Date: 202005
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: PC-12
Operator: Fractional
Flight plan: IFR
Mission: Training
Flight phase: Parked
Second aircraft: Cessna Citation Undifferentiated or Other Model
Reporter organization: Fractional
Reporter function: Captain; Instructor
Reporter qualification: Flight Crew Commercial
Human factors: Situational Awareness
Anomaly: Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control
Detector: Person Flight Crew
When detected: Pre-flight
Result: Flight Crew Regained Aircraft Control
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We were located on the ramp closest to the line shack/hangar facing towards the runway with a Phenom 300 in the spot to our left; a fuel truck was parked in front of the right wing of the Phenom. The ramp has a noticeable up-hill slope. It was before the FBO typically opened and the only FBO staff was the one line person who we arranged early hours with to fuel us in the morning. We were ready for engine start up but decided to wait for the Phenom to finish fueling. While sitting in the cockpit we saw a Citation Sovereign land and taxi into the ramp. Both myself and the other pilot (I was sitting right seat conducting captain upgrade training for the upgrade candidate sitting in the left seat) saw the Citation come into the ramp at an unsafe speed and turn around very rapidly in front of; and in to close proximity to; the fuel truck. I think we each said something like 'whoa' and/or 'what the...'. It was difficult to tell from our position but we both thought that the wing tip of the Citation was going to impact either the left wing of the Phenom or the cab of the fuel truck; we think that it cleared the fuel truck by less than feet. In the turn there was also significant jet blast that hit the Phenom and the fuel truck; we were partially shielded by the fuel truck and were further away but still felt noticeable jet blast. The Citation then shut down along the grass in front of the Phenom and angled to the left (to be parallel to the grass). In this position the Citation was pointing directly away from us. One pilot exited the Citation and was on his phone. Shortly after the Citation shut down I was looking at charts on my EFB when I heard my other pilot say 'Oh S**T!'. I looked up and saw the Citation rolling back directly towards us and the fuel truck. The line person who was operating the fuel truck and the Citation pilot were attempting to stick various chocks under the nose wheel and right main gear. They managed to get the airplane stopped after it had rolled back about 30 feet. Myself and the other pilot were both about to egress our aircraft and get to a safe location when they were able to get the Citation to stop rolling. The line person was instrumental in stopping the Citation but was also nearly run over by it in the effort. Given the actions of the Citation crew; with contributing factors of the ramp layout and slope; we were put into a dangerous situation. Had the Citation not been able to be stopped by throwing chocks underneath it who knows what would have happened. While I don't think there's anything our company could do to avoid situations such as these; it's possible the airport and/or FBO could adjust it's procedures or ramp parking layout to mitigate some of these risks. Ultimately though; we are subject to the people around us and can only be vigilant and aware that other operators my not be as safe and responsible as we are.




Synopsis: PC-12 Captain described a near-collision on the ramp when a Citation was not properly secured at shutdown and began to roll toward them.