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ASN Wikibase Occurrence # 175577
Last updated: 23 July 2020
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Date:16-APR-2015
Time:12:27
Type:Silhouette image of generic BN2P model; specific model in this crash may look slightly different
Britten-Norman BN-2B-20 Islander
Owner/operator:Roc Aviation Company
Registration: B-68802
C/n / msn: 2241
Fatalities:Fatalities: 0 / Occupants: 4
Other fatalities:0
Aircraft damage: Minor
Location:near Taitung Airport (TTT/RCFN) -   Taiwan
Phase: En route
Nature:Ferry/positioning
Departure airport:Taitung Airport (TTT/RCFN)
Destination airport:Taipei-Sung Shan Airport (TSA/RCSS)
Investigating agency: ASC
Narrative:
An Roc Aviation Company (RAC) BN-2B-20 Islander aircraft, operated on a ferry flight from Taitung to Taipei.
After took off the generator warning light illuminated and the left engine rpm dropped. The flight crew judged that the left engine had failed. Therefore, emergency procedures were performed, and flight crew requested to return Taitung Airport. After inspection, the left engine damage was found.

Findings related to probable causes:
A post occurrence examination found that 5 out of 8 stud bolt nuts were not at their positions. During engine overhaul, under torque condition might exist when number 3 cylinder was installed. This caused insufficient tightness of number 3 cylinder and crankcase connection. The accumulated flight hours of left engine were more than 1,400 hours. Long term operation of engine and axial movement of piston led to the looseness of stud bolt nuts. Some stud bolt nuts might be separated before the occurrence to produce vibration at the mating surface of number 3 cylinder and crankcase during engine operation. Subsequent bending or fracture of stud bolts thus caused the separation of number 3 cylinder from crankcase and then damaged to left engine.

Sources:

http://www.asc.gov.tw/upload/acd_att/B-68802%20Executive%20Summary.pdf


Images:

Photo of B-68802 courtesy AirHistory.net


Taipei - Sung Shan (RCSS / TSA)
17 September 2017; (c) Robbie Shaw

Revision history:

Date/timeContributorUpdates
20-Apr-2015 19:34 harro Added
21-May-2016 06:38 harro Updated [Time, Cn, Total occupants, Source, Narrative]

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