Sikorsky S-76C+ crash near Tallinn, Estonia

Copterline Flight 103, a Sikorsky S-76C+ on a scheduled service from Tallinn to Helsinki, crashed into Tallinn Bay three minutes after takeoff. While climbing through 1,380ft at 130 knots, the main rotor forward hydraulic actuator suffered an uncommanded extension due to copper-aluminium plasma coating flakes blocking the hydraulic ports. The helicopter pitched up, rolled left, then spun 13 times over 37 seconds before impacting the water. All 14 on board were killed by drowning. Sikorsky disputed the findings but the NTSB issued urgent safety recommendations for servo inspections across all 600 S-76s worldwide. Copterline later sued Sikorsky and went bankrupt in 2010.