Airworthiness Directive · Amendment 39-22601 · Engine mount section
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-3 airplanes, all serial numbers, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) (Viking) Model DHC-3 airplanes. This AD was prompted by a report of cracking in the left-hand side (LHS) and right- hand side (RHS) lower engine mount pickup fittings. This AD requires a one-time inspection of the affected parts for cracking, deformation, corrosion, fretting or wear, paint or surface coating damage, and loose, missing, or broken fasteners, and applicable corrective actions. This AD also requires reporting the inspection results. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 6 months after the effective date of this AD, do a detailed visual inspection of the lower engine mount pickup fittings part numbers (P/Ns) C3FS46-7 and C3FS46-8 and the upper engine mount pickup fittings P/Ns C3FS42-5 and C3FS42-6 for cracking, deformation (altered form or shape), corrosion, fretting or wear, paint or surface coating damage (loose, delaminating, flaking, peeling, chipping of the coating or paint, exposed bare metal, or corroded), and loose, missing, or broken fasteners, in accordance with Part A, steps 1 through 8, of the Accomplishment Instructions in Viking Service Bulletin V3/0012, Revision NC, dated January 20, 2022 (Viking SB V3/0012).
(2) If any crack or deformation (altered form or shape) of any engine mount pickup fitting is found during the detailed visual inspection required by paragraph (g)(1) of this AD, before further flight, replace the fitting with a new or serviceable part, in accordance with Part A, step 10, of the Accomplishment Instructions in Viking SB V3/0012. For purposes of this AD, “new” means zero hours time-in-service.
(3) If any paint or surface coating of the engine mount pickup fitting is found damaged (loose, delaminating, flaking, peeling, chipping of the coating or paint, exposed bare metal, or corroded) during the detailed visual inspection required by paragraph (g)(1) of this AD, before further flight, repair the fitting in accordance with Part 1 of Viking PSM 1-3-5, DHC-3 Otter Supplemental Inspection and Corrosion Control Manual, Revision IR, dated December 21, 2017 (Viking PSM 1-3-5, Revision IR), and Part A, step 12, of the Accomplishment Instructions in Viking SB V3/0012. Where Part 1 of Viking PSM 1-3-5, Revision IR, specifies contacting Viking if the alloy and condition of an affected engine mount pickup fitting cannot be identified, this AD requires contacting the Manager, International Validation Branch, FAA; Transport Canada; or Viking's Transport Canada Design Approval Organization (DAO) for instructions.
(4) If any loose, missing, or broken fastener is found during the detailed visual inspection required by paragraph (g)(1) of this AD, before further flight, replace the fastener with a new fastener, do a detailed visual inspection of the fastener hole to detect cracking, corrosion, an elongated bore hole, bore surface roughness, or other defects (abnormalities when compared to a new part), and repair any damage found or replace the engine mount pickup fitting with a new or serviceable part if damage is beyond repairable limits, in accordance with Part 1 of Viking PSM 1-3-3 DHC-3 Otter Repair Manual, dated August 1, 1963, and Part A, step 9, of the Accomplishment Instructions in Viking SB V3/0012.
(5) If any corrosion, wear, or fretting to any engine mount pickup fitting is found during the detailed visual inspection required by paragraph (g)(1) of this AD, before further flight, contact the Manager, International Validation Branch, FAA; Transport Canada; or Viking's Transport Canada DAO to obtain instructions for an approved repair and, within the compliance timeframe specified therein, do the repair. If approved by the DAO, the approval must include the DAO-authorized signature. Alternatively, before further flight, replace the engine mount pickup fitting with a new or serviceable part in accordance with Part A, step 10, of the Accomplishment Instructions in Viking SB V3/0012.
Report the inspection results from the detailed visual inspection required by paragraph (g)(1) of this AD at the applicable time specified in paragraph (h)(1) or (2) of this AD in accordance with Part A, step 14, of the Accomplishment Instructions in Viking SB V3/0012.
(1) For inspections done on or after the effective date of this AD: Submit the report within 30 days after the inspection.
(2) For inspections done before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.
