As a freshman in college a buddy and I attempted to do this. We gave blood then went down to the local pub that was known to be friendly to underage kids. Unfortunately for us (or maybe fortunately) the bartender wouldn't serve us because it was too early in the day.

Clearly you haven't been to Washington Dulles C terminal. https://commons.wikimedia.org/wiki/File:Inside_Concourse_C.jpg

Granted the main terminal has a huge soaring roofline, but the C building is the opposite with lower normal height ceilings.