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ASN Wikibase Occurrence # 223987
Last updated: 24 April 2019
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Date:13-AUG-2017
Time:17:00
Type:Silhouette image of generic J3 model; specific model in this crash may look slightly different
Piper J3C
Owner/operator:Berkshire Aviation Enterprises Inc
Registration: N98550
C/n / msn: 18763
Fatalities:Fatalities: 0 / Occupants: 2
Other fatalities:0
Aircraft damage: Substantial
Category:Accident
Location:Salisbury, CT -   United States of America
Phase:
Nature:Training
Departure airport:Great Barringto, MA (GBR)
Destination airport:Great Barringto, MA (GBR)
Investigating agency: NTSB
Narrative:
During cruise flight, the airplane experienced a total loss of engine power, and the flight instructor performed a forced landing into trees. The engine crankshaft was replaced about 4 years and about 317 hours of operation before the accident. Teardown examination of the engine revealed that the crankshaft gear screws were fractured, and the crankshaft gear was separated from the crankshaft. Fretting was observed near two of the four crankshaft screw holes and corresponded to two elongated screw holes on the crankshaft gear. The crankshaft and crankshaft gear did not contain a dowel pin as specified in the most current versions of the manufacturer’s illustrated parts catalog and overhaul manual, which were published more than 2 years before the crankshaft replacement. Additionally, the crankshaft gear did not contain a dowel pin hole, which was consistent with a crankshaft gear for an older, different model engine. Both publications contained numerous instructions and references to use a crankshaft gear with a dowel pin hole and to align the gear to the crankshaft with a dowel pin, which would pilot the crankshaft gear on the crankshaft. Thus, it is likely that when the crankshaft was replaced, maintenance personnel did not use the most recent manuals and installed a crankshaft gear for a different engine, which led to the crankshaft gear’s failure and the subsequent loss of all engine power.

Probable Cause: An improper replacement of the crankshaft by maintenance personnel, which resulted in a failure of the crankshaft gear and total loss of engine power.

Sources:

NTSB: https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20170813X83417&key=1

Accident investigation:
cover
  
Investigating agency: NTSB
Status: Investigation completed
Duration: 1 year and 8 months
Download report: Final report


Revision history:

Date/timeContributorUpdates
15-Apr-2019 14:42 ASN Update Bot Added

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