One of the causes of over-current draw with aircraft RC systems is binding in the linkage. Particularly the nose wheel steering and the throttle. Make sure that you center the servo before making any adjustments (that goes for ALL servos) then make sure that the servo movement does not try to exceed the available movememt of the particular control you are working with.

If it's the throttle, do NOT try to force the throttle to go further than the carb throttle arm will allow. It is often overlooked and is frequently a source of linkage binding. The same with the nose wheel. If you try to move it more than it will move, the servo will keep pushing or pulling and will do two things: bind causing over draw of the battery and probably "buzz" as you described.

We have outlined the necessary throttle mechanical adjustments in prior posts so do a little searching to find the appropriate info (do NOT rely on computer radio end-point settings) to make sure that you have good throttle resolution as well as no binding. This also applies to every other action that the servos are working.

These are settings that really deserve your maximun attention to because, in the case of binding servos and over current (possibly the cause of the buzzing noise), is a much faster drain on your battery pack. If it drains to quickly, it could quit in the middle of a flight with the results being disasterous.

CGr.