AD 2013-26-14

We are superseding Airworthiness Directive (AD) 2008-08-04 for certain Airbus Model A318, A319, A320, and A321 series airplanes. AD 2008-08-04 required repetitive inspections for cracking in the forward lug of the support rib 5 fitting of the left and right main landing gear (MLG), and repair or replacement of any cracked MLG fitting if necessary. AD 2008-08-04 also required modification of the rib bushings of the left and right MLG, which ended the repetitive inspections. This new AD requires, for airplanes on which certain modifications or repairs have been done, repetitive inspections for cracks of the forward lug of each left-hand and right-hand MLG support rib 5 fitting, and repair if necessary; and adds Model A318 series airplanes to the applicability. Replacement of an MLG support rib 5 fitting terminates the repetitive inspection requirements for the MLG support rib 5 fitting at that position. This AD was prompted by reports of cracks found in the forward lug of the MLG support rib 5 fitting. We are issuing this AD to prevent cracking in the forward lug of the MLG, which could result in failure of the lug and consequent collapse of the MLG during takeoff or landing.

Final rule.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

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

Sec. 39.13 [Amended]

0 2. The FAA amends Sec. 39.13 by removing airworthiness directive (AD) 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), and adding the following new AD:

2013-26-14 Airbus: Amendment 39-17723. Docket No. FAA-2011-1253; Directorate Identifier 2011-NM-079-AD.

(a) Effective Date

This airworthiness directive (AD) becomes effective May 2, 2014.

(b) Affected ADs

This AD supersedes AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008).

(c) Applicability

This AD applies to Airbus Model A318-111, A318-112, A318-121, A318-122, 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.

(d) Subject

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

(e) Reason

This AD was prompted by reports of cracks found in the forward lug of the main landing gear (MLG) support rib 5 fitting. We are issuing this AD to prevent cracking in the forward lug of the MLG, which could result in failure of the lug and consequent collapse of the MLG during takeoff or landing.

(f) Compliance

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

(g) Retained Repetitive Detailed Inspections With Changes

This paragraph restates the requirements of paragraph (f) of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), with changes. Except for airplanes on which Airbus modification 32025 has been accomplished in production, within 8 days after June 7, 2006 (the effective date of AD 2006-11-04, Amendment 39-14608 (71 FR 29578, May 23, 2006)), or before further flight after a hard landing, whichever is first: Perform a detailed inspection for cracking in the forward lug of the support rib 5 fitting of the left- and right-hand MLG, and, if any crack is found, replace the MLG fitting with a new fitting before further flight, in accordance with a method approved by the Manager, International Branch, ANM- 116, Transport Airplane Directorate, FAA, or the European Aviation Safety Agency (EASA) (or its delegated agent). Repeat the inspection thereafter at intervals not to exceed 8 days, or before further flight after a hard landing, whichever is first. As of May 19, 2008 (the effective date of AD 2008-08-04), the repetitive inspections required by paragraph (k) of this AD must be accomplished in lieu of the repetitive inspections required by this paragraph.

(h) Retained Optional Inspection Method With Revised Service Information

This paragraph restates the provisions of paragraph (g) of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), with revised service information. Performing an ultrasonic inspection for cracking in the forward lug of the support rib 5 fitting of the left- and right-hand MLG, in accordance with an applicable method specified in paragraph (h)(1) or (h)(2) of this AD, is an acceptable alternative method of compliance for the initial and repetitive inspections required by paragraph (g) of this AD.
(1) In accordance with a method approved by the Manager, International Branch, ANM-116, or the EASA (or its delegated agent).
(2) In accordance with Task 57-29-03-270-801-A-01, Gear Rib Forward Lug Attachment for the Main Gear Before Modification 32025J2211, of Subject 57-29-03, Inspection of the Gear Rib Forward and

[[Page 17420]]

Aft Lug Attachment for the Main Gear (for Model A318, A319, and A320 series airplanes); or Task 57-29-04-270-801-A-01, Gear Rib Forward Lug Attachment for the Main Gear Before Modification 32025J2211, of Subject 57-29-04, Inspection of the Gear Rib Forward and Aft Lug Attachment for the Main Gear (for Model A321 series airplanes); both of Chapter 57, Wings, of the Airbus A318/A319/A320/A321 Nondestructive Testing Manual, Revision 89, dated August 1, 2011.

