Here you can download free plans for a foam rc plane.
SR71 Blackbird - PowerUp 4.0 smartphone/iPhone controlled RC Airplane
How I Cut Foam Wing Cores for RC Airplanes
Arduino F22 Raptor RC Plane
GEPRC CineEYE HD Micro Cinewhoop Review
How-to: A cheap fueling system for rc airplanes
WPL V3 sound kit comparison and demo.
How to make rc plane connections explained in details
MAIDEN FLIGHT AND REVIEW DIY SAVAGE BOBBER RC PLANE MALAYSIA
Online calc of the CG of an RC airplane