In the Blue Sky rules each ship fires at every plane in range. When there are a lot of planes or ships this can take quite some time. This modification of Blue Sky allows for one roll for each aircraft, and the possibility of the plane being shot down with just one shot - or escaping heavy fire unscratched.

You will need to modify the published AA values for ships (see below).

AA range is twenty hexes and/or levels (where each level counts as one hex).

For each plane in range of AA from any AA position or any part of a ship total the AA values of all firing positions or ships. This is the AA total.

When planes are flying straight and level add one to all firing positions for their AA value.

For each target roll 1d20. Any roll equal to or less than the AA total causes a hit with the following exceptions:

Determining ship AA values

To determine ship AA valuse consult some reference work such as Conway's All The World's Fighting Ships 1922 - 1946. Determine the number and type of guns on the ship of five inches or less.

• If the ship carries any guns, its AA value is 1.
• For every three (3) whole guns (ie, five counts as three), of three inch to five inch, add one to the AA value.
• For every eight (8) whole guns (ie, fifteen counts as eight), of less than three inches, add one to the AA value.

Some examples:

• USN Lexington carried 8 - 8" guns, 12 - 5" guns, and 48 - 0.5" guns. Her AA value would be 11. (One plus four for the 5" guns, plus six for the 48 guns of less than 3").
• IJN Fubuki class DDs carried 6 - 5" guns and 2 machine guns. Their AA value would be 3. (One plus two for the 5" guns).
• IJN Tone carried 8 - 8" guns, 8 - 5" guns, and 12 - 25mm machine guns. Her AA value would be 4. (One plus two for the 5" guns plus 1 for the 25mm guns).