ANC25LA059 · Cessna 170B
Cessna 170B · Accident: system/component malfunction/failure (non-power) during landing
From Kantishna Airport (5Z5) to an unrecorded destination
Event
- NTSB case
- ANC25LA059
- 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
- Event fatalities
- Unknown
- 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
Cessna 170B
- Aircraft type
- Cessna 170
- 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
- N2655D
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Kantishna Airport (5Z5), Kantishna, AKTo not recorded
- Aircraft age
- About 69 years (built 1956)
- 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
- System/component malfunction/failure (non-power)
- 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
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot reported that, during the landing roll in a tailwheel-equipped airplane on a remote airstrip, he encountered a depression in the landing surface, resulting in the separation of the left main wheel. The left main landing gear leg subsequently dug into the ground and folded back against the fuselage, which caused substantial damage to the fuselage near the main landing gear attach points. After exiting the airplane, the pilot observed that the left main gear leg had fractured above the axle bolts, and the tire, axle, and lower portion of the main landing gear spring had separated from the airplane. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. Photos of the fracture surfaces from the main landing gear spring were examined by the NTSB Materials Laboratory. The features observed were consistent with a fatigue fracture and corrosion. It is likely that a fatigue crack initiated due to corrosion damage at the fracture origin.
Probable cause
The failure of the left main landing gear spring due to a fatigue fracture during landing on uneven terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC25LA059
- Event ID
- 20250630200423
- Case number
- ANC25LA059
- 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, coordinates, cause areas. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2025-06-25.
- API snapshot SHA-256: 99c6281f7ff70ae701ed88dbfe8b7c3ca38ea4ba2cf8c545d32a908ada50b755; retrieved 2026-09-16T20:01:18.556Z.