Federal Aviation Administration (FAA), DOT.
Notice of proposed rulemaking (NPRM).
We propose to adopt a new airworthiness directive (AD) for all Airbus Model A310–203, –221, –222, –304, –322, –324, and –325 airplanes. This proposed AD was prompted by an evaluation by the design approval holder (DAH) indicating that the wing bottom skin at the main landing gear (MLG) reinforcing plate is subject to widespread fatigue damage (WFD). This proposed AD would require a modification of the wing bottom skin at the MLG reinforcing plate. We are proposing this AD to address the unsafe condition on these products.
We must receive comments on this proposed AD by July 3, 2017.
You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
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For service information identified in this NPRM, contact Airbus SAS, Airworthiness Office—EAW, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email
You may examine the AD docket on the Internet at
Dan Rodina, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057–3356; telephone 425–227–2125; fax 425–227–1149.
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
Fatigue damage can occur locally, in small areas or structural design details, or globally, in widespread areas. Multiple-site damage is widespread damage that occurs in a large structural element such as a single rivet line of a lap splice joining two large skin panels. Widespread damage can also occur in multiple elements such as adjacent frames or stringers. Multiple-site damage and multiple-element damage cracks are typically too small initially to be reliably detected with normal inspection methods. Without intervention, these cracks will grow, and eventually compromise the structural integrity of the airplane. This condition is known as widespread fatigue damage. It is associated with general degradation of large areas of structure with similar structural details and stress levels. As an airplane ages, WFD will likely occur, and will certainly occur if the airplane is operated long enough without any intervention.
The FAA's WFD final rule (75 FR 69746, November 15, 2010) became effective on January 14, 2011. The WFD rule requires certain actions to prevent structural failure due to WFD throughout the operational life of certain existing transport category airplanes and all of these airplanes that will be certificated in the future. For existing and future airplanes subject to the WFD rule, the rule requires that DAHs establish a limit of validity (LOV) of the engineering data that support the structural maintenance program. Operators affected by the WFD rule may not fly an airplane beyond its LOV, unless an extended LOV is approved.
The WFD rule (75 FR 69746, November 15, 2010) does not require identifying and developing maintenance actions if the DAHs can show that such actions are not necessary to prevent WFD before the airplane reaches the LOV. Many LOVs, however, do depend on accomplishment of future maintenance actions. As stated in the WFD rule, any maintenance actions necessary to reach the LOV will be mandated by airworthiness directives through separate rulemaking actions.
In the context of WFD, this action is necessary to enable DAHs to propose LOVs that allow operators the longest operational lives for their airplanes, and still ensure that WFD will not occur.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2016–0170, dated August 19, 2016 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for all Airbus Model A310–203, –221, –222, –304, –322, –324, and –325 airplanes. The MCAI states:
In response to the FAA Part 26 rule, wing structural items of the Airbus A310 design that are deemed potentially susceptible to Widespread Fatigue Damage (WFD) have been assessed. The bottom skin at the main landing gear (MLG) reinforcing plate has been highlighted as an area susceptible to Multi Site Damage (MSD).
This condition, if not corrected, could reduce the structural integrity of the wing.
Airbus performed a detailed widespread fatigue damage tolerance analysis of the bottom skin at the MLG reinforcing plate, and concluded that a modification is necessary to the fastener holes at the inboard edge of the reinforcing plate forward of the rear spar. The modification consists of inspection [related investigative actions of a check and a rotating probe inspection] and a first oversize of the critical holes on the first two rows of fasteners [and corrective actions,
For the reasons described above, this [EASA] AD requires certain modifications to the wing bottom skin at the MLG reinforcing plate, forward of the wing rear spar [including related investigative actions of a check and a rotating probe inspection and corrective actions,
You may examine the MCAI in the AD docket on the Internet at
We reviewed Airbus Service Bulletin A310–57–2104, dated December 15, 2015. The service information describes procedures for a modification of the left hand (LH) and right hand (RH) wing bottom skin at the MLG reinforcing plate, including related investigative actions and applicable corrective actions. 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 the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design.
The compliance time for the replacement specified in this proposed AD for addressing WFD was established to ensure that discrepant structure is replaced before WFD develops in airplanes. Standard inspection techniques cannot be relied on to detect WFD before it becomes a hazard to flight. We will not grant any extensions of the compliance time to complete any AD-mandated service bulletin related to WFD without extensive new data that would substantiate and clearly warrant such an extension.
We estimate that this proposed AD affects 8 airplanes of U.S. registry.
We estimate the following costs to comply with this proposed AD:
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, Part A, Subpart III, Section 44701: General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
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 July 3, 2017.
None.
This AD applies to Airbus Model A310–203, –221, –222, –304, –322, –324, and –325 airplanes, certificated in any category, all manufacturer serial numbers.
Air Transport Association (ATA) of America Code 57, Wings.
This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the wing bottom skin at the main landing gear (MLG) reinforcing plate is subject to widespread fatigue damage (WFD). We are issuing this AD to prevent multi-site damage in the bottom skin at the MLG reinforcing plate, which could result in reduced structural integrity of the wing.
Comply with this AD within the compliance times specified, unless already done.
The following provisions also apply to this AD:
(1)
(2)
(3)
(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA Airworthiness Directive 2016–0170, dated August 19, 2016, for related information.
(2) For more information about this AD, contact Dan Rodina, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057–3356; telephone 425–227–2125; fax 425–227–1149.
(3) For service information identified in this AD, contact Airbus SAS, Airworthiness Office—EAW, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email