time.