Citation X (C750)
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Time Pressure; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Aircraft; Procedure; Human Factors
The lower rudder indicator display was reversed.  [With] left rudder input; the lower indicator moves to the right; not left.  We probably flew this plane six times over three days without recognizing the discrepancy. We were aware that the plane had been serviced for a defective lower rudder indicator the day before by review of the logbook; so we were alert to check its operation.  When performing the flight control check as part of preflight; we saw movement of the indicator when the rudder was moved; when the flaps were lowered we saw additional movement of the upper rudder indicator; as expected.  Somehow we missed the fact that the lower rudder display was reversed.  I cannot explain how we misinterpreted the display for so long. We saw movement and must have interpreted it the way we expected it to be; not the way it actually was. The first day we picked up the plane was rushed. However; we talked about the pressure and slowed all of our preparations down so we wouldn't shortcut anything; yet we still missed the display reversion on our first flight; then carried that oversight through several more days. I am reminding myself of the expected indication before I run a checklist item; so as to break the complacency or rote response I may have built up over time.
[Narrative contains no additional information.]
C750 flight crew noted on preflight that the lower rudder movement indicator moved in the opposite direction of actual rudder movement. Discrepancy was noted after several flights had been flown in the same aircraft.