# NTSB WPR21LA121: Cessna 150J, N60290, Lodi, CA, March 3, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: March 3, 2021, 12:20 local (20:20 UTC) - Place: Lodi, CA - Coordinates: 38.131706, -121.1703 - Nearby events: https://openairdocs.org/map.md?lat=38.1317&lon=-121.1703&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 102703 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA121 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102703/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102703 - Page: https://openairdocs.org/ntsb/WPR21LA121 ## Probable cause A total loss of engine power during cruise flight due to a fatigue crack in the No. 3 cylinder connecting rod shaft resulting from either preignition or detonation, which resulted in a forced landing and impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna 150J, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2071820), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna 150J, 3 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=2071820), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 150J, 9 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2071820), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Cessna 150J, 4 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=2071820), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot receiving instruction and flight instructor had planned a local instructional flight on the day of the accident. Shortly into the flight after they reached their cruise flight altitude, they experienced a total loss of engine power. The airplane was substantially damaged during a forced landing in a field. Postaccident examination of the engine revealed that the connecting rod shaft for the No. 3 cylinder had fractured due to fatigue cracking. The buildup of combustion deposits suggested the event was caused by either preignition or detonation or both, which would have been the result of the use of a lower grade fuel or operating the engine at high power settings with an excessively lean mixture. Although a trace amount of automotive fuel was detected in the fuel line to the carburetor, fuel records indicate that the pilot had been using 100LL consistently. The operating fuel used by the previous owner is unknown; however, the previous owner implied that he used 100LL during conversations with the current owner. The pilot’s leaning practices showed that he regularly leaned the mixture to reach best rpm and enrichened three turns. ## Factual narrative On March 3, 2021, about 1220 Pacific standard time, a Cessna 150J airplane, N60290, was substantially damaged when it was involved in an accident near Lodi, California. The instructor and pilot receiving instruction were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. According to the pilot receiving instruction they departed the airport uneventfully and climbed to their cruise altitude, 3,000 ft mean sea level. The pilot receiving instruction donned an instrument instruction tool at 200 ft above ground level. Once they reached cruise altitude, the pilot reduced power to 2,450 rpm, applied carburetor heat, and leaned the fuel/air mixture to achieve best rpm. He followed the airplane’s cruise checklist, scanned the engine instruments and did not observe any anomalies as each instrument was reporting normal operation. Approximately 5 minutes later, he heard a sound that resembled a gun shot, and the propeller stop rotating. The instructor took control of the airplane and announced “my controls” while the pilot searched for a suitable place to land and attempted to restart the engine but was unsuccessful. Although they were surrounded by fields, their options for suitable landing sites were limited due to trees or other obstacles. They were able to glide the airplane to the end of an almond tree field where the airplane contacted trees before coming to rest in the field. Photographs of the airplane taken by local law enforcement showed substantial damage to the wings and empennage. Postaccident examination of the engine revealed that the top of the engine case was fractured with a hole that extended about 7 inches in diameter. Additionally, the lower case had fractured around the circumference of No. 4 cylinder. Continuity of the throttle and mixture controls was confirmed from the cockpit to their respective arms at the carburetor. The No. 3 cylinder connecting rod was fractured at the connecting rod shank and was mechanically damaged. The No. 4 cylinder barrel rim was bent outboard towards the crankcase. A borescope inspection of No. 3 cylinder revealed that the connecting rod bushing end was still attached to the piston pin, but the piston ring seal was fractured, and part of a piston ring was exposed. No evidence of oil starvation or thermal damage was observed. Metallurgical analysis of the No. 3 cylinder connecting rod revealed that the fractured face exhibited crack arrest marks consistent with fatigue cracking. The fatigue crack emanated from the outer surface at one corner of the arm. A portion of the fatigue crack also displayed mechanical damage that destroyed some of the fatigue crack features; however, the origin of the fatigue crack did not exhibit any indications of mechanical damage such as a gouge. The No. 3 cylinder piston contained evidence of heavy combustion deposits at the outer crown. Similar deposits were also observed near the spark plug ports and the intake andexhaust valves. Postaccident examination of the airplane revealed that the carburetor input fuel line contained a smell that resembled automotive gasoline. The owner stated that he had only used 100 low lead aviation grade gasoline (100LL) in the 60 total flight hours he had accumulated in the accident airplane since he purchased it. Fuel receipts showed that the pilot purchased 12.3 gallons of 100LL the day before the accident and 17 gallons off 100LL on the day of the accident According to the owner, the previous owner had implied that he only ever used 100LL during their correspondence. The fuel from the accident site was not tested. The pilot stated that he regularly used carburetor heat due to a “serious issue with carb ice” as he had that day when he reached cruise altitude. He would have adjusted the carburetor heat until the carburetor heat temperature gauge reached a certain temperature and then leaned the mixture out to achieve best rpm before enrichening the mixture about 3 full turns. The previous owner who flew the airplane from the engine’s most recent overhaul had passed away and was not available for a statement. According to the Federal Aviation Administration Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25B), detonation is defined as “an uncontrolled, explosive ignition of the fuel-air mixture within the cylinder’s combustion chamber. It causes excessive temperatures and pressures which, if not corrected, can quickly lead to failure of the piston, cylinder or valves.” The section also provides several causes of detonation, including the use of a lower grade fuel than specified by the manufacturer and operating the engine at high power settings with an excessively lean mixture. According to the PHAK, preignition occurs when “the fuel-air mixture ignites prior to the engine’s normal ignition event. Premature burning is usually caused by a residual hot spot in the combustion chamber, often created by a small carbon deposit on a spark plug, a cracked spark plug insulator, or other damage in the cylinder that causes a part of heat sufficiently to ignite the fuel-air charge. Preignition causes the engine to lose power and produces high operating temperatures. As with detonation, preignition may also causes severe engine damage bcuase the expanding gases exert excessive pressure on the piston while still on its compression stroke.” It should also be noted that detonation and preignition can occur simultaneously and/or one may be caused by the other. ## Aircraft - Registration: [N60290](https://openairdocs.org/aircraft/N60290), registered now, S/N 15070201, built 1969 (OpenAirDocs) - Reported make and model: CESSNA 150J - Registry model: [Cessna 150J](https://openairdocs.org/model/cessna-150j) (registry code 2071820) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15070201 - Year built: 1969 - Airframe hours: 6036.8 - Engines: Continental O-200 SERIES 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, September 21, 2021, 54.7 hours before - Departed: 1O3, Lodi, CA - Equipment: ADS-B, Electronic flight bag or handheld device, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review January 23, 2020; seat: left; restraint: 4-point; flight hours: 182 total, 59 in this make and model, 108 as pilot in command, 51 in the last 90 days, 14 in the last 30 days, 4 in the last 24 hours - Flight instructor; age 25; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review August 15, 2020; seat: front; restraint: 4-point; flight hours: 1,014 total, 911 as pilot in command, 123 in the last 90 days, 54 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 6 knots - Visibility: 10 statute miles - Temperature: 63 °F, dew point 36 °F - Altimeter: 29.76 inHg - Observed at: KSCK, 15 nm away - METAR: KSCK 031955Z 31006KT 10SM CLR 17/02 A2976 RMK AO2 SLP078 T01670017 ## 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 20210303008429A](https://openairdocs.org/incident/20210303008429A), Mar 3, 2021: Cessna 150J, Lodi, CA, Substantial damage. Crash landed in an orchard after engine failure. No injuries to the two occupants. Substantial aircraft damage. ## Docket (8 files) The files NTSB released with the investigation on September 15, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102703. 25.6 MB in all. - Materials laboratory factual report 22-018 (item 1, PDF, 7 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13672215&FileExtension=pdf&FileName=22-018%20-%20con%20rod-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 9 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14280080&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Record of conversations (item 3, PDF, 5 pages, 484 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14280304&FileExtension=pdf&FileName=Record%20of%20Conversation%20pilot_Redacted-Rel.pdf - Aircraft examination report (item 4, PDF, 9 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14279183&FileExtension=pdf&FileName=airplane%20examination%20report-Rel.pdf - Powerplant examination report (item 5, PDF, 11 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14280090&FileExtension=pdf&FileName=Engine%20exam%20report-Rel.pdf - Aircraft logbooks (item 6, PDF, 14 pages, 16.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14280332&FileExtension=pdf&FileName=aircraft%20logs_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 7, PDF, 1 page, 479 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14280108&FileExtension=pdf&FileName=Signed%20Release%20of%20Wreckage%201_Redacted-Rel.pdf - Accident photographs (item 8, PDF, 3 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14280668&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf 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.