# NTSB WPR20LA042: Cessna 182, N182EF, Carlsbad, CA, December 13, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: December 12, 2019, 19:00 local (Dec 13, 2019, 03:00 UTC) - Place: Carlsbad, CA - Coordinates: 33.146389, -117.33361 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.1464&lon=-117.3336&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: 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: FAA-FSDO, PPonk Engines, Mechanic - NTSB case key (mKey): 100689 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20LA042 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100689/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100689 - Page: https://openairdocs.org/ntsb/WPR20LA042 ## Probable cause The fatigue failure of the crankshaft. Contributing to the accident was the undocumented installation of the supercharger, which resulted in increased stress on the crankshaft. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng supercharger](https://openairdocs.org/ntsb-findings/01058560): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Cessna 182P, 1 case](https://openairdocs.org/ntsb-findings/01058560/cases.md?model=2075816), [All aircraft, 12 cases](https://openairdocs.org/ntsb-findings/01058560/cases.md) - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna 182P, 2 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=2075816), [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: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 182P, 15 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2075816), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## Analysis The pilot stated that during the flight, the airplane’s engine started to run rough. Despite troubleshooting, the engine roughness increased followed by “flash explosions” from the engine and the smell of oil in the cabin. The engine lost total power, and the pilot performed a forced landing to an interstate highway. The airplane landed hard, which resulted in substantial damage to the fuselage. A postaccident examination of the engine revealed that the Nos. 5 and 6 connecting rods separated from the crankshaft. The crankshaft separated into three sections. One of the separations was at the crankshaft cheek forward and adjacent to the No. 3 bearing journal, and the separation surfaces displayed beach marks consistent with fatigue cracking. Metallurgical examination revealed that the fracture appeared to initiate below the outer nitride layer near an oxide inclusion within the metal. The engine was overhauled and converted from the original Continental O-470-U engine to a PPA O-470-50 engine per a supplemental type certificate (STC). Additionally, a supercharger was installed on the engine, which was not part of the engine conversion STC. No logbook entries were found regarding the installation of the supercharger. It is likely that the installation of the supercharger contributed additional stress to the crankshaft during operation, which resulted in the separation of the crankshaft and subsequent catastrophic engine failure. ## Factual narrative On December 12, 2019, about 1900 Pacific standard time, a Cessna 182P airplane, N182EF, sustained substantial damage when it was involved in an accident near Carlsbad, California. The private pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that the engine started to run rough during the approach to McClellan-Palomar Airport (CRQ), Carlsbad, California. About a minute later, despite the pilot’s troubleshooting, the engine roughness increased. The pilot noticed the engine monitor showed normal operating indications; however, the alternator voltage light illuminated, and the engine continued to run rough. The pilot stated he saw two “flash explosions” from the left side of the engine and propeller area followed by the smell of oil in the cabin, and the engine lost total power. The pilot subsequently performed a forced landing to the southbound side of Interstate 5. The airplane landed hard, and the nose landing gear collapsed. Postaccident examination of the airplane revealed that the aft fuselage was buckled near the cabin door area, and oil covered the belly of the airplane. There were two holes in the engine crankcase between Nos. 5 and 6 cylinders, and it was noted that a supercharger was attached to the accessory section of the engine. Review of the engine logbook showed that the Continental O-470-U engine was overhauled and converted to a PPA O-470-50 engine per engine Supplemental Type Certificate (STC) SE4985NM by P. Ponk Aviation on December 20, 2018. The conversion changed the cylinders to those used on Continental IO-520 engines and increased engine displacement by 50 cubic inches. The PPA O-470-50 engine was shipped to the owner and installed on the airplane on February 15, 2019. At the time of the accident, the engine had accumulated about 