ANC17LA022 · Piper PA 18-150
Piper PA 18-150 · Accident: landing gear collapse
From Ninilchik, AK to Birchwood Airport (PABV)
Event
- NTSB case
- ANC17LA022
- 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
Piper PA 18-150
- Aircraft type
- Piper PA-18
- 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
- N82563
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Ninilchik, AKTo Birchwood Airport (PABV), Chugiak, AK
- Aircraft age
- About 40 years (built 1977)
- 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
- Landing · landing roll
- Defining eventThe 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
- Landing gear collapse
- 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
- Aircraft › Aircraft systems
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was landing the airplane on a gravel runway when the right main landing gear collapsed; subsequently, both wings struck the ground. A postaccident examination revealed that the outer radius of the attaching lug on the extension tube that connected the wheel axle to the left main landing gear shock unit was fractured at the shock unit attachment. Visual examination of the fractured lug fitting revealed a flat fracture surface that was perpendicular to the long axis of the fitting, which had extensive evidence of rust and pitting throughout the circumference of the fitting.
Probable cause
A fracture and collapse of the main landing gear. Contributing to the accident was corrosion to the hydrasorb lug fitting.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC17LA022
- Event ID
- 20170503X85252
- Case number
- ANC17LA022
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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, cause areas. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2017-04-30.
- API snapshot SHA-256: efeb6978543ff317447f93c149a7b2774eaaf26164c1404aa220353a519e7b92; retrieved 2026-09-16T05:13:48.046Z.