Quote Originally Posted by Sebastian Finke View Post
You'll want composites, like carbon fibre. In terms of density nothing beats that. 3D print an aircraft under 120kg? Never happen...
In America there is an Ultralight airplane category for those single-seater aircraft what weigh less than 254 lbs (115 kg). And believe me, there are already many of them flying. There are some regulations for those type of aircraft, like the maximum 102 km/h speed, stall speed is less than 44 km/h and of course the weight limitation. If you are interested in, you can find many examples here: https://www.eaa.org/en/eaa/aviation-...light-aircraft
http://www.ultralightnews.com/ssulbg.../pictures.html
Yes, some of those look a little bit ugly, but with today's technology it's more than possible to build one what looks and flies amazing.