2017-16569. Airworthiness Directives; Airbus Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede Airworthiness Directive (AD) 2016-02-01, which applies to certain Airbus Model A320-211, -212, and -231 airplanes. AD 2016-02-01 requires repetitive inspections to detect cracks of the pressurized floor fittings at a certain frame, and renewal of the zone protective finish or replacement of fittings with new fittings if necessary. AD 2016-02-01 also provides an optional modification that is terminating action for the repetitive inspections. Since we issued AD 2016-02-01, the manufacturer conducted an additional fatigue analysis of cracking of the pressurized floor fittings and determined that the optional modification should be a required action. This proposed AD would retain the requirements of AD 2016-02-01, and would require accomplishment of the modification. This proposed AD is intended to complete certain mandated programs intended to support the airplane reaching its limit of validity (LOV) of the engineering data that support the established structural maintenance program. We are proposing this AD to address the unsafe condition on these products.

DATES:

We must receive comments on this proposed AD by September 29, 2017.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Airbus, Airworthiness Office—EIAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone [phone]; fax [phone]; email [e-mail]; Internet http://www.airbus.com. You may view this referenced service information at the FAA, Transport Standards Branch, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0716; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Sanjay Ralhan, Aerospace Engineer, International Section, Transport Standards Branch, FAA, 1601 Lind Avenue SW., Renton, WA 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2017-0716; Product Identifier 2016-NM-165-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed 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 proposed AD.

Discussion

As described in FAA Advisory Circular 120-104 (http://www.faa.gov/​documentLibrary/​media/​Advisory_​Circular/​120-104.pdf), several programs have been developed to support initiatives that will ensure the continued airworthiness of aging airplane structure. The last element of those initiatives is the requirement to establish a LOV of the engineering data that support the structural maintenance program under 14 CFR 26.21. This proposed AD is the result of an assessment of the previously established programs by the design approval holder (DAH) during the process of establishing the LOV for the affected airplanes. The actions specified in this proposed AD are necessary to complete certain programs to ensure the continued airworthiness of aging airplane structure and to support an airplane reaching its LOV.

On January 9, 2016, we issued AD 2016-02-01, Amendment 39-18380 (81 FR 4878, January 28, 2016) (“AD 2016-02-01”), for certain Airbus Model A320-211, -212, and -231 airplanes. AD 2016-02-01 was prompted by an extended service goal analysis by the manufacturer, which revealed that the compliance times and repetitive inspection intervals to detect and correct fatigue cracking in the pressurized floor fittings at frame (FR) 36 should be reduced to meet the original design service goal. AD 2016-02-01 requires repetitive visual inspections to detect cracks of the pressurized floor fittings at FR 36, and renewal of the zone protective finish or replacement of fittings with new fittings if necessary. AD 2016-02-01 also provides an optional terminating action for the repetitive inspections. We issued AD 2016-02-01 to detect and correct fatigue cracking in the pressurized floor fittings at FR 36, which could result in failure of a floor fitting and subsequent depressurization of the fuselage.

Since we issued AD 2016-02-01, the manufacturer conducted an additional fatigue analysis to extend the service goal of the airplane and to meet the limit of validity requirements of the widespread fatigue damage (WFD) regulations. Also, the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2016-0181, dated September 13, 2016 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for certain Airbus Model A320-211, -212, and -231 airplanes. The MCAI states:

During centre fuselage certification full scale fatigue testing, damage was found on the pressurized floor fittings at Frame (FR) 36, below the lower surface panel. This condition, if not detected and corrected, could affect the structural integrity of the aeroplane.

To prevent such damage, Airbus developed modification 21282, which was introduced in production from MSN [manufacturer serial number] 0105, to reinforce the pressurized floor fitting lower surface by changing material. For affected in-service aeroplanes, Airbus issued Service Bulletin (SB) A320-57-1028, introducing repetitive inspections, and SB A320-57-1029, which provides modification instructions.

DGAC [Direction Générale de l'Aviation Civile] France issued AD 95-099-067 to require these repetitive inspections and, depending on findings, corrective action(s), while the modification was specified in that [French] AD as optional terminating action for these inspections.

Following new analysis in the frame of Extended Service Goal exercise, the inspection thresholds and intervals were revised to meet the original Design Service Goal. Consequently, EASA issued AD 2013-0226 [which corresponds to FAA AD 2016-02-01 (81 FR 4878, January 28, 2016)] to retain the requirements of DGAC France AD 95-099-067, which was superseded, but required those actions within reduced compliance times.

Since that [EASA] AD was issued, in the frame of Widespread Fatigue Damages analysis, the situation has been reassessed and it has been decided to reclassify the modification, still stated as `optional' terminating action in EASA AD 2013-0226, to the status `mandatory'.

For the reasons described above, this [EASA] AD retains the requirements of EASA AD 2013-0226, which is superseded, but requires embodiment of the modification as specified in Airbus SB A320-57-1029.

You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0716.

Related Service Information Under 1 CFR Part 51

Airbus has issued Service Bulletin A320-57-1028, Revision 02, dated June 3, 2013. The service information describes procedures for an inspection to detect cracks of the pressurized floor fittings at FR 36, renewal of the zone protective finish, and replacement of fittings with new fittings.

Airbus has also issued Service Bulletin A320-57-1029, Revision 02, dated June 16, 1999. The service information describes procedures for modification of the pressurized floor fittings at FR 36.

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 Proposed 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 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.

Costs of Compliance

We estimate that this proposed AD affects 13 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection	11 work-hours × $85 per hour = $935 per inspection cycle	$0	$935 per inspection cycle	$12,155 per inspection cycle.
Modification	85 work-hours × $85 per hour = $7,225	5,320	12,545	163,085.

We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this proposed 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 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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2016-02-01, Amendment 39-18380 ( 81 FR 4878, January 28, 2016), and adding the following new AD:

Airbus: Docket No. FAA-2017-0716; Product Identifier 2016-NM-165-AD.

(a) Comments Due Date

We must receive comments by September 29, 2017.

(b) Affected ADs

This AD replaces AD 2016-02-01, Amendment 39-18380 (81 FR 4878, January 28, 2016) (“AD 2016-02-01”).

(c) Applicability

This AD applies to Airbus Model A320-211, -212, -214, and -231 airplanes, certificated in any category, manufacturer serial numbers up through 0104 inclusive.

(d) Subject

Air Transport Association (ATA) of America Code 57, Wings.

(e) Reason

This proposed AD is intended to complete certain mandated programs intended to support the airplane reaching its limit of validity (LOV) of the engineering data that support the established structural maintenance program. We are proposing this AD to prevent fatigue cracking in the pressurized floor fittings at frame 36, which could result in the reduced structural integrity of the floor fittings and subsequent depressurization of the fuselage.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Inspection

(1) At the latest of the times specified in paragraphs (g)(1)(i), (g)(1)(ii), and (g)(1)(iii) of this AD: Do a detailed inspection of the pressurized floor fittings at FR 36, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-57-1028, Revision 02, dated June 3, 2013. Repeat the inspection thereafter at intervals not to exceed 9,300 flight cycles or 18,600 flight hours, whichever occurs first.

(i) Before exceeding 20,900 flight cycles or 41,800 flight hours, whichever occurs first since first flight of the airplane.

(ii) Within 9,300 flight cycles or 18,600 flight cycles since the most recent inspection accomplished in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-57-1028, Revision 02, dated June 3, 2013.

(iii) Within 1,250 flight cycles or 2,500 flight hours after March 3, 2016 (the effective date of AD 2016-02-01), without exceeding 12,000 flight cycles since the most recent inspection accomplished in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-57-1028, Revision 02, dated June 3, 2013.

(2) If any crack is found during any inspection required by paragraph (g)(1) of this AD: Before further flight, repair using a method approved by the Manager, International Section, Transport Standards Branch, FAA; or the European Aviation Safety Agency (EASA); or Airbus's EASA Design Organization Approval (DOA).

(h) Modification

Before exceeding 48,000 total flight cycles or 96,000 total flight hours, whichever occurs first since first flight of the airplane: Modify (replace aluminum fittings with titanium fittings) the pressurized floor fittings at FR 36, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-57-1029, Revision 02, dated June 16, 1999. Accomplishment of this modification is terminating action for the repetitive inspections required by paragraph (g) of this AD for the modified airplane only.

(i) Credit for Previous Actions

(1) This paragraph provides credit for the inspection required by paragraph (g) of this AD, if that inspection was performed before the effective date of this AD using Airbus Service Bulletin A320-57-1028, dated August 12, 1991; or Revision 01, dated June 3, 2013.

(2) This paragraph provides credit for the modification required by paragraph (h) of this AD, if that modification was performed before the effective date of this AD using Airbus Service Bulletin A320-57-1029, dated August 12, 1991; or Revision 01, dated November 10, 1992.

(j) Other FAA AD Provisions

The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Section, Transport Standards Staff, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the International Section, send it to the attention of the person identified in paragraph (k)(2) of this AD. Information may be emailed to [e-mail]. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(2) Contacting the Manufacturer: As of the effective date of this AD, for any requirement in this AD to obtain corrective actions from a manufacturer, the action must be accomplished using a method approved by the Manager, International Section, Transport Standards Branch, FAA; or the EASA; or Airbus's DOA. If approved by the DOA, the approval must include the DOA-authorized signature.

(k) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA AD 2016-0181, dated September 13, 2016, for related information. This MCAI may be found in the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0716.

(2) For more information about this AD, contact Sanjay Ralhan, Aerospace Engineer, International Section, Transport Standards Branch, FAA, 1601 Lind Avenue SW., Renton, WA 98057-3356; telephone [phone]; fax [phone].

(3) For service information identified in this AD, contact Airbus, Airworthiness Office—EIAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone [phone]; fax [phone]; email [e-mail]; Internet http://www.airbus.com. You may view this referenced service information at the FAA, Transport Standards Branch, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.

Issued in Renton, Washington, on July 28, 2017.

John P. Piccola, Jr.,

Acting Director, System Oversight Division, Aircraft Certification Service.