The prototype of the Avic AG600 Kunlong amphibian has made its first flight, after an apparently difficult development program. The aircraft has become the third large Chinese airplane to make a first flight in the past five years, following the Avic Y-20 airlifter and Comac C919 narrowbody commercial aircraft.   The first AG600 took off Dec. 24 from the runway of Zhuhai Jinwan Airport (formerly ...