@Thilo
Far more practical just to dial your internet radio into a Chinese language radio station if you're that keen to learn Mandarin.
To be clear, I'm not aware of any helicopter pilot flying jobs in China for non-Chinese speaking foreign helicopter pilots. I'd be very surprised if that situation were to change any time soon. But I have been wrong on occasion before, so tune in your internet radio and start listening.
Finally, I suggest not parking your sail boat within canon range of the China coast, for the reason Fareastdriver alluded to at #18.