Investigation Summary
The aircraft, a vintage Douglas DC-3C, experienced a failure of the left engine shortly after departure from Texel. The critical issue was the failure of the propeller to feather; a feathered propeller aligns with the airflow to minimize drag, but in this instance, the blades remained in a position that created massive aerodynamic resistance. The pilots struggled to maintain altitude and control against the asymmetric drag. Investigation by the Netherlands Aviation Safety Board highlighted that the crew had limited opportunities to practice such high-stress emergencies due to the lack of a DC-3 flight simulator. The combination of mechanical failure and human factors—specifically the inability to manage the drag of a non-feathered propeller—resulted in the aircraft striking the shallow waters of the Wadden Sea.
Final Conclusions
The primary cause was the failure of the left engine followed by the failure of the propeller feathering system. Contributing factors included the crew's lack of proficiency in handling an engine-out scenario with a windmilling propeller and the absence of modern training aids (simulators) for the historic aircraft type.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Propeller Feathering System
A system designed to turn propeller blades parallel to the airflow in the event of an engine failure to stop the propeller from spinning (windmilling) and reduce drag.
Pratt & Whitney R-1830 Engine
The radial engines powering the DC-3; the left unit suffered an internal failure during the climb.
Interesting Facts
- 01The aircraft was a former Finnish Air Force and Finnair DC-3 built in 1943.
- 02All 32 occupants, including 26 passengers and 6 crew/staff, perished in the impact.
- 03The accident is often referred to in the Netherlands as the 'Dakotaramp' (Dakota Disaster).
- 04The Dutch Dakota Association (DDA) was a foundation dedicated to preserving classic aircraft.
- 05The crash site was located in shallow water/mudflats, complicating initial rescue efforts.
Safety Actions & Advisories
Crew Proficiency Standards
The investigation led to stricter requirements for crew training and proficiency checks for pilots operating historic or 'vintage' transport aircraft in the Netherlands.
Maintenance Oversight
Enhanced oversight of maintenance procedures for older radial engines and feathering mechanisms was implemented for foundation-owned aircraft.