My brother flies all around the world as a systems engineer, as does my cousin who is a sales manager for a large pharmaceutical company. Generally, overseas travel comes with international companies that require attendance at meetings at other offices, and UK firms that specialise in consultancy work, advising other firms.
Despite it sounding glamorous, it's not. My cousin flies to NY every other week - has a two hour meeting and jumps back on a plane to come home (while having to do work on her laptop on the plane).