Airworthiness Directive · Amendment 39-15212 · Viking Air Limited Model DHC-7 Airplanes
Viking Air Limited Model DHC-7 Airplanes
This AD applies to all Viking Air Limited Model DHC-7-1, DHC-7-100, DHC-7-101, DHC-7-102, and DHC-7-103 airplanes, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited Model DHC-7 airplanes. This AD requires an inspection of certain SM-200 servo drive units (power servo motor and housing assemblies) for certain markings, related investigative action if necessary, and modification if necessary. This AD results from a report that some SM-200 servo drive units that were not in configuration MOD H are installed on Model DHC-7 airplanes. MOD H prevents the internal clutch fasteners from backing out. We are issuing this AD to prevent the possibility of internal clutch fasteners from backing out, which could cause an inadvertent servo engagement and consequent reduced controllability of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 12 months after the effective date of this AD: Inspect the SM-200 power servo motor and housing assembly, part numbers 4006719-904, -913 and -933, to determine if MOD H is marked, and before further flight, do all applicable related investigative action and modifications of the power servo motor and housing assembly, in accordance with the Accomplishment Instructions of Viking Alert Service Bulletin 7-22-20, dated May 29, 2006.
Note 1: The alert service bulletin refers to Honeywell Alert Service Bulletin 4006719-22-A0016 (Pub. No. A21-1146-008), Revision 001, dated November 1, 2004, as an additional source of service information for doing the inspection, related investigative action, and modifications.
