@jacobg I think that makes airplanes too vulnerable. You would need to make them cheaper.
Cheaper airplanes and more effective AA might well be more realistic, but be careful about shifting the balance.
This topic is specifically to list house rules for units in whatever Axis and Allies game intended for. Please however list said game for a particular collection for clarification, the text enlarged and bolded.
Axis and Allies Global
Cruiser - Attack: 3, Defense: 3, Movement: 3, Cost: 11, Special: Can bombard during an Amphibious Assault per Transport.
Tactical Bomber - Attack: 3, Defense: 3, Movement: 4, Cost: 10, Special: Can Attack at 4 when paired with a Tank or Fighter, Can damage Air Bases and Naval Bases.
Strategic Bomber - Attack: 4, Defense: 1, Movement: 6, Cost: 11, Special: Can damage any Facilities, may only Attack at 2 against Naval Units, add 2 in damage if originated from an operational Air Base.
Anti-Aircraft Artillery - Attack: -, Defense: -, Movement: 1, Cost: 6, Special: During the first round for combat (attacking or defending), it may shoot up to 3 Air Units, if any are 1, said unit is destroyed and may not fire back, may not be used in additional combat rounds except as a casualty.