### 62219 Federal Register / Vol. 74, No. 227 / Friday, November 27, 2009 / Rules and Regulations

procedures specified in paragraph (l) of this AD.

(j) Where paragraph 1.E. of Boeing Alert Service Bulletin 777–53A0054, dated August 7, 2008, specifies to ‘‘contact Boeing for inspection requirements for operation beyond 60,000 total flight-cycles after first repaint,’’ for those airplanes, this AD requires contacting the Manager, Seattle Aircraft Certification Office (ACO), for all inspection requirements of this AD and doing the requirements.
Report

(k) At the applicable time specified in paragraph (k)(1) or (k)(2) of this AD: Submit a report of positive findings of cracks found during the inspection required by paragraph (g) of this AD to the Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124–2207. Alternatively, operators may submit reports to their Boeing field service representatives. The report must contain, at a minimum, the inspection results, a description of any discrepancies found, the airplane serial number, and the number of flight cycles and flight hours on the airplane. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et
seq. ), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number
2120–0056.

(1) If the inspection was done on or after the effective date of this AD: Submit the report within 30 days after the inspection.

(2) If the inspection was done before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.
Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, Seattle 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: Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057– 3356; telephone (425) 917–6577; fax (425) 917–6590. Or, e-mail information to 9–ANM– Seattle-ACO–AMOC–Requests@faa.gov.

(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 an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle 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. Material Incorporated by Reference (m) You must use Boeing Alert Service Bulletin 777–53A0054, dated August 7, 2008, 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 Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H–65, Seattle, Washington 98124–2207; telephone 206–544–5000, extension 1; fax 206–766– 5680; e-mail me.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 or 425–227–1152.

(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. Issued in Renton, Washington, on November 12, 2009. Stephen P. Boyd, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E9–28169 Filed 11–25–09; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2009–1073; Directorate Identifier 2009–NM–174–AD; Amendment**  **39–16097; AD 2007–15–06 R1]**

**RIN 2120–AA64**

**Airworthiness Directives; Airbus Model A318–111 and –112 Series Airplanes,**  **and Model A319, A320, and A321 Series Airplanes** 

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

**ACTION :**  Final rule; request for
comments.

**SUMMARY :**  The FAA is revising an existing airworthiness directive (AD), which applies to all Airbus Model A318–111 and –112 series airplanes, and all Model A319, A320, and A321 series airplanes. That AD currently requires revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness to incorporate new limitations for fuel tank systems. This AD clarifies the intendedeffect of the AD on spare and onairplane fuel tank system components. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

**DATES :**  This AD is effective December 14, 2009.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of December 14, 2009.

On August 28, 2007 (72 FR 40222, July 24, 2007), the Director of the Federal Register approved the incorporation by reference of certain other publications listed in the AD.

We must receive any comments on this AD by January 11, 2010.

**ADDRESSES :**  You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

• Fax: 202–493–2251.

• Mail: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

• Hand Delivery: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; e-mail: account.airwortheas@airbus.com; Internet http:// www.airbus.com. 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 street address for the Docket Office (telephone 800–647– 5527) is in the **ADDRESSES** section. Comments will be available in the AD docket shortly after receipt.

**FOR FURTHER INFORMATION CONTACT :**  Tim Dulin, Aerospace Engineer,


### 62220 Federal Register / Vol. 74, No. 227 / Friday, November 27, 2009 / Rules and Regulations

International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–2141; fax (425) 227–1149.

**SUPPLEMENTARY INFORMATION :** 

Discussion

On July 13, 2007, we issued AD 2007– 15–06, Amendment 39–15135 (72 FR 40222, July 24, 2007). That AD applied to all Airbus Model A318–111 and –112 series airplanes, and all A319, A320, and A321 series airplanes. That AD required revising the Airworthiness Limitations section (ALS) of the Instructions for Continued Airworthiness to incorporate new limitations for fuel tank systems.

Critical design configuration control limitations (CDCCLs) are limitation requirements to preserve a critical ignition source prevention feature of the fuel tank system design that is necessary to prevent the occurrence of an unsafe condition. The purpose of a CDCCL is to provide instruction to retain the critical ignition source prevention feature during configuration change that may be caused by alterations, repairs, or maintenance actions. A CDCCL is not a periodic inspection.

