CHI98LA227 · Commonwealth 185
Commonwealth 185 · Accident: loss of engine power during initial climb
From Private airstrip to an unrecorded destination
Event
- NTSB case
- CHI98LA227
- 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
Commonwealth 185
- Aircraft type
- Commonwealth 185
- 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
- N92997
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Private airstripTo not recorded
- 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
- 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
- Loss of engine 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
- Fuel system, carburetor
- Unqualified person › Maintenance, adjustment, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The FAA inspector stated that the aircraft lost power soon after takeoff from the private airstrip. Post accident investigation showed that the aircraft was using auto-gas. There was no Supplemental Type Certificate (STC) found to be issued by the FAA for the use of auto-gas for the aircraft in question. Approximately 1/4 cup of oil was drained from the number two cylinder. The lower spark plug of the number two cylinder was oil fouled. The number one cylinder upper spark plug lead fell apart when removed from the cylinder. The right magneto did not produce a spark when a functional test was conducted. The pilot had stated that on the day of the accident he had noticed that the carburetor of his aircraft was running 'Over.' The pilot stated that he readjusted the carburetor to specifications. The most recent annual inspection was completed on October 10, 1996. The last 90-day student solo sign off was in October of 1997. According to the pilot's written statement there was no record of flying for at least 90 days prior to the date of the accident.
Probable cause
the improper adjustment of the carburetor by an unqualified person. Factors to the accident were the annual inspection not being complied with and the lack of recent experience of the pilot.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI98LA227
- Event ID
- 20001211X10273
- Case number
- CHI98LA227
- 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: investigation status. 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: 89095c6a29e9474ca03884a54b39a4b7634f7a4756a810da861c9fef7c0a7b7c; retrieved 2026-09-21T20:47:58.108Z.