I can't figure out how the Airlift ability works in Civ6. The Airlift button only appears when a unit is in the city where the Aerodrome is built -- not when a unit is on the Aerodrome itself -- but when I click the button the green hexes appear around that city's Aerodrome but not around any other cities' Aerodromes. What's the point of airlifting a unit only a few hexes from the city to the airport district? I'm in a real dilemma because right now I have an coastal Aerodrome loaded with 3 aircraft that have already committed their actions and I've spotted an embarked enemy unit 2 hexes away. Chances are it's going to disembark on top of my Aerodrome and pillage it, destroying my aircraft and making the district unusable for about 10 turns. I knew the risk and had it defended by an Infantry unit a few turns earlier, then I completed Satellites and upgraded to Mech Infantry and rushed it to support my attacking army. The AI either exploited my mistake or just got lucky launching a raid into my undefended territory. If the airlift ability worked the way it should work, I could airlift one or several garrisoned units from cities with Aerodromes across the map. I don't know if there's a range limit to airlifting or I don't understand how to do it properly or if the airlift ability is broken in Civ6.