Bhutan has so far only one international airport that caters to the needs of visitors coming in through flights. Though, within country, there are domestic flights to Yonphula in eastern Bhutan, Bumthang in central Bhutan and Gelephu in south-central Bhutan. The international airport at Paro is located at 7,300 feet above sea level and surrounded by mountains and hills as high as 16,000 feet. The flight between Paro and Kathmandu is one of the most exciting one as the aircraft passes over four of the five highest mountains in the world.
Bhutan's National Air Carrier, Druk Air operates regular flights to / from Delhi, Kolkatta, Bagdogra, Guwahati, Bodh Gaya, Mumbai (India), Bangkok (Thailand), Kathmandu (Nepal), Dhaka (Bangladesh) and Singapore.
From 10th Oct, 2013, other local carrier Bhutan Airlines – Tashi Air Pvt Ltd began its commercial flight operation on Paro – Bangkok sector and now operates regular flights to / from Kolkatta, Delhi, Bodh Gaya, Bangkok and Kathmandu.
Both Druk Air & Bhutan Airlines (Tashi Air) operate with Airbus A 319 aircraft (while Druk Air also has one ATR aircraft & operates mostly domestic flights with this and sometime also to Kathmandu & Kolkatta sector depending upon load factor or other requirements).
Since not many airlines are available for travelling to Paro so it is recommended to make your flight reservation well in advance to manage space especially during peak tourist season months. Both Bhutanese airlines maintain exceptional safety record.
Entry / Exit to Bhutan is also possible by surface through Phuentsholing, Samdrup Jongkhar and Gelephu . Bagdogra airport, in the state of West Bengal (India) is the nearest airport, approximate 165 km (4.1/2 hour drive) from Phuentsholing while Samdrup Jongkhar is about 110 km and 3 hours drive from Guwahati airport, Assam (India). Gelephu in south – central Bhutan is other entry / exit point, it is approximate 260km from Thimphu and this journey will take you through sub-tropical areas of Bhutan before entering the alpine zone and then finally to Bhutan's capital city.
Badrapur (about 5.1/2 hours drive from Bhutan's southern town of Phuentsholing) and Birat Nagar (7 hours drive from Phuenthsoling) are two other nearby airports in Nepal, those are connected with regular flights from Kathmandu.