(i) Retained Optional Terminating Action With Changes

This paragraph restates the provisions of paragraph (h) of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), with changes. Repair of the forward lugs of the support rib 5 fitting of the left- and right-hand MLG done before the effective date of this AD, in accordance with a method approved by the Manager, International Branch, ANM-116, or the EASA (or its delegated agent), constitutes terminating action for the requirements of paragraphs (g), (h),(k), (l), and (m) of this AD.

(j) New Referenced Conditions With Revised Affected Airplanes

To identify affected airplanes in paragraphs (k), (m), and (o) of this AD, this AD refers to the following conditions:
(1) Airplanes on which the modification of the MLG rib bushes specified in Airbus Mandatory Service Bulletin A320-57-1118 has been done.
(2) Airplanes on which a repair of the MLG support rib 5 fitting, as specified in paragraph 5.C. of Subsection 57-26-13, Attachments--Main Landing Gear, of the Airbus A319 Structural Repair Manual (SRM), Revision November 1, 2004; paragraph 5.D. of Subsection 57-26-13, Attachments--Main Landing Gear, of the Airbus A320 SRM, Revision November 1, 2004; or paragraph 5.D. of Subsection 57-26-13, Attachments--Main Landing Gear, of the Airbus A321 SRM, Revision February 1, 2005; as applicable; has been done.
(3) Airplanes on which replacement in service of the MLG support rib 5 specified in Airbus Repair Instruction R572-58507 andAirbus Repair Drawing R572-58209, or Airbus Repair Instruction R572-45020 and Airbus Repair Drawing R572-45019, as applicable, has been done.

(k) Retained Repetitive Inspections With Changes

This paragraph restates the requirements of paragraph (i) of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), with changes. For airplanes on which none of the actions specified in paragraphs (j)(1), (j)(2), and (j)(3) of this AD have been done, except for airplanes on which Airbus modification 32025 has been accomplished: At the applicable time specified in paragraphs (k)(1) and (k)(2) of this AD, or before further flight after a hard landing, whichever is first, do a visual inspection or ultrasonic inspection for cracking in the forward lug of the support rib 5 fitting of the left and right MLG, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-57-1138, Revision 01, dated October 27, 2006. Repeat the inspection thereafter at the applicable interval specified paragraphs (k)(1) and (k)(2) of this AD, or before further flight after a hard landing, whichever is first, until the modification required by paragraph (m) of this AD has been accomplished. Accomplishing the initial inspection terminates the requirements of paragraph (g) of this AD.
(1) For Model A318, A319, and A320 airplanes, inspect at the applicable times specified in paragraphs (k)(1)(i) and (k)(1)(ii) of this AD.
(i) If the most recent inspection is a detailed inspection done in accordance with paragraph (g) of this AD: Inspect within 150 flight cycles after the most recent detailed inspection. Repeat the inspection thereafter at intervals not to exceed 150 flight cycles after a visual inspection.
(ii) If the most recent inspection is an ultrasonic inspection done in accordance with paragraph (h) of this AD: Inspect within 940 flight cycles after the most recent ultrasonic inspection. Repeat the inspection thereafter at intervals not to exceed 940flight cycles after an ultrasonic inspection.
(2) For Model A321 airplanes, inspect at the applicable times specified in paragraphs (k)(2)(i) and (k)(2)(ii) of this AD.
(i) If the most recent inspection is a detailed inspection done in accordance with paragraph (g) of this AD: Inspect within 100 flight cycles after the most recent detailed inspection. Repeat the inspection thereafter at intervals not to exceed 100 flight cycles after a visual inspection.
(ii) If the most recent inspection is an ultrasonic inspection done in accordance with paragraph (h) of this AD: Inspect within 630 flight cycles after the most recent ultrasonic inspection. Repeat the inspection thereafter at intervals not to exceed 630 flight cycles after an ultrasonic inspection.

