You mean like downward into the ground?
Flying into the ground doesn't get you to the other side of the world. Flying level to the ground does. Even if the world is round.
Just get a giant beach ball and a toy plane and try this out for yourself. Fly your little toy plane in a circle around the beach ball with the bottom of the plane facing the ground. Does the plane ever had to point towards the beach ball in order to go around the beach ball? Of course not. The bottom of the plane is always facing the beach ball. You can go around and around the ball without ever pointing "down" towards it. If you ever actually point down towards the round beach ball, you crash into it.
Now, how the hell can you chase the sun to go to a country on the other side of the world, like get to India from Los Angeles via Hawaii/Tokyo/Singapore whatever chasing the setting sun, and then continue chasing the setting sun from India via Dubai/Spain/London back to New York and then Los Angeles, if the Earth ain't fukking round?
You ever been in a moving car? Can you toss a ball from the back seat to the front seat, even though the car is moving and doesn't stay in the same spot? Since everything in the car has inertia, it's like it's not moving in the car, and you can toss the ball wherever, even though the front of the car where the ball lands is actually going 60mph.
Same with the Earth. Everything held to the Earth by the Earth's gravity is moving at about 1000 mph, but you don't feel that shyt at all because it's all moving together, just like you don't feel the speed of a plane when it's moving at a constant speed. When the plane flies from one part of the Earth to the other, the speed of the Earth is irrelevant as to which country you'll end up in, just like when you're walking through a train the speed of the train is irrelevant as to which car you will end up in.