The flight control computers (FCC-850) use control algorithms with gain parameters that determine the magnitude and speed of corrections applied to the control surfaces (via SVO-85 servos) in response to deviations from the reference (whether in attitude, altitude, etc.). In turbulent conditions, wind gusts cause momentary and irregular deviations.

A control system with high gains would react aggressively to each gust, attempting to correct the deviation immediately, resulting in abrupt control movements that could lead to discomfort and potential structural stress. By selecting TURB mode, the pilot commands the FCCs to reduce the gains of the control algorithms.

This makes the system more tolerant of transient deviations, leading to less reactive and smoother commands to the servos. The aircraft may deviate slightly more from the ideal reference, but it will do so in a dampened manner, without fighting the turbulence.

Is this TURB function being simulated?

Alan / From Brazil.