wingtip ailerons/elevons
 

I was watching a video of Markus Rummer flying his CARF rookie and notice that he added what seems to be wingtip ailerons/elevons for a lack of a better description. Markus is a very talented pilot and is impressive to watch, but I was wondering what is the added benefit to these "wingtip" ailerons/elevons?

http://www.rcuniverse.com/forum/atta...mentid=2182971http://www.rcuniverse.com/forum/atta...mentid=2182972http://www.rcuniverse.com/forum/atta...mentid=2182973


https://youtu.be/DiuMULAxG3E

They could either be simple mass balance tabs to help reduce flutter etc at speed or aerodynamic balance tabs that reduce load on servo/ pilot whilst increasing effectivness of the surface, chances are looking atthe shape that they are a mix of both

Thank you!