Many modelers use in training a discrete instrument. Its advantages — low cost and high reliability. But from failures nobody is guaranteed, and discrete hardware problems can lead to jamming of the steering wheel in extreme position. To be able in any case to save the model, just need to modify the drive wheels, causing a few power elements (regardless of their type, whether electromagnets, solenoids, or the centrifugal machine with thrusters on the course or pitch) to work in a single wheel, and separately for half.
When “jamming” of one of the channels or the Executive units will always remain the option of using an adjacent channel to put the second half of the helm is also in an extreme situation and without a crash to complete a project. For small areas of rudders, typical electronic circuits, their resistance to air flow can be neglected.