Originally Posted by
MrOrange
I was reading into hour building overseas for PPL licence holders and understand that they have to apply to the country in question in which they wish to train in, in order to have their license verified, converted etc.
Yes, that is necessary to fly on airplanes registered in that state. If you fly a plane of the state where your license is based over into the other state, you do not need to get your license converted as far as i know, although it might be needed if you plan to be based in that other state permanently. Of course, if a state is not an ICAO member (are there any?) that system does not work with licenses of that state though.
Originally Posted by
MrOrange
It got me wondering; where commercial pilots, especially long haul ones fly in and out of many countries and potentially fly over many others, what happens with them? I assume they don't have to apply to have their licenses recognized by dozens of different countries? Do airlines simply agree with each country that they can fly in/out/over them and said county trusts that their pilots are adequately licensed, or does it work differently?
Pretty much the same as above, pilots that do hold a license of the state of registry of the aircraft will be accepted to fly according to both ICAO and bilateral agreements in to, out of or over other states. As usual, there is an odd case, the EASA system. Each of the currently 28 EU states plus the EASA members Iceland, Norway and Switzerland automatically validate each other countries licenses, therefore any pilot issued with a license of any of those 31 states (30 in the future, once the UK left the EU without a deal or after the transition period without any further agreement on EASA/aviation) can operate any airplane he is rated to fly from any of the 31 states. That is regulated by agreements registered at ICAO. To be able to do that the ICAO had to change Annex 1 to allow for a structure like that.