> But again if you want to get technical, the Constitution restricts Congress's authority to provide for the common defense to having an army or a navy, but not an Air Force
It allows Congress to raise "Armies" (plural) and a Navy, and it allows Congress to choose how to equip and train the Armies it raises. I don't see that it prevents it from choosing to a equip one of the armies primarily with fixed-wing aircraft, training it in doctrine for employment of such equipment, and give it the name "Air Force" to distinguish it from other armies that are differently equipped and trained.
It allows Congress to raise "Armies" (plural) and a Navy, and it allows Congress to choose how to equip and train the Armies it raises. I don't see that it prevents it from choosing to a equip one of the armies primarily with fixed-wing aircraft, training it in doctrine for employment of such equipment, and give it the name "Air Force" to distinguish it from other armies that are differently equipped and trained.