Fei Biu or Flying Darts were a traditional weapon in the Wing Chun System. Some state the mechanics are related to those of the Dao (Knives) - and are known to be Invisible. A wave of the hand and the blades are in the target. Fok Bo Chuen?, Yuen Kay Shan and Yuen Chai Wan's first Sifu, was known to be a very skilled master with the flying darts. Yuen Kay Shan was so good he could kill a bird in a tree. The skills were lost, as Sum Num Sigung candidly has stated he could never quiete figure out how to use them like Yuen Kay Shan!