FSX Acceleration Bell P39 Airacobra When the United States entered World War II, the Bell P-39 was its primary fighter plane. By war's end, nearly 10,000 had been produced in nearly 48 variants, making the 'Airacobra' one of Bell's most successful aircraft ever. Original CFS2 freeware model by SimTech. Upgraded to FS2004/FSX Acceleration by A.F.Scrub.(Works in FSX Standard edition with loss of canopy transparancies)