![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/4/45/525_GKY_%252831495047476%2529.jpg/640px-525_GKY_%252831495047476%2529.jpg&w=640&q=50)
2016 Bell 525 Relentless prototype crash
From Wikipedia, the free encyclopedia
The 2016 Bell 525 Relentless prototype crash occurred during a test flight on July 6, 2016, near Italy, Texas, destroying the prototype Bell 525 Relentless helicopter and killing the two occupants.[1] The helicopter broke up in flight[2] while traveling about 229 mph (199 kn) at an altitude of about 2,000 feet (610 m);[3] the main rotor contacted and severed the tail boom due to severe vertical oscillations. The crew were performing one engine inoperative (OEI) recovery testing; the test induced a scissors-mode vibration in the main rotor, which resulted in involuntary collective control input. The unintended biomechanical feedback loop exacerbated the vibration, until the rotor contacted the tail-boom.
![]() N525TA in 2015 | |
Accident | |
---|---|
Date | July 6, 2016 (2016-07-06) |
Summary | In-flight breakup |
Site | Italy, Texas, US 32.2443°N 96.9130°W / 32.2443; -96.9130 |
Aircraft | |
Aircraft type | Bell 525 Relentless |
Operator | Bell Aircraft |
Registration | N525TA |
Flight origin | Arlington Municipal Airport (GKY) |
Destination | Arlington Municipal Airport (GKY) |
Occupants | 2 |
Passengers | 0 |
Crew | 2 |
Fatalities | 2 |
Survivors | 0 |
The destruction of the prototype delayed type certification of the Bell 525 for a year and a filter was added to the collective input control to avoid recurrence of the biomechanical feedback.