What is the big event in Chapter 12 in Dragon Wings By Laurence Yep?

The big event in Chapter 12 is Windrider's trip in his flying machine. He gets his machine off the ground and flies all around the valley. Unfortunately, as he begins his decent toward the hilltop, one wing touches the hill and breaks apart, causing Windrider to crash. Windrider, however, survives the crash with only a broken leg and some broken ribs.