After a deep research and testing in association with James from RC Air Adventures
we concluded that PLA and PETG are the best choices for a printable airplane now (2018)

This table is the summary of the most relevant material´s properties for a 3D printed airplane.

-Tensile strength. It is the maximum stress level that a 3D printed part can withstand in Z direction before breaking. We show Z direction because is the weakest and most important for a 3D printed airplane, if you analyze our “wing ultimate load test” the failure took place under a Z direction load.  This value tell us that PLA will be better for situations where the loads are applied relatively slow (no impacts) like aerobatic maneuvers.

Another important element that improve tensile strength of any 3D printed part is the extruder temperature. In this video Stefan from CNC kitchen explain us how printing  temperature affect strength. 

-Elastic modulus value of PETG is lower, this mean that you need to apply less force to deform the material. In other words, PETG is more flexible than PLA. ​

-Notched impact strength. This test will help us to understand the behavior of the airplane in case of crash, impact resistance of PETG is around 3 times better than PLA.

-PETG has a higher glass transition temperature, 80 °C  vs 60 °C .  This property will allow you to leave your airplane in a hotter environment.

-Warping of course is another difficult issue with PETG. Because its rate of
shrinkage is a bit higher than that of PLA any temperature differential in the part can cause different speeds of contraction, creating warped structures. To eliminate warping in general, one must have a temperature controlled environment in which to fabricate the part. 

Which is the best material for a 3D printed plane?

We are sorry, but we are not going to answer this question, we shared all the information

 The conclusion is yours!