E9-25645. Airworthiness Directives; Rolls-Royce plc RB211 Trent 700 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Rolls-Royce plc (RR) RB211 Trent 700 series turbofan engines. That AD currently requires initial and repetitive borescope inspections of the high pressure-and-intermediate pressure (HP-IP) turbine internal and external oil vent tubes for coking and carbon buildup, and cleaning or replacing the vent tubes if necessary. This proposed AD would require the same actions, but would add additional inspections of the vent flow restrictor. This proposed AD results from further analysis that the cleaning of the vent tubes required by AD 2007-02-05 could lead to loosened carbon fragments, causing a blockage downstream in the vent flow restrictor. We are proposing this AD to prevent internal oil fires due to coking and carbon buildup that could cause uncontained engine failure and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by December 28, 2009.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

Contact Rolls-Royce plc, P.O. Box 31, Derby, England; telephone: [phone]; fax: [phone], for the service information identified in this proposed AD.

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: [e-mail]; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2005-19559; Directorate Identifier 2004-NE-03-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

On January 12, 2007, the FAA issued AD 2007-02-05, Amendment 39-14892 (72 FR 2603, January 22, 2007). The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, notified us that an unsafe condition may exist on RB211 Trent 700 series turbofan engines. Since AD 2007-02-05 was issued, EASA advises that further analysis has now identified that previous intervention actions may have exacerbated the problem of carbon formation in the vent pipe. These intervention actions are believed to loosen carbon fragments which are subsequently released during engine operation, leading to blockage downstream in the vent flow restrictor. The resultant reduced vent pipe flow will then cause accelerated carbon buildup inside the pipe and increased likelihood of an internal oil fire.

Relevant Service Information

We have reviewed and approved the technical contents of Rolls-Royce plc Alert Service Bulletin (ASB) No. RB.211-72-AE302, Revision 7, dated April 30, 2009. That ASB describes procedures for borescope inspections of the HP-IP turbine internal and external oil vent tubes for coking and carbon buildup, and cleaning or replacing the vent tubes if necessary. That ASB also describes procedures for visual inspections of the vent pipe restrictor immediately after pipe cleaning and a high-power engine run. For internal oil vent tubes to pass inspection, they must allow cleaning tool, number HU80298, to pass through them. EASA classified this service bulletin as mandatory and issued AD 2007-0201 and AD 2007-0202 (corrected August 8, 2007), to ensure the airworthiness of these RB211 Trent 700 series turbofan engines in Europe.

Bilateral Agreement Information

This engine model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of Section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Under this bilateral airworthiness agreement, EASA kept us informed of the situation described above. We have examined the findings of the EASA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require initial and repetitive borescope inspections of the HP-IP turbine internal and external oil vent tubes for coking and carbon buildup, and cleaning or replacing the vent tubes if necessary. This proposed AD would also require visual inspections of the vent flow restrictor immediately after pipe cleaning and a high-power engine run. We are issuing this AD to prevent internal oil fires due to coking and carbon buildup that could cause uncontained engine failure and damage to the airplane. The proposed AD would require that you do these actions using the service information described previously.

Table 1 Clarification

We found it necessary to clarify the second sentence in the first column of the Initial Inspection Table 1, which we carried forward from AD 2007-02-05. We changed “Has fewer than 10,000 hours TSN or fewer than 2,500 CSN on the effective date of this AD” to “Has fewer than 10,000 hours TSN and fewer than 2,500 CSN on the effective date of this AD.”

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 33 engines of U.S. registry. We also estimate that it would take about one work-hour per engine to comply with this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $2,000 per engine. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $68,640.

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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that the proposed 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. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. 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

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

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

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

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-14892 (72 FR 2603, January 22, 2007) and by adding a new airworthiness directive, to read as follows:

Rolls-Royce plc: Docket No. FAA-2005-19559; Directorate Identifier 2004-NE-03-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by December 28, 2009.

Affected ADs

(b) This AD supersedes AD 2007-02-05, Amendment 39-14892.

Applicability

(c) This AD applies to Rolls-Royce plc (RR) RB211 Trent 768-60, RB211 Trent 772-60, and RB211 Trent 772B-60 series turbofan engines. These engines are installed on, but not limited to, Airbus A330-243, -341, -342 and -343 series airplanes.

Unsafe Condition

(d) This AD results from further analysis that the cleaning of the vent tubes required by AD 2007-02-05 could lead to loosened carbon fragments, causing a blockage downstream in the vent flow restrictor. We are issuing this AD to prevent internal oil fires due to coking and carbon buildup that could cause uncontained engine failure and damage to 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.

Initial Inspections, Cleaning, and Replacements

(f) Using the schedule in Table 1 of this AD, borescope-inspect and clean as necessary, the high pressure-and-intermediate pressure (HP-IP) turbine internal oil vent tubes, external oil vent tubes, and bearing chamber.

Table 1—Initial Inspection Schedule

If the engine or the 05 module:	Then initially inspect:
Has reached 10,000 hours time-since-new (TSN) or reached 2,500 cycles-since-new (CSN) on the effective date of this AD	Within 3 months after the effective date of this AD.
Has fewer than 10,000 hours TSN and fewer than 2,500 CSN on the effective date of this AD	Within 3 months after reaching 10,000 hours TSN or 2,500 CSN, whichever occurs first.
Is returned for an engine shop visit	Before returning to service.

(1) If after cleaning, there is still carbon in the vent tube that prevents cleaning tool number HU80298 from passing through the tube, then replace the internal oil vent tube within 10 cycles-in-service (CIS).

(2) If after cleaning, there is still carbon of visible thickness in either of the two external oil vent tubes, then replace the external oil vent tube before further flight.

(3) Use paragraphs 3.A. through 3.A.(7) of the Accomplishment Instructions of RR Alert Service Bulletin (ASB) No. RB.211-72-AE302, Revision 7, dated April 30, 2009, to do the borescope inspections and cleaning of the oil vent tubes and bearing chamber.

Initial Visual Inspection of the Vent Flow Restrictor

(g) For engines that, on the effective date of this AD, have not accumulated 25 service cycles since the last cleaning and inspection, visually inspect the vent flow restrictor either after a high-power ground run or within 25 service cycles of the last cleaning and inspection.

(h) For engines that, on the effective date of this AD, have accumulated 25 or more service cycles since the last cleaning and inspection, visually inspect the vent flow restrictor either after a high-power ground run or within 25 service cycles after the effective date of this AD.

(i) Use paragraph 3.A.(8) of the Accomplishment Instructions of RR ASB No. RB.211-72-AE302, Revision 7, dated April 30, 2009, to do the visual inspections.

Repetitive Inspections, Cleaning, and Replacements

(j) Within 6,400 hours time-in-service since last inspection and cleaning, or within 1,600 cycles-since-last inspection and cleaning, or at the next engine shop visit, whichever occurs first, borescope-inspect the HP-IP turbine internal and external oil vent tubes and bearing chamber, and clean the oil vent tubes as necessary.

(1) If after cleaning there is still carbon in the internal oil vent tube that prevents cleaning tool, number HU80298, from passing through the tube, then replace the internal oil vent tube within 10 CIS.

(2) If after cleaning there is still carbon of visible thickness, in either of the two external oil vent tubes, then replace the external oil vent tube before further flight.

(3) Use paragraphs 3.A. through 3.A.(7) of the Accomplishment Instructions of RR ASB No. RB.211-72-AE302, Revision 7, dated April 30, 2009, to do the borescope inspections and cleaning of the oil vent tubes and bearing chamber.

(k) Visually inspect the vent flow restrictor either after a high-power ground run or within 25 service cycles after performing the cleaning and inspection specified in paragraph (f) through (f)(3) of this AD. Use paragraph 3.A.(8) of the Accomplishment Instructions of RR ASB No. RB.211-72-AE302, Revision 7, dated April 30, 2009, to do the visual inspection.

Definition

(l) For the purpose of this AD, an engine shop visit is induction of the engine into the engine shop for any cause.

Alternative Methods of Compliance

(m) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(n) European Aviation Safety Agency AD 2007-0201, dated August 1, 2007, and AD 2007-0202 (corrected August 8, 2007), also address the subject of this AD. Rolls-Royce plc ASB No. RB.211-72-AE302, Revision 7, dated April 30, 2009, pertains to the subject of this AD. Contact Rolls-Royce plc, P.O. Box 31, Derby, England; telephone: [phone]; fax: [phone], for the service information identified in this AD.

(o) Contact James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

Issued in Burlington, Massachusetts, on October 16, 2009.

Robert J. Ganley,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.