U.S. Dept. Homeland Security recommends that stringed instruments be transported as carry-on items.
Check with airline before going to the airport. If the case exceeds size limitations, ship by air express or buy a ticket for the instrument.
Each country has its own regulations, so transport cannot be guaranteed.
"Air travel is a privilege and not a right."
The traveler should stay with his instrument while it is being checked, which usually requires adding 30 minutes or so to suggested arrival time. Do not pack any tools, etc. with the instrument.

www.finecases.com/about/airline-travel.html

Hitch-hiking is safer! Or travel by private plane.