Tapley popped in 16 points while Franklin added 14 and 10 rebounds as the Aztecs (17-2, 3-0 MWC) won a 10th straight game.
San Diego State notched its 42nd straight home victory while playing an unranked opponent.
The Falcons (11-6, 1-2) were led by Taylor Broekhuis with 16 points.
Mike Fitzgerald added 14 in the Air Force loss.
Notable deaths of 2014 [PHOTOS]