Date: 201308
Local time of day: 0601-1200
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Light: Daylight
Aircraft: Citation Excel (C560XL)
Operator: Fractional
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Fractional
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Workload; Situational Awareness
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action; Flight Crew Diverted; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Procedure; Company Policy; Chart Or Publication; Aircraft
Primary problem: Aircraft

Narrative: I was the SIC and Pilot Flying (PF); a Part 91 flight with one passenger. After climbing through FL200 I noticed that the yoke was shaking a bit with the autopilot engaged. I asked the PIC if he thought this was normal; and he replied he did not. We made the decision to divert; as we were only about 50 NM south and the field conditions (i.e.; runway length) was most suitable for a possible emergency landing if the worse were to happen. I requested FL210 from Center and advised them of our condition; not requiring assistance at that time but were going to divert. I disconnected all automation (AP and YD) and accelerated to 280 KIAS slowly to see the affect on the vibration; and it got worse. We then decided to maintain 250 KIAS as we knew the aircraft would probably be safe at that speed.The PIC was on the phone with the ACP while I was flying. After hanging up he informed me that the ACP requested that we go to a different airport due to another aircraft being available to complete this trip. The PIC declined due to its runway length and proximity to our position. Upon approach; I noticed the vibrations would lesson as I slowed; so I maintained about 230 KIAS while on with Approach Control; until base turn.  We had an uneventful landing. We deplaned the passenger and I stayed with him for an additional 3 hours until his recovery arrived and he was on his way. As I had vibrations in the flight controls before; I didn't really give this much thought until the evening after the event. I looked on the maintenance log for the status of that aircraft and it is currently stating 'NOTE: ALL WAS FOUND WAS WORN HARDWARE THEY ARE IN WORK REPLACING. DUE TO THIS BEING A REPEAT WE WILL NEED AN OCF.' I then became furious after reading this note. All was found was worn hardware? How many aircraft accidents have been attributed to this? In addition; there were NO notes in the maintenance logbook about any previous write-ups. If we had known that this aircraft had previous issues; we would have been more alert to detect when something may go bad.  In my previous career; the aircraft maintenance log went back at least several weeks so the current crew can familiarize themselves with that particular plane's 'quirks.'  I would like to know why someone has chosen not to maintain at least some sort of database where the crew can look up previous write-ups on their own. I want to know why this aircraft had a repeat issue with a FLIGHT CONTROL that we were not made aware of.




Synopsis: A CE-560XL crew diverted after a flight control vibration was detected during climb. The crew discovered similar anomalies documented in previous maintenance logs which were not available for the crew's preflight review.