Airworthiness Directive · Amendment 39-18334 · Wings
Viking Air Limited Airplanes
This AD applies to Viking Air Limited DHC-3 airplanes, all serial numbers, certificated in any category.
We are adopting a new airworthiness directive (AD) for Viking Air Limited Model DHC-3 Airplanes. 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 corrugation cracking found at various wing stations and on the main spar lower cap. We are 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) through (f)(4) of this AD:
(1) Within 30 days after January 4, 2016 (the effective date of this AD), determine the accumulated wing flight cycles or wing flight hours for each wing by contacting Technical Support at Viking Air Limited. You can find contact information for Viking Air Limited in paragraph (i) of this AD.
(2) Within 30 days after January 4, 2016 (the effective date of this AD), determine all installed supplemental type certificates (STC) or modifications affecting the wings. Based on the accumulated air time determined from paragraph (f)(1) of this AD and before the initial inspection required in paragraph (f)(3) of this AD, install access panels as follows:
(i) If the airplane is free of STCs or any other modifications affecting the wings, install additional inspection access panels following the Accomplishment Instructions Part A of Viking DHC-3 Otter Service Bulletin No. V3/0002, Revision “C”, dated April 30, 2014.
(ii) If the airplane is fitted with STC SA2009NY (which can be found on the internet at: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/F7309B7D9B008C588625734F00730144?OpenDocument&Highlight=sa02009ny), incorporate additional inspection access panels following the Accomplishment Instructions of Viking Air Limited SB 3-STC (03-50)-001, Revision “NC”, dated July 3, 2013.
Note 1 to paragraph (f)(2)(ii) of this AD: STC SA03-50 would be the Canadian equivalent of the United States (FAA) STC SA2009NY.
(iii) If there are other STCs or modifications affecting the wings the operator must contact the FAA to request an FAA-approved alternative method of compliance using the procedures in paragraph (g)(1) of this AD and 14 CFR 39.19. To develop these procedures, we recommend you contact the STC holder for guidance in developing substantiating data.
(3) Based on the accumulated air time on the wings determined in paragraph (f)(1) of this AD, perform initial and repetitive borescope and visual inspections of both the left-hand and right-hand wing box following Part B of the Accomplishment Instructions of Viking DHC-3 Otter Service Bulletin V3/0002, Revision “C”, dated April 30, 2014, using the inspection schedules specified in Table 1 of paragraph (f)(3) of this AD:
| Effectivity | Initial inspection | Repetitive inspection |
|---|---|---|
| If Viking Air Limited SB V3/0002, Revision “A”, dated February 22, 2013; or Viking Air Limited SB V3/0002, Revision “B”, dated July 3, 2013; were complied with prior to January 4, 2016 (the effective date of this AD) | The initial inspection is not required since the inspection was accomplished while complying with Revision “A” or “B” of Viking Air Limited SB V3/0002 | Repetitively inspect not to exceed every 1,600 wing flight hours accumulated after the last inspection or 2,100 wing flight cycles after the last inspection, whichever occurs first. |
| If, as of January 4, 2016 (the effective date of this AD), the airplane has less than 31,200 wing flight hours | Inspect within 800 wing flight hours after January 4, 2016 (the effective date of this AD), or within 6 months January 4, 2016 (the effective date of this AD), whichever occurs first | Repetitively inspect not to exceed every 1,600 wing flight hours accumulated after the last inspection or 2,100 wing flight cycles after the last inspection, whichever occurs first. |
| If, as of January 4, 2016 (the effective date of this AD), the airplane has 31,200 wing flight hours or more but less than 31,600 wing flight hours | Inspect upon or before accumulating 32,000 wing flight hours or within 6 months after January 4, 2016 (the effective date of this AD), whichever occurs first | Repetitively inspect not to exceed every 1,600 wing flight hours accumulated after the last inspection or 2,100 wing flight cycles after the last inspection, whichever occurs first. |
| If, as of January 4, 2016 (the effective date of this AD), the airplane has 31,600 wing flight hours or more | Inspect within 400 wing flight hours accumulated after January 4, 2016 (the effective date of this AD) or 3 months after January 4, 2016 (the effective date of this AD), whichever occurs first | Repetitively inspect not to exceed every 1,600 wing flight hours accumulated after the last inspection or 2,100 wing flight cycles after the last inspection, whichever occurs first. |
(4) If any cracks are found, contact Technical Support at Viking Air Limited for an FAA-approved repair and incorporate the repair before further flight. You can find contact information for Viking Air Limited in paragraph (i) of this AD. The FAA-approved repair must specifically reference this AD.
