AD 2017-14-11

We are superseding Airworthiness Directive (AD) 2007-13-08, for certain Airbus Model A318, A319, A320, and A321 series airplanes. AD 2007-13-08 required repetitive inspections of the auxiliary power unit (APU) starter motor, APU inlet plenum, and APU air intake for discrepancies; repetitive cleaning of the APU air intake; and applicable corrective actions. This AD expands the applicability of AD 2007-13-08, and includes an optional terminating installation for the repetitive actions. This AD was prompted by a determination that the unsafe condition could occur on additional airplanes. We are issuing this AD to address the unsafe condition on these products.

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) 2007-13-08, Amendment 39-15112 (72 FR 33877, June 20, 2007), and adding the following new AD:

2017-14-11 Airbus: Amendment 39-18955; Docket No. FAA-2016-9567; Directorate Identifier 2016-NM-147-AD.

(a) Effective Date

This AD is effective August 21, 2017.

(b) Affected ADs

This AD replaces AD 2007-13-08, Amendment 39-15112 (72 FR 33877, June 20, 2007) (``AD 2007-13-08'').

(c) Applicability

This AD applies to Airbus airplanes identified in paragraphs (c)(1), (c)(2), (c)(3), and (c)(4) of this AD, all manufacturer serial numbers, certificated inany category.
(1) Model A318-111, -112, -121, and -122 airplanes.
(2) Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes.
(3) Model A320-211, -212, -214, -231, -232, and -233 airplanes.
(4) Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes.

(d) Subject

Air Transport Association (ATA) of America Code 49, Airborne Auxiliary Power.

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(e) Reason

This AD was prompted by a report of a fire in the auxiliary power unit (APU) air intake. An analysis demonstrated that, following numerous unsuccessful APU start attempts in flight, there is a risk of reverse flow, which could lead to flame propagation to the APU air inlet and air intake duct. This AD was also prompted by the determination that AD 2007-13-08 only addresses the unsafe condition for certain airplanes. We are issuing this AD to detect and correct reverse flow during APU startup, which could lead to flame propagation in the APU air inlet and intake duct. Such conditions could result in an in-flight fire in the APU area.

(f) Compliance

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

(g) Repetitive Inspections and Corrective Actions

Except as provided by paragraph (i) of this AD, within 600 flight hours after July 25, 2007 (the effective date of AD 2007-13- 08), or within 60 days after the effective date of this AD, whichever occurs later: Inspect the APU starter motor, APU air inlet plenum, and APU air intake of each affected APU identified in table 1 to paragraphs (g), (h), (i)(2)(ii), (j), and (k) of this AD for discrepancies; and do all applicable corrective actions before further flight; in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-49-1068, Revision 01, dated February 2, 2006. Repeat the inspection thereafter at intervals not to exceed 600 flight hours.

Table 1 to Paragraphs (g), (h), (i)(2)(ii), (j), and (k) of This AD--Affected APU and
Electronic Control Box (ECB) ------------------------------------------------------------------------
APU ECB part Nos. (P/N) ------------------------------------------------------------------------ APIC APS 3200..................... 4500003D, 4500003E, 4500003F,
4500003G, 4500003H, or 4500003J. Honeywell 131-9A.................. 3888394-120201, 3888394-121202,
3888394-121203, 3888394-221202, or
3888394-221203. Honeywell GTCP36-300.............. 307950-1, 307950-2, 307950-3, 307950-
4, 304640-1, 304640-2, 304640-3,
304640-4, 304817-1, 304817-2, or
3888394-230300. ------------------------------------------------------------------------

(h) Repetitive Cleanings

Except as provided by paragraph (i) of this AD, prior to the accumulation of 2,400 flight hours since first flight of the airplane, or within 600 flight hours after July 25, 2007 (the effective date of AD 2007-13-08), or within 60 days after the effective date of this AD, whichever occurs latest, unless accomplished previously in accordance with Airbus Service Bulletin A320-49-1098, dated June 21, 2011: Clean the APU air intake of each affected APU identified in table 1 to paragraphs (g), (h), (i)(2)(ii), (j), and (k) of this AD, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-49-1068, Revision 01, dated February 2, 2006. Repeat the cleaning task thereafter at intervals not to exceed 2,400 flight hours.

(i) Exceptions to Requirements in Paragraphs (g) and (h) of This AD

(1) For airplanes equipped with an APU and associated ECB part number identified in table 2 to paragraphs (i)(1), (i)(2)(ii), and (j) of this AD, the actions specified in paragraphs (g) and (h) of this AD are not required.

Table 2 to Paragraphs (i)(1), (i)(2)(ii), and (j) of This AD--Non-
Affected ECB ------------------------------------------------------------------------
APU ECB Part Nos. (P/N) ------------------------------------------------------------------------ APIC APS 3200..................... 4500003K, 4500003L, or 4500003M. Honeywell 131-9A.................. 3888394-121204, 3888394-121205,
3888394-221204, 3888394-221205, or
3888394-321206. Honeywell GTCP36-300.............. 304640-5, 304817-3, or 3888394-
230301. ------------------------------------------------------------------------

(2) For airplanes on which Airbus Modification 35803, 35936, 152289, 152645, 155015, or 157848 has been embodied in production, the actions specified in paragraphs (g) and (h) of this AD are not required provided that, within 30 days after the effective date of this AD, the applicable actions specified in paragraphs (i)(2)(i) and (i)(2)(ii) of this AD are done.
(i) The part number of the installed ECB is identified.
(ii) Any affected ECB identified in table 1 to paragraphs (g), (h), (i)(2)(ii), (j), and (k) of this AD that is found to be installedis replaced with an ECB having a part number identified in table 2 to paragraphs (i)(1), (i)(2)(ii), and (j) of this AD, as applicable to the APU installed on the airplane; and the replacement is done in accordance with the Accomplishment Instructions of the applicable service information identified in paragraph (i)(2)(ii)(A), (i)(2)(ii)(B), (i)(2)(ii)(C), (i)(2)(ii)(D), (i)(2)(ii)(E), or (i)(2)(ii)(F) of this AD; or using a method approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, or the European Aviation Safety Agency (EASA), or Airbus's EASA Design Organization Approval (DOA).
(A) Airbus Service Bulletin A320-49-1070, dated July 28, 2006.
(B) Airbus Service Bulletin A320-49-1075, Revision 01, dated December 1, 2006.
(C) Airbus Service Bulletin A320-49-1077, Revision 04, dated February 27, 2013.
(D) Airbus Service Bulletin A320-49-1098, dated June 21, 2011.
(E) Airbus Service Bulletin A320-49-1102, dated January 3, 2012.
(F)Airbus Service Bulletin A320-49-1107, Revision 02, dated May 10, 2016.
(3) For airplanes on which an APU ECB having a part number approved after the effective date of this AD is installed, the actions specified in paragraphs (g) and (h) of this AD are not required, provided the conditions specified in paragraphs (i)(3)(i) and (i)(3)(ii) of this AD are met.
(i) The part number must be approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or EASA; or Airbus's EASA DOA.
(ii) The installation must be accomplished in accordance with airplane modification instructions approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or EASA; or Airbus's EASA DOA.

(j) Optional Terminating Action

Replacing an affected ECB identified in table 1 to paragraphs (g), (h), (i)(2)(ii), (j), and (k) of this AD with an ECB having a part number identified in table 2 to paragraphs (i)(1), (i)(2)(ii), and (j) of this AD, as applicable to the APU installed on the airplane, constitutes terminating action for the repetitive inspections required by paragraphs (g) and (h) of this AD. The replacement must be done in accordance with the Accomplishment Instructions of the applicable service information identified in paragraph (i)(2)(ii)(A), (i)(2)(ii)(B), (i)(2)(ii)(C), (i)(2)(ii)(D), (i)(2)(ii)(E), or (i)(2)(ii)(F) of this AD, or using a method approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or EASA; or Airbus's EASA DOA.

(k) Parts Installation Prohibition

As of the effective date of this AD, no person may install on any airplane an APU with an associated ECB identified in table 1 to paragraphs (g), (h), (i)(2)(ii), (j), and (k) of this AD.

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(l) Credit for Previous Actions

This paragraph provides credit for actions specified in paragraphs (i)(2) and (j) of this AD, if those actions were performed before the effective date of this AD using any of the service information specified in paragraphs (l)(1) through (l)(7) of this AD.
(1) Airbus Service Bulletin A320-49-1075, dated September 22, 2006, which was incorporated by reference in AD 2007-13-08.
(2) Airbus Service Bulletin A320-49-1077, dated March 21, 2007, which is not incorporated by reference in this AD.
(3) Airbus Service Bulletin A320-49-1077, Revision 01, dated August 9, 2007, which is not incorporated by reference in this AD.
(4) Airbus Service Bulletin A320-49-1077, Revision 02, dated July 1, 2008, which is not incorporated by reference in this AD.
(5) Airbus Service Bulletin A320-49-1077, Revision 03, dated December 8, 2008, which is not incorporated by reference in this AD.
(6) Airbus Service Bulletin A320-49-1107, dated November 5, 2013, which is not incorporated by reference in this AD.
(7) Airbus Service Bulletin A320-49-1107, Revision 01, dated July 28, 2015, which is not incorporated by reference in this AD.

(m) 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 manager of the International Branch, send it to the attention of the person identified in paragraph (n)(2) of this AD. Information may be emailed to: 9-ANM-116-AMOC-REQUESTS@faa.gov.
(i) 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.
(ii) AMOCs approved previously for AD 2007-13-08are approved as AMOCs for the corresponding provisions of paragraphs (g) and (h) of this AD.
(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 Branch, ANM-116, Transport Airplane Directorate, FAA; or EASA; or Airbus's EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature.

(n) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA AD 2016-0176, dated August 31, 2016; corrected September 1, 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-2016-9567.
(2) For more information about this AD, contact 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.
(3) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (o)(5) and (o)(6) of this AD.

(o) 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 this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise.
(3) The following service information was approved for IBR on August 21, 2017.
(i) Airbus Service Bulletin A320-49-1077, Revision 04, dated February 27, 2013.
(ii) Airbus Service Bulletin A320-49-1098, dated June 21, 2011.
(iii) Airbus Service Bulletin A320-49-1102, dated January 3, 2012.
(iv) Airbus Service Bulletin A320-49-1107, Revision 02, dated May 10, 2016.(4) The following service information was approved for IBR on July 25, 2007 (72 FR 33877, June 20, 2007).
(i) Airbus Service Bulletin A320-49-1068, Revision 01, dated February 2, 2006.
(ii) Airbus Service Bulletin A320-49-1070, dated July 28, 2006.
(iii) Airbus Service Bulletin A320-49-1075, Revision 01, dated December 1, 2006.
(5) For 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 notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2007-13-08, Amendment 39-15112 (72 FR 33877, June 20, 2007) (``AD 2007-13-08''). AD 2007-13-08 applied to certain Airbus Model A318, A319, A320, and A321 series airplanes. The NPRM published in the Federal Register on January 6, 2017 (82 FR 1623). The NPRM was prompted by a determination that the unsafe condition could occur on additional airplanes. The NPRM proposed to continue to require repetitive inspections of the APU starter motor, APU inlet plenum, and APU air intake for discrepancies; repetitive cleaning of the APU air intake; and applicable corrective actions. We are issuing this AD to detect and correct reverse flow during APU startup, which could lead to flame propagation in the APU air inlet and intake duct. Such conditions could result in an in-flight fire in the APU area.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2016-0176, dated August 31, 2016; corrected September 1, 2016 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for all Airbus Model A318, A319, A320, and A321 airplanes. The MCAI states:

An operator reported black smoke at the rear of the fuselage during taxi after landing. The smoke was caused by a fire in the auxiliary power unit (APU) air intake. The subsequent analysis demonstrated that, following numerous unsuccessful APU start attempts in flight, there is a risk of reverse flow leading to flame propagation to the APU air inlet and air intake duct.
This condition, if not detected and corrected, could result in an in-flight fire in the APU area.
Prompted by these findings, Airbus issued Service Bulletin (SB) A320-49-1068 to provide inspection and cleaning instructions. The applicable Flight Crew Operating Manual (FCOM) already contained a limitation for the number of APU start attempts, as follows:

APU STARTER After 3 starter motor duty cycles, wait 60 minutes before attempting 3 more cycles

To address this potential unsafe condition, EASA issued AD 2006- 0153 to require repetitive inspections of the APU starter motor, APU inlet plenum and APU air intake [for discrepancies], as well as repetitive cleaning of the APU air intake [and applicable corrective actions].
As the reverse flow inside the APU can only occur in flight with the APU inlet closed, various modifications (mod) were developed to introduce a new electronic control box (ECB) with associated software, the functionality of which keeps the APU inlet door open for 15 minutes, following an APU auto-shutdown in flight. Consequently, AD 2006-0153 [which corresponds to FAA AD 2007-13-08], was revised reducing the Applicability by excluding certain post-mod aeroplanes, and introducing these modifications as optional terminating actions.
After EASA AD 2006-0153R2 was issued, it was determined that, as an APU ECB can be replaced (or moved from one aeroplane to another) in service, inadvertently installing a pre-mod ECB would reintroduce the unsafe condition. Prompted by this finding, EASA issued AD 2016- 0159, retaining the requirements of EASA AD 2006-0153R2, which was superseded, expanding the Applicability and including references to additional optional terminating actions.
Since EASA AD 2016-0159 was issued, it was determined that paragraph (5) of the [EASA] AD contained some erroneous statements, inadvertently excluding certain aeroplanes, those that have Airbus mod 23698 or mod 24498 embodied in production, from the repetitive actions.
For the reason described above, this [EASA] AD retains the requirements of EASA AD 2016-0159, which is superseded, and corrects paragraph (5). For post-mod aeroplanes where, inadvertently, an `affected' ECB has been installed in service, this AD adds the requirementto restore those aeroplanes to post-mod configuration by installation of a `serviceable' ECB. This [EASA] AD also introduces some editorial changes, not affecting the required actions.
This [EASA] AD is republished as it was determined that one `affected' and one `non-affected' ECB were inadvertently omitted in the Tables.

Discrepancies include a defective APU starter motor, misaligned brush wear indicator-pin, oil contamination of the brush wear indicator, and dirt, debris, dust, sand, oil, combustible residues, grease and other contaminations of the APU inlet plenum. Corrective actions include replacement of the APU starter motor and cleaning the APU air intake, if necessary. 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-2016-9567.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA's response to each comment.

Support for the NPRM

United Airlines and Air Line Pilots Association, International, stated their support for the content of the NPRM.

Request To Include Missing Part Number

Airbus asked that electronic control box (ECB) part number (P/N) 3888394-230300 for APU GTCP36-300 be added to table 1 to paragraph (g) of the proposed AD. Airbus stated that the part number is missing in the table.
We agree with the commenter's request. We have added ECB P/N 3888394-230300 for APU GTCP36-300 to table 1 to paragraphs (g), (h), (i)(2)(ii), (j), and (k) of this AD. That part number was omitted from EASA AD 2016-0176, dated August 31, 2016; however, EASA issued a correction, which added that part number, on September 1, 2016. We have also included the corrected EASA AD in this final rule.

Request To Provide Retrofit Installation Method and Interchangeability Information

Virgin America asked that the proposed AD requirements provide anapproved retrofit installation method for P/N 3888394-321206. Virgin America also asked that the proposed AD requirements clearly state the interchangeability or lack of

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interchangeability for the part numbers identified in table 2 of the proposed AD.
Virgin America stated that it receives the Airbus Illustrated Parts Catalog (IPC) on a quarterly basis, which it regularly corrects to remove interchangeability. Virgin America added that in addition to correcting the IPC every quarter, it has repeatedly requested that Airbus Airworthiness and Engineering synchronize their viewpoint of how the IPC is intended to be utilized by operators. Virgin America noted that since EASA has corresponding ADs, it would mean that no ECB can be considered ``interchangeable'' by Airbus, since accomplishing a service bulletin is not the same as accomplishing an airplane maintenance manual. Virgin America requested this coordination within Airbus, both from an ever increasing manpower requirement (i.e., the more ADs, the more IPCs that need interchangeability monitored and removed quarterly) and also from a parts support request, since some parts providers use the IPC as the means to pool and issue parts. Virgin America concluded that a separate pool of non-interchangeable parts adds significantly to the cost impact of the proposed AD.
We acknowledge the commenter's concerns; however, an approved retrofit installation method and interchangeability of part numbers are not addressed by this AD. While there might be merit to the commenter's suggestions, this AD is not the appropriate document in which to evaluate those suggestions. Therefore, we have not changed this AD in this regard.

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 NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

Airbus has issued the following service information, which describes procedures for replacing the ECB. These documents are distinct since they apply to different airplane models in different configurations.
Airbus Service Bulletin A320-49-1077, Revision 04, dated February 27, 2013.
Airbus Service Bulletin A320-49-1098, dated June 21, 2011.
Airbus Service Bulletin A320-49-1102, dated January 3, 2012.
Airbus Service Bulletin A320-49-1107, Revision 02, dated May 10, 2016.
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.

Costs of Compliance

We estimate that this AD affects 1,182 airplanes of U.S. registry.
The actions required by AD 2007-13-08, and retained in this AD, take about 4 work-hours per product, at an average labor rate of $85 per work-hour. Based on these figures, the estimated cost of the actions that are required by AD 2007-13-08 is $340 per product.
We also estimate that it will take about 4 work-hours per product to comply with the 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 on U.S. operators to be $401,880, or $340 per product.
We have received no definitive data that will 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.

List of Subjects in 14 CFR Part 39

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