# NTSB WPR23LA215: Piper J3C-65, N77583, Belfair, WA, June 4, 2023 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: June 4, 2023, 11:30 local (18:30 UTC) - Place: Belfair, WA - Coordinates: 47.472075, -122.80606 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.4721&lon=-122.8061&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 192310 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR23LA215 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192310/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192310 - Page: https://openairdocs.org/ntsb/WPR23LA215 ## Probable cause The total loss of engine power due to the fatigue failure of the crankshaft accessory drive gear. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Accessory gear-boxes](https://openairdocs.org/ntsb-findings/01058300): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Piper J3C-65, 1 case](https://openairdocs.org/ntsb-findings/01058300/cases.md?model=7100510), [All aircraft, 19 cases](https://openairdocs.org/ntsb-findings/01058300/cases.md) - [Engine (reciprocating): recip eng rear section](https://openairdocs.org/ntsb-findings/01058540): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Piper J3C-65, 2 cases](https://openairdocs.org/ntsb-findings/01058540/cases.md?model=7100510), [All aircraft, 42 cases](https://openairdocs.org/ntsb-findings/01058540/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible; cases with it: [Piper J3C-65, 5 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=7100510), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Piper J3C-65, 6 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=7100510), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) ## Analysis The flight instructor reported that during an instructional flight, while approaching the airport to land, there was a loud noise followed by a total loss of engine power. The flight instructor took control of the airplane and initiated a forced landing to an open area. During the landing roll, the airplane impacted rough and rising terrain. The left wing was partially separated, and landing gear was collapsed. Postaccident examination of the engine found the crankshaft accessory drive gear had failed. Metallurgical examination of the crankshaft and gear remnants revealed the fracture surfaces of two of the gear teeth had signatures of fatigue. Mechanical damage to the terminus of the observed fatigue cracks prevented determination of the initiating event that resulted in the eventual failure of the gear. The failed gear prevented both magnetos from operating, which resulted in a total loss of engine power due to a lack of ignition. ## Factual narrative On June 4, 2023, at 1130 Pacific daylight time, a Piper J-3C-65, N77583, was substantially damaged when it was involved in an accident near Belfair, Washington. The flight instructor and the student pilot were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor stated that he and the student pilot had been practicing maneuvers before they proceeded toward the Bremerton National Airport (PWT), Bremerton, Washington. The student pilot performed the before-landing checklist, which included checking fuel and turning on carburetor heat, as they were about 2 miles from runway 02. Shortly after, they heard a loud noise followed by a total loss of engine power. The flight instructor took control of the airplane and initiated a forced landing to an open area. During the landing roll, the airplane impacted rough and rising terrain. The left wing partially separated, and landing gear collapsed, which resulted in substantial damage to the fuselage. A postaccident examination of the airframe and engine revealed that, when the propeller was rotated, neither magneto coupling could be heard firing. The right magneto was removed, and remnants of the crankshaft accessory drive gear were observed in the accessory case. No additional, non-impact related anomalies were noted with the engine or airframe. The engine was disassembled, and the crankshaft and the gear remnants were removed and sent to the National Transportation Safety Board Materials Laboratory for further examination. The fracture faces of the gear contained mechanical damage. Two of the fracture faces contained fatigue striations typical of fatigue cracking that emanated from the root of the gear. The fatigue crack in these two gear fragments extended through the entire width of the gear. The terminus of each fatigue crack was not defined because of the severe mechanical damage on the fracture faces. The engine had accumulated about 278 hours since last overhaul and about 20 hours since the last annual inspection. The total number of hours on the engine could not be determined. ## Aircraft - Registration: [N77583](https://openairdocs.org/deregistered/N77583-2024-10-12), registration cancelled 2024-10-12, S/N 22073, built 1946 (OpenAirDocs) - Reported make and model: PIPER J3C-65 - Registry model: [Piper J3C-65](https://openairdocs.org/model/piper-j3c-65) (registry code 7100510) (OpenAirDocs) - Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 22073 - Year built: 1946 - Airframe hours: 6658 - Engines: Continental C90-8FJ 90 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Kirkish George P - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 12, 2022, 20 hours before - Departed: 2S1, Vashon, WA - Destination: PWT, Bremerton, WA - Airport: PWT, Bremerton Ntl - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; injuries: minor; commercial, flight instructor; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review November 22, 2022; seat: rear; flight hours: 19,198 total, 6,000 in this make and model, 19,198 as pilot in command, 17 in the last 90 days - Student pilot; injuries: serious; medical: sport pilot; seat: front; restraint: lap only ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 11 knots, gusting 18 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 41 °F - Altimeter: 30.24 inHg - Observed at: KPWT, 2 nm away - METAR: KPWT 041856Z AUTO 04011G18KT 10SM CLR 18/05 A3024 RMK AO2 SLP244 T01780050 ## 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 20230604013529A](https://openairdocs.org/incident/20230604013529A), Jun 4, 2023: Piper J3C-65, Belfair, WA, Substantial damage. Instructor with student pilot, while flying for instruction, was on the way to bremerton, WA airport, when enigine quit. No electrical system on this aircraft,… ## Docket (4 files) The files NTSB released with the investigation on November 7, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192310. 7.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 4.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17025666&FileExtension=pdf&FileName=NTSB%20Pilot%20Accident%20Report_Redacted-Rel.pdf - Wreckage examination report (item 2, PDF, 4 pages, 102 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17025227&FileExtension=pdf&FileName=WPR23LA215%20Exam%20Report-Rel.pdf - Materials laboratory factual report 24-019 (item 3, PDF, 5 pages, 796 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17022269&FileExtension=pdf&FileName=24-019%20%20crankshaft-Rel.pdf - Photos (item 4, PDF, 8 pages, 7 photos, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17840500&FileExtension=pdf&FileName=Photos-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.