From the manual v2_5_5
The maximum range at which the group's aircraft will operate. Available options are anywhere between one and unlimited (the maximum range of the aircraft in miles). As setting the groups range to zero is impossible, zero is used to set the range to unlimited, which is the default when the game starts. Group range will be ignored for the purposes of combat performance, landing safety, calculating the number of aircraft sent for a mission, transfer range, and replacements availability. AI will not use this setting. Note you
can set anything but ranges over the aircrafts maximum have no effect.
If I set range for an air unit manually to fx. 300, it says "Group range: 300(10), indicating that the range in hexes is 10? If I set it to 299, one less, instead. It says 299(9) so the range in hexes should have dropped one. I take this that the range factor is 30 and not 40 as some have mentioned, or 10, as I believe the manual states.
Then why cant I bomb units within range, with zero miles flown, air base in open or light forest, clear weather, etc? I could air drop supplies, but bombing on the same range seems broken.