The Wright R-1820 Cyclone 9 is an American air-cooled piston 9-cylinder aircraft engine developed by Curtiss-Wright and widely used on various aircraft types in the 1930s and 1950s. Outside the US, it was also manufactured under license in Spain by Hispano-Suiza and in the Soviet Union.  Used on the following aircraft: Bloch MB.221, Boeing B-17 Flying Fortress Boeing 307, Brewster F2A Buffalo, Curtiss AT-32-A Condor, Curtiss SBC-4 Helldiver, Curtiss P-36 Mohawk, Curtiss SC Seahawk, Curtiss-Wright CW-21, Douglas A-33, Douglas B-18 Bolo, Douglas DC-2, Douglas DC-3 (DST, G-102 ? G-202), Douglas Super DC-3, R4D-8 / C-117, Douglas DC-5, Douglas DF Wright SGR-1820G-2, Douglas SBD Dauntless, FMA Ae. MB.2 Bombi, General Motors FM-2 Wildcat, Grumman TF-1 / C-1 Trader, Grumman E-1 Tracer, Grumman FF, Grumman F3F, Grumman XF5F, Grumman XP-50, Grumman HU-16 Albatross, Grumman J2F Duck, Grumman S-2 Tracker, Lockheed 14, Lockheed Model 18 Lodestar, Lockheed Hudson, Martin B-10, North American T-6 Texan, North American O-47, North American P-64, North American T-28B/C/D Trojan, Northrop YC-125 Raider, Ryan FR Fireball, copetr Piasecki H-21, copter Sikorsky S-58/HUS/HSS/H-34.