WPR13LA167 · Enstrom F-28F
Enstrom F-28F · Accident: loss of engine power (total) on approach
From Joslin Field Magic Valley Regional Airport (TWF) to Joslin Field Magic Valley Regional Airport (TWF)
Event
- NTSB case
- WPR13LA167
- 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 F-28F
- Aircraft type
- Enstrom F-28
- 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
- N918DK
- Operator
- Wybenga Steve
- Onboard fatalities
- Unknown
- Route
- From Joslin Field Magic Valley Regional Airport (TWF), Twin Falls, IDTo 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
- Approach · VFR pattern downwind
- 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
- Loss of engine power (total)
- 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 as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The student pilot reported that, during the helicopter's fourth landing, the engine started to sputter and lose rpm. He lowered the collective and added power, and the engine rpm increased. When he raised the collective, the engine lost power again. As he turned the helicopter to land it on the runway, the engine lost total power, and he performed an autorotation to a field. During the landing, one of the helicopter's skids got stuck in soft dirt, and the helicopter subsequently rolled onto its left side. Postaccident examination of the airframe and engine revealed no flight control or fuel system continuity anomalies. The single-drive dual magneto, ignition harness, and spark plugs were removed for further examination. The examination revealed that the left distributor gear was internally timed to the counter clockwise (CCW) marking and that the right distributor gear was internally timed to the clockwise (CW) marking. However, both distributor gears should have been timed relative to the CCW markings in accordance with the magneto manufacturer's Service Support Manual. When one of the distributor gears is timed to the CW markings instead of the CCW markings, a four-teeth difference in timing between the gears can occur. According to the magneto service representative and the magneto manufacturer's magneto specialist, the four-teeth timing difference would only have resulted in faster wear on the magneto's internal components. Given that the magneto was recently overhauled, it is likely that the magneto was operating as designed at the time of the engine loss. The reason for the loss of engine power could not be determined.
Probable cause
A total loss of engine power for reasons that could not be determined because postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR13LA167
- Event ID
- 20130327X65321
- Case number
- WPR13LA167
- 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: 4bb8c2ed1c43fe25cce2d3a35b66e97bf9afc75e608fa6b946b8a25bba11c72a; retrieved 2026-09-15T21:10:46.357Z.