E9-9479. Airworthiness Directives; Rolls-Royce plc RB211 Trent 800 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 RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent 895-17 turbofan engines with high pressure (HP) compressor rotor rear stage 5 and 6 discs and cone shafts, part numbers (P/Ns) FK25230 and FK27899 installed. This proposed AD would require removing these parts at new reduced cycle limits. This proposed AD results from Rolls-Royce plc reducing the lives of these parts and changing the life calculating method to use “Standard Duty Cycles” with “Multiple Flight Profile Monitoring” and “Flight Cycles” with “Heavