# NTSB WPR19LA014: North American SNJ, N7969C, Agoura Hills, CA, October 23, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: October 23, 2018, 13:44 local (20:44 UTC) - Place: Agoura Hills, CA - Coordinates: 34.138053, -118.724441 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.1381&lon=-118.7244&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: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 98532 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR19LA014 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98532/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98532 - Page: https://openairdocs.org/ntsb/WPR19LA014 ## Probable cause The failure of the No. 5 piston rod end due to fatigue, which resulted in a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [North American SNJ-5, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=6400418), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [North American SNJ-5, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=6400418), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/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: [North American SNJ-5, 2 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=6400418), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [North American SNJ-5, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=6400418), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot reported that, shortly after departure, he heard two loud bangs followed by total loss of engine power. The pilot performed a forced landing to a highway, during which the airplane swerved to the left, the left wing impacted a concrete center divider, and a postimpact fire ensued. Initial examination of the engine found that the No. 2 cylinder was cracked, and the No. 1 cylinder and the base between the Nos. 4 and 5 cylinders displayed damage. Disassembly of the engine revealed the piston-end master rod piece from the No. 5 cylinder fractured through the I-beam shaft. Microscopic examination of the fracture surface showed evidence of fatigue. The initiation point of the fatigue fracture was damaged due to mechanical contact during the failure sequence. The accident is consistent with a total loss of engine power following the failure of the No. 5 master rod end. The initiating point and cause of the fatigue failure could not be identified based on the available evidence. ## Factual narrative On October 23, 2018, about 1344 Pacific daylight time, a North American SNJ-5 airplane, N7969C, was destroyed when it was involved in an accident near Agoura Hills, California. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that, shortly after departure, he heard two loud bangs, followed by total loss of engine power, and he performed a forced landing to a highway. After touchdown, the airplane swerved to the left, the left wing impacted a concrete divider, and a postimpact fire ensued. The airplane was equipped with an R-1340-AN1 nine-cylinder, radial engine. Examination of the engine showed that the No. 2 cylinder was cracked between the 10th and 11th (from bottom of head) cylinder head cooling fin. Another crack on the No. 2 cylinder extended from the sparkplug to the base of the head. Additional damage was noted at the base between the Nos. 4 and 5 cylinders, and on the No. 1 cylinder. Disassembly showed that the No. 5 master cylinder rod end had failed on the piston side. Examination of the master rod end by the NTSB Materials Laboratory showed a fracture initiation region on the I-beam shaft, based on fine chevron and river pattern markings. The fracture surface in the immediate origin region was damaged due to mechanical contact during the failure sequence. A higher magnification image of the fracture surface adjacent to the origin region exhibited striation features typical of fatigue crack growth in hardened steel. ## Aircraft - Registration: [N7969C](https://openairdocs.org/aircraft/N7969C), registered now, S/N 43974 (OpenAirDocs) - Reported make and model: North American SNJ (5) - Registry model: [North American SNJ-5](https://openairdocs.org/model/north-american-snj-5) (registry code 6400418) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 43974 - Year built: 1958 - Airframe hours: 6841 - Engines: Pratt & Whitney R1340 AN1 600 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Personal, Part 91 - Operator: Condor Squadron Officers & Airmens Assoc - Registered owner: Condor Squadron Officers & Airmens Assoc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 18, 2018 - Departed: VNY, Van Nuys, CA - Destination: VNY, Van Nuys, CA - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: none; flight instructor, airline transport, commercial; airplane ratings: single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; seat: front; flight hours: 11,764 total, 382 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 55 °F - Altimeter: 29.84 inHg - Observed at: KVNY, 12 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 20181023020599A](https://openairdocs.org/incident/20181023020599A), Oct 23, 2018: North American SNJ-5, Agoura Hills, CA, Substantial damage. Aircraft departed vny airport. 6 min after takeoff, the aircraft suffered an engine problem that caused a loss of engine power. The pilot chose to land on the… ## Other investigations on N7969C (2) 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 GAA17CA242](https://openairdocs.org/ntsb/GAA17CA242), Apr 20, 2017: North American SNJ (N7969C), Van Nuys, CA, substantial damage. Probable cause: The pilot’s failure to maintain directional control of the airplane during the landing roll with a quartering tailwind. - [NTSB LAX78FUQ05](https://openairdocs.org/ntsb/LAX78FUQ05), Dec 7, 1977: N American SNJ-5 (N7969C), Van Nuys, CA, substantial damage ## Docket (3 files) The files NTSB released with the investigation on September 1, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98532. 7.2 MB in all. - Materials laboratory factual report 19-051 (item 1, PDF, 9 pages, 7 photos, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9946225&FileExtension=pdf&FileName=Materials%20Laboratory%20Factual%20Report%2019-051-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12642033&FileExtension=pdf&FileName=6120_Flat_Redacted-Rel%20(1)-Rel.pdf - Engine exam notes (item 3, PDF, 11 pages, 14 photos, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9663364&FileExtension=pdf&FileName=Engine%20Exam%20Notes%20-%20WPR19LA014_Redacted-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.