SEA04LA078 · Robinson R-22 Mariner
Hillsboro Aviation Robinson R-22 Mariner · Accident: loss of engine power while maneuvering
From King County International Airport - Boeing Field (BFI) to Chehalis Centralia Airport (CLS)
Event
- NTSB case
- SEA04LA078
- 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 R-22 Mariner
- Aircraft type
- Robinson R-22
- 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
- N6291T
- Operator
- Hillsboro Aviation
- Onboard fatalities
- Unknown
- Route
- From King County International Airport - Boeing Field (BFI), Seattle, WATo Chehalis Centralia Airport (CLS), Chehalis, WA
- 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
- Maneuvering
- 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
- Loss of engine 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
- Reason for occurrence undetermined
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilots reported that while maneuvering around the airport for landing, about 1,000 feet AGL, the engine suddenly and without warning quit. The flight instructor took over the controls while the private pilot attempted to restart the engine without success. The flight instructor then entered an autorotation to an open field. About 30 feet AGL, the instructor raised the collective to cushion the landing, however, he did not apply enough right pedal control and the helicopter yawed to the left and the right landing skid hit the ground subsequently collapsing. The helicopter rolled over and came to rest on its right side. The day after the accident, the helicopter was righted. The battery was reconnected and the engine was started and run for three minutes at idle power. The helicopter was then transported to a repair facility where the engine was inspected. During the inspection, no evidence of a mechanical failure or malfunction was found. The engine was then placed in a test cell and run through several test parameters. The engine was found to meet normal test specifications.
Probable cause
A loss of engine power for undetermined reasons.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA04LA078
- Event ID
- 20040506X00566
- Case number
- SEA04LA078
- 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: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2004-05-06.
- API snapshot SHA-256: 20e24d41599f7f819e11233b07238e7d3dd9c74abcdef2fedc2fb0a566504303; retrieved 2026-09-22T07:36:35.087Z.