Stealth planes can not be found on the radar and this can be very deadly. The Horten 229 has a stealth feature to not be found on radar
This used wooden wings, and thats the key to stealth from radar
How it worked:
Radar is a wave and when it hits a object it creates a circle on the radar, wood absorbs radar waves
I know the Horten 229 is Nazi tech but never used (not even by the allies), only founded by the allied forces