It is common to enter Bhutan from Nepal by flight. But you can only book flight tickets through the two Bhutanese Airlines called Druk Air and Bhutan Airlines. There are many direct flights from Kathmandu (Nepal Tribhuvan International Airport) to Paro(Bhutan Paro International Airport) every week. It is about 1.5 hours fly. Feel free to contact our travel consultant for more information about the flights between Nepal and Bhutan.