Acks - 100..500lb (I usually always have 500lb loaded, so they'll do it. Leaves some room for errors)
Standard buildings (i.e. Fuel tanks, Ammo depots, Radar dish) - 500lb
Hangars - 3000lb (Vehicle hangar goes down easier sometimes)
HQ Building - up to 10,000lb (takes incremental damage)
Az
II.(K)/JG2