André Somers wrote:

Maybe others can append the relevant authorities for other countries?

Germany: http://www.lba.de/
France: http://www.dgac.fr/
Switzerland: http://www.aviation.admin.ch/
Spain: http://ais.aena.es/
Poland: http://www.ais.pata.pl/
Austria: http://www.bmvit.gv.at/

You'll find phone numbers and e-mail addresses there, if you search for
them.

Stefan