SEA05IA115 · Piper PA-46-350P
Piper PA-46-350P · Incident: airframe, component or system failure
Event
- NTSB case
- SEA05IA115
- 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
- Incident
- 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
- Unknown
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Not recorded
Piper PA-46-350P
- Aircraft type
- Piper PA-46
- 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
- N27PG
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo 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
- Unknown
- 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
- Unknown
- 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
- Minor
Cause areas
- Wing, spar › Fatigue
- Wing, spar › Fractured
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
During an annual inspection, a crack was found in the lower wing spar cap of the subject aircraft. That discovery was reported via email to the NTSB's Northwest Regional Office. It was later determined that a fatigue crack had initiated at a rivet hole on the horizontal surface of the right wing lower spar cap, and propagated through approximately 80 percent of that surface. The NTSB materials laboratory determined that there was no evidence of inclusions, discontinuities, corrosion pitting, or material defects at the crack origins. All dimensional measurements were within engineering drawing specifications, and hardness and conductivity parameters for the aluminum alloy specified for the wing spar cap material were within material tolerances. During the investigation it was determined that at the time the crack was detected, the aircraft had flown 5,273 hours. Of that total time, approximately 1,100 hours were flown as part of a low-level pipeline patrol mission. It was further determined that as part of the certification process, Piper Aircraft had determined that the "general use" safe time in service (TIS), adjusted with a scatter pattern of eight, was 10,723 hours for the wing structure. The certification process did not include determination of a safe time in service when any portion of the aircraft's life included being used in a "pipeline survey" mission profile. The investigation also determined that the two rivet holes through which the crack passed (one of which was the point of origin) were the locations where two of the rivets that held the lower wing skin on in an area addressed by Piper Service Bulletin 796B, Part One. This service bulletin was published by Piper to address "loose and working rivets along the lower spar cap." In part, the bulletin states, "If this condition exists, and is left uncorrected over an extended period of time, the structural integrity of the wing could be compromised." The actions delineated in this service bulletin had not been performed on this aircraft (N27PG) even though loose and working (smoking) rivets were found at the subject location on the lower skins of both wings.
Probable cause
The initiation and propagation of a fatigue crack, over 5,273 hours of cyclic in-flight usage, through approximately 80 percent of the aircraft's right wing spar lower cap.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA05IA115
- Event ID
- 20050623X00860
- Case number
- SEA05IA115
- 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: 655106a0a74aed2c27eccabe3ac9813663d4bda1c1b8c561149eb59f49f25031; retrieved 2026-09-18T21:15:58.808Z.