What happened
On June 10, 2024, at approximately 16:35 Alaska daylight time, a float-equipped DeHavilland DHC-2 bearing registration N4957 was involved in an accident near Port Alsworth, Alaska. The aircraft, operated by Talon Air Service, Inc., departed Kijik Lake, Alaska, with the pilot and five passengers, en route to Longmere Lake, near Soldotna, Alaska.
Following takeoff, the pilot adjusted the engine controls and flaps for climb. Approximately three miles into the flight, the pilot noted a decrease in manifold pressure. Although the engine initially responded to increases in propeller and throttle controls, the engine subsequently lost all power. The pilot executed a forced landing into a heavily wooded area, which caused substantial damage to the wings and fuselage. The accident resulted in one serious injury, while the pilot and remaining passengers were not injured.
Passengers reported that the aircraft performed an extreme, steep left turn at a low altitude, with one passenger describing the aircraft as being in a near-vertical attitude. One passenger also noted an increase in engine noise roughly five seconds before the impact with the terrain.
The investigation
An examination of the engine revealed that it rotated freely by hand. The spark plugs showed normal wear and no damage, and the cylinder bases and nuts showed no signs of distortion or over-boosting. The exhaust and induction systems were found to be free of anomalies. All engine controls were functional and exhibited full travel.
Investigators found that the main fuel line was disconnected at the engine side of the firewall, and fuel was available from all three tanks. The magnetos were secure, and the timing was set at approximately 24° before top dead center. Inspection of the oil screen showed no debris or magnetic material. While the propeller tips exhibited bending consistent with the impact, there was no rotational scoring. No mechanical abnormalities were found that would have prevented normal engine operation.