LAX00LA062 · Cessna 172A
Cessna 172A · Accident: partial loss of engine power (mechanical failure) en route
From Merced Regional Macready Field (MCE) to an unrecorded destination
Event
- NTSB case
- LAX00LA062
- 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 172A
- 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
- N7249T
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Merced Regional Macready Field (MCE), Merced, CATo 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
- 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
- Partial loss of engine power (mechanical 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
- Other maintenance personnel › Maintenance, installation, improper
- Throttle/power lever, linkage › Loose part/bolt/nut/clamp/etc
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While en route to the practice area, the student pilot performed several practice turns. She noted a loss of altitude, added throttle to regain altitude, but did not receive corresponding power indication. She checked the fuel selector to make sure it was in the on position, and then checked the engine gages. No discrepancies were noted. Carburetor heat was applied with no response and the rpm's continued to drop. She crosschecked the engine instruments, and reapplied carburetor heat with no change. With the rpm's continuing to drop, she made an emergency landing in a plowed dirt field. The engine was inspected, and it was noted that the retaining nut that attaches the serrated throttle lever to the serrated throttle shaft of the carburetor was loose, and the cotter pin was missing. The serrated portion of the throttle lever was unable to properly engage with the serrated stop of the throttle shaft. The carburetor had been replaced during the annual inspection on June 6, 1999, to comply with Airworthiness Directives. No further discrepancies were noted.
Probable cause
A partial loss of engine power due to the failure of maintenance personnel to properly install and safety the throttle arm to the carburetor throttle shaft.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX00LA062
- Event ID
- 20001212X20382
- Case number
- LAX00LA062
- 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: 76b695aca49e9723aa71c134b8eb3e7a83ec1b0a677587bb8fa83454b76d5b4a; retrieved 2026-09-21T20:19:25.868Z.