besides FSET there is another source of aerial imagery, at least for the USA. USGS provides public domain images with 1m resolution, in specific areas even with higher resolution. The good thing: There are no restrictions to use and publish these images for flight simulators as long as this is freeware and give credit to the USGS.
The image coordinates are provided in a XML file. To create a TFW we have to read some lines from the file and have to know the pixel size of the image.
Is somebody capable to do this job? It is so exhausting to create let's say 30 TFW files manually.