Apparently "Living Quarters" are required to launch intercept aircraft at an alien target. It took me a while to figure out why i my secondary bases could never attack alien craft.
However without the living quarters i can buy and equip and even launch those planes, but they refuse to go anywhere.
It doesn't make sense to me that aircraft require living quarters, since other buildings such and the command center, radar, and storage which realistically require people, don't require the living quarters because that staff is not one of the 4 employees simulated by the game.
However if you do decide this prerequisite is desirable, it should be explained in the documentation.
On 2.2 MacOsX Universal
(submitted to sourceforge also)
