This specific 3D model, "3D Airport-Airport 3D model purchase", is an asset made available by "Unknown author".
You can download this asset for free at "Unknown platform" by following the link.
The license for this digital asset is "Unknown license".
STL (Stereolithography, filesize: 442 MB), OBJ (OBJ, filesize: 442 MB), JPG (JPG, filesize: 442 MB), 3DS (3D Studio, filesize: 442 MB), DAE (Collada, filesize: 442 MB), DWG (AutoCAD, filesize: 442 MB), DXF (DXF, filesize: 442 MB), FBX (Autodesk FBX, filesize: 504 MB), SKP (Sketchup, filesize: 442 MB), WRL (VRML, filesize: 442 MB), MAX (Autodesk 3ds Max, filesize: 442 MB), LS10 (Lumion, filesize: 442 MB), TEXTURES (Textures, filesize: 442 MB)