Airworthiness Directive · Amendment 39-19644 · Flight controls
Viking Air Limited (Type Certificate Previously Held by Bombardier Inc.; de Havilland, Inc.) Airplanes
This AD applies to Viking Air Limited (type certificate previously held by Bombardier Inc.; de Havilland, Inc.) Models 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) Models 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) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as occurrences of excessive wear of elevator cables at pulley location station (STA) 270.3. The FAA is issuing this AD to require actions to address the unsafe condition on these products.
Unless already done, do the following actions in paragraphs (f)(1) and (2) of this AD.
(1) Within the next 90 days after the effective date of this AD or upon reaching the life limit for replacing an elevator or rudder control cable, whichever occurs first, inspect the cables for abnormal wear at pulley location STA 270.3. If there is abnormal wear on a cable, before further flight, in addition to replacing the life-limited cable from service, replace the corresponding pulley. For purposes of this AD, abnormal wear is defined as either of the following:
(i) Wear on an individual wire exceeding 40 percent of the original wire size or the blending of worn areas on the adjacent wires exceeding 40 percent; or
(ii) More than three broken wires in a one-inch span of 7 × 7 cable or six broken wires in a one-inch span of 7 × 19 cable.
(2) Within the next 90 days after the effective date of this AD, revise the Airworthiness Limitations section of your maintenance program by adding the following requirements:
(i) At the scheduled replacement of each life-limited elevator and rudder control cable, inspect the cable for abnormal wear at pulley location STA 270.3.
(ii) If there is abnormal wear on the cable at the pulley location, before further flight, in addition to removing the life-limited cable from service, replace the corresponding pulley.