(l) Retained Corrective Action

This paragraph restates the requirements of paragraph (j) of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008). If any cracking is found during any inspection required by paragraph (k) of this AD: Before further flight, repair or replace the cracked MLG fitting, in accordance with a method approved by the Manager, International Branch, ANM-116, or the EASA (or its delegated agent).

(m) Retained Rib Bushing Modification With Revised Service Information

This paragraph restates the requirements of paragraph (k) of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), with revised service information. Except for airplanes on which the actions specified in paragraph (j)(1) or (j)(3) of this AD have been done, and except for airplanes on which Airbus modification 32025 have been done: Within 60 months after May 19, 2008 (the effective date of AD 2008-08-04), modify the rib bushings of the left and right MLG, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Airbus Mandatory Service Bulletin A320-57-1118, Revision 05, dated July 23, 2012, except that the liquid penetrant inspection specified in this service information is not required by this AD. Accomplishing this modification terminates the requirements of paragraphs (g) and (k) of this AD, and then the requirements of paragraph (n) of this AD must be done.

(n) New Post-Modification/Post-Repair Inspections

For airplanes on which the actions specified in paragraph (j)(1), (j)(2), or (m) of this AD have been done: At the later of the times specified in paragraphs (n)(1) and (n)(2) of this AD, do a detailed inspection for cracks of the forward lug of each left-hand and right-hand MLG support rib 5 fitting, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A320-57A1166, Revision 01, dated October 19, 2011. Repeat the inspection thereafter at intervals not to exceed 500 flight cycles.
(1) Within 2,000 flight cycles after accomplishing the modification specified in paragraph (j)(1) or (m) of this AD, or the repair specified in paragraph (j)(2) of this AD, as applicable.
(2) Within 250 flight cycles after the effective date of this AD, without exceeding 3 months after the effective date of this AD.

(o) New Repair of Cracking Found During Post-Modification/Post-Repair

If any crack is detected during any inspection required by paragraph (n) of this AD: Before further flight, repair using a method approved by either the Manager, International Branch, ANM- 116, FAA, or the EASA (or its delegated agent).

(p) New Optional Terminating Action

Replacement of a MLG support rib 5 fitting at any position (left-hand or right-hand), as specified in paragraph (j)(3) of this AD, terminates the requirements of paragraphs (k) and (n) of this AD for the MLG support rib 5 fitting at that position.

(q) New Repetitive Detailed Inspection for Certain Airplanes

For airplanes on which the actions specified in paragraph (j)(3) of this AD have been done: Within 60 months after the replacement or within 500 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection of the forward lug of each left-hand and right-hand MLG support rib 5 fitting that has been replaced, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A320-57A1166, Revision 01, dated October 19, 2011. Repeat the inspection thereafter at intervals not to exceed 500 flight cycles.

(r) New Repetitive Inspections for Airplanes With Airbus Modification 32025

For airplanes on which Airbus modification 32025 has been done: At the applicable time specified in paragraph (r)(1) (r)(2), (r)(3), or (r)(4) of this AD, do a detailed inspection for cracks of the forward lug of each left-hand and right-hand MLG support rib 5 fitting, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-57-1168, dated November 7, 2011. Repeat the inspection

