ERA11LA383 · Cessna 150L
Cessna 150L · Accident: powerplant system/component malfunction/failure during initial climb
From Plymouth Municipal Airport (PYM) to Plymouth Municipal Airport (PYM)
Event
- NTSB case
- ERA11LA383
- 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 150L
- Aircraft type
- Cessna 150
- 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
- N150ET
- Operator
- Richard C Murphy · private individual
- Onboard fatalities
- Unknown
- Route
- From Plymouth Municipal Airport (PYM), Plymouth, MATo Plymouth Municipal Airport (PYM), Plymouth, MA
- 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
- Initial climb
- 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
- Powerplant system/component malfunction/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
- Aircraft › Aircraft power plant
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
During initial climb, the engine began to run rough and experienced a partial loss of power. The pilot elected to land straight ahead into a cranberry bog. The pilot believed the loss of engine power was due to a stuck cylinder valve. Postaccident examination of the engine revealed that the No. 2 cylinder intake and exhaust valve springs exhibited excessive corrosion and carbon deposits, consistent with lack of use, which made them more susceptible to sticking. The extent of the corrosion was such that it presented over a long period of time and should have been addressed during routine maintenance. No other defects were noted with the engine that would have resulted in a partial loss of power.
The airplane had been operated for 17 hours since its most recent annual inspection, which was completed 11 months prior to the accident. The engine had been operated for 256 hours since its most recent overhaul, which was completed more than 10 years prior to the accident. The same airplane was involved in a forced landing to a cranberry bog 8 years earlier due to a stuck cylinder valve.
Probable cause
A partial loss of engine power during initial climb due to a stuck cylinder valve, which resulted from excessive corrosion and carbon deposits on the valve springs due to inadequate maintenance.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA11LA383
- Event ID
- 20110706X24824
- Case number
- ERA11LA383
- 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: 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: 1a717d56a1628b4e7754cd25503f3adce4f3e5bdd7f304a9f53cc158865f3701; retrieved 2026-09-15T16:24:13.686Z.