This website is for aviation professionals and enthusiasts alike, and there’s something I need to clear up once and for all. I’ve seen way too many posts about this online, and frankly, I’m fed up. And yes, these posts come from both enthusiasts and professionals. So, let’s settle this.
An aircraft flies because of the shape of its wings and how those wings interact with airflow. Long story short: when air flows around a wing, or when a wing moves through the air, if the speed is sufficient, the pressure above the wing decreases slightly, and the pressure below increases slightly. This difference creates lift, allowing the aircraft to take off, climb, stay in the air, or descend—if the airflow slows down.
Got it? Good. Still with me?
Now, let’s move on. As I mentioned, lift is generated when air flows around a wing. This happens either because the wing moves through the air (thanks to thrust) or because the air moves while the wing stays relatively stationary (like in a wind tunnel or when the wind is blowing). The key point: it’s all about air moving around the wing.
So, yes, if you put an aircraft in front of a big enough fan, it will take off. That’s basically how wind tunnels work.
Notice I didn’t mention anything about the wheels turning? That’s because it doesn’t matter. If you put an aircraft on a treadmill, it will NOT take off. The thrust will try to move the aircraft forward, but the treadmill will counteract this by moving the wheels backward, keeping the plane stationary relative to the ground and, crucially, to the air around it.
No air moving around the wing = no lift. Long story short: an aircraft on a treadmill will not take off. Engines on or off, it makes no difference. Without airflow over the wings, nothing happens.
I hope this clears things up and saves us from at least some of the pointless posts and debates on social media. Let’s focus on what really matters. Feel free to refer any discussions to this post and let’s move on.
Leave a Reply