Incident Overview
On July 12, 2023, at approximately 1630 Alaska daylight time, a DeHavilland DHC-2 airplane, registration N302BL, sustained substantial damage during an accident near Twin Hills, Alaska. The aircraft was operating as a Title 14 Code of Federal Regulations Part 91 business flight. The pilot reported no injuries, while two passengers received minor injuries and two others sustained serious injuries.
Pilot and Passenger Accounts
According to the pilot, shortly after takeoff from the water, a loud “bang” was heard, after which the airplane impacted the water. Passengers described hearing a sound resembling a “cable snap” or “hitting a hammer on a piece of metal.” Following the noise, the airplane executed a hard left turn, causing the left wing to dip into the water. The aircraft then pivoted around that point, eventually coming to rest mostly submerged and fragmented.
Postaccident Examination
Examination of the wreckage revealed that the left wing had separated from the fuselage, consistent with impact damage. The right wing had been removed to facilitate recovery. Flight control continuity was verified from the cockpit controls to the points where cables were cut during recovery. The left flap attachment arm remained attached to the flap but was bent and twisted; the right flap attachment arm was undamaged. The fuel selector was found set to the aft tank. The floats and fly wires were not recovered from the lake and thus were unavailable for examination.
The throttle control was near the closed position, and the mixture control was at idle. All spark plug attachments and cylinder base nuts were intact and tight. Manual rotation of the propeller yielded thumb compression on all cylinders. A lighted borescope inspection of the cylinders revealed no anomalies. When spun with an electric drill, all magneto leads produced a spark.
Maintenance History
A review of the maintenance logbooks indicated that the engine had accumulated 66 hours since an overhaul completed approximately six months before the accident.