Please consider the following comments from Olaf Jansen's Smoky God;
"If my father and I were curiously observed by the ship's occupants, this strange race of giants offered us an equal amount of wonderment. There was not a single man aboard who would not have measured fully twelve feet in height. They all wore full beards, not particularly long, but seemingly short-cropped. They had mild and beautiful faces, exceedingly fair, with ruddy complexions. The hair and beard of some were black, others sandy, and still others yellow. The captain, as we designated the dignitary in command of the great vessel, was fully a head taller than any of his companions. The women averaged from ten to eleven feet in height. Their features were especially regular and refined, while their complexion was of a most delicate tint heightened by a healthful glow[Footnote]. [Footnote begin, Italic] "According to all procurable data, that spot at the era of man's appearance upon the stage was in the now lost 'Miocene continent,' which then surrounded the Arctic Pole. That in that true, original Eden some of the early generations of men attained to a stature and longevity unequaled in any countries known to postdiluvian history is by no means scientifically incredible." - Wm.F.Warren, "Paradise Found," p.284. [Footnote end, No Italic] Both men and women seemed to possess that particular case of manner which we deem a sign of good breeding, and, notwithstanding their huge statures, there was nothing about them suggesting awkwardness. As I was a lad in only my nineteenth year, I was doubtless looked upon as a true Tom Thumb. My father's six feet three did not lift the top of his head above the waist line of these people."
This is because they are born within the hollow earth, protected from the harmful rays of The Sun. The UFO occupants who are human are not from a place where they are subjected to the Sun's rays as we are on the surface of the Earth. For example, on Venus there is a cloud mantle and the lunar occupants have a thick atmosphere and mostly seem to live underground.
So, are the human UFO occupants 12 feet tall? Has anyone ever reported such a thing?