I currently got 2 Krill 41% Extra 330SCs. One for 3D and one for IMAC flying. Both have the Champion SRS, both are flown with the PowerBox Core Radio, both have MKS high torque Servos on all surfaces (HBL380s on one and HBL3850s on the other). Both use two PBR-26D receivers per airplane. Everything was working fine on both of these airplanes up until today. I made several flights today and noticed on my 3D airplane that the aileron rolls were very slow in the air even though I was flying on full rates. It just didn't feel right in the air. I knew something wasn't right because in the previous flights before today, the airplane had much faster roll rates and elevator/rudder response. I soon figured out that my ailerons weren't deflecting to the 100% rate in flight even though they did on the ground. They were deflecting only up to 30-40% during the flight while rifle rolling which didn't happen before a few weeks ago. As soon as I landed the ailerons/rudder/elevator were traveling at 100% on the ground but not during flight. I then decided to apply pressure with both thumbs to each control surface and noticed that each surface was stalling/blow back while moving each control stick on the radio. This was occuring on everything including both ailerons, rudder, and each elevator half. At first I thought I had a servo problem/cable problem but it's happening on all surfaces when pressure is applied with your hands to create resistance just like in the air. I didn't have this problem before. I'm running everything at 7,4 volts with 2 Pulse 2S 5000mAh Lipo batteries which are fairly new and were purchased earlier this year. The only thing I changed in the CORE before flying today was I eliminated the dual rates on my airplane as I prefer max travel on my planes for 3D. I thought this problem was only on this airplane but decided to check my other 41% 330SC for IMAC flying on the ground and I got the same results! When pressure is applied on each surface while deflecting, every surface stalls on me! With a little pressure, every surface stalls on me and it would definitely happen in the air but I can't fly and test it out because this is a very serious problem. I'm running 3 Servos per wing and 2 on each elevator/ rudder. I don't know what's going on all I know is that both planes are getting blowback/stalling on each surface during flight and after landing when pressure is applied on every surface. The Max current shown on the champion is only 8.4 to 9.6 amps which is way to low for this big of an airplane.