Download of FlightProSim 1.9.1 was on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The program's installer files are generally known as FPSLaunch.exe or FPS_LAUNCH.exe etc.
This program is an intellectual property of IDB Group. The following versions: 2.2 and 1.9 are the most frequently downloaded ones by the program users. We recommend checking the downloaded files with any free antivirus. The program lies within Games, more precisely Simulation.
From the developer:
FlightProSim offers 'Real Life Flying' with accurate worldwide scenery based on actual military mapping, over 20,000 of the world's airports and 80 different planes.
You also get changeable weather, 20,000 airports, life like controls, NASA flight models, World Wide Scenery based on US Defense Mapping.
You may want to check out more software, such as The Grey Wolves Expansion or RailDriver for TRS2004, which might be related to FlightProSim.