Airworthiness Directive · Amendment 39-22059 · Wing structure
Viking Air Limited (Type Certificate Previously Held by Bombardier Inc. and de Havilland, Inc.) Airplanes
This AD applies to Viking Air Limited (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) Model DHC-6-1, DHC-6-100, DHC-6-200, DHC-6-300, and DHC-6-400 airplanes, all serial numbers, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited (Viking) (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) Model DHC-6-1, DHC-6-100, DHC- 6-200, DHC-6-300, and DHC-6-400 airplanes. This 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 identifies the unsafe condition as cracks and corrosion damage to the aileron internal structure. This AD requires visually inspecting the entire aileron internal structure, correcting any damage found, and reporting the inspection results to Viking. The FAA is issuing this AD to address the unsafe condition on these products.
At the compliance time specified in paragraph (g)(1) or (2) of this AD, inspect the left-hand (LH) and right-hand (RH) aileron internal structures for cracks, corrosion, and other damage and take any necessary corrective actions in accordance with the Accomplishment Instructions, steps II.A. through II.A.3. of Viking DHC-6 Twin Otter Service Bulletin V6/0066, Revision A, dated December 9, 2019 (Viking SB V6/0066, Revision A).
(1) For each LH or RH aileron that has accumulated 16,000 or more hours time-in-service (TIS), 32,000 or more flight cycles (FC), or 10 or more years since first installation on an airplane, whichever occurs first: Within 6 months after the effective date of this AD.
(2) For each LH or RH aileron that has accumulated less than 16,000 hours TIS, less than 32,000 FC, and less than 10 years since first installation on an airplane: Within 6 months after accumulating 16,000 hours TIS, 32,000 FC, or 10 years, whichever occurs first.
Within 30 days after the inspection required by paragraph (g)(1) or (2) of this AD or within 30 days after the effective date of this AD, whichever occurs later, report to Viking the information requested on the Inspection Reply Form, page 7, of Viking SB V6/0066, Revision A.
