I'm not sure if this is a bug or an FR, but the current state is not IMHO ideal.
If you try to transfer a soldier attached to a lander, the game won't let you, so you think, that the aircraft and soldier is considered a unit for purposes of transfer.
However, if you transfer an equipped and crewed aircraft to another base, it will be transfered without any weapons or any of it's crew.
Similarly if you transfer a soldier, he will arrive without any equipment.
99.% of the time i believe that the player would want the soldiers and aircraft to retain his/its equipment and the aircraft it's crew. But currently there's a lot of extra clicking to reassemble a crew/aircraft at a new base.
On 2.2 MacOsX Universal
(Also reported on Sourceforge)