The only airline that operates flights to Bhutan is the Druk Air, Bhutan's national carrier and the only airline operating in Bhutan. The Druk Air's fleet consists of two British Aerospace jets, BAe 146s; all are specially designed for Bhutan. The Druk Air itself has established an irreproachable safety record, without a single accident since its inception in 1983.
However, again the disadvantage is that the airline has a limited sector of operation and that too only on certain days of the week that makes planning an itinerary quite complicated. Hence, the itinerary should be planned in advance in order to avoid such unpleasant situations when you want to arrive to Bhutan on Tuesday, but the only itinerary is available for the next Tuesday only.
The disadvantage is that the Druk Air jets have a little number of seats (in some jets there are seventy two seats) that also results in the complication of itinerary planning. In addition, Paro Airport, located in the mountains, is subject to the caprices of nature, and weather conditions sometimes prevent flight landing and taking off.
Flights to Bhutan are available from Bangkok in Thailand, Kathmandu in Nepal, Delhi and Calcutta in India, and Dhaka in Bangladesh several times each week.
There are five flights a week from Bangkok to Paro flying via Calcutta and Dhaka (Tuesday, Wednesday, Friday, Saturday and Sunday) and back to Bangkok on Monday, Tuesday, Thursday, Friday and Saturday. The Druk Air operates two flights a week from Delhi and Kathmandu to Paro (Monday and Thursday) and also back to Delhi and Kathmandu on Monday and Thursday. During the summer, winter and spring season, the Druk Air flies to Delhi and Kathmandu from Paro on Wednesday and Sunday. Thus, the number of flights and tickets to Bhutan is limited.
Air tickets are issued only after your visa is approved by the Home Ministry of Bhutan. The air-tickets cannot be issued until the visa is approved. The process of visa confirmation takes a week or more.
Despite all inconveniences, on clear days flights to Bhutan offer spectacular views of the Himalayan mountain range, including the Mt. Everest, Mt. Kanchenjunga, Chomolhari, Kula Kangri and many other peaks of the Himalayas. Perhaps, these unique views can compensate all inconveniences of booking flights to Bhutan.
If you want to combine a visit to Bhutan with India sightseeing, you can enter Bhutan by road through the border town of Phuentsoling. Phuentsoling is the only entry point to Bhutan except Paro airport. Those, who travel to far Eastern Bhutan, can exit the country through the border town of Samdrup Dzonkar to Guwahati Airport in Assam of India. From Guwahati there are flights available to Calcutta and Delhi.