SEA05LA058 · Rotorway Exec 162F
Rotorway Exec 162F · Accident: airframe, component or system failure en route
From Southwest Oregon Regional Airport (OTH) to Norway, OR
Event
- NTSB case
- SEA05LA058
- 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
Rotorway Exec 162F
- Aircraft type
- Rotorway EXEC 162
- 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
- N20539
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Southwest Oregon Regional Airport (OTH), North Bend, ORTo Norway, OR
- 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
- First occurrenceThe 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
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Rotor drive system › Disconnected
- Rotor drive system, main rotor driven pulley › Disintegrated
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
While in cruise flight, the pilot detected a burning rubber smell and heard "strange loud noises" just as both the engine and rotor rpm began to fluctuate. Soon thereafter, the engine began to lose power, and the pilot elected to make an autorotational landing. He headed for a nearby opening, which turned out to be a cemetery, and as he touched down among the gravestones with zero forward speed, the aircraft rolled over onto its right side. Immediately after it rolled to the side, flames appeared in the cockpit, but the pilot was able to escape out of the left side of the helicopter. A post-accident teardown inspection of the engine and drive assembly revealed that the upper main drive pulley bearing, a double ball bearing assembly, had partially disintegrated, leading to the decoupling of the main rotor shaft drive from the engine output drive shaft. The upper ball bearings were loose in the assembly, and their retaining cage had been destroyed. All of the subject bearings displayed excessive wear, flat spots, and significant thermal damage. Although there was very little grease remaining in the assembly, and the lower drive belt sheave grease passage set screw was found backed half way out, it could not be positively determined whether a lack of lubrication initiated the sequence of events leading to the failure of the bearing assembly, or whether the grease had been consumed by the heat generated by an internal failure resulting from other factors. According to the pilot/builder of the helicopter, he had adhered to the required 25 hour grease service intervals since the aircraft had been built, approximately 115 hours prior to the accident.
Probable cause
The disintegration, for undetermined reasons, of the upper main drive pulley assembly bearing, while in cruise flight, leading to the decoupling of the main rotor drive assembly from the engine drive assembly. Factors include the absence of any suitable forced landing area, leading to a landing between the gravestones of a cemetery.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA05LA058
- Event ID
- 20050311X00302
- Case number
- SEA05LA058
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: 40fccada5749f341885bbedc56c63f6a8d8f3baaf11e237c76080178eebd61e5; retrieved 2026-09-21T19:03:52.213Z.