You may have seen model airplanes. These model airplanes are smaller than the real thing, and while the outside might look like the real thing, the inside does not. Many models are scale models . This means that every part of the airplane is made smaller by the same amount. In aeronautics, researchers and engineers use models to design and modify airplanes.
Aeronautical researchers can make a scale model and mount it in a wind tunnel .
A wind tunnel is a tube or tunnel through which air is blown. So, instead of an airplane flying through the air, a scale model of the airplane is mounted in a wind tunnel and air is blown around it. Some wind tunnels are very large and can hold models that are the size of the real airplane. Some wind tunnels are very small and can only hold very tiny scale models of the airplane, or maybe a scale model of a part of the airplane. This may sound slow, but this is near takeoff and landing speeds for many airplanes.