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NTSB Aircraft Accident Reports · Accident report
In-Flight Breakup of Bell 525 Relentless Helicopter
Attribution
This is the abstract and citation. Full text lives at NTSB Aircraft Accident Reports — we link out rather than host. All credit to the authors and National Transportation Safety Board.
Abstract
Verbatim from NTSB Aircraft Accident Reports. Not paraphrased, not summarized.
Bell 525 prototype helicopter in-flight breakup near Italy, TX, July 6, 2016 — 2 fatalities. Investigation of the developmental-flight-test in-flight breakup of a Bell 525 Relentless prototype. NTSB found a 6 Hz vibration filter interaction with the pilot biodynamic feedback caused divergent collective control inputs that exceeded the structural limits. Findings drove changes to FAA flight test certification programs and OEM human-vehicle coupling analysis requirements.
Author
- National Transportation Safety Board NTSB
Keywords
- flight test
- biodynamic feedback
- rotorcraft certification
- pilot induced oscillation
Citation: National Transportation Safety Board (2019). In-Flight Breakup of Bell 525 Relentless Helicopter. National Transportation Safety Board. NTSB Aircraft Accident Reports ID AAR-19/02. https://www.ntsb.gov/investigations/AccidentReports/Pages/AAR1902.aspx ↗