Not an airplane, a normal plane. A flat, level surface. If the diagrams I have posted so far are inadequate, follow the link I already posted to the Flat Earth Podcast site. It's where I get this stuff anyways.
If you can do me a huge favor. Please explain your flat earth in your own words. If you notice my concave earth thread, I did this when asked. I didn't push people to a website, if I did is because people were calling me an astronaut. lol
Just explain this model the best way you know how, in your own words, without referring to your podcast. You should at least have a working understanding on what you believe? You have read books, spent thousands of hours on this study, so it shouldn't take you more than a few minutes...right?