Boeing and China Southern Airlines recently completed successful demonstration flights using Required Navigation Performance – Authorization Required (RNP-AR) procedures at the Kanas Airport, Xinjiang Province, China. The Kanas procedure development, which is the first RNR AR implementation in the Xinjiang Region, is also the first collaborative RNP AR project between China Southern Airlines and Boeing. The demonstration flights were conducted using the 4000th Boeing Next-Generation 737. Opened in 2007, Kanas Airport is a seasonal airport in a valley of the Altay Mountains that mainly serves tourists to the Kanas Nature Reserve, a natural ecosystem formed by lakes, rivers, glaciers, forests and grasslands. However, weather conditions in the area can be difficult for aviation; flights are often held, diverted to other airports or even cancelled.