In older civ series, you started with armies, then weak navies, then quite strong navies, and then air units were introduced. The introduction of air units changes things -- big time. However, CivBE doesn't have this historical barrier. All factions landing on the planet clearly have an enormous amount of knowledge of aeronautics simply displayed by the fact that they made the journey and (most?) the colonists survived. Their knowledge would obviously be far beyond our current knowledge. So, where does this put air units as far as the start goes in CivBE? To me, it would make sense to have some basic scouting air unit(s) become available fairly soon. I'm thinking the Civ5 gunship but it cannot attack and with the ability to not be targeted unless the aliens or rival has a special unit or ability (think drone). Also, the inability to pick up "goody huts" just because moving 6 hexes a turn with goody huts out there seems silly. From there, I really don't know. Like I said before, air units are a massive game changer on so many levels in Civ5 and 4. The first to great war bombers can basically defend or attack anyone, first to get a good amount of interceptors either takes air supremacy or nullifies it, then there are atomic bombs which make interceptors even more valuable (on both sides), and lastly their are stealth bombers which basically means the same thing as great war bombers except that there is no counter true counter.