SEA99LA174 · Piper PA-28-180
Piper PA-28-180 · Accident: propeller failure/malfunction en route
From Bremerton National Airport (PWT) to an unrecorded destination
Event
- NTSB case
- SEA99LA174
- 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-28-180
- Aircraft type
- Piper PA-28
- 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
- N9395J
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Bremerton National Airport (PWT), Bremerton, WATo not recorded
- 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
- 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
- Unknown › Maintenance, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While in cruise at 2,000 feet altitude and 2,000 RPM there was a sudden loud noise and vibration. The pilot reduced power and executed an emergency landing. Post-landing examination of the aircraft revealed that approximately six inches of one propeller blade had separated from the propeller. The Sensenich Corporation, fixed pitch, aluminum propeller, model 76EM8S5-0-60, was submitted to the Safety Board's Materials Laboratory, Washington, DC, for further metallurgical examination. The examination revealed a flat, chordwise fracture area that contained crack arrest positions and radial marks typical of fatigue cracking. Microscopy revealed that the origin area was located within a notch at the leading edge at the flat side of the blade. The depth of the notch was about 0.008 inch. The leading edge of the blade contained sanding marks, typical of a blend repair, in the vicinity of the notch. The sanding marks did not extend into the deepest part of the notch, directly adjacent to the fracture surface at the origin area. FAA Advisory Circular 43.13-1A, Section 3 'Repair of Metal propellers,' paragraph 585(a) discusses procedures applied to the repair of aluminum propellers. Specifically, this reference addresses rounding out of nicks, scars, cuts, etc. by advising '...exercise care to remove the deepest point of the injury.' The total time on the propeller was unavailable and the party who executed the propeller dressing procedure was not known.
Probable cause
The separation of a propeller blade tip due to fatigue, and the improper maintenance procedure.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA99LA174
- Event ID
- 20001212X19893
- Case number
- SEA99LA174
- 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: fa18046d4a0e50e175bacda8e43e0274d36cfd80aa5c318b4b59653e616a4f7d; retrieved 2026-09-22T14:00:29.485Z.