My first job was at XP-Simulation, I was in charge of making airports sceneries for Flight Simulator 2004 / X, and also for professional training simulators used by real pilots :
3D modeling, texture sets for day and night sceneries, LODs, taxiways and ground markings according to certified documentation, export on different 3D engines (SDK or specific tools), final tests and validation.
Low-poly meshes :
C130 (military transport aircraft)
Airpot terminals exemples
More images :