***This report was modified on June 4, 2020. Please see the docket for this accident to view the original report.*** The pilot in the Panzl S-330 airplane reported that he was landing and had turned on the airport runway pilot-controlled lighting about 5 miles before arriving at the airport and transmitted a 2-mile final radio call over the airport's CTAF. He landed the airplane and made "S" turns on runway 28 because "it is not possible to see the opposite threshold" when established on the runway. When the pilot began a right turn to exit the runway at the midfield taxiway, a De Havilland DHC-6 Twin Otter airplane that had initiated a takeoff roll from the opposite end of the runway impacted his airplane. The airport's runway does not have a parallel taxiway, and it is standard practice to back taxi to the departure end. The pilot in the Twin Otter reported that he transmitted his intentions to taxi to the midfield intersection and to depart from runway 10. He did not activate the pilot-controlled runway lighting but recalled that he had noticed that the pilot-controlled lighting had been turned on, and he taxied to the hold short line and did not see any airplanes. He back taxied to the approach end of runway 10 and maneuvered his airplane to take off. During the takeoff roll, the airplane's left wing struck the Panzl S-330. Neither pilot recalled hearing radio transmissions on the CTAF. The Twin Otter sustained substantial damage to the left wing spar. Both pilots reported that there were no preaccident mechanical failures or malfunctions with their airplanes that would have precluded normal operation.