>>530266705
2 air slots is the ideal assuming you paypig to 7 slots total for ground/shi(t)ps (if you only have 6 slots then just 1 air slot)
first for fighter (or multirole at high tier), second for bomber/strike/attacker (heli at high tier)
even if you just play ARB this also lets you put xp where its most useful for each type before they are maxed, g tolerance doesn't fucking matter for bombers that rip wings at 2g but gunner vitality (gunner firing skills are kinda pointless since they don't fire without manual control anymore) is very useful