[[Page 17421]]

thereafter at intervals not to exceed 500 flight cycles.
(1) For airplanes on which the MLG support rib 5 has not been modified or repaired since the first flight of the airplane as of the effective date of this AD: Within 60 months after the first flight of the airplane, or within 500 flight cycles after the effective date of this AD, whichever occurs later.
(2) For airplanes on which the MLG support rib 5 has been replaced as specified in paragraph (j)(3) of this AD as of the effective date of this AD: Within 60 months after the replacement of the MLG support rib 5, or within 500 flight cycles after the effective date of this AD, whichever occurs later.
(3) For airplanes on which the MLG support rib 5 has been repaired according to the SRM or a repair approval sheet as of the effective date of this AD: At the later of the times specified in paragraph (r)(3)(i) or (r)(3)(ii) of this AD.
(i) Within 2,000 flight cycles after the repair.
(ii) Within 250 flight cycles or 3 months after the effective date of this AD, whichever occurs first.
(4) For airplanes having a manufacturerserial number (S/N) listed in figure 1 to paragraph (r)(4) of this AD, and on which the MLG support rib 5 has been inspected before the effective date of this AD according to specific Airbus repair instructions or technical disposition: At the later of the times specified in paragraph (r)(4)(i) or (r)(4)(ii) of this AD.

Figure 1 to Paragraph (r)(4) of This AD
[Manufacturer serial number (S/N)] ------------------------------------------------------------------------

------------------------------------------------------------------------
S/N-- ------------------------------------------------------------------------
1965 2056 2155
2274 2278 2288
2321 2478 2586
2588 2612 2672
2688 2707 2929
2942 3089 3117
33613427 3486
3489 3806 3891
3937 4243 4345 ------------------------------------------------------------------------

(i) Within 2,000 flight cycles after the last inspection done using specific Airbus repair instructions or a technical disposition, or within 60 months since first flight of the airplane, whichever occurs later.
(ii) Within 250 flight cycles or 3 months after the effective date of this AD, whichever occurs first.

(s) New Repair of Cracking

If any crack is detected during any inspection required by paragraph (q) or (r) of this AD: Before further flight, repair using a method approved by either the Manager, International Branch, ANM- 116, FAA, or the EASA (or its delegated agent).

(t) Credit for Previous Actions

(1) This paragraph provides credit for the actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Chapter 51-90-00 of the Airbus A318/ A319/A320/A321 Nondestructive Testing Manual, Revision February 1, 2003, which is not incorporated by reference in this AD.
(2) This paragraph provides credit for the actions required by paragraph (h) of this AD, if those actions were performed before the effective date of this AD using the service information specified in paragraph (t)(2)(i) or (t)(2)(ii) of this AD.
(i) Chapter 57-29-03 of the Airbus A318/A319/A320/A321 Nondestructive Testing Manual, Revision February 1, 2005 (for Model A318, A319, and A320 airplanes), which is not incorporated by reference in this AD.
(ii) Chapter 57-29-04 of the Airbus A318/A319/A320/A321 Nondestructive Testing Manual, Revision May 1, 2005 (for Model A321 airplanes), which is not incorporated by reference in this AD.
(3) This paragraph provides credit for the actions specified in paragraph (i) of this AD, if those actions were performed before the effective date of this AD using the applicable service information specified in paragraph (t)(3)(i), (t)(3)(ii), or (t)(3)(iii) of this AD.
(i) Paragraph 5.C. of Chapter 57-26-13, Attachments--Main Landing Gear, of the Airbus A319 SRM, Revision November 1, 2004, which is not incorporated by reference in this AD.
(ii) Paragraph 5.D. of Chapter 57-26-13, Attachments--Main Landing Gear, of the Airbus A320 SRM, Revision November 1, 2004, which is not incorporated by reference in this AD.
(iii) Paragraph 5.D. of Chapter 57-26-13, Attachments--Main Landing Gear, of the Airbus A321 SRM, Revision February 1, 2005, which is not incorporated by reference in this AD.
(4) This paragraph provides credit for the inspections required by paragraphs (n) and (r) of this AD, if the inspections were performed before the effective date of this AD using Airbus Service Bulletin A320-57A1166, dated January 12, 2011, which is not incorporated by reference in this AD.
(5) This paragraph provides credit for the modification required by paragraph (m) of this AD, if the modification was performed before May 19, 2008 (the effective date of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), using the service information identified in paragraph (t)(5)(i), (t)(5)(ii), (t)(5)(iii), (t)(5)(iv), or (t)(5)(v) of this AD.

