Date: 201505
Local time of day: 1201-1800
Light: Daylight
Aircraft: Challenger 300
Operator: Fractional
Operating under: Part 91
Flight phase: Parked
Reporter organization: Corporate
Reporter function: First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Time Pressure; Situational Awareness
Second reporter function: Captain
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Aircraft
Detector: Person Flight Crew; Person Ground Personnel
When detected: Aircraft In Service At Gate
Result: Aircraft Aircraft Damaged
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: I did a normal preflight on assigned aircraft. With the brake set and preflight done we got a brake fail Crew Alert System (CAS). We shut the plane down and restarted it trying to clear the CAS. It would not clear so the captain wrote up the plane. Soon after I recieved a message to get alternate aircraft ready. I then went outside and put the pins in and did a post flight and told ground crew we were grounded and taking another plane. I don't remember if chalks were in or not. I then took my bags and went to alternate aircraft to preflight. Soon after heard the APU shut down on original aircraft and the capt arrived at the alternate aircraft. While getting clearance I heard a bang; looked up and saw original aircraft contacting another jet in front of me. The aircraft was left on the ramp with no chalks. Better communication are needed between flight crews and ground personnel.


Second narrative: Knowing that the parking brake was set I asked the fueler to please remove the smashed chocks from the wheels. Prior to our departure from the ramp the plane had a mechanical issue that canceled our trip. My normal flow prior to departure is to check exterior doors (closed) and remove any remaining chocks or cones. Otherwise we wait 10 minutes for irritated line personnel or upset passengers. As a result of us dealing with a exterior maintenance issue; I am not sure of the status of the chocks at this point. Whether I followed my departure flow will be cleared up in the video footage. The trip to an alternate aircraft. My First Officer (FO) pinned the gear and placed required pitot static covers then moved to our next plane; while I completed paperwork. While walking to alternate aircraft an FBO employee asked what was going on? I advised that original aircraft was broke and that we were taking an alternate aircraft.I had just exited the FBO after using the lavatory. I saw the original aircraft moving very fast across the ramp with a line guy trotting next to the right wing. My first impression was a mechanic was taxiing the plane to maintenance. Then I realized the line guy was actually a pilot trying to stop the plane. 36 minutes had elapsed at this point from us leaving the original aircraft.Chocks were not in place. Possible gusty wind. Possible jet blast. Ramp doesn't have sufficient downhill grade to allow a heavy plane to start moving in my experience.I took pictures immediately; then contacted my supervisor for instruction. More attentive present line personnel are needed especially for chock placement awareness.


Synopsis: Originally-assigned aircraft developed a maintenance problem and crew was assigned an alternate aircraft. Chocks were not reinstalled on the original aircraft. Original aircraft then began to roll and struck another (third) aircraft.