WPR12LA219 · Enstrom F28 F
Enstrom F28 F · Accident: system/component malfunction/failure (non-power) en route
From Elko Regional Airport (EKO) to Joslin Field Magic Valley Regional Airport (TWF)
Event
- NTSB case
- WPR12LA219
- 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
Enstrom F28 F
- Aircraft type
- Enstrom F28
- 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
- N63VP
- Operator
- Michael W. Lattin · private individual
- Onboard fatalities
- Unknown
- Route
- From Elko Regional Airport (EKO), Elko, NVTo Joslin Field Magic Valley Regional Airport (TWF), Twin Falls, ID
- Aircraft age
- Not recorded
- 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
- En route · cruise
- 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
- Aircraft › Aircraft oper/perf/capability
- Aircraft › Aircraft propeller/rotor
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot reported that on a previous flight, he encountered an uncommanded roll, so he checked the three main rotor Lamiflex bearings prior to departure. He said one bearing showed no indication of a pending failure, the second showed some indication of approaching failure, and the third showed a minor indication that it was beginning to fail. From past experience, the pilot said that he believed that he still had several hours before the bearings would fail and that he could safely proceed with the flight. A few miles from the intended destination, a vibration started and became progressively worse to the point where the pilot was losing control of the helicopter. The pilot subsequently made what he described as a “controlled crash landing,” which resulted in substantial damage to the helicopter. A postaccident examination revealed that the No. 2 main rotor Lamiflex bearing failed, which resulted in the loss of control. A review of maintenance logbooks found that the helicopter was not in compliance with either its annual inspection requirement or with FAA Airworthiness Directive 94-17-15, which required repetitive inspections of the helicopter’s main rotor Lamiflex bearings.
Probable cause
The pilot's inability to maintain helicopter control during cruise flight due to the failure of the No. 2 main rotor Lamiflex bearing. Contributing to the accident was the pilot's decision to operate the helicopter with a known deficiency and the helicopter’s noncompliance with the mandatory scheduled inspection of the main rotor bearings.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR12LA219
- Event ID
- 20120520X30745
- Case number
- WPR12LA219
- 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. 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: 911a9df02337b8e22ad3010cbacfc0873521e2a368a2e7b7b644a75804694b48; retrieved 2026-09-15T18:11:24.235Z.