This begs the question if it would be good practice to replace a throttle servo after "x" number of hours in service? Condsider vacuum pumps in full scale planes: even if working properly at the time, usually they get replaced after 400 hours, or whatever the manufacturer deems to be the service life, since they are failure-prone and when they fail it is with little or no warning. Should we treat throttle servos the same way? And are the flight control surface servos as vulnerable to vibration-induced failure as the throttle servo? Perhaps not, as they do not have a direct connection to the engine like the throttle servo...just thinking out loud