When I first connect my battery on my Electrostik, the aileron servos, HS-81 servos, buzz like the dickens. The minute I give the
slightest deflection of the aileron stick, the buzzing stops. It does not occur for the rest of the flight. I had replaced the original ES80 servos because they stripped after a few flights. I do not recall the ES80 servos buzzing when I first fired up the battery. It seems like only the HS81 servos do this. I have no problems during the flight. Strange!

Cajuncharley