Complex sentence: Many countries issue licenses which are based on ICAO Annex 1 and 6 as well as ICAO DOC 7192 D3, however not all countries have adopted a mandatory license and joint responsibility/flight watch operational control systems.
Split into simpler sentences: Many countries issue licenses which are based on ICAO Annex 1 and 6 as well as ICAO DOC 7192 D3. Unfortunately not all countries have adopted a mandatory license and joint responsibility/flight watch operational control systems.