ERA16LA054 · Robinson Helicopter Company R44 II
Timberview Helicopters Robinson Helicopter Company R44 II · Accident: system/component malfunction/failure (non-power)
From Destin Executive Airport (DTS) to Destin Executive Airport (DTS)
Event
- NTSB case
- ERA16LA054
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Robinson Helicopter Company R44 II
- Aircraft type
- Robinson R44
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N7512N
- Operator
- Timberview Helicopters
- Onboard fatalities
- Unknown
- Route
- From Destin Executive Airport (DTS), Destin, FLTo Destin Executive Airport (DTS), Destin, FL
- Aircraft age
- About 12 years (built 2003)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Other
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- System/component malfunction/failure (non-power)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Not determined › Not determined
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The commercial pilot was performing a power check before an air tour flight with three passengers onboard. While raising the collective, he heard a loud "pop." He then immediately lowered the collective and secured the helicopter.
Postaccident examination of the helicopter revealed that an overstress fracture existed between the tail rotor driveshaft and intermediate flex plate. Examination revealed that all the hardware was in place except for a washer, which is required at each connection between the clutch shaft yoke and flex plate per a caution in the helicopter's maintenance manual. The maintenance manual also contained measurements to determine proper shimming required at the intermediate flex plate. A review of maintenance records revealed that, about 11 flight hours before the accident, the sprag clutch had been removed and replaced. The mechanic who performed the clutch removal and installation stated that the measurements he took at the intermediate flex plate during and after his repairs were the same. He also indicated that, when they installed new hardware, he obtained the same dimensions. Although a misalignment of the intermediate flex coupling would place significant tension along the entire length of the driveshaft between the main rotor gearbox and tail rotor gearbox and a missing washer both could have caused a fatigue-type failure of the tail rotor drive line, the parts fractured due to overstress, not fatigue; therefore, it is unlikely that the missing hardware contributed to the failure. The reason for the overstress fracture between the tail rotor driveshaft and intermediate flex plate could not be determined based on the available evidence.
Probable cause
The overstress fracture between the tail rotor driveshaft and intermediate flex plate for reasons that could not be determined based on the available evidence.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA16LA054
- Event ID
- 20151201X72017
- Case number
- ERA16LA054
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 0a8cf7f2b4bef26eb38e9fe0b088e7df890bd2ec556753dfe5ca984957a819fb; retrieved 2026-09-16T03:00:05.165Z.