Airworthiness Directive · Amendment 39-15741 · Flight controls
Viking Air Limited DHC-6 Series Airplanes
This AD applies to Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 airplanes, serial numbers (SNs) 1 through 696, that
(1) have not had modifications 6/1676 and 6/1726 installed; and
(2) are certificated in any category.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued 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:
Unless already done, within 6 calendar months after December 30, 2008 (the effective date of this AD), do the following actions using Boeing Canada de Havilland Division Service Bulletin No. 6/508, Revision “A,” dated January 31, 1990:
(1) Incorporate de Havilland Modification 6/1676, which assures downward deflection of the elevators when the control locks are engaged.
(2) Incorporate de Havilland Modification 6/1726, which adds to the control lock a warning flag that covers up essential flight instruments on the pilot's instrument panel.
Note: This AD differs from the MCAI and/or service information as follows: No differences.
