We booked that flight from Kolkata to Xining (changing plane in Kunming) via Internet. The Kolkata Airport is very confusing and the flight was NOT indicated on the boards, we learned it was not cancelled, asking at the desk. It appeared only at the last moment. So the beginning seemed quite difficult... but then we had no problems. One must get used to the somehow strange (and caotic) rules and practice of controlls, formalities and so on, but the planes, the service and punctuallity is really ok. The connection in Kunming worked perfectly. A good flight with no problems!
Attention: often it is difficult to change money at the airport and cash-machines sometimes do not work!!!