Accident Piper J3C-65 Cub N77583, Sunday 4 June 2023
ASN logo
 

Date:Sunday 4 June 2023
Time:12:30 LT
Type:Silhouette image of generic J3 model; specific model in this crash may look slightly different    
Piper J3C-65 Cub
Owner/operator:Private
Registration: N77583
MSN: 22073
Year of manufacture:1946
Total airframe hrs:6658 hours
Engine model:Continental C90-8FJ
Fatalities:Fatalities: 0 / Occupants: 2
Other fatalities:0
Aircraft damage: Substantial
Category:Accident
Location:Belfair, WA -   United States of America
Phase: En route
Nature:Training
Departure airport:Vashon, WA (2S1)
Destination airport:Bremerton-Polacca Airport, WA (PWT/KPWT)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
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.

Probable Cause: The total loss of engine power due to the fatigue failure of the crankshaft accessory drive gear.

Accident investigation:
cover
  
Investigating agency: NTSB
Report number: WPR23LA215
Status: Investigation completed
Duration: 1 year and 5 months
Download report: Final report

Sources:

NTSB WPR23LA215

Location

Revision history:

Date/timeContributorUpdates
05-Jun-2023 17:32 Captain Adam Added
27-Jun-2023 16:10 Anon. Updated
29-Jun-2023 01:32 Captain Adam Updated
24-Nov-2024 15:08 ASN Update Bot Updated [Time, Operator, Other fatalities, Phase, Departure airport, Source, Narrative, ]

Corrections or additions? ... Edit this accident description

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2025 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314
www.FlightSafety.org