SEA06LA074 · Central Copters Lancair IV-P
Central Copters Lancair IV-P · Accident: total loss of engine power (mechanical failure) on approach
From Spokane International Airport (KGEG) to Bozeman Yellowstone International Airport (KBZN)
Event
- NTSB case
- SEA06LA074
- 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
- Instrument Meteorological Cond
Central Copters Lancair IV-P
- Aircraft type
- Central Copters LANCAIR IV-P
- Category
- Airplane
- 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
- N671
- Operator
- Mark W. Duffy · private individual
- Onboard fatalities
- Unknown
- Route
- From Spokane International Airport (KGEG), Spokane, WATo Bozeman Yellowstone International Airport (KBZN), Belgrade, MT
- 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
- 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
- Total loss of engine power (mechanical 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
- Turboshaft engine, power output shaft › Disconnected
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
While on final for a night visual approach, the quill shaft between the reduction gear box and the power section of the engine decoupled. This resulted in a loss of drive input to the propeller, and ultimately to an off-field forced landing on rough/uneven terrain. Although the initial touchdown was successful, during the rollout the aircraft impacted the terrain, and after it came to a stop a small fire developed near the engine exhaust. Although the occupants tried to put out the fire, they were unable to do so, and the aircraft was eventually consumed by the fire.
Probable cause
The total loss of drive power to the aircraft's propeller while on a visual final approach, due to the decoupling of the quill shaft between the reduction gearbox and the engine power section. Factors include a dark night, no suitable terrain on which to land, and the rough/uneven nature of the terrain upon which the pilot had to execute his forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA06LA074
- Event ID
- 20060421X00468
- Case number
- SEA06LA074
- 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 2006-04-15.
- API snapshot SHA-256: a95fa60c60939424d7a157ffc026bbd652ddf868d041823609dcaf30972ee286; retrieved 2026-09-22T04:59:43.306Z.