Premise: Diqing Shangri-La Airport (IATA: DIG, ICAO: ZPDQ) is an airport serving Shangri-La City, Diqing Tibetan Autonomous Prefecture, Yunnan Province, China. The airport does not have any taxiways(other than the one leading to the terminal building), requiring planes landind there to backtaxi to the terminal building.
Hypothesis: Pilots need special training to backtaxi.