Date: 201711
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Challenger 350
Operator: Fractional
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class E ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Fractional
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Human-Machine Interface; Situational Awareness
Second reporter function: Pilot Flying; Captain
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew FLC Overrode Automation; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Airspace Structure
Primary problem: Aircraft

Narrative: Due to heavy volume going into ZZZ and ATC turning the airport take-off/landing configuration; all aircraft landing there were told to expect holding. Everyone was getting a hold at the ZZZ VOR. I was entering that hold as per the STAR in the FMS. I was having difficulties getting the FMS to take the information. Suddenly; the FMS gave an unusual message in the scratchpad and then blanked out completely. We were then assigned to hold at ZZZZZ intersection on the STAR. The FMS had returned to its normal condition and I proceeded to enter the hold. As we were entering the hold we were constantly given descents. I announced to ATC that we were entering the hold. She responded worth another descent. Then another controller came on the frequency and told us to tighten up the turns in the hold and that our pattern was too large. We checked the FMS for any errors and found none. We did notice that the autopilot was performing half-bank turns. There was no notification on the flight mode annunciator on the PFD that this mode was active. We responded to ATC that we would fix the problem. Again; we went through the default settings to see if there was some reason why this was happening. Then we were given a heading by ATC and vectored to rejoin the arrival. The flight continued without incident. Upon landing as I checked the flight information; I noticed that it looked as if the FMS had timed out; saying the flight was only 46 minutes long; which was incorrect. But; we surmised that 46 minutes ago was about the time the FMS had initially timed out.The only explanation I have for why the autopilot was flying the holding pattern the way it was is due to the strange occurrence when the FMS gave me the error message and blacked out. We checked and double checked the FMS programming. We scoured the approach plate making sure we didn't program the hold incorrectly. We rechecked the FMS settings for any anomalies that could have been set in the defaults. And we could simply find no reason whatsoever to explain the strange actions of the autopilot and FMS.


Second narrative: [Report narrative contained no additional information.]


Synopsis: CL-350 flight crew reported that the autopilot was flying a holding pattern in an irregular pattern when it got an error message and blacked out.