There was no understanding of the basic principles of hang gliding. They were on flat ground, so it's no surprise they couldn't build up any speed running. The hang glider hung like a limp cloth, never filling up and lifting into the air.
在對滑翔翼的性能及飛行原理極度缺乏認識，人又在平地的情況下，自然怎麼跑，翼身就像破布一樣，軟趴趴地飛不起來。