Citation X (C750)
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
While climbing out of 10;000 ft; we experience a primary stab trim fail. We advised ATC that we would continue the climb as we troubleshoot an issue; but FL280 would be the max for now. We complied with the checklist for Primary Stab Trim Fail and turned on Secondary trim. We entered a Present Position hold while we contacted maintenance and we all agreed that we would return and attempt a power cycle on the airplane; rather than continue to our destination in the event it did not reset on the ground. We advised ATC that we were returning. The checklist does not have further action items in the event that the secondary trim is functional. However; the checklist for complete trim failure talks about max flaps 2. We briefed that if we encountered any adverse trim while selecting flaps full; that we would immediately reselect flaps 2 and go around. We also advised that we wanted a runway into the wind with minimal crosswind. No adverse effects were noted and we landed without incident. Upon a power cycle of the aircraft; the message and primary stab trim system reset and functioned normally for the remainder of the flight. Occasionally the primary stab trim can inadvertently be deactivated by touching a single trim controller. However; in this instance; no one was touching the flight controls and the autopilot was engaged in smooth air.
During climb out; while transitioning through 10;000 ft; the autopilot inadvertently disconnected along with an Amber Primary Trim failure caution message. We informed ATC and decided to enter a hold at FL230 to run checklist and consult our maintenance. We identified and ran the appropriate checklist but were unable to correct the situation. We exited the hold and returned to the departure airport; which was the nearest suitable airport; and landed using the secondary pitch trim system. After shutting the airplane down and restarting it from 'Black' the pitch trim was regained and tested and functioned properly.
CE750 flight crew reported an autopilot disconnect and alert message for primary stabilizer trim failure during the climb. Secondary trim functioned normally; but the crew elected to return to the departure airport.