Bell 525 crash near Italy, Texas, United States

The first Bell 525 Relentless prototype (FTV1, N525TA) broke up in flight during a developmental test flight near Italy, Texas, about 30 miles south of Arlington Municipal Airport. Both test pilots, Jason Grogan and Erik Boyce, were killed. The helicopter was travelling at approximately 229 mph at 2,000ft when a severe vibration in the main rotor system caused a biomechanical feedback loop through the fly-by-wire flight controls. The rotor blades dropped from their normal plane of rotation and sliced through the tailboom and nose. It was the first civilian helicopter to use fly-by-wire controls. Bell settled lawsuits with the families and the 525 program was delayed by years.