SEA02LA046 · Cessna 421C
Cessna 421C · Accident: airframe, component or system failure on approach
From Santa Monica Municipal Airport (SMO) to Friedman Memorial Airport (SUN)
Event
- NTSB case
- SEA02LA046
- 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
Cessna 421C
- Aircraft type
- Cessna 421
- 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
- N421DG
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Santa Monica Municipal Airport (SMO), Santa Monica, CATo Friedman Memorial Airport (SUN), Hailey, ID
- 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
- Approach
- 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
- Substantial
Cause areas
- Hydraulic system › Contamination, water
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
While on approach to the Friedman Memorial airport (Hailey, Idaho), the pilot of the Cessna 421C lowered the landing gear but failed to receive a gear down and locked indication on the right main gear. He attempted to lower the landing gear utilizing the nitrogen blow down system, again without success. The pilot then executed a landing with the nose and left main gear extended. Post-crash examination revealed a small amount of water in the landing gear hydraulic lines. When the landing gear system was purged and replenished with uncontaminated fluid the gear operated without malfunction both normally and with the use of the blow down system. Temperature at Hailey, Idaho, remained well below freezing before and after the accident.
Probable cause
Water contamination within the aircraft's landing gear hydraulic line(s) which froze and blocked the line(s) preventing extension of the right main gear. A factor was the below freezing environmental conditions which the aircraft was operating in prior to and during the approach and landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA02LA046
- Event ID
- 20020311X00328
- Case number
- SEA02LA046
- 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: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2002-03-02.
- API snapshot SHA-256: eb2e61e0b228d4ecc7bf0795ab770acc858f8cdf3b536871ef30e2da38613678; retrieved 2026-09-22T11:05:46.534Z.