Actions Since AD was Issued

Since we issued that AD, we have determined that it is necessary to clarify the AD’s intended effect on spare and on-airplane fuel tank system components, regarding the use of maintenance manuals and instructions for continued airworthiness.

Section 91.403(c) of the Federal Aviation Regulations (14 CFR 91.403(c)) specifies the following:

No person may operate an aircraft for which a manufacturer’s maintenance manual or instructions for continued airworthiness has been issued that contains an airworthiness limitation section unless the mandatory * * * procedures * * * have been complied with.

Some operators have questioned whether existing components affected by the new CDCCLs must be reworked. We did not intend for the AD to retroactively require rework of components that had been maintained using acceptable methods before the effective date of the AD. Owners and operators of the affected airplanes therefore are not required to rework affected components identified as airworthy or installed on the affected airplanes before the required revisions of the ALS. But once the CDCCLs are incorporated into the ALS, future maintenance actions on components must be done in accordance with those CDCCLs. Relevant Service Information

AD 2007–15–06 cites Airbus A318/ A319/A320/A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 1, dated December 19, 2005; and Airbus A318/A319/A320/A321 ALS Part 5—Fuel Airworthiness Limitations, dated February 28, 2006. Since we issued that AD, Airbus has revised the referenced service information and issued Airbus A318/A319/A320/A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 2, dated July 8, 2008. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI. FAA’s Determination and Requirements of This AD

The affected product(s) have been approved by the aviation authority of another country, and are approved for operation in the United States. We are issuing this AD because we evaluated all pertinent information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design. This new AD retains the requirements of the existing AD, and adds a new note to clarify the intended effect of the AD on spare and on-airplane fuel tank system components. Costs of Compliance

Based on the service information, we estimate that this AD would affect about 720 products of U.S. registry. We also estimate that it would take about 2 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of the AD on U.S. operators to be $115,200, or $160 per product.
FAA’s Justification and Determination of the Effective Date

This revision merely clarifies the intended effect on spare and on-airplane fuel tank system components, and makes no substantive change to the AD’s requirements. For this reason, it is found that notice and opportunity for prior public comment for this action are unnecessary, and good cause exists for making this amendment effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the **ADDRESSES** section. Include ‘‘Docket No. FAA– 2009–1073; Directorate Identifier 2009– NM–174–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.

We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this 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 have 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 the regulation:

1. Is not a ‘‘significant regulatory action’’ under Executive Order 12866;

2. Is not a ‘‘significant rule’’ under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

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


### 62221 Federal Register / Vol. 74, No. 227 / Friday, November 27, 2009 / Rules and Regulations

See the **ADDRESSES** section for a location to examine the regulatory evaluation. 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 part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

**PART 39—AIRWORTHINESS DIRECTIVES** 

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

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

**§ 39.13 [Amended]**

■ 2. The FAA amends § 39.13 by removing amendment 39–15135 (72 FR 40222, July 24, 2007) and adding the following new AD:

2007–15–06 R1 Airbus: Amendment 39– 16097. Docket No. FAA–2009–1073; Directorate Identifier 2009–NM–174–AD.

Effective Date

(a) This airworthiness directive (AD) is effective December 14, 2009.

Affected ADs

(b) This AD revises AD 2007–15–06, Amendment 39–15135.
Applicability

(c) This AD applies to all Airbus Model A318–111 and –112 airplanes; Model A319– 111, –112, –113, –114, –115, –131, –132, and –133 airplanes; Model A320–111, –211, –212, –214, –231, –232, and –233 airplanes; and Model A321–111, –112, –131, –211, –212, –213, –231, and –232 airplanes; certificated in any category.

Note 1: This AD requires revisions to certain operator maintenance documents to include new inspections and critical design configuration control limitations (CDCCLs). Compliance with the operator maintenance documents is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections and CDCCLs, the operator may not be able to accomplish inspections and CDCCLs described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (i) of this AD. The request should include a description of changes to the required inspections and CDCCLs that will preserve the critical ignition source prevention feature of the affected fuel system.

Unsafe Condition

(d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.
Compliance

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

Restatement of AD 2007–15–06, With Revised Service Information

Revise Airworthiness Limitations Section (ALS) To Incorporate Fuel
Maintenance and Inspection Tasks

(f) Within 3 months after August 28, 2007 (the effective date of AD 2007–15–06), revise the ALS of the Instructions for Continued Airworthiness to incorporate Airbus A318/ A319/A320/A321 ALS Part 5—Fuel Airworthiness Limitations, dated February 28, 2006, as defined in Airbus A318/A319/ A320/A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 1, dated December 19, 2005 (approved by the European Aviation Safety Agency (EASA) on March 14, 2006), Section 1, ‘‘Maintenance/ Inspection Tasks;’’ or Airbus A318/A319/ A320/A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 2, dated July 8, 2008 (approved by the EASA on December 19, 2008), Section 1, ‘‘Maintenance/ Inspection Tasks.’’ For all tasks identified in Section 1 of Document 95A.1931/05, the initial compliance times start from August 28, 2007, and the repetitive inspections must be accomplished thereafter at the intervals specified in Section 1 of Document 95A.1931/05.

Note 2: Airbus Operator Information Telex (OIT) SE 999.0076/06, dated June 20, 2006, identifies the applicable sections of the Airbus A318/A319/A320/A321 Airplane Maintenance Manual necessary for accomplishing the tasks specified in Section 1 of Document 95A.1931/05.

Revise ALS To Incorporate CDCCLs

(g) Within 12 months after August 28, 2007, revise the ALS of the Instructions for Continued Airworthiness to incorporate Airbus A318/A319/A320/A321 ALS Part 5— Fuel Airworthiness Limitations, dated February 28, 2006, as defined in Airbus A318/A319/A320/A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 1, dated December 19, 2005 (approved by the EASA on March 14, 2006), Section 2, ‘‘Critical Design Configuration Control Limitations;’’ or Airbus A318/A319/A320/ A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 2, dated July 8, 2008 (approved by EASA on December 19, 2008), Section 2, ‘‘Critical Design Configuration Control Limitations.’’
No Alternative Inspections, Inspection Intervals, or CDCCLs

(h) Except as provided by paragraph (i) of this AD: After accomplishing the actions specified in paragraphs (f) and (g) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used. New Information
Explanation of CDCCL Requirements

Note 3: Notwithstanding any other maintenance or operational requirements, components that have been identified as airworthy or installed on the affected airplanes before the revision of the ALS, as required by paragraphs (f) and (g) of this AD, do not need to be reworked in accordance with the CDCCLs. However, once the ALS has been revised, future maintenance actions on these components must be done in accordance with the CDCCLs.

Other FAA AD Provisions

(i) 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: Tim Dulin, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–2141; 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 FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

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

Related Information

(j) EASA Airworthiness Directive 2006– 0203, dated July 11, 2006, also addresses the subject of this AD.
Material Incorporated by Reference

(k) You must use Airbus A318/A319/A320/ A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 1, dated December 19, 2005; Airbus A318/A319/ A320/A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 2, dated July 8, 2008; and Airbus A319/A319/A320/A321 ALS Part 5—Fuel Airworthiness Limitations, dated February 28, 2006; as applicable; 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 Airbus A318/A319/A320/A321 Fuel


### 62222 Federal Register / Vol. 74, No. 227 / Friday, November 27, 2009 / Rules and Regulations

Airworthiness Limitations, Document 95A.1931/05, Issue 2, dated July 8, 2008, under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The Director of the Federal Register previously approved the incorporation by reference of Airbus A318/A319/A320/A321 Fuel Airworthiness Limitations, Document 95A.1931/05, Issue 1, dated December 19, 2005; and Airbus A319/A319/A320/A321 ALS Part 5—Fuel Airworthiness Limitations, dated February 28, 2006; on August 28, 2007 (72 FR 40222, July 24, 2007).

(3) For service information identified in this AD, contact Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; e-mail: account.airworth-eas@airbus.com; Internet http://www.airbus.com.

(4) 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 or 425–227–1152.

