Due to the sudden climate change, flights can be delayed and cancelled in Nepal. Mostly, it happens in the winter and rainy seasons. Langtang Excursion PVT. LTD. is not responsible for such cases. We request you to have some more spare days when you are travelling to the high altitude places like the Everest region, which include the flight via Lukla. As a final way out, we can fly helicopter and it should be paid by your travel insurance.