Refuelling and carrier landings and takeoffs are more challenging than anything that airliners or freighters will experience.
Really? At one level they all seem (mechanically) to be fairly straightforward 3D processes, though perhaps for any human element involved needing nerves of steel at some point in proceedings.....as for refueling ( I assume you are talking air to air) most navs I flew with were convinced that AAR (hose and drogue) involved just six "commands" i.e. up/down, left/right/ forward and "
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I'll accept we are getting close to genuine autonomous airline ops being just around the corner when we've seen routine automated operations with 737/A320 sized aircraft between basic airfields with mostly visual approaches (such as those found in the Greek islands, elsewhere in Europe and probably all over the States).