What: China Southern Boeing 737-300 en route from Kunming to Zhengzhou
Where: en route
When: Jul 17th 2010
Who: 130 passengers
Why: After takeoff and reaching cruise level, cabin pressure was lost. Oxygen masks were deployed, and the flight returned to Kunming where it made a safe landing. Twenty passengers were hospitalized with ear pain.
A replacement flight was provided six hours later.