The aeronaut can see for himself that Earth is a Plane. The appearance presented to him, even at the highest elevation he has ever attained, is that of a concave surface - this being exactly what is to be expected of a surface that is truly level, since it is the nature of level surfaces to appear to rise to a level with the eye of the observer. This is ocular demonstration and proof that Earth is not a globe.
The problem with the Globe Earth model is that it is completely the opposite of what the Bible says. In the Globe model, there is no separation of waters from the waters below. In fact, there are no waters above. Neither is there a barrier separating earths air from the vacuum of “space”. We are told that “gravity”, an invisible force even “scientists” do not understand, is what holds the air and the water onto the earth. But never has anyone ever been able to produce a real vacuum without a barrier around it to keep the air separated from the vacuumed space. There must be a solid barrier or it does not work. In this way, the globe makes no sense.
Astronomers have never agreed amongst themselves about a rotating Moon revolving round a rotating and revolving Earth - this Earth, Moon, planets and their satellites all, at the same time dashing through space, around the rotating and revolving Sun, towards the constellation Hercules, at the rate of four millions of miles a day! And they never will: agreement is impossible! With the a Earth a plane and without motion, the whole thing is clear. And if a straw will show which way the wind blows, this may be taken as a pretty strong proof that the Earth is not a globe.

200) And finally, from Dr. Rowbotham, “Thus we see that this Newtonian philosophy is devoid of consistency; its details are the result of an entire violation of the laws of legitimate reasoning, and all its premises are assumed. It is, in fact, nothing more than assumption upon assumption, and the conclusions derived therefrom are willfully considered as things proved, and to be employed as truths to substantiate the first and fundamental assumptions. Such a ‘juggle and jumble’ of fancies and falsehoods extended and intensified as in theoretical astronomy is calculated to make the unprejudiced inquirer revolt with horror from the terrible conjuration which has been practised upon him; to sternly resolve to resist its further progress; to endeavour to over-throw the entire edifice, and to bury in its ruins the false honours which have been associated with its fabricators, and which still attach to its devotees. For the learning, the patience, the perseverance and devotion for which they have ever been examples, honour and applause need not be withheld; but their false reasoning, the advantages they have taken of the general ignorance of mankind in respect to astronomical subjects, and the unfounded theories they have advanced and defended, cannot be otherwise than regretted, and ought to be by every possible means uprooted.”

So, before God created land and all living things, “darkness was on the face of the deep,” a large expansive ocean. Water does not curve. In its resting state, the surface of a body of water always remain level, hence, it describes it as the “face of the deep.” It is true that small amounts of water may “curve” because of surface tension, and larger amounts of water move and “curve” when disturbed. But, the surface of all resting water is always level, flat. It does not matter how curved or rough the land is below the water.
What if the earth was a sphere in inverse? I'm no scientist but I found this discussion by accident and it challenged both beliefs in me. There was a ride at a local amusement park that was cylindrical and would start spinning with the floor eventually falling out beneath us. We would stay attached to the sides. Eventually they would slow the spinning down and we would loosen up from the wall. Is it possible that the Earth envelops the sun, moon, stars and "outer space" as we know? That everything we know is inside as opposed to outside our world we know and experience? Very interesting subject nonetheless.
170) People even claim to see satellites with their naked eyes, but this is ridiculous considering they are smaller than a bus and allegedly 100+ miles away; It is impossible to see anything so small that far away. Even using telescopes, no one claims to discern the shape of satellites but rather describes seeing passing moving lights, which could easily be any number of things from airplanes to drones to shooting stars or other unidentified flying objects.

14 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years: 15 And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so. 16 And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also. 17 And God set them IN THE FIRMAMENT of the heaven to give light upon the earth, 18 And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good.
133) In direct sunlight a thermometer will read higher than another thermometer placed in the shade, but in full, direct moonlight a thermometer will read lower than another placed in the shade. If the Sun’s light is collected in a large lens and thrown to a focus point it can create significant heat, while the Moon’s light collected similarly creates no heat. In the "Lancet Medical Journal,” from March 14th, 1856, particulars are given of several experiments which proved the Moon's rays when concentrated can actually reduce the temperature upon a thermometer more than eight degrees. So sunlight and moonlight clearly have altogether different properties.
On January 25th, 2016 Atlanta rapper B.o.B., who has self-identified as a member of the Flat Earth Society, tweeted a photograph of himself against a skyline, then tweeted a screenshot from Flat Earth Movement literature that proclaimed that Polaris (the North Star) can be seen 20° south of the Equator. Neil DeGrasse Tyson answered the rapper's question, writing "Polaris is gone by 1.5 deg S. Latitude. You’ve never been south of Earth’s Equator, or if so, you've never looked up." 