(5) 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

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_ locations.html. Issued in Renton, Washington, on November 16, 2009. Stephen P. Boyd, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E9–28159 Filed 11–25–09; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2009–0674; Directorate Identifier 2009–NE–25–AD; Amendment 39–**  **16092; AD 2009–24–05]**

**RIN 2120–AA64**

**Airworthiness Directives; Rolls-Royce plc RB211–Trent 800 Series Turbofan**  **Engines**

**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 results from mandatory continuing airworthiness information (MCAI) issued 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: Under certain ambient conditions, ice can accumulate on the walls of the fuel pipes within the aircraft fuel system, which can then be released downstream when fuel flow demand is increased. This released ice can then collect on the fuel-to-oil heat exchanger (FOHE) front face and limit fuel flow through the FOHE.

We are issuing this AD to prevent ice from blocking the FOHE, which could result in an unacceptable engine power loss, and loss of control of the airplane.

**DATES :**  This AD becomes effective January 4, 2010. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of January 4, 2010.

**ADDRESSES :**  The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12–140, Washington, DC
20590–0001.

**FOR FURTHER INFORMATION CONTACT :**  James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov; telephone (781) 238–7176; fax (781)
238–7199.

You can get the service information identified in this AD from Rolls-Royce plc, P.O. Box 31, DERBY, DE24 8BJ, UK; telephone 44 (0) 1332 242424; fax 44 (0)
1332 249936.

**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 July 23, 2009 (74 FR 36422). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

This Airworthiness Directive has been raised following an incident involving dual loss of engine response in the final stages of approach leading to touchdown short of the runway. The phenomenon involved in the loss of engine response has also been seen in flight affecting just one engine.

Post incident analysis and investigation has established that, under certain ambient conditions, ice can accumulate on the walls of the fuel pipes within the aircraft fuel system, which can then be released downstream when fuel flow demand is increased. This released ice can then collect on the FOHE front face and limit fuel flow through the FOHE. This type of icing event was previously unknown and creates ice concentrations in the fuel system beyond those specified in the certification requirements. To mitigate the risk of engine FOHE blockage, this AD requires replacing the FOHE, part number (P/N) 55003001–1 or 55003001–11, with a FOHE that has been modified using Rolls-Royce plc Alert Service Bulletin (ASB) No. RB.211–79–AG257, Revision 1, dated September 14, 2009.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received. Request To Eliminate ‘‘Or Equivalent’’ From Paragraph (e)

Delta Airlines requests that we eliminate the words ‘‘or equivalent’’ from paragraph (e) of the proposed AD.

We agree. We deleted them from paragraph (e) of the AD. Requests To List the Replacement FOHE P/N or Subsequent Post Alert Service Bulletin FOHE P/N

American Airlines, Rolls-Royce plc, Boeing, and the Airlines Pilot Association (ALPA) request that we require replacing the FOHE, P/N 55003001–1 or 55003001–11, with a FOHE P/N 55003001–21, or subsequent post Rolls-Royce plc ASB No. RB.211– 79–AG257 FOHE P/N.

We partially agree. Rulemaking requirements do not permit advance approval of unknown future revisions to service bulletins and part numbers. However, we agree that we can clarify the compliance to identify the modification needed to replace the FOHE. We changed paragraph (e) to state ‘‘Unless already done, within 6,000 flight hours after the effective date of this AD, but no later than January 1, 2011, replace the FOHE, P/N 55003001– 1 or 55003001–11, with an FOHE modified using Rolls-Royce plc ASB No. RB.211–79–AG257, Revision 1, dated September 14, 2009. Request To Change the Summary and Discussion Paragraphs

Boeing requests that we change the Summary and Discussion paragraphs from ‘‘under certain ambient conditions, ice can accumulate on the walls of the fuel pipes within the aircraft fuel system’’ to ‘‘under certain ambient conditions, ice can accumulate on the walls of the fuel pipes within the aircraft and/or engine fuel systems.’’ The commenter states that the current wording suggests that ice accumulation is possible only in the aircraft-side wing and strut fuel feed lines. Post incident analysis and investigation could not conclusively identify where in the feed lines ice accumulated, nor did it exclude the possibility of accumulation