(i) Airbus Service Bulletin A320-57-1118, dated September 5, 2002, which is not incorporated by reference in this AD. (ii) Airbus Service Bulletin A320-57-1118, Revision 01, dated August 28, 2003, which is not incorporated by reference in this AD. (iii) Airbus Service Bulletin A320-57-1118, Revision 02, dated August 2, 2006, which is not incorporated by reference in this AD. (iv) Airbus Service Bulletin A320-57-1118, Revision 03, dated April 23, 2007, which is not incorporated by reference in this AD. (v) Airbus Mandatory Service Bulletin A320-57-1118, Revision 04, dated June 4, 2008, which is not incorporated by reference in this AD.

(u) Other FAA AD Provisions

The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, Transport Airplane Directorate, 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 Branch, send it to ATTN: Sanjay Ralhan, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, WA 98057- 3356; telephone 425-227-1405; fax 425-227-1149. Information may be emailed to: 9-ANM-116-AMOC-REQUESTS@faa.gov. 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. The AMOC approval letter must specifically reference this AD. AMOCs approved previously in accordance with AD 2006-11-04, Amendment 39- 14608 (71 FR 29578, May 23, 2006); and AD 2008-08-04, Amendment 39- 15456 (73 FR 19975, April 14, 2008); are approved as AMOCs for the corresponding provisions of 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 ensure the product is airworthy before it is returned to service.

(v) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA Airworthiness Directive 2012-0032, dated February 24, 2012, for related information. You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2011-1253-0002.
(2) Service information identified in this AD that is not incorporated by reference in this AD may be obtained at the addresses specified in paragraphs (w)(5) and (w)(6) of this AD.

(w) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use the following service information to do the actions required by this AD, unless the AD specifies otherwise.
(3) The following service information was approved for IBR on May 2, 2014.

(i) Airbus Mandatory Service Bulletin A320-57-1118, Revision 05, dated July 23, 2012. (ii) Airbus Mandatory Service Bulletin A320-57A1166, Revision 01, dated October 19, 2011. (iii) Airbus Service Bulletin A320-57-1168, dated November 7, 2011.

[[Page 17422]]

(iv) Task 57-29-03-270-801-A-01, Gear Rib Forward Lug Attachment for the Main Gear Before Modification 32025J2211, of Subject 57-29-03, Inspection of the Gear Rib Forward and Aft Lug Attachment for the Main Gear, of Chapter 57, Wings, of the Airbus A318/A319/A320/A321 Nondestructive Testing Manual, Revision 89, dated August 1, 2011. (v) Task 57-29-04-270-801-A-01, Gear Rib Forward Lug Attachment for the Main Gear Before Modification 32025J2211, of Subject 57-29-04, Inspection of the Gear Rib Forward and Aft Lug Attachment for the Main Gear, of Chapter 57, Wings, of the Airbus A318/A319/A320/A321 Nondestructive Testing Manual, Revision 89, dated August 1, 2011.

(4) The following service information was approved for IBR on May 19, 2008 (73 FR 19975, April 14, 2008):
(i) Airbus Service Bulletin A320-57-1138, Revision 01, dated October 27, 2006.
(ii) Reserved.
(5) For Airbus service information identified in this AD, contact Airbus, Airworthiness Office--EIAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email: account.airworth-eas@airbus.com; Internet http://www.airbus.com.
(6) You may view this service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.
(7) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion

We issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 to supersede AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008). AD 2008-08-04 applied to certain Airbus Model A318, A319, A320, and A321 series airplanes. The SNPRM published in the Federal Register on October 3, 2012 (77 FR 60325). We preceded the SNPRM with a notice of proposed rulemaking (NPRM) that published in the Federal Register on November 23, 2011 (76 FR 72350). The NPRM proposed to continue to require repetitive inspections for cracking in the forward lug of the support rib 5 fitting of the left and right main landing gear (MLG), and repair or replacement of any cracked MLG fitting if necessary; and modification of the rib bushings of the left and right MLG, which ended the repetitive inspections. The NPRM also proposed to require, for airplanes on which certain modifications or repairs have been done, repetitive inspections forcracks of the forward lug of each left-hand and right-hand MLG support rib 5 fitting, and repair if necessary; and to remove Model A318 series airplanes from the applicability. The NPRM was prompted by reports of cracks found in the forward lug of the MLG support rib 5 fitting. The SNPRM proposed to revise the NPRM by adding Model A318 airplanes and others to the applicability; and requiring repetitive detailed inspections for cracks of the MLG support 5 fitting, and repair of any cracks. We are issuing this AD to prevent cracking in the forward lug of the MLG, which could result in failure of the lug and consequent collapse of the MLG during takeoff or landing.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2012-0032, dated February 24, 2012 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe conditionfor the specified products. The MCAI states:

Several cases of corrosion of the Main Landing Gear (MLG) support Rib 5 fitting lug bores have been reported on A320 family aeroplanes. In some instances, corrosion pits caused the cracking of the forward lug (sometimes through its complete thickness). If not detected, the cracking may lead to the complete failure of the fitting and thus could affect the structural integrity of the MLG installation.
EASA AD 2007-0213 [(http://ad.easa.europa.eu/blob/easa_ad_2007_0213_superseded.pdf/AD_2007-0213_1), which corresponds to FAA AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008)] was issued to address this condition and required a repetitive inspection program of the MLG support Rib 5 fitting forward lugs and, as terminating action, the embodiment of Airbus Service Bulletin (SB) A320-57-1118.
After that [EASA] AD was issued, a case of Rib 5, ruptured at the 4 o'clock position, was discovered on an aeroplane on which the terminating action of EASA AD 2007-0213 had already been embodied in accordance with Airbus SB A320-57-1118.
Investigation of that case revealed that corrosion damage and cracking that should have been removed by repair machining was below the level of detectability of the Non Destructive Test (NDT) technique that cleared the surfaces prior to bush installation.
This condition, if not detected and corrected, could affect the structural integrity of the aeroplane.
To correct this potential unsafe condition, EASA issued AD 2011- 0011 [(http://ad.easa.europa.eu/blob/easa_ad_2011_0011_superseded.pdf/AD_2011-0011_1), which corresponds to FAA AD 2012- 15-17 (77 FR 47273, August 8, 2012)], superseding EASA AD 2007-0213, to:

--retain the requirements of EASA AD 2007-0213 for aeroplanes on which the MLG Rib Bushes have not been modified/repaired in accordance with the instructions of Airbus SB A320-57-1118, or Airbus SRM 57-26-13, or the identified Airbus Repair Instructions, as applicable, and --require, for all aeroplanes on which Airbus SB A320-57-1118 has been embodied in service, or on which Airbus SRM 57-26-13 or the identified Airbus Repair Instructions have been applied, a repetitive inspection program [for cracks] of the MLG support Rib 5 fitting forward lugs and, depending on findings, the accomplishment of the associated corrective actions, and --reduce the Applicability by deleting A318 aeroplanes, as Airbus modification 32025 is embodied in production on both left-hand (LH) and right-hand (RH) wings for all A318 aeroplanes.

After that [EASA] AD was issued, three cases of corrosion of Rib 5 were discovered on aeroplanes on which Airbus modification 32025 had been embodied in production. Investigations revealed that the unsafe condition addressed by [EASA] AD 2011-0011 could occur or develop on those aeroplanes as well.
For the reasons described above, this [EASA] AD retains the requirements of EASA AD 2011-0011, which is superseded, extends the applicability to all aeroplanes, and requires for aeroplanes on which Airbus modification 32025 has been embodied in production, repetitive inspections of the MLG support Rib 5 fitting forward lugs and, depending on findings, the accomplishment of applicable corrective actions.

The unsafe condition is cracking in the forward lug of the MLG, which could result in failure of the lug and consequent collapse of the MLG during takeoff or landing. You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2011- 1253-0002.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received.

Support for the SNPRM (77 FR 60325, October 3, 2012)

United Airlines (UAL) stated that it generally agrees with the intent of the SNPRM (77 FR 60325, October 3, 2012).
US Airways (AWE) stated that it agrees with the need to add the post-modification inspections, because themandated bushing modification has not proven to be an effective permanent corrective action. AWE also stated that it agrees with the method and frequency of these additional inspections.

Request To Extend Compliance Time

UAL requested that we extend the compliance time specified in paragraph (n)(2) of the SNPRM (77 FR 60325, October 3, 2012) from within 2,000 flight cycles after accomplishing the modification or within 250 flight cycles after the effective date of the AD, without exceeding 3 months after the effective date of the AD, whichever occurs later. UAL requested that the compliance time be changed to within 500 flight cycles after the effective date of the AD or within 6 months after the effective date of the AD, whichever occurs later. UAL stated that the majority of its Model A319 and A320 series airplanes have accumulated more than 2,000 flight cycles since

[[Page 17418]]

accomplishing the modification. UAL stated that it is requesting this change in order to ``reduce the impact due to the special routing required for the inspection,'' possible MLG removal for repair/ replacement of MLG support rib 5 fitting, and a large demand on man- power. UAL stated that extending the compliance time will allow it to perform the required inspection at a more suitable maintenance opportunity.
We do not agree with the commenter's request to extend the compliance time in paragraph (n)(2) of this AD. The commenter did not provide technical justification for extending the compliance time. The compliance time for the actions specified in paragraph (n)(2) in this AD was developed after conducting a risk assessment and analyzing the impact on operators. In consideration of these factors, we determined that the compliance times, as proposed, represent an appropriate interval in which to conduct the inspection after the modification within the fleet, while still maintaining an adequate level of safety. However, under the provisions of paragraph (u) of this AD, we might approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. We have not changed this final rule in this regard.

Requests To Include Revised Service Information

Airbus and AWE requested that we add Airbus Mandatory Service Bulletin A320-57-1118, Revision 05, dated July 23, 2012, to paragraph (m) of the SNPRM (77 FR 60325, October 3, 2012). Airbus also requested that we add Airbus Service Bulletin A320-57-1118, Revision 03, dated April 23, 2007; and Revision 04, dated June 4, 2008; to paragraph (t)(5) of the SNPRM. AWE stated that adding Airbus Mandatory Service Bulletin A320-57-1118, Revision 05, dated July 23, 2012, as authorized instructions for modification work would reduce alternative method of compliance coordination.
We partially agree with the commenters' requests. Airbus Mandatory Service Bulletin A320-57-1118, Revision 05, dated July 23, 2012, states that ``no additional work is required by this revision for airplanes modified by any previous issue.'' However, this service bulletin revision adds a liquid penetrant inspection. We have added Airbus Mandatory Service Bulletin A320-57-1118, Revision 05, dated July 23, 2012, in paragraph (m) of this final rule as an appropriate source of service information, and specified that the liquid penetrant inspection specified in this service information is not required by this AD. We have added paragraphs (t)(5)(iv) and (t)(5)(v) to this final rule to provide credit for certain actions accomplished before May 19, 2008 (the effective date of AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 18, 2008)), using Airbus Service Bulletin A320-57-1118, Revision 03, dated April 23, 2007; or Revision 04, dated June 4, 2008.

