Actually the edited post above was by me ... and I did understand what the poster was saying (thanks to a little knowledge and Babelfish) but that's not the point.
The rules are that Forums will converse in English, unless otherwise arranged and then only for Forums where there is a suitable native speaking Moderator. This is PPRuNe policy, take it or leave it.
If you don't want this Forum moderated or for it to continue in English, then the answer is an easy one, we can close it. But that would be a little bit of a knee jerk reaction.
Remember this jet4hire, you don't pay for the site and you don't take the legal responsibilities for anything that is said on it. If you did, then you could make the decisions on what is acceptable and what is not. The other option is to open your own site and have it in any language you want.