After the IS-1 further improvements were made which led the IS-2. The IS-2 first flew in 1941 with a new M-88 radial engine, and although it produced the same power as the M-63 on the IS-1, it had a smaller diameter and was thus more aerodynamic giving it a top speed of 316mph. Armament was upgraded from four 7.62mm ShKAS MG's firing at 1800rpm to two ShKAS and two 12.7mm DShK MG's firing at 600rpm.

 

 

Ultimately, while the design proved its concept, the added weight from the actuating mechanism almost completely negated the added lift from the lower wing and left the IS-2 in a useless limbo where it was less maneuverable but faster than contemporary biplanes and more maneuverable but slower than contemporary monoplanes.

 

Development was cancelled to to these disappointing performance figures and the German invasion of Russia.

 

Engine: 1,100hp Shvetsov M-88

Wingspan: 27.4ft (8.3m)

Length: 23.4ft (7.1m)

Height: 10.7ft (3.3m)

Wing Area: 497.8 sq.ft (46.3 sq.m)

Empty Weight: 6,555lbs (2,973kg)

Loaded Weight: 6,941lbs (3,148kg)

Wing Loading: 13.9lbs/sq.ft (68.1kg/sq.m)