ANC04CA076

During the initial climb after takeoff the float-equipped airplane encountered a downdraft and was unable to climb. Rising terrain and trees necessitated a downwind turn. During the turn, the airplane continued to descend, and the airplane impacted swampy terrain adjacent to the floatplane base. The pilot attributed the downdraft to either the large wildfire-induced cumulus clouds 1/2 mile east of the airport, or the winds gusting over rising terrain from the southwest.

On July 11, 2004, about 1315 Alaska daylight time, a float-equipped Cessna 180J airplane, N888FF, sustained substantial damage during an in-flight collision with terrain when it encountered a downdraft during the initial climb after takeoff from the Bettles Seaplane Base, Bettles, Alaska. The airplane was being operated by the commercial pilot as a visual flight rules (VFR) personal local flight under Title 14, CFR Part 91 when the accident occurred. The pilot and sole passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on July 12, the pilot said after takeoff the airplane encountered a downdraft and started descending. He believed the downdraft may have been the result of large wildfire-induced cumulus clouds about 1/2 mile east of the airport, or winds gusting over rising terrain from the southwest. He said there was rising terrain ahead, and he made a downwind turn to escape the downdraft. He said in the turn the airplane continued to descend, and impacted swampy terrain adjacent to the seaplane base. The pilot said prior to the accident there were no mechanical anomalies with the airplane, but the airplane received major damage to its wings, fuselage, tail, floats, and engine during the accident.