2010-19144. Airworthiness Directives; Airbus Model A318-111 and A318-112 Airplanes and Model A319, A320, and A321 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

We are revising an earlier NPRM for the products listed above. This action revises the earlier NPRM by expanding the scope. 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:

Damage to the lower lateral fittings of the 80VU rack, typically elongated holes, migrated bushes [bushings], and/or missing bolts have been reported in-service. In addition damage to the lower central support fitting (including cracking) has been reported.

In the worst case scenario a complete failure of the 80VU fittings in combination with a high load factor or strong vibration could lead to failure of the rack structure and/or computers or rupture/disconnection of the cable harnesses to one or more computers located in the 80VU. This rack contains computers for Flight Controls, Communication and Radio-navigation. These functions are duplicated across other racks but during critical phases of flight the multiple system failures/re-configuration may constitute an unsafe condition.

* * * * *

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

DATES:

We must receive comments on this proposed AD by August 30, 2010.

ADDRESSES:

You may send comments 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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone [phone]; fax [phone]; e-mail: [e-mail]; Internet http://www.airbus.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. 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;​; or in person at the Docket Operations office 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:

Tim Dulin, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

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 ADDRESSES section. Include “Docket No. FAA-2008-0670; Directorate Identifier 2007-NM-339-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

We proposed to amend 14 CFR part 39 with an earlier NPRM for the specified products, which was published in the Federal Register on June 24, 2008 (73 FR 35601). That earlier NPRM proposed to require actions intended to address the unsafe condition for the products listed above.

Since that NPRM was issued, the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2007-0276R1, dated March 18, 2010 (corrected April 12, 2010) (referred to after this as “the MCAI”), to revise EASA AD 2007-0276, dated October 26, 2007, which we referred to in the NPRM. The MCAI adds an optional terminating action to the repetitive inspections. The MCAI states:

Damage to the lower lateral fittings of the 80VU rack, typically elongated holes, migrated bushes [bushings], and/or missing bolts have been reported in-service. In addition damage to the lower central support fitting (including cracking) has been reported.

In the worst case scenario a complete failure of the 80VU fittings in combination with a high load factor or strong vibration could lead to failure of the rack structure and/or computers or rupture/disconnection of the cable harnesses to one or more computers located in the 80VU. This rack contains computers for Flight Controls, Communication and Radio-navigation. These functions are duplicated across other racks but during critical phases of flight the multiple system failures/re-configuration may constitute an unsafe condition.

For the reasons described above, EASA AD 2007-0276 was issued to require repetitive [detailed] inspection of the lower lateral 80VU fittings for damage and [repetitive detailed] inspection of the lower central 80VU support for damage and cracking, and the accomplishment of associated corrective actions, depending on findings.

Since AD 2007-0276 was issued, Airbus introduced a new reinforced lower central support for the 80VU.

This [EASA] AD has been revised to introduce the new reinforced lower central support as an optional terminating action to the repetitive inspections.

* * * * *

The associated corrective actions include repair or replacement of the lower lateral fittings and/or replacement of the lower central support. Modifying the 80VU lower lateral fittings (the modification includes replacing the 80VU lower lateral fittings) eliminates the need for the repetitive inspection of the lower lateral fittings. Replacing the 80VU lower central support (i.e., replacing the pyramid fitting on the 80VU rack with a new, reinforced fitting) eliminates the need for the repetitive inspection of the lower central support. You may obtain further information by examining the MCAI in the AD docket.

Also, we have determined that for any cracking found during an inspection specified in paragraph (i) of this supplemental NPRM (referred to as paragraph (f)(3) in the NPRM), the corrective action specified in paragraph (j) of this supplemental NPRM (referred to as paragraph (f)(4) in the NPRM) must be done before further flight. Our policy specifies the requirement to repair known cracks before further flight (though we might make exceptions to this policy in certain cases of unusual need, as discussed below). This policy is based on the fact that such damaged airplanes do not conform to the FAA-certificated type design and, therefore, are not airworthy until a properly approved repair is made. We consider the compliance times in this AD to be adequate to allow operators to acquire parts to have on hand in the event that a crack is detected during inspection. Therefore, we have determined that, due to the safety implications and consequences associated with such cracking, any subject 80VU rack lower central support that is found to be cracked must be replaced or modified before further flight.

Also, since the NPRM was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this supplemental NPRM.

Comments

We have considered the following comments received on the earlier NPRM.

Requests To Include Optional Terminating Action

Northwest Airlines, and Air Transport Association (ATA) on behalf of its members United Airlines and US Airways, request that we refer to a new Airbus service bulletin under development that provides a permanent terminating action for the central support fitting. United points out that the terminating action is preferable because the inspection proposed in the NPRM is intrusive to aircraft systems and very time consuming.

We agree with the commenters' request to refer to the new Airbus service information as the appropriate source of service information for modification of the central support. Since issuance of the NPRM, Airbus has issued Service Bulletin A320-53-1215, dated November 5, 2008. That service bulletin describes procedures for replacing the lower central support of the 80VU rack with a new, reinforced support. We have added paragraph (k) to this supplemental NPRM to specify that doing this replacement terminates the requirements of paragraphs (g) and (i) of this AD. We have also revised paragraph (d) of this supplemental NPRM to include reference to the ATA Code 53: Fuselage, which is the subject of Airbus Service Bulletin A320-53-1215, dated November 5, 2008.

Explanation of Additional Revised Service Information

Since we issued the NPRM, Airbus has issued Mandatory Service Bulletin A320-25A1555, Revision 01, including Appendix 1, dated February 18, 2008; and Mandatory Service Bulletin A320-25A1555, Revision 02, including Appendix 1, dated November 5, 2008. Airbus has also issued Service Bulletin A320-25-1557, Revision 01, dated February 7, 2008; and Service Bulletin A320-25-1557, Revision 02, dated November 5, 2008. (We referred to Airbus Service Bulletins A320-25A1555 and A320-25-1557, both dated June 14, 2007, in the NPRM as the appropriate source of service information for doing the proposed actions.) Airbus issued Revision 01 of those service bulletins to include minor improvements in the procedures. Airbus issued Revision 02 of those service bulletins to include a reference to the terminating action specified in Airbus Service Bulletin A320-53-1215, dated November 5, 2008.

No additional work is necessary for airplanes on which any revision of these service bulletins has been accomplished before the effective date of this AD; therefore, we have revised paragraphs (g) and (n) of this supplemental NPRM to refer to Revision 02 of Airbus Service Bulletins A320-25A1555 and A320-25-1557. We have also revised paragraphs (h) and (i) of this supplemental NPRM to refer to Revision 02 of Airbus Mandatory Service Bulletin A320-25A1555. We have also revised this supplemental NPRM to include a new paragraph (l) to give credit for actions accomplished before the effective date of this AD in accordance with the Airbus service bulletins listed in Table 1 of this AD.

Clarification of Repetitive Interval

We have revised the repetitive interval specified in paragraph (g)(2) of this supplemental NPRM (referred to as paragraph (f)(1)(i) in the NRPM) to specify that the next inspection must be done within 24,000 flight cycles after doing the replacement and thereafter the inspection must be done at intervals not to exceed 4,500 flight cycles. Paragraph (f)(1)(ii) of the NPRM specified a repetitive interval of 24,000 flight cycles for airplanes on which the repair (replacement) had been done. However, after exceeding 24,000 flight cycles since the replacement, the inspections must be done at intervals not to exceed 4,500 flight cycles in order to adequately address the identified unsafe condition.

We have also revised the repetitive interval specified in paragraph (i)(2) of this supplemental NPRM (referred to as paragraph (f)(3)(ii) in the NRPM) to specify that the next inspection must be done within 24,000 flight cycles after doing the repair or replacement and thereafter the inspection must be done at the applicable intervals specified in paragraph (i)(1)(i) or (i)(1)(ii) of this AD. Paragraph (f)(3)(ii) of the NPRM specified a repetitive interval of 24,000 flight cycles for airplanes on which the repair or replacement had been done. However, after exceeding 24,000 flight cycles since the repair or replacement, the inspections must be done within the applicable intervals specified in paragraph (i)(1)(i) or (i)(1)(ii) of this AD in order to address the identified unsafe condition.

We have also revised paragraphs (i)(1)(i) and (i)(1)(ii) of this AD (referred to as paragraphs (f)(3)(i)(A) and (f)(3)(i)(B) of the NPRM) by removing the phrase “as of the effective date of the AD.” The repetitive intervals specified in those paragraphs are not dependent on how many flight cycles the support has accumulated as of the effective date of the AD, e.g., for a lower central support that has accumulated 23,000 total flight cycles (at the time the inspection specified in paragraph (i) is done), the inspection should be repeated at intervals not to exceed 4,500 flight cycles until the lower central support has accumulated 30,000 total flight cycles and then the inspection should be repeated at intervals not to exceed 500 flight cycles.

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.

Certain changes described above expand the scope of the earlier NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this proposed AD.

Differences Between This AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.

We might also have proposed different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are highlighted in a Note within the proposed AD.

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 678 products of U.S. registry. We also estimate that it would take about 82 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $85 per work-hour. Required parts would cost about $2,592 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these costs. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $6,483,036, or $9,562 per product.

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.

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); and

3. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

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 adding the following new AD:

Airbus: Docket No. FAA-2008-0670; Directorate Identifier 2007-NM-339-AD.

Comments Due Date

(a) We must receive comments by August 30, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Airbus Model A318-111, A318-112, A319-111, A319-112, A319-113, A319-114, A319-115, A319-131, A319-132, A319-133, A320-111, A320-211, A320-212, A320-214, A320-231, A320-232, A320-233, A321-111, A321-112, A321-131, A321-211, A321-212, A321-213, A321-231, and A321-232 airplanes, certificated in any category, all manufacturer serial numbers, except airplanes on which Airbus Modification 34804 has been embodied in production or on which Airbus Service Bulletins A320-25-1557 and A320-53-1215 have been done in service.

Subject

(d) Air Transport Association (ATA) of America Code 25: Equipment/Furnishings, and Code 53: Fuselage.

Reason

(e) The mandatory continuing airworthiness information (MCAI) states:

Damage to the lower lateral fittings of the 80VU rack, typically elongated holes, migrated bushes [bushings], and/or missing bolts have been reported in-service. In addition damage to the lower central support fitting (including cracking) has been reported.

In the worst case scenario a complete failure of the 80VU fittings in combination with a high load factor or strong vibration could lead to failure of the rack structure and/or computers or rupture/disconnection of the cable harnesses to one or more computers located in the 80VU. This rack contains computers for Flight Controls, Communication and Radio-navigation. These functions are duplicated across other racks but during critical phases of flight the multiple system failures/re-configuration may constitute an unsafe condition.

* * * * *

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Repetitive Inspections of the 80V Rack Lower Lateral Fittings

(g) Prior to the accumulation of 24,000 total flight cycles, or within 500 flight cycles after the effective date of this AD, whichever occurs later: Do a special detailed inspection of the 80VU rack lower lateral fittings for damage (e.g., broken fitting, missing bolts, migrated bushings, material burr, or rack in contact with the fitting) of the 80VU rack lower lateral fittings, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A320-25A1555, Revision 02, dated November 5, 2008. Repeat the inspection thereafter at the interval specified in paragraph (g)(1) or (g)(2) of this AD, as applicable. Modifying the 80VU lower lateral fittings, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-25-1557, Revision 02, dated November 5, 2008, terminates the inspection requirements of this paragraph.

(1) For airplanes on which the 80VU rack lower lateral fittings have not been replaced in accordance with the Airbus Mandatory Service Bulletin A320-25A1555: Repeat the inspection thereafter at intervals not to exceed 4,500 flight cycles.

(2) For airplanes on which the 80VU rack lower lateral fittings have been replaced in accordance with Airbus Mandatory Service Bulletin A320-25A1555: Do the next inspection within 24,000 flight cycles after doing the replacement and repeat the inspection thereafter at intervals not to exceed 4,500 flight cycles.

(h) If any damage is found during any inspection required by paragraph (g) of this AD, do all applicable corrective actions (inspection and/or repair) in accordance with the Accomplishment Instructions and timeframes given in Airbus Mandatory Service Bulletin A320-25A1555, Revision 02, dated November 5, 2008.

Repetitive Inspections of the 80V Rack Lower Central Support

(i) Prior to the accumulation of 24,000 total flight cycles, or within 500 flight cycles after the effective date of this AD, whichever occurs later: Do a special detailed inspection of the 80VU rack lower central support for cracking, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A320-25A1555, Revision 02, dated November 5, 2008. Repeat the inspection thereafter at the interval specified in paragraph (i)(1) or (i)(2) of this AD, as applicable. Replacing the pyramid fitting on the 80VU rack with a new, reinforced fitting, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1215, dated November 5, 2008, terminates the inspection requirements of this paragraph.

(1) For airplanes on which the 80VU rack lower central support has not been repaired or replaced in accordance with Airbus Mandatory Service Bulletin A320-25A1555 or Airbus Service Bulletin A320-25-1557: Repeat the inspection thereafter at the interval specified in paragraph (i)(1)(i) or (i)(1)(ii) of this AD, as applicable.

(i) For airplanes on which the lower central support has accumulated 30,000 total flight cycles or more: At intervals not to exceed 500 flight cycles.

(ii) For airplanes on which the lower central support has accumulated less than 30,000 total flight cycles: At intervals not to exceed 4,500 flight cycles, without exceeding 30,750 total flight cycles on the support for the first repetitive inspection.

(2) For airplanes on which the 80VU rack lower central support has been repaired or replaced in accordance with Airbus Mandatory Service Bulletin A320-25A1555 or Airbus Service Bulletin A320-25-1557: Do the next inspection within 24,000 flight cycles after the repair or replacement and thereafter repeat the inspection at the interval specified in paragraph (i)(1)(i) or (i)(1)(ii) of this AD, as applicable.

(j) If any crack is found during any inspection required by paragraph (i) of this AD, before further flight, replace the pyramid fitting on the 80VU rack with a new, reinforced fitting, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1215, dated November 5, 2008. Doing this replacement terminates the inspection requirements of paragraph (i) of this AD.

Optional Terminating Action

(k) Doing the actions specified in paragraphs (k)(1) and (k)(2) of this AD terminates the requirements of paragraphs (g) and (i) of this AD.

(1) Replacing the pyramid fitting on the 80VU rack with a new, reinforced fitting, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1215, dated November 5, 2008.

(2) Modifying the 80VU lower lateral fittings, in accordance with Airbus Service Bulletin A320-25-1557, Revision 02, dated November 5, 2008.

Credit Service Bulletins

(l) Actions done before the effective date of this AD in accordance with the service information identified in Table 1 of this AD are acceptable for compliance with the corresponding requirements of this AD.

Table 1—Previous Revisions of Service Information

Service information	Revision level	Date
Airbus Mandatory Service Bulletin A320-25A1555	01	February 18, 2008.
Airbus Service Bulletin A320-25A1555	Original	June 14, 2007.
Airbus Service Bulletin A320-25-1557	Original	June 14, 2007.
Airbus Service Bulletin A320-25-1557	01	February 7, 2008.

FAA AD Differences

Note 1:

This AD differs from the MCAI and/or service information as follows:

(1) Although the MCAI or service information allows further flight after cracks are found during compliance with the required action, (j) of this AD requires that you do a corrective action before further flight.

(2) Although the MCAI specifies doing a repair or replacement and repetitive inspections after the repair or replacement is done if cracking is found in the 80VU rack lower central support, paragraph (j) of this AD requires that you perform a replacement, which eliminates the need for further repetitive inspections of the part.

Other FAA AD Provisions

(m) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, ANM-116, International Branch, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Tim Dulin, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.

Related Information

(n) Refer to MCAI EASA Airworthiness Directive 2007-0276R1, dated March 18, 2010 (corrected April 12, 2010), and the service information identified in Table 2 of this AD, for related information.

Table 2—Related Service Information

Service information	Revision level	Date
Airbus Mandatory Service Bulletin A320-25A1555	02	November 5, 2008.
Airbus Service Bulletin A320-25-1557	02	November 5, 2008.
Airbus Service Bulletin A320-53-1215	Original	November 5, 2008.

Issued in Renton, Washington, on July 27, 2010.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.