Here you can download free plans for a foam rc plane.
First flight of my homemade G-650 RC jet ✈
How to Make an RC Plane Using Packing Material (Thermocol)
How To Make RC Plane at Home
How to make RC Airplane - Part 2 / DIY
Eachine E119 Flybarless RC Helicopter - Maiden Flight 2020
BettaFPV Cetus Pro & Ganza
So you want to build micro RC planes...$30 Micro RTF
DIY How to Build a Rc Plane at Home
Online calc of the CG of an RC airplane