A Cessna 560XL aircraft operated by Air Charter Scotland landed at Kemi-Tornio airport on Thursday December 2, 2021. The aircraft taxied to the apron and parked on stands 3 and 4 at an angle relative to the terminal building. An apron service worker of Groundpower, which was providing ground handling services, received the aircraft and placed chocks fore and aft of the nosewheel. The return flight to Edinburgh was set to depart on Sunday December 5. The aircraft remained parked for almost three days, and its engines were not operated during this period. The pilots arrived at the aircraft on the day of departure at approximately 11:00. After removing the aircraft covers, they conducted an exterior inspection and carried out preparations for warming-up the cold-soaked aircraft. Because no external heaters were available and the aircraft did not have an APU, this could only be done by running the engines. Outside air temperature had dropped to approximately -26 øC overnight and during the morning. During pre-start checks the pilots noticed that the brake system circuit breaker had tripped and the brake system annunciator light was illuminated. After calling the company’s line maintenance controller they assumed that the indication was caused by extended parking in sub-zero temperatures. Following start-up, engine power was increased in small increments during approximately 40 min, and after approximately 30 min the circuit breaker was reset, but the annunciator light remained on. Oil temperature in both engines increased slowly, and the pilots decided to carry out a deicing systems test. Power was increased on the right engine while power on the left engine was simultaneously reduced. As a result, the aircraft moved forward unexpectedly. The nosewheel pushed the front chock over a thin layer of compacted snow for a short distance until the chock slid aside, off the wheel’s track. The captain applied brakes to stop the aircraft, to no effect. He simultaneously reduced power on the engines to idle and used nosewheel steering to maneuver the aircraft to the right, away from the terminal building (Figure 2). However, the left wing leading edge struck a metal lamp post at the edge of the apron at approximately 12:38. The aircraft rotated approximately 90ø to the left relative to the direction of travel and came to a halt with the nosewheel in snow at the edge of the apron. The captain cut off fuel supply to the engines soon after the impact. The distance that the aircraft traveled was approximately 20 m. The impact created a dent in the wing leading edge that extended all the way to the wing spar. The cable from a ground power unit (GPU) had been connected to the aircraft. Bending force imparted by the cable plug on the fuselage-mounted receptacle caused deformation of the receptacle. The accident did not result in injuries. 1. Conclusion: An exterior inspection before a warm-up run shall be conducted with care regardless of the prevailing conditions. The pilots had not checked mainwheel chocking during parking. 2. Conclusion: The ground operations manual was not complied with. 3. Conclusion: The use of the emergency brake system is usually practised in takeoff and landing situations, not during maneuvering on the apron. 4. Conclusion: Cold degraded the pilots’ physical and mental performance. 5. Conclusion: A tripped circuit breaker and an annunciator light indicate an inadequately diagnosed system anomaly. 6. Conclusion: All potential risks had not been assessed properly in advance. Unclearly delineated responsibilities in company management resulted in a situation where potential risks related to operations to a new, unfamiliar aerodrome had not been assessed.