Panzer General Allied Assault

This can be most easily achieved in a skirmish. First, edit a deck and add as many air cards as possible. Then start a skirmish making sure that your select the deck you just edited. Set the victory conditions to only "destroy all enemy units" to make the battle last longer.

When drawing cards, buy as many as possible. Build up your prestige by controlling more territory so you can buy more cards. Play all air cards you draw, don't sacrifice any of them. During your turn use as many cards as possible so that you cycle through them faster. Make sure you leave at least one enemy unit alive until you get the achievement.

This is most easily achieved during an online game, as online games tend to run longer than levels in the singleplayer campaign.

Every draw phase, buy as many cards as possible to try and get as many 'Air' cards as you can. You should focus on controlling as much territory early-on, as that gets you Prestige which can be used to buy cards.

Play Air cards whenever you draw them. You should have ample time to crank through 6 of them.

Note, you can setup an online game to last a little longer by setting the victory conditions in a custom match to only be 'Occupy home space' and 'Occupy 3 adjacent spaces on home row'.

Alternatively, boost with a friend in a Player Match.