Investigation number
Occurrence date
Report release date
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Investigation type
External Investigation
Investigation status

During a maintenance inspection of a Pacific Aerospace CT4/B aircraft, registered VH-YCR, a significant crack was identified within the rear spar of the aircraft’s left wing. The Civil Aviation Safety Authority (CASA) requested technical assistance from the ATSB in the metallurgical examination of the spar. To facilitate this assistance, the ATSB initiated an external investigation under the provisions of the Transport Safety Investigation Act 2003.

The ATSB has concluded the metallurgical examination of the rear spar and provided the results of that work to CASA on 4 May 2022.

CASA is responsible for, and will administer, the release of any information from the ATSB’s examination. Any enquires relating to the matter should be directed to CASA at

Crack in rear wing spar

Source: CASA



The information contained in this update is released in accordance with section 25 of the Transport Safety Investigation Act 2003 and is derived from the initial investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that will enhance the ATSB's understanding of the accident as outlined in this update. As such, no analysis or findings are included.

Aircraft Details
Pacific Aerospace Corporation