20) If Earth were truly constantly spinning Eastwards at over 1000mph, vertically-fired cannonballs and other projectiles should fall significantly due west. In actual fact, however, whenever this has been tested, vertically-fired cannonballs shoot upwards an average of 14 seconds ascending, 14 seconds descending, and fall back to the ground no more than 2 feet away from the cannon, often directly back into the muzzle.

The theory of a rotating and revolving earth demands at theory to keep the water on its surface; but, as the. theory which is given for this purpose is as much opposed to all human experience as the one which it is intended to uphold, it is an illustration of the miserable makeshifts to which astronomers are compelled to resort, and affords, a proof that the Earth is not a globe.

Quite simply you cannot. It is widely stated you would need to be at a height of at least 40,000 ft to get even a hint of curvature if earth were round. Commercial aircraft are not allowed to fly this high. They are only allowed to fly just under this altitude. 36,000ft might be typical. In addition, the windows on commercial aircraft are small and heavily curved. Even if they flew high enough for a person to see curvature, it would still not be visible to passengers.
148) Quoting “Earth Not a Globe!” by Samuel Rowbotham, “It is found by observation that the stars come to the meridian about four minutes earlier every twenty-four hours than the sun, taking the solar time as the standard. This makes 120 minutes every thirty days, and twenty-four hours in the year. Hence all the constellations have passed before or in advance of the sun in that time. This is the simple fact as observed in nature, but the theory of rotundity and motion on axes and in an orbit has no place for it. Visible truth must be ignored, because this theory stands in the way, and prevents its votaries from understanding it.”
71) It is often possible to see the Chicago skyline from sea-level 60 miles away across Lake Michigan. In 2015 after photographer Joshua Nowicki photographed this phenomenon several news channels quickly claimed his picture to be a “superior mirage,” an atmospheric anomaly caused by temperature inversion. While these certainly do occur, the skyline in question was facing right-side up and clearly seen unlike a hazy illusory mirage, and on a ball-Earth 25,000 miles in circumference should be 2,400 feet below the horizon.
99) Viewed from a ball-Earth, Polaris, situated directly over the North Pole, should not be visible anywhere in the Southern hemisphere. For Polaris to be seen from the Southern hemisphere of a globular Earth, the observer would have to be somehow looking “through the globe,” and miles of land and sea would have to be transparent. Polaris can be seen, however, up to over 20 degrees South latitude.
If you are a Christian and you believe the Bible is the True Word of God, then you need to set aside all previous beliefs and accept what the Bible says, not what the world and the media say. Remember, the Bible tells us that we have an enemy, called Satan. It says in John 8:44 about Satan, that, “He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.” And also in Revelation 12:9 it describes what happened to Satan and what he is doing on earth: “And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.”
78) From Anchorage, Alaska at an elevation of 102 feet, on clear days Mount Foraker can be seen with the naked eye 120 miles away. If Earth were a ball 25,000 miles in circumference, Mount Foraker’s 17,400 summit should be leaning back away from the observer covered by 7,719 feet of curved Earth. In reality, however, the entire mountain can be quite easily seen standing straight from base to summit.
25.) The surveyor's plans in relation to the laying of the first Atlantic Telegraph cable, show that in 1665 miles – from Valentia, Ireland, to St . John's, Newfoundland – the surface of the Atlantic Ocean is a LEVEL surface – not the astronomers' "level," either! The authoritative drawings, published at the time, are a standing evidence of the fact, and form a practical proof that Earth is not a globe.
79.) The remark is common enough that we can see the circle of the Earth if we cross the ocean, and that this proves it to be round. Now, if we tie a donkey to a stake on a level common, and he eats the grass all around him, it is only a circular disc that he has to do with, not a spherical mass. Since, then, circular discs may be seen anywhere – as well from a balloon in the air as from the deck of a ship, or from the standpoint of the donkey, it is a proof that the surface of the Earth is a plane surface, and, therefore, a proof that the Earth is not a globe.

The aeronaut can see for himself that Earth is a Plane. The appearance presented to him, even at the highest elevation he has ever attained, is that of a concave surface - this being exactly what is to be expected of a surface that is truly level, since it is the nature of level surfaces to appear to rise to a level with the eye of the observer. This is ocular demonstration and proof that Earth is not a globe.
136) Many people think that modern astronomy’s ability to accurately predict lunar and solar eclipses is a result and proof positive of the heliocentric theory of the universe. The fact of the matter however is that eclipses have been accurately predicted by cultures worldwide for thousands of years before the “heliocentric ball-Earth” was even a glimmer in Copernicus’ imagination. Ptolemy in the 1st century A.D. accurately predicted eclipses for six hundred years on the basis of a flat, stationary Earth with equal precision as anyone living today. All the way back in 600 B.C. Thales accurately predicted an eclipse which ended the war between the Medes and Lydians. Eclipses happen regularly with precision in 18 year cycles, so regardless of geocentric or heliocentric, flat or globe Earth cosmologies, eclipses can be accurately calculated independent of such factors.