SEA01LA023 · Piper PA-30
Piper PA-30 · Accident: propeller failure/malfunction en route
From Bozeman Yellowstone International Airport (BZN) to Stevensville Airport (32S)
Event
- NTSB case
- SEA01LA023
- 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
- 0
- 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
Piper PA-30
- Aircraft type
- Piper PA-30
- 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
- N7062Y
- Operator
- Chapman, Doug S. · private individual
- Onboard fatalities
- Unknown
- Route
- From Bozeman Yellowstone International Airport (BZN), Bozeman, MTTo Stevensville Airport (32S), Stevensville, 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
- En route · descent
- 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
- Propeller failure/malfunction
- 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
- Propeller system/accessories, blade › Fatigue
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During a descent, and while passing through approximately 8,000 feet mean sea level, a sudden, violent airframe vibration developed in the twin engine Piper PA-30, and the pilot shut down the right engine. He then noticed a portion of the one of the propeller's tips missing. Metallurgical examination of the blade revealed a fatigue fracture initiating from a dent about 0.2 inch from the leading edge of the blade. The dent measured approximately 0.07 inch wide in the chordwise direction and about 0.03 inch deep and was covered with flat black paint. The propeller log indicated repeated historical occasions whereby the propeller had been dressed and painted. FAA Advisory Circular 43.13-1B/2A, 'Aircraft Inspection, Repair & Alterations' states in Section 4. 'Repair of Metal Propellers,' paragraph 8-73(a) 'Flaws in Edges,' that the mechanic should '...Exercise care to remove the deepest point of the injury and also remove any raised metal around the edges of the injury....'
Probable cause
Fatigue of the right propeller blade resulting in an in-flight separation of the blade tip. A contributing factor was the improper maintenance procedure.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA01LA023
- Event ID
- 20001212X22344
- Case number
- SEA01LA023
- 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. 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: aa642a223d937aaa85e953b4f61a2f7145b0da87544e2ad0228376c791a03978; retrieved 2026-09-22T12:19:43.246Z.