It offers the perfect solution for the simmer who suffers from "hangar boredom." It is the ultimate museum, the perfect AI traffic filler, and the best way to experience niche aircraft you will never find on the payware market.
It sounds like you're referring to a community-created compilation for a flight simulator — likely , X-Plane , or FSX/P3D — containing 140 add-on aircraft bundled into one package, with the -final- tag suggesting it's the last version released by that particular author or group. 140 add-on planes compilation pack -final-