Incident Overview
A pilot of a turbo prop airplane reported that, after starting the engine using a ground power unit (GPU), he exited the aircraft. He disconnected the GPU and removed the wheel chocks. The airplane then began to roll down an incline.
Pilot Actions
The pilot jumped into the airplane through the aft cargo door and attempted to climb into the pilot's seat, but was unable to do so. He then pulled the fuel to cut off, and the airplane impacted trees.
Parking Brake Account
The pilot stated that he had set the parking brake before starting the airplane. However, he believed that either he failed to set it completely or he bumped it when he exited the pilot's seat to disconnect the GPU.
Damage
The airplane sustained substantial damage to both wings and the right wing lift strut.
Mechanical Status
The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.