Question

The reason for using quadruplex actuation system is _______

(a) precise movement

(b) to counteract heavy air loads on the control surfaces

(c) quick reaction to the control stick movement

(d) as a fail safe mechanism

The question was asked at a job interview.

My query is from Fly-By-Wire Technology topic in chapter Fly by Wire Flight Control of Avionics

Answer 1

Right option is (d) as a fail safe mechanism

To explain I would say: A quadruplex actuation system consists of four independent actuators whose output drives the power control unit. The fail-safe mechanism of the quadruplex system is that when one fails three can override it. All four actuators have totally independent power and control electronics.