What happened
On 13 October 2011, an Airlines PNG Bombardier DHC-8-103, registered P2-MCJ, was performing a scheduled passenger flight from Nadzab to Madang. During the flight, the crew diverted from their original path to avoid heavy thunderstorms and cloud cover. While maneuvering to descend beneath the clouds for a visual approach to Madang, the aircraft entered a steep descent. Because the propellers were maintained at a cruise setting of 900 RPM, the aircraft's airspeed increased until it reached its maximum operating speed (VMO).
As the aircraft passed through 10,500 feet, the VMO overspeed warning activated. In an attempt to manage the speed, the pilot adjusted the power levers, but this triggered a simultaneous overspeed of both propellers, with speeds exceeding 1,200 RPM by more than 60%. This event caused significant damage to the left engine and rendered both engines inoperable. The intense noise from the overspeeding propellers made communication between the crew members extremely difficult, and smoke from the engine damage entered the cabin.
Following the mechanical failure, the right engine shut down due to a malfunction in the propeller control unit. The crew, focused on finding a landing site, did not perform standard emergency checklists. The aircraft descended rapidly toward the Guabe River area. The pilot opted for a forced landing near the mouth of the river to avoid the large boulders located in the riverbed. The aircraft struck the terrain at 114 knots with the landing gear and flaps retracted. The impact caused the tail and left wing to detach, and a post-crash fire consumed the wreckage.
Of the 32 people on board, there were 3 survivors and 29 fatalities.
Findings
- The crew was primarily focused on external visual monitoring to avoid thunderstorms, which led to a lack of attention to the increasing airspeed.
- The aircraft's airspeed reached VMO during a steep descent while propellers remained at cruise RPM.
- A malfunction in the propeller control unit caused the right engine to shut down following the initial overspeed event.