LAX91LA323 · Cessna C-172P
South Bay Aviation Cessna C-172P · Accident: partial loss of engine power (mechanical failure) en route
From Harry Reid International Airport (LAS) to Zamperini Field (TOA)
Event
- NTSB case
- LAX91LA323
- 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 C-172P
- Aircraft type
- Cessna C-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
- N54694
- Operator
- South Bay Aviation
- Onboard fatalities
- Unknown
- Route
- From Harry Reid International Airport (LAS), Las Vegas, NVTo Zamperini Field (TOA), Torrance, 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 · descent
- 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)
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Wire, transmission
- 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
- Company maintenance personnel › Maintenance, replacement, not performed
- Other maintenance personnel › Maintenance, overhaul, improper
- Throttle/power lever, bellcrank › Jammed
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PILOT DECIDED TO DIVERT TO HESPERIA DUE TO WEATHER. DURING THE ENROUTE LET DOWN, THE PILOT DISCOVERED THAT THE THROTTLE CONTROL WAS FROZEN AND COULD NOT BE MOVED WHEN HE ATTEMPTED TO ADD POWER. THE THROTTLE WAS FROZEN AT AN ENGINE POWER LEVEL INSUFFICIENT TO MAINTAIN LEVEL FLIGHT AND THE AIRCRAFT COLLIDED WITH HIGH TENSION POWER LINES WHILE ATTEMPTING TO MANEUVER TO THE RUNWAY. THE AIRCRAFT WAS EXAMINED BY FAA AIRWORTHINESS INSPECTORS WHO CONFIRMED THAT THE THROTTLE WAS FROZEN IN AN INTERMEDIATE SETTING. THE ENGINE WAS OVERHAULED ON JUNE 18, 1991. AT THAT TIME THE CARBURETOR WAS ALSO OVERHAULED, INCLUDING THE INSTALLATION OF NEW THROTTLE BUSHINGS AND A SHAFT. BETWEEN THE ENGINE OVERHAUL AND THE DATE OF THE ACCIDENT, THE AIRCRAFT DISCREPANCY LOG SHEETS MAINTAINED BY SOUTHBAY AVIATION DOCUMENTED SIX PRIOR COMPLAINTS BY RENTER PILOTS THAT THE THROTTLE WAS STICKING ON AN INTERMITTENT BASIS. THE CORRECTIVE ACTION RECORDED ON THE DISCREPANCY SHEETS CONSISTED OF REPLACING THE THROTTLE CABLE.
Probable cause
A STUCK ENGINE THROTTLE DUE TO IMPROPER MAINTENANCE PROCEDURES.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX91LA323
- Event ID
- 20001212X17612
- Case number
- LAX91LA323
- 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: 8ae96157c1ba82e6fcf92c1820252cb316c3340226bb145cb18f5ae3680534f6; retrieved 2026-09-23T03:55:05.549Z.