More free addon planes than any other site! Complete aircraft. 1000's of freeware addons for your Flight Simulator! Over 4000 pages of free downloads. 14.70Mb (679 downloads) This is an FSX twin package of two observation aircraft of the 1930s, the Douglas O-43 and O-46, originally designed by the late Paul …Free addons and downloads for Lockheed Martin Prepar3D, P3D, Microsoft Flight Simulator and Flight Sim series.