We flew from Los Angeles in the early morning. The total flying time is about 19 hours from LA to Katmandu. We flew Thai Airways. As far as I am aware there are still no nonstop flights between those two cities. We made stops in Seoul, South Korea, and a 12 hour layover in Bangkok, Thailand. On the connection flight to Katmandu make sure you request tickets for the right side of the plane because then you will be able to see the Himalayas. There is a 1200 Rupee departure tax from the Katmandu Tribhuvan Airport.
Parts of the land that we flew over are very impressive. We flew up the western coast of North America and then crossed over the Bering Straights. Towards the northern coast of North America we flew over chunks of floating ice and large ice caps. The sun never set so we had continuous daylight. I took over a hundred photographs just of icebergs and polar caps. I have never seen a territory so isolated and stark. The ice caps seemed to extend forever and in places the ice was shimmering so brightly that you could not look at it for very long. When we flew over Japan out pilot pointed out Mt. Fuji. This is an impressive mountain, covered with snow and towering over the landscape.
On flights of such length it is hard to keep from becoming bored. You find yourself counting minutes and then realizing that you are still hours from your destination. Some people bring inflatable pillows, but I find that those are too restricting. When I want to rest I usually lay my head on an extra shirt. Card games, and books are good ideas for long flights. I also recommend frequent walks around the plane. This helps break some of the monotony of the flight.