Peter Nyffeler wrote:

"a partire dal 30 giugno 2004 tutti i velivoli
....
I don't speak Italian, but as far as I can understand this means transponders
will be mandatory for gliders

Peter, you have just become a victim of what translators call a "wrong
friend". (In German "falscher Freund", I don't know whether it is really
called a "wrong friend" in English.)

A wrong friend is a word in a foreign language that sounds like a word
in a known language but means a different thing. Here, "velivolo" sounds
like the french "velivole" (glider pilot) which you probably know, but
means "motorized aircraft".

(BTW: Computer translations are full of wrongly translated "wrong
fiends". One of the most famous is Control Panel, which is everywhere
translated as "Kontrollfeld" instead of "Einstellungsfeld". Just another
step towards the decay of western culture.)

Stefan