The prop is distorted; I hear no sounds; The pilot's head is in the way.
These symptoms are indications that the plugin is not loading. You can confirm this by going to X-Plane's "Plugins>Plugin Admin" menu. If the plugin is loaded correctly, you'll either see a "SASL" or the name of the plane in the plugin window. If not, your plugin is not loading.
Other reasons for plugin malfunction are: conflicts with other plugins (such as Gizmo), and inadvertent deletion/movement of plugin files. Occasionally, users have reported incomplete downloads, also leading to plugin malfunction.
Another common reason for plugins not to load properly is, if the aircraft's folder has been renamed. Long folder names actually cause plugins to fail to load on some operating systems. If you have renamed the folder of the plane you're trying to use, please try shortening the name, and eliminating any symbols that are not letters or numbers.