unfortunately there is no dropzone really close to Frankfurt - as far as I know.
The closest ones are smaller dropzones which I don't know. Recommendable are for e.g. Hassfurt www.fsz-hassfurt.de) about 150km east of Frankfurt or Eisenach (www.fscdaedalus.de) as well about 150km northeast of Frankfurt. In Eisenach you can meet the most famous skydivers in Germany as this is the German headquarter for relativ work.
