Discussion
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2018-0058, dated March 14, 2018 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for all Airbus Model A350-941 airplanes. The MCAI states:
Occurrences have been reported by Airbus A350 operators of malfunctions of Station Position Pick-Off Units (SPPU). Investigations indicated that internal wiring failures occurred due to water ingress via certain electrical connectors, inducing subsequent icing during flight.
This condition, if not detected and corrected, could lead to hidden sensor signal drift (at flap station 3) which, in combination with an independent failure of a flap down drive disconnect, might lead to in-flight detachment of the outer flap surface, possibly resulting in damage to theaeroplane, and/or injury to persons on the ground.
Airbus determined that the SPPU calibration test can highlight all hidden faults, but this test is only scheduled after removal/ installation of the equipment. Consequently, to address this potential unsafe condition, Airbus issued the SB [Service Bulletin A350-27-P021, dated February 13, 2018], providing instructions to accomplish the SPPU calibration test at regular intervals.
For the reason described above, this [EASA] AD requires repetitive SPPU calibration test and, depending on findings, accomplishment of applicable corrective action(s) [applying corresponding airplane fault isolation].
Pending the results of the on-going investigation, this [EASA] AD is still considered to be an interim measure and further [EASA] AD action may follow.
You may examine the MCAI on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018- 0269.
Related Service Information Under 1 CFR Part 51Airbus has issued Service Bulletin A350-27-P021, dated February 13, 2018. The service information describes performing repetitive SPPU calibration tests, and applying the corresponding airplane fault isolation if necessary. 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 ADDRESSES section.
FAA's Determination and Requirements of This AD
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 issuing this AD because we evaluated all pertinent information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.
FAA's Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this
[[Page 15049]]
rule because malfunctions of the SPPU and failures of the internal wiring due to water ingress via certain electrical connectors can induce icing, which under certain conditions, could lead to in-flight detachment of the outer flap surface, and consequent damage to the airplane. Therefore, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in fewer than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include ``Docket No. FAA-2018-0269; Product Identifier 2018-NM-051-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD based on those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.
Costs of Compliances
We estimate that this AD affects 6 airplanes of U.S. registry. We estimate the following costs to comply with this AD:
Estimated Costs ----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- SPPU calibration test.......... 2 work-hours x $85 per $0 $170 per test $1,020 per test
hour = $170 per test cycle. cycle
cycle. ----------------------------------------------------------------------------------------------------------------
We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this AD.
Authority for This Rulemaking
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.
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 transport category airplanes to the Director of the System Oversight Division.
Regulatory Findings
We determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:
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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.