Rubberbands asked "Are you (Junker) suggesting that pilots and sailors blindly follow their computer navigation systems to get from Point A to Point B and, in the meantime, don't actually have a clue where they are?" To which Junker replied less than an hour later "That is exactly what I'm suggesting. I'm sure from experience of flying particular routes repeatedly they gain an intrinsic understanding of their bearings. They aren't pulling out maps to chart courses in an airplane." Perhaps this is true in today's ships and airplanes, where the computer reigns supreme, but in pre-digital days this was not the case. Early aviators absolutely DID navigate in flight using paper maps, and sailors always have and still do so as a backup if GPS should fail them. And those maps are/were projections based on an assumption of a round earth. If the assumption of a round earth were false, then maps based upon that assumption would not be an accurate representation of the world. They might be navigable in some parts of the world, but they would be worthless in others.
In today's world, ships and planes routinely arrive where they are trying to go, and they arrive in the amount of time one expects of a round earth. Therefore one of the following must be true:
1. All pilots who fly more than merely local routes, and all mariners who navigate ships across the ocean, they all merely pretend to use RE navigation when in reality they know and use FE navigation, and therefore all of them are a part of the conspiracy to keep FE a secret.
2. All those people are fools, they think they're navigating a round earth when in fact they've been duped by mapmakers and GPS programmers who pretend their maps represent RE when they actually represent FE, placing all mapmakers in the conspiracy.
3. None of those people are in the know, they all mistakenly believe RE, the maps are based on RE and are worthless, and my statement about ships and planes routinely arriving at their destinations is false. They are actually lost at sea in large numbers or making landfall wildly off course due to navigating under false RE assumptions with bogus RE maps. There must be a massive coverup to hide all these missing ships and planes from the news, which is an even bigger pool of conspirators.
4. None of the above, because maps based on RE assumptions actually get you where you want to go.