Roland Sommer Senior has been around for a long time in the F3X community, competing and designing F3B for many years, before switching attention to F3K. Over the past several years, Senior has made waves in the F3K community with several highly successful designs, including its the Concept Xtreme 2 and 3, suitable for calmer conditions. Used as a complete series by champions, the CX series can be seen on podiums around the world.

The CX4 was part of Senior's quest in pursuing a design that can handle the tough winds that seems to always appear during large competitions. With that in mind, the criteria for the plane had to be that it must have fast acceleration, a good L/D (or, range), good launch, and still keep it's flight behavior timid enough to actually release the plane's potential.

What Senior created was exactly that, and created an instant following with the design in the US, and then spreading over to Europe and Asia. A trait that seemed to shock pilots most was the ease and ability for pilots to fly the plane to its potential, something that is rare with planes of high performance, often requiring lots of time tweaking, tuning, and stick time to perfect.

This is the top-drive version of the CX4 built in the Czech Republic. This partnership has allowed the CX4 to be produced in higher numbers than previously possible, which has made it possible for us to bring to more pilots and keep the prices down.
  • Hollow core sandwich structure
  • 1-piece fuselage
  • 1-piece wing
  • Top drive
  • Wing: Rohacell sandwich material, Textreme, Carboline, fiberglass
  • Fuselage: Carbon
  • Tail group: Solid Rohacell core, carbon spar, fiberglass
Flight Characteristics:
  • Good launch
  • Good L/D and penetration
  • Good handling
  • Easy to fly to potential performance 
  • Wing airfoil: Proprietary
Recommended Gear:
  • Receiver: FrSky X4R
  • Flaperons: KST X08
  • Tails: KST X08
  • Battery: Turnigy Nanotech 1S LiPo 600mah - 800mah

Concept CX4 TD