## 432 Federal Register / Vol. 76, No. 3 / Wednesday, January 5, 2011 / Rules and Regulations

1,000 flight cycles after doing the blend out, do an HFEC inspection of the blend out on the center section rib hinge bearing lug; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90–55A016, Revision 1, dated February 17, 2010. Repeat the HFEC inspection of the blend out thereafter at intervals not to exceed 400 flight cycles until the replacement specified by paragraph (j) is done.

(j) If any cracking is detected during any inspection required by paragraph (i) of this AD, before further flight, replace the horizontal stabilizer center section rib with a new horizontal stabilizer center section rib, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90–55A016, Revision 1, dated February 17, 2010.

(k) If during any inspection required by paragraph (g) or (h) of this AD, any crack is found having a length between Points ‘A’ and ‘B’ greater than 0.15 inch or crack length between Points ‘C’ and ‘D’ greater than 0.05 inch, as identified in Boeing Alert Service Bulletin MD90–55A016, Revision 1, dated February 17, 2010: Before further flight, replace the horizontal stabilizer center section rib with a new horizontal stabilizer center section rib, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90–55A016, Revision 1, dated February 17, 2010.

(l) For any airplane having a horizontal stabilizer center section rib replaced during the actions required by paragraph (j) or (k) of this AD: Before the accumulation of 7,200 total flight cycles on the new horizontal stabilizer center section rib, do the actions required by paragraph (g) of this AD, and do all applicable actions specified in paragraphs (h), (i), (j), and (k) of this AD.
Credit for Actions Accomplished According to Previous Issue of Service Bulletin

(m) Actions accomplished before the effective date of this AD according to Boeing Alert Service Bulletin MD90–55A016, dated December 16, 2009, are considered acceptable for compliance with the corresponding actions required by paragraphs (g), (h), (i), (j), and (k) of this AD.
Exception to the Service Bulletin

(n) Where Boeing Alert Service Bulletin MD90–55A016, Revision 1, dated February 17, 2010, specifies a compliance time ‘‘ after the original issue date on the service bulletin, ’’ this AD requires compliance within the specified compliance time after the effective date of this AD.
Alternative Methods of Compliance (AMOCs)

(o)(1) The Manager, Los Angeles Aircraft Certification Office (ACO), 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: Roger Durbin, Aerospace Engineer, Airframe Branch, ANM–120L, FAA, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, California 90712–4137; telephone (562) 627– 5233; fax (562) 627–5210.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. 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.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

Related Information

(p) For more information about this AD, contact Roger Durbin, Aerospace Engineer, Airframe Branch, ANM–120L, FAA, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, California 90712–4137; telephone (562) 627–5233; fax (562) 627–5210.
Material Incorporated by Reference

(q) You must use Boeing Alert Service Bulletin MD90–55A016, Revision 1, dated February 17, 2010, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin MD90–55A016, Revision 1, dated February 17, 2010, under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, 3855 Lakewood Boulevard, MC D800–0019, Long Beach, California 90846– 0001; telephone 206–544–5000, extension 2; fax 206–766–5683; e-mail dse.boecom@boeing.com; Internet https:// www.myboeingfleet.com.

(3) You may review copies of the 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.

(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call 202–741– 6030, or go to http://www.archives.gov/ federal

_register/code

_ of

_ federal

_regulations/ ibr

_locations.html.
Issued in Renton, Washington, on December 22, 2010. Jeffrey E. Duven, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2010–32993 Filed 1–4–11; 8:45 am]

**BILLING CODE 4910–13–P** 

### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0952; Directorate Identifier 2010–NM–131–AD; Amendment**  **39–16555; AD 2011–01–02]**

**RIN 2120–AA64**



### Airworthiness Directives; Airbus Model **A330–201, –202, –203, –223, and –243 Airplanes; Airbus Model A330–300**  **Series Airplanes; and Airbus Model A340–200 and –300 Series Airplanes** 

**AGENCY** 

### : Federal Aviation Administration (FAA), Department of Transportation (DOT).

**ACTION** 

### : Final rule.

**SUMMARY** 

### : We are adopting a new airworthiness directive (AD) for the products listed above. This 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:

[T]he FAA published SFAR 88 (Special Federal Aviation Regulation 88).

By mail referenced 04/00/02/07/01–L296 of March 4th, 2002 and 04/00/02/07/03–L024 of February 3rd, 2003 the JAA [Joint Aviation Authorities] recommended to the National Aviation Authorities (NAA) the application of a similar regulation.

The aim of this regulation is to require * * * a definition review against explosion hazards.



### * * * * * Failure of the auxiliary power unit (APU) bleed leak detection system could result in overheat of the fuel tank located in the horizontal stabilizer and ignition of the fuel vapors in that tank, which could result in a fuel tank explosion and consequent loss of the airplane. We are issuing this AD to require actions to correct the unsafe condition on these products.

**DATES** 

### : This AD becomes effective February 9, 2011.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of February 9, 2011.

**ADDRESSES** 

### : You may examine the AD docket on the Internet at http:// www.regulations.gov or in person at the U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC.

**FOR FURTHER INFORMATION CONTACT** 

### : Vladimir Ulyanov, Aerospace Engineer,


## 433 Federal Register / Vol. 76, No. 3 / Wednesday, January 5, 2011 / Rules and Regulations

International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–1138; fax (425) 227–1149.

**SUPPLEMENTARY INFORMATION** 

### :

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on October 1, 2010 (75 FR 60655). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

[T]he FAA published SFAR 88 (Special Federal Aviation Regulation 88).

By mail referenced 04/00/02/07/01–L296 of March 4th, 2002 and 04/00/02/07/03–L024 of February 3rd, 2003 the JAA [Joint Aviation Authorities] recommended to the National Aviation Authorities (NAA) the application of a similar regulation.

The aim of this regulation is to require all holders of type certificates for transport aircraft certified after 01 January 1958 with a capacity of 30 passengers or more, or a payload of 3 402 kg or more, to carry out a definition review against explosion hazards.

To be compliant with SFAR88/JAA INT/ POL 25/12 requirements, this AD requires the installation of the updated FWC [flight warning computer] software standard which ensures correct operation of the APU bleed leak detection system before each flight. 

### Failure of the auxiliary power unit (APU) bleed leak detection system could result in overheat of the fuel tank located in the horizontal stabilizer and ignition of the fuel vapors in that tank, which could result in a fuel tank explosion and consequent loss of the airplane. You may obtain further information by examining the MCAI in the AD docket.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.

Conclusion

We reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

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 required different actions in this AD from those in the MCAI in order to follow our FAA policies. Any such differences are highlighted in a Note within the AD. Costs of Compliance

We estimate that this AD will affect 53 products of U.S. registry. We alsoestimate that it will take about 5 workhours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Required parts will cost about $0 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 parts. 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 this AD to the U.S. operators to be $22,525, or $425 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 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 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); 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 AD and placed it in the AD docket. 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 the NPRM, 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. Comments will be available in the AD docket shortly after receipt. List of Subjects in 14 CFR Part 39

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

■ 

### 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:
2011–01–02 Airbus: Amendment 39–16555. Docket No. FAA–2010–0952; Directorate Identifier 2010–NM–131–AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective February 9, 2011.

Affected ADs

(b) None.
Applicability

(c) This AD applies to the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD.

(1) Airbus Model A330–201, –202, –203, –223, –243, –301, –302, –303, –321, –322, –323, –341, –342 and –343 airplanes, all manufacturer serial numbers except those on which Airbus modification 51790 has been embodied in production or Airbus Service Bulletin A330–31–3066, A330–31–3082, A330–31–3093, or A330–31–3105 has been


## 434 Federal Register / Vol. 76, No. 3 / Wednesday, January 5, 2011 / Rules and Regulations

embodied in service; certificated in any category.

(2) Airbus Model A340–211, –212, –213, –311, –312, and –313 airplanes, all manufacturer serial numbers; certificated in any category. Subject

(d) Air Transport Association (ATA) of America Code 31: Instruments.

Reason

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

[T]he FAA published SFAR 88 (Special Federal Aviation Regulation 88).

By mail referenced 04/00/02/07/01–L296 of March 4th, 2002 and 04/00/02/07/03–L024 of February 3rd, 2003 the JAA [Joint Aviation Authorities] recommended to the National Aviation Authorities (NAA) the application of a similar regulation.

The aim of this regulation is to require * * * a definition review against explosion hazards.


### * * * * * Failure of the auxiliary power unit (APU) bleed leak detection system could result in overheat of the fuel tank located in the horizontal stabilizer and ignition of the fuel vapors in that tank, which could result in a fuel tank explosion and consequent loss of the airplane.
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.

Actions

(g) Within 6 months after the effective date of this AD, do the applicable actions specified in paragraphs (g)(1) and (g)(2) of this AD.

(1) For Model A330–201, –202, –203, –223, –243, –301, –302, –303, –321, –322, –323, –341, –342 and –343 airplanes: Install flight warning computer (FWC) software standard T3 (part number (P/N) LA2E20202T30000) on both FWCs, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A330–31–3146, including Appendix 01, Revision 01, dated May 5,
2010.

(2) For Model A340–211, –212, –213, –311, –312, and –313 airplanes: Install FWC software standard L11 (P/N LA2E0060D110000) on both FWCs, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A340– 31–4125, Revision 01, dated December 9,
2008.

(h) Prior to or concurrently with accomplishing the corresponding requirements of paragraph (g) of this AD, install FWC software standard T2–0 in accordance with the Accomplishment Instructions of Airbus Service Bulletin A330– 31–3125, dated December 31, 2008 (for Model A330–201, –202, –203, –223, –243, –301, –302, –303, –321, –322, –323, –341, –342 and –343 airplanes).

(i) Prior to or concurrently with accomplishing the corresponding requirements of paragraph (g) of this AD, install FWC software standard L10–1 in accordance with the Accomplishment Instructions of Airbus Service Bulletin A340– 31–4111, dated February 5, 2007 (for Model A340–211, –212, –213, –311, –312, and –313 airplanes).

(j) Actions done before the effective date of this AD in accordance with Airbus Service Bulletin A330–31–3146, dated February 2, 2010; or A340–31–4125, dated October 27, 2008; are acceptable for compliance with the corresponding requirements of paragraph (g) of this AD.

FAA AD Differences

Note 1: This AD differs from the MCAI and/or service information as follows: No differences.

Other FAA AD Provisions

(k) 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. Send information to ATTN: Vladimir Ulyanov, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–1138; fax (425) 227–1149. 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 FAAapproved 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: A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120–0056. Public reporting for this collection of information is estimated to be approximately 5 minutes per response, including the time for reviewing instructions, completing and reviewing the collection of information. All responses to this collection of information are mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn: Information Collection Clearance Officer, AES–200.

Related Information

(l) Refer to MCAI European Aviation Safety Agency (EASA) Airworthiness Directive 2010–0089, dated May 10, 2010, and the service information identified in Table 1 of this AD, for related information.



### T ABLE 

### 1—R ELATED 

### S ERVICE 

### I NFORMATION

Airbus Service Bulletin— Revision— Dated—

A330–31–3125 ................................................................................................................... .............. Original ...................... December 31, 2008. A330–31–3146, including Appendix 01 ........................................................................................... 01 .............................. May 5, 2010. A340–31–4111 ................................................................................................................... .............. Original ...................... February 5, 2007. A340–31–4125 ................................................................................................................... .............. 01 .............................. December 9, 2008.

Material Incorporated by Reference

(m) You must use the applicable service information contained in Table 2 of this AD to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Airbus SAS—Airworthiness Office—EAL, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 45 80, e-mail airworthiness.A330-A340@airbus.com; Internet http://www.airbus.com.

(3) You may review copies of the 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. (4) You may also review copies of the 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/ code

_ of

_ federal

_ regulations/ibr

_ locations. html.


## 435 Federal Register / Vol. 76, No. 3 / Wednesday, January 5, 2011 / Rules and Regulations

T ABLE 

### 2—M ATERIAL 

### I NCORPORATED BY 

### R EFERENCE

Airbus Service Bulletin— Revision— Dated—

A330–31–3125 ................................................................................................................... .............. Original ...................... December 31, 2008. A330–31–3146, including Appendix 01 ........................................................................................... 01 .............................. May 5, 2010. A340–31–4111 ................................................................................................................... .............. Original ...................... February 5, 2007. A340–31–4125 ................................................................................................................... .............. 01 .............................. December 9, 2008.

Issued in Renton, Washington, on December 17, 2010. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2010–32653 Filed 1–4–11; 8:45 am]

**BILLING CODE 4910–13–P**



### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0797; Directorate Identifier 2010–NM–141–AD; Amendment**  **39–16562; AD 2011–01–09]**

**RIN 2120–AA64**



### Airworthiness Directives; B/E **Aerospace Protective Breathing Equipment (PBE) Part Number 119003–**  **11 Installed on Various Transport Airplanes** 

**AGENCY** 

### : Federal Aviation Administration (FAA), DOT.

**ACTION** 

### : Final rule.

**SUMMARY** 

### : We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires removing affected PBE units. This AD was prompted by reports of potentially defective potassium superoxide canisters used in PBE units, which could result in an exothermic reaction and ignition. We are issuing this AD to prevent PBE units from igniting, which could result in a fire and possible injury to the flightcrew or other persons.

**DATES** 

### : This AD is effective February 9,
2011.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of February 9, 2011.

**ADDRESSES** 

### : For service information identified in this AD, contact B/E Aerospace, Inc., Commercial Aircraft Products Group, RGA Department, 10800 Pflumm Road, Lenexa, KS 66215; telephone (913) 338–7378; fax (913) 469–8419; Internet http:// www.beaerospace.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 Management Facility 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 address for the Docket Office (phone: 800–647–5527) is Document Management Facility, U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

**FOR FURTHER INFORMATION CONTACT** 

### : David Fairback, Aerospace Engineer, Systems and Propulsion Branch, ACE–116W, FAA, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 946–4154; fax (316) 946–4107; e-mail David.Fairback@faa.gov.

**SUPPLEMENTARY INFORMATION** 

### :

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to the specified products. That NPRM published in the Federal Register on August 18, 2010 (75 FR 50941). That NPRM proposed to require removing affected PBE units.

Comments

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

Boeing supported the contents of the NPRM. Request To Withdraw the NPRM

Continental Airlines stated that Boeing has indicated in Fleet Team Digest 737NG–FTD–25–10003 that all defective B/E Aerospace PBEs have been successfully captured. We infer that Continental requested that we withdraw the NPRM.

We disagree with the request to withdraw the NPRM. We have not received assurance of such accomplishment. We contacted B/E Aerospace and it reported that their records show 422 of the 600 affected PBEs were contained, leaving 178 affected PBEs in the field. We have not changed the final rule in regard to this issue.
Request To Clarify Affected Serial Numbers

ABX Air requested that we clarify that no further action is required for PBEs with serial numbers outside the range. ABX Air suggested adding a new paragraph (g)(3) to the final rule to state

‘‘ For any PBE not having a serial number from 003–50730M to 003–51329M inclusive: No further action is required. ’’

We agree that no further action is necessary for PBEs with serial numbers outside the range specified in paragraph (g)(1) of this AD. We added a new paragraph (g)(3) to this final rule. We have also clarified paragraph (g)(2) of this AD to state that once the replacement has been done, no further action is required by paragraph (g) of this AD. However, paragraph (h) of this AD prohibits installations of the PBEs within the serial number range.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.
Costs of Compliance

We estimate that this AD affects up to 600 airplanes of U.S. registry.

We estimate the following costs to comply with this AD: