Citation X (C750)
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Procedure
Acting as the SIC (Second in Command) on a flight; I conducted the initial exterior and interior preflight. As part of the checklist; I accomplished the rotary test. The last item was a bulb test for instrument panel lights. During this test I did notice that the lights in all of the four of the Flight Control Shutoff Switches did illuminate. During the post flight it was determined that while all four buttons did illuminate; not all of the bulbs illuminated. While troubleshooting the system it was determined that the PCU monitoring card was not installed in the aircraft. We only accomplish this test on the first flight of every day; and none of my other crew members mentioned any anomalies. While this is only a bulb test in the future; I must be much more diligent to each and every light bulb. [Due to] the fact that all four buttons did light up; my mind saw no anomalies. Had I noticed an anomaly I would have written it up for maintenance action. I never had any intention of taking off in an aircraft with any outstanding maintenance issue. This was an oversight on my part. There was no EICAS message or any other indication that there was a problem; and twice in the checklist we confirmed that there were no lights on in these switches. In the future I will be much more diligent in the normal preflight activities.
CE-750 Captain reported that post flight; it was discovered that not all instrument panel bulbs were illuminating as required due to a missing part.