It's quite common nowadays to have folks up bombers and try to do what 999000 does, but here's the kicker: Even if they fail, they make you waste your ammo, the attackers cycle out, but there's no replacements, and the folks finishing off the town get hosed thrice over.
Keep that in mind folks: You see bombers upping at a capped field, let them go. The ammo you have has to last until you capture the field!