150 hours since the overhaul and conversion. An engine logbook entry dated September 4, 2019, noted that the engine oil and supercharger fluid were changed about 50 hours of operation before the accident, and an entry dated November 4, 2019, noted that the engine oil was changed and the supercharger belt was checked about 2 hours of operation before the accident. Review of STC SE4985NM showed that a supercharger installation was not part of the modification, nor were maintenance procedures outlined for one. Additionally, no logbook entries or documentation regarding the installation of the supercharger were found. Disassembly of the engine revealed that the Nos. 5 and 6 connecting rods were separated from the crankshaft. Connecting rod parts and metal fragments were found in the oil sump. The crankshaft was found separated into three sections. One of the separations was at the crankshaft cheek forward and adjacent to the No. 3 bearing journal, and the separation surfaces displayed beach marks consistent with fatigue cracking. According to a metallurgical exam conducted by Continental AerospaceTechnologies (CAT), the fracture appeared to initiate below the outer nitride layer near an oxide inclusion within the metal. ## Aircraft - Registration: [N182EF](https://openairdocs.org/aircraft/N182EF), registered now, S/N 18261392, built 1972 (OpenAirDocs) - Reported make and model: Cessna 182 (P) - Registry model: [Cessna 182P](https://openairdocs.org/model/cessna-182p) (registry code 2075816) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18261392 - Year built: 1972 - Airframe hours: 3235.3 - Engines: Continental O-470-50 265 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 5, 2019 - Departed: EMT, El Monte, CA - Destination: CRQ, Carlsbad, CA - Airport: KCRQ, McCellan - Equipment: Satellite tracking device, Onboard weather, Electronic flight bag or handheld device, ADS-B, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review February 19, 2019; seat: left; restraint: 3-point; flight hours: 1,454 total, 1,430 in this make and model, 1,354 as pilot in command, 60 in the last 90 days, 20 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 260° at 10 knots - Lowest ceiling: none - Temperature: 63 °F - Altimeter: 30.14 inHg - Observed at: CRQ, 3 nm away ## 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 20191212018529A](https://openairdocs.org/incident/20191212018529A), Dec 12, 2019: Cessna 182P, Carlsbad, CA, Substantial damage. Pilot stated that on slow descent into kcrq, his engine started running rough. He checked mixture and throttle settings. He then checked his engine monitoring… ## Docket (10 files) The files NTSB released with the investigation on June 14, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100689. 33.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 5.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13259152&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - NTSB engine examination summary (item 2, PDF, 6 pages, 642 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13916561&FileExtension=pdf&FileName=WPR20LA042%20Engine%20Examination%20Summary-Rel.pdf - Continental aerospace technologies materials lab report (item 3, PDF, 3 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13259162&FileExtension=pdf&FileName=CAT%20Met%20Lab%20467211_Redacted-Rel.pdf - Engine monitor data (item 4, PDF, 47 pages, 437 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13916349&FileExtension=pdf&FileName=Engine%20Data_Redacted-Rel.pdf - Engine logbook (item 5, PDF, 13 pages, 13.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13259237&FileExtension=pdf&FileName=Engine%20Logbook_Redacted-Rel.pdf - Aea release certificate for crankshaft (item 6, PDF, 2 pages, 6.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13259500&FileExtension=pdf&FileName=18-18%20%20AEA%20Release%20Certif%20for%20%20%20Crankshaft_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation-smalldridge (item 7, PDF, 1 page, 718 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13259510&FileExtension=pdf&FileName=Party%20Form-Smalldridge%20Mx_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation-cat (item 8, PDF, 11 pages, 385 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13981258&FileExtension=pdf&FileName=NTSB%20Party%20Form-CAT_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation-p. ponk aviation (item 9, PDF, 1 page, 919 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13994700&FileExtension=pdf&FileName=NTSB%20Cert%20-%20Party%20Rep%20-%20P%20Ponk%20Aviation%20S%20Knopp_Redacted-Rel.pdf - Photo array-airplane photos document supplied by owner (item 10, PDF, 9 pages, 20 photos, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13611128&FileExtension=pdf&FileName=Photo%20Array-Supplied%20by%20Owner-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.