# NTSB LAX93LA345: Cessna 172G, N4143L, Avalon, CA, September 6, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 6, 1993, 14:24 local (21:24 UTC) - Place: Avalon, CA - Coordinates: 33.380161, -118.450988 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.3802&lon=-118.4510&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report June 30, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28468 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA345 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28468/pdf - Page: https://openairdocs.org/ntsb/LAX93LA345 ## 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. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - normal - engine assembly,crankcase - undertorqued (cause) - maintenance,installation - improper, unqualified person (cause) - maintenance,inspection - inadequate, company maintenance personnel (cause) - lubricating system,oil port/passage,internal - blocked(partial) (cause) - engine assembly,connecting rod - failure,total (cause) - Ditching, descent - emergency ## Analysis 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. ## Factual narrative On September 6, 1993, at 1424 hours Pacific daylight time, a Cessna 172G, N4143L, ditched in the Pacific Ocean about 100 yards off shore from Avalon on Catalina Island, California. The ditching was precipitated by a partial loss of engine power. The aircraft was operated by Rick Lucia Aviation of Ramona, California, and was rented by the pilot for a cross country personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The aircraft incurred substantial damage. The certificated private pilot, and his two passengers were not injured. The flight originated at Ramona on the day of the mishap at 1330 hours as a personal cross country flight to Catalina Island, and return. According to the pilot, 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 in Avalon Bay about 100 yards off shore. Boats rescued the occupants and the aircraft sank in about 30 feet of water. After recovery, the aircraft and engine were examined by a Safety Board investigator at Long Beach, California, on September 14, 1994. During the examination, the engine was disassembled for detailed internal review. 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 Cruise Air Aviation, work order 4167 and attached discrepancy sheet, the number two cylinder base seal 'O' ring was replaced by the aircraft owner and signed off by a company inspector. Cruise Air Aviation is the holder of a FAA Repair Station authorization, number LF3R655L. The referenced maintenance records and work orders are attached to this report. ## Aircraft - Registration: [N4143L](https://openairdocs.org/deregistered/N4143L-2012-11-07), registration cancelled 2012-11-07, S/N 17254212, built 1966 (OpenAirDocs) - Reported make and model: CESSNA 172G - Registry model: [Cessna 172G](https://openairdocs.org/model/cessna-172g) (registry code 2072420) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17254212 - Airframe hours: 3375 - Engines: CONTINENTAL O-300-G 145 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Operator: Rick Lucia Aviation - Registered owner: Brent Sundin - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 24, 1993, 55 hours before - Departed: L39, RAMONA, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 240 total, 63 in this make and model, 177 as pilot in command, 2 in the last 90 days, 2 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 30 statute miles - Lowest ceiling: none ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19930906033059A](https://openairdocs.org/incident/19930906033059A), Sep 6, 1993: Cessna 172G, Avalon, CA, Destroyed. Rough engine,smoke, power loss. Ditched in Avalon bay. Found broken connecting rods. Recent cylinder o ring seals. ## Other investigations on N4143L (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB OAK71DVA60](https://openairdocs.org/ntsb/OAK71DVA60), Feb 15, 1971: Cessna 172 (N4143L), Dinuba, CA, substantial damage From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.