There are three lifts in the base Sel. Also, your wanting to go up does not send the elevator automatically down to you, overriding the original instructions. Third, the base is two floors. Hangars are the ground floor, quarters, common rooms and the meeting hall are the second floor. Every part of the base can be reached by either stairs or lift; there is no need for "Climbing through air ducts". If you want a full schematic layout of the base, I will be happy to provide one for you.