Please note the forum rule Number One: "All posts must be in English". ( see http://www.rotax-owner.com/en/rotax-forum/rules ). In a conversation like this where it's obvious that many people involved know French, I can see the temptation to post in French, for precise expression. It's more polite to follow the rules, though!
If you really feel the need to post something in your native language - I do consider it is OK to post in [favorite non-English language] in a thread like this as long as you ALSO post the translate.google.com equivalent in English, directly below it. (Google translate isn't perfect, but it at least gives everyone else the gist of what you are saying!) It only takes a few seconds... :)
example:
bonjour Jacques,
J'ai lu votre article sur ULMAG concernant le système d'équilibrage des hélices Balance Master -
J'aimerai prendre contact avec vous concernant ce sujet car moi j'ai du nouveau concernant un nouveau système d'équilibrage et j'aimerais connaitre votre avis compte tenu de votre expérience dans ce domaine
Salutations
Ali
==============
hello Jacques,
I read your article on ULMAG regarding the Balance Master propeller balancing system -
I would like to contact you regarding this subject because I am new about a new balancing system and I would like to know your opinion given your experience in this field
Greetings
Ali