Do NOT install the 3421's on the elevators. BV calls for the 3301 which is the digital replacement for the 3321's and they work very well. Problem is that space is limited in the horizontal stab. For the rudders install 9411's, in lieu of the recommended 3421's. I don't know anything about the airtronics servos but I have close to 100 flights on my XL with a P-120 and have had zero problems with the 3301's on the elevators.


David Reid