On December 6, 1999, about 0958 Alaska standard time, a wheel equipped Cessna 208B airplane, N5187B, sustained substantial damage after colliding with snow-covered terrain during takeoff from the Bethel Airport, Bethel, Alaska. The flight was being conducted under Title 14, CFR Part 135, as a scheduled commuter flight, operated by Arctic Circle Air, Inc., as Flight 30. The certificated airline transport pilot, and the sole pilot-rated passenger aboard, were not injured. Visual meteorological conditions prevailed, and company VFR flight following procedures were in effect for the flight to Marshall, Alaska. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on December 6, the pilot reported that he arrived at the airport about 0800, and performed a preflight inspection of the accident airplane. He said that the airplane had been parked outside all night, and added that the wings, horizontal stabilizer, elevators, and windscreen had a "noticeable amount of frost on them." The pilot reported that he used a broom, while standing of a ladder, to remove an accumulation of frost, and light snow. He then returned to the hanger to wait for the load of cargo to arrive. He said that due to scheduling delays, the cargo did not arrive at the airport until about 0850, at which time the cargo was loaded, and the pilot prepared for departure. He said that before departure, he did not recheck the wings or flight control surfaces for any additional frost accumulation. The pilot reported that while departing runway 36, about 100 feet above the runway, he retracted 10 degrees of flaps. He added that as the airplane climbed to about 200 feet above the runway, he retracted the remaining 10 degrees of flaps, and the airplane descended while rolling to the left. The pilot stated that he had to apply full right aileron to keep the airplane upright. He said full power was already applied to the engine, but the airplane continued to descend. The airplane landed on the runway, about 200 feet from the runway threshold, and continued off the end of the runway, into snow-covered terrain. The airplane sustained substantial damage to the propeller, fuselage, and wings.