Requests To Change Certain Document References

AWE requested we revise the service bulletin reference in the Relevant Service Information section of the SNPRM from``A320-75-1168'' to ``A320-57-1168.'' Airbus requested that we correct references to Airbus Repair Drawings ``R57258209'' and ``R57245019'' in paragraph (g)(3) of the SNPRM to Airbus Repair Drawing ``R572-58209'' and ``R572- 45019,'' respectively. Airbus also requested that we amend paragraph (h)(2) of the SNPRM (77 FR 60325, October 3, 2012) to refer to ``NTM task 57-29-03-270-801-A-01 for A318/A319/A320 and NTM task 57-29-04- 270-801-A-01 for A321 [series airplanes].''
We agree with the commenters' requests. The Relevant Service Information section of the SNPRM referenced by AWE is not restated in this final rule; therefore, no change to this final rule is needed in this regard. The content of paragraph (g)(3) of the SNPRM (77 FR 60325, October 3, 2012) referenced by Airbus was located in paragraph (j)(3) of the SNPRM, not in paragraph (g)(3) of the SNPRM, as the commenter specified. We have revised paragraphs (h)(2) and (j)(3) of this final rule accordingly.

Request To Include Repair Drawing

AWE requested that we include Airbus Repair Drawing R572-48341 in paragraph (g)(2) of the SNPRM (77 FR 60325, October 3, 2012). AWE stated that this drawing is the current and most advanced version of the repair scheme for corrosion and crack findings, and that Airbus issues this drawing when operators request repair design data. AWE also stated that there are still some issues with the details of this repair drawing, but it has collected comments and submitted them to Airbus for incorporation. AWE also noted that Airbus drawing number ``R572481'' cited (by a different commenter) under ``Request to Reference a Repair Drawing'' in the preamble of the SNPRM (77 FR 60325, October 3, 2012) should be ``R572-48341.''
We disagree with the commenter's request. The commenter did not provide specific data to substantiate that airplanes repaired with Airbus Repair Drawing R572-48341 would be applicable to the MLG support rib 5 fitting configuration. The commenter also did not provide justification for including a document with potential errors. However, according to the provisions of paragraph (u) of this AD, we might approve requests to include airplanes repaired by Airbus Repair Drawing R572-48341 as an appropriate action for the MLG support rib 5 fitting repair specified in paragraph (j)(2) of this AD. We have not changed this final rule in this regard.

Additional Changes Made to This Final Rule

We have converted table 1 to paragraph (k) of the SNPRM (77 FR 60325, October 3, 2012) to the text given in paragraphs (k)(1) and (k)(2) of this final rule for formatting purposes only.
We have also revised table 2 to paragraph (r)(4) of the SNPRM (77 FR 60325, October 3, 2012) to figure 1 to paragraph (r)(4) of this AD for formatting purposes only.
We have revised the citation of the service information referenced in paragraph (t)(2) of the SNPRM (77 FR 60325, October 3, 2012) and moved the service information into new paragraphs (t)(2)(i) and (t)(2)(ii) of this AD. The documents have not changed.

Conclusion

We reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting this AD with the changes described previously and minor editorial changes. We have determined that these changes:
Are consistent with the intent that was proposed in the SNPRM (77 FR 60325, October 3, 2012) for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the SNPRM (77 FR 60325, October 3, 2012).

Differences Between This AD and the MCAI or Service Information

This AD differs from the MCAI and/or service information as follows:
Although the MCAI or service information allows further flight after cracks are found during compliance with certain required actions, paragraphs (l) and (p) of this AD require repair or replacement before further flight.
Airbus Mandatory Service BulletinA320-57-1118, Revision 05, dated July

[[Page 17419]]

23, 2012, describes a liquid penetrant inspection. This AD does not require that inspection.

Costs of Compliance

We estimate that this AD will affect about 740 products of U.S. registry.
The actions that are required by AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April 14, 2008), and retained in this AD take about 73 work-hours per product, at an average labor rate of $85 per work-hour. Required parts cost about $3,860 per product. Based on these figures, the estimated cost of the currently required actions is $10,065 per product.
We estimate that it will take about 3 work-hours per product to comply with the new basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be up to $188,700, or $255 per product.
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.

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.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2011-1253; 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 AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone 800-647- 5527) is in the ADDRESSES section.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.