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LAX93LA345 · Cessna 172G

6 Sept 1993 · Avalon, CA, United States

Rick Lucia Aviation Cessna 172G · Accident: partial loss of engine power (mechanical failure) en route

From L39 · Ramona, CA to an unrecorded destination

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Event

NTSB case
LAX93LA345
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 172G

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
N4143L
Onboard fatalities
Unknown
Route
From L39 · Ramona, 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
Destroyed

Cause areas

  • Company maintenance personnel › Maintenance, inspection, inadequate
  • Engine assembly, connecting rod › Failure, total
  • Engine assembly, crankcase › Undertorqued
  • Lubricating system, oil port/passage, internal › Blocked(partial)
  • Unqualified person › Maintenance, installation, improper

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The aircraft was in cruise flight about 10 miles from the island when a puff of smoke emanated from the engine cowling and the engine began to run rough. The pilot stated the aircraft could not maintain altitude and he ditched in the ocean about 100 yards off shore. The engine was disassembled and the numbers one and two connecting rods were found fractured, with heat discoloration observed on the number two bearing. Heavy fretting was found on the number two bearing surface and the associated crankcase bearing journal support. The numbers three and four cam shaft journals were observed to be visibly out of round, with heavy wear noted. Examination of the engine log book and the maintenance records from the operator revealed that the cylinder base seal for the number two cylinder was replaced on May 25, 1993, about 55 hours prior to the accident. According to the records the number two cylinder base seal 'O' ring was replaced by the aircraft owner and the work signed off by an FAA Repair Station inspector.

Probable cause

the oil starvation related failure of the number 1 and 2 connecting rods due to improper torque of the crankcase through bolts at the number 2 cylinder, which allowed fretting of the bearing surfaces and the resulting closure of the oil ports. The under torque condition was due to improper installation procedures used by the aircraft owner, and, the inadequate inspection procedures utilized by the certifying repair station.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record LAX93LA345
Event ID
20001211X13422
Case number
LAX93LA345
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: b09cba2d64f71ffee5b75bb700805087126504b5eb026c5be3ec4d70d1628118; retrieved 2026-09-23T01:39:08.057Z.