LAX97LA103 · Cessna 172F
Cessna 172F · Accident: total loss of engine power (non-mechanical) en route
From Sonoma Valley Airport (0Q3) to O56 · Novato, CA
Event
- NTSB case
- LAX97LA103
- 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
Cessna 172F
- Aircraft type
- Cessna 172
- 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
- N3757F
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Sonoma Valley Airport (0Q3), SONOMA VALLEY, CATo O56 · Novato, CA
- 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
- Total loss of engine power (non-mechanical)
- 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
- Pilot in command › Carburetor heat, not used
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
A few minutes after takeoff the engine began to run rough and quit, forcing the pilot to ditch. After ditching, the aircraft partially sank in the shallow bay. The pilot sprained his ankle during the water landing and decided to stay with the aircraft. He was located the following morning after manually activating the ELT. The aircraft had last been refueled several weeks before the accident but had not flown until the day of the accident. The pilot estimated there were 28 gallons of fuel remaining. The aircraft logbooks did not reveal any discrepancies. The aircraft was not inspected after the accident. The temperature dew point spread noted in the carburetor icing probability chart is 'moderate icing - cruise power or serious icing - glide power.'
Probable cause
total loss of engine power due to carburetor icing and the pilot's failure to use carburetor heat.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX97LA103
- Event ID
- 20001208X07424
- Case number
- LAX97LA103
- 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. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1997-02-14.
- API snapshot SHA-256: afab0a5b3dd34be1e351ea37452eadd3c2eb499e58c65cbb707a212ca2dacb63; retrieved 2026-09-21T21:30:27.104Z.