Futaba GY401+S9257 gyro and servo set for RC electric helicopters  [GY401+S9257]

Futaba GY401 AVCS gyro with S9257 standard servo

The Futaba GY401 AVCS gyro paired with the S9257 standard servo is presented here as an RC-scale control package intended for electric RC helicopters. The gyro uses an Angular Vector Control System (AVCS) with SMM sensor technology to reduce trim drift and maintain heading hold, while the S9257 provides a compact, standard-voltage servo output for tail or control surfaces.

This combination is designed for model use: the gyro integrates sensor and control circuitry into a compact conductive resin case for improved EMC resistance, and supports remote gain adjustment and mode switching from a compatible transmitter. The gyro’s DS mode allows compatibility with Futaba digital servos to preserve high-speed response when a digital servo is fitted.

Installation focus: the gyro’s compact footprint and preconfigured mounting pads simplify placement inside typical electric RC helicopter fuselages, and the remote gain function supports on-field tuning without ground adjustments. The S9257 servo follows standard wiring and voltage ranges used in model craft, so integration with existing Futaba receivers and tail linkages is straightforward when matched to the controller output.

For model pilots who need a compact heading-hold gyro with remote tuning and a reliable standard servo for tail or control mounting, this set provides a matched pairing intended for electric RC helicopter installations; select wiring and gain settings according to your airframe and transmitter capabilities.