Sure you can, and you're protected even without filing it. It's just like boat designs, house designs, etc. Try making a car that looks just like a Corvette...
If I’m not mistaken, air foil shapes were developed by the NACA, forerunner to NASA. That would make the crossectional shape kinda like ‘Public Domain’ stuff. As to the actual wing design — yeah that probably would be proprietary. Who purchased Fairchild Aircraft’s assets?