# Proposed AD FAA-2008-0368: Viking Air Limited Models DHC-6-1, DHC- 6-100, DHC-6-200, and DHC-6-300 Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Comment period closed
- Products: Viking Air
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: March 31, 2008, 73 FR 16782
- Comments due: April 30, 2008
- Docket: FAA-2008-0368 (https://www.regulations.gov/docket/FAA-2008-0368, where comments are filed)
- Project: 2008-CE-007-AD
- FR document: E8-6469
- Official PDF: https://openairdocs.org/files/sha256/99/9a/999a9bc60fec7a71c4345ab9d12a70b9973438bfca36f6fb0b47ae42058f895f (from https://www.govinfo.gov/content/pkg/FR-2008-03-31/pdf/E8-6469.pdf)
- Federal Register: https://www.federalregister.gov/documents/2008/03/31/E8-6469/airworthiness-directives-viking-air-limited-models-dhc-6-1-dhc-6-100-dhc-6-200-and-dhc-6-300
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B8670E6DCECD8D528625741D00680A5A.0001
- Page: https://openairdocs.org/proposed/FAA-2008-0368

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

There have been reports of inter-rivet cracking on several wing front spar adapter assemblies (P/N C6WM1027-1) on the horizontal and vertical flanges. It was determined that the cracking was caused by stress corrosion in the short transverse grain initiated by local riveting induced stresses.

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

## Notices in this docket

- Mar 31, 2008: Notice of proposed rulemaking (NPRM). (first notice), FR document E8-6469, comments due Apr 30, 2008 (https://www.federalregister.gov/documents/2008/03/31/E8-6469/airworthiness-directives-viking-air-limited-models-dhc-6-1-dhc-6-100-dhc-6-200-and-dhc-6-300)

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