Brad Roberts’ Onex

By Michael Stephan

Last month I paid a visit to Brad Robert’s OneX project. After a bit of time off from it, I was glad to see all the recent progress. That airplane is
nearly complete. He has all the firewall forward finished. The instrumentation is in and functional. He is using the MGL Avionics instrumentation as is common in many Sonex builds, due to the compactness of the unit and the limit space available in the panel. We did a few functional checks on the control system and everything is looking good. The only construction left was on the outboard wing panels which includes the unique folding mechanism.

Like he did with his RV-7, Brad plans to paint the OneX before the first flight. On the bright side, there is a lot less airplane to paint with the Onex. He used the Stewart system on the RV and he plans to use that paint again. It is a water-borne paint and is much safer to use and he got good results with it on the RV.


The OneX is an interesting plane. The kit from Sonex is very refined and simple construction that incorporates blind rivets. It is no slouch in the air either. The 80 hp Aerovee engine provides ample power to pull the plane at a brisk 155 mph, and even though the wings fold the OneX is aerobatic.

You can learn more about the OneX at
Our Chapter has several projects that I expect will finish this year and Brad’s OneX might be the first.