Federal Aviation Administration (FAA), Department of Transportation (DOT).
Notice of proposed rulemaking (NPRM).
We propose to adopt a new airworthiness directive (AD) for certain Viking Air Limited Models DHC–2 Mk. I and DHC–2 Mk. III airplanes. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated 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 cracks reported on the forward and aft float strut wire pull fittings. We are issuing this proposed AD to require actions to address the unsafe condition on these products.
We must receive comments on this proposed AD by March 28, 2019.
You may send comments by any of the following methods:
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For service information identified in this proposed AD, contact Viking Air Limited Technical Support, 1959 De Havilland Way, Sidney, British Columbia, Canada, V8L 5V5; telephone: (North America) (800) 663–8444; fax: (250) 656–0673; email:
You may examine the AD docket on the internet at
Aziz Ahmed, Aerospace Engineer, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone: (516) 287–7329; fax: (516) 794–5531; email:
We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the
We will post all comments we receive, without change, to
Transport Canada, which is the aviation authority for Canada, has issued AD Number CF–2018–10, dated April 18, 2018 (referred to after this as “the MCAI”), to correct an unsafe condition for certain Viking Air Limited Models DHC–2 Mk. I and DHC–2 Mk. III airplanes. The MCAI states:
Cracks have been reported on the Forward and Aft float strut wire pull fittings on DHC–2 Mk. I aeroplanes equipped with the 5600 lb gross weight increase kit installed in accordance with STC SA92–63 or SA00299NY and on DHC–2 Mk. III aeroplanes equipped with the 6000 lb gross weight increase kit installed in accordance with STC SA91–18 or SA945NE. An investigation found that the forward and aft wire pull fittings (P/N VALTBS1245–1/–2 and P/N VALTBS1244–1, respectively) are prone to stress corrosion cracking at low cycles/hours.
Failure of these wire pull fittings will reduce the strength of the float undercarriage below the required structural capability and could result in a failure of the undercarriage causing the aeroplane to tip over and be submerged.
Therefore this AD requires that the forward and aft wire pull fittings be replaced with P/N VALTBS1245–3/–4 and P/N VALTBS1244–3/–4 (LH/RH) fittings respectively. These fittings are geometrically similar to the legacy fittings and are made of a different aluminum alloy that is less susceptible to stress corrosion cracking.
In addition to replacing the fittings, it is necessary to implement a recurring visual inspection of the fittings to assure continuing airworthiness.
You may examine the MCAI on the internet at
In preparation of AD actions such as notices of proposed rulemaking and immediately adopted final rules, it is the practice of the FAA to obtain technical information and information on the operational and economic impact from design approval holders and aircraft operators. We discussed certain aspects of this AD by email with Viking. A copy of these email contacts can be found in the rulemaking docket. For information on locating the docket, see “Examining the AD Docket.”
Viking has issued Service Bulletin (SB) Number V2/003, Revision NC, dated November 28, 2012, for Model DCH–2 Mk. I airplanes, and SB Number V2/002, Revision A, dated September 12, 2011, for Model DCH–2 Mk. III airplanes. For the applicable airplanes, the service information describes procedures for replacing the forward and aft float strut wire pull fittings and specifies implementing repetitive visual inspections of the fittings. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the
This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with this State of Design Authority, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.
The MCAI requires returning cracked fittings to Viking, and this proposed AD would not. The MCAI also prohibits installation of an affected wire pull fitting on any airplane, and this proposed AD would not.
We estimate that this proposed AD will affect 136 products of U.S. registry. We also estimate replacing the fittings would take about 12 work-hours at an average labor rate of $85 per work-hour, and required parts would cost about $2,741. Based on these figures, we estimate a cost of $3,761 per airplane and $511,496 for the U.S. operator fleet.
Inspecting the fittings would take about .5 work-hour for an estimated cost of $42.50 per airplane and $5,780 for the U.S. fleet, per inspection cycle.
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. “Subtitle VII: Aviation Programs,” describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in “Subtitle VII,
This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to small airplanes, gliders, balloons, airships, domestic business jet transport airplanes, and associated appliances to the Director of the Policy and Innovation Division.
We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this proposed regulation:
(1) Is not a “significant regulatory action” under Executive Order 12866,
(2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
49 U.S.C. 106(g), 40113, 44701.
We must receive comments by March 28, 2019.
None.
This AD applies to following Viking Air Limited airplanes, certificated in any category:
(1) Model DHC–2 Mk. I airplanes altered by Supplemental Type Certificate (STC) SA92–63 or SA00299NY with a float strut wire pull fitting part number (P/N) VALTBS1245–1,P/N VALTBS1245–2, or P/N VALTBS1244–1; and
(2) Model DHC–2 Mk. III airplanes altered by STC SA91–18 or SA945NE with a float strut wire pull fitting P/N VALTBS1245–1,P/N VALTBS1245–2, or P/N VALTBS1244–1.
Air Transport Association of America (ATA) Code 53: Fuselage.
This AD was prompted by mandatory continuing airworthiness information (MCAI) originated 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 cracks reported on the forward and aft float strut wire pull fittings. We are issuing this AD to prevent failure of the wire pull fittings that could reduce the strength of the float undercarriage below the required structural capability, resulting in a failure of the undercarriage causing the airplane to tip over and submerge.
Unless already done, do the following actions.
(1) Within 90 days after the effective date of this AD:
(i) Replace each forward wire pull fitting P/N VALTBS1245–1 and P/N VALTBS1245–2 with P/N VALTBS1245–3 Left Hand (LH) or P/N VALTBS1245–4 Right Hand (RH) by following the Accomplishment Instructions, section A, steps 1 through 8, of Viking Service Bulletin No. V2/003, Revision NC, dated November 28, 2012 (SB No. V2/003), or Viking Service Bulletin No. V2/002, Revision A, dated September 12, 2011 (SB No. V2/002), as applicable to your model airplane.
(ii) Within 110 hours time-in-service (TIS) after the replacement of the forward wire pull fittings and thereafter at intervals not to exceed 110 hours TIS, visually inspect each forward wire pull fitting for corrosion and cracks. If any corrosion or cracking is found during any of the required inspections, before further flight, replace the fitting with fitting P/N VALTBS1245–3 (LH) or P/N VALTBS1245–4 (RH).
(2) Within 180 days after the effective date of this AD:
(i) Replace each aft wire pull fitting P/N VALTBS1244–1 with P/N VALTBS1244–3 (LH) or P/N VALTBS1244–4 (RH) by following the Accomplishment Instructions, section B, steps 1 through 8, of SB No. V2/003 or SB No. V2/002, as applicable to your model airplane.
(ii) Within 110 hours TIS after the replacement of the aft wire pull fittings and thereafter at intervals not to exceed 110 hours TIS, visually inspect each aft wire pull fitting for corrosion and cracks. If any corrosion or cracking is found during any of the required inspections, before further flight, replace the fitting with fitting P/N VALTBS1244–3 (LH) or P/N VALTBS1244–4 (RH).
The following provisions also apply to this AD:
(1)
(2)
Refer to MCAI Transport Canada AD Number CF–2018–10, dated April 18, 2018, for related information. You may examine the MCAI on the internet at