Set of Turboprop Engines (Polygon mesh 3D model) is available on CGTrader for $399. Original author: 3D-Horse. Specs: 3500667 polys, 3564043 verts.
OBJ (OBJ, filesize: 257 MB), MAX (Autodesk 3ds Max, filesize: 442 MB), LWO (Lightwave, filesize: 133 MB), MA (Autodesk Maya, filesize: 610 MB), 3DS (3D Studio, filesize: 92 MB), HRC (Autodesk Softimage, filesize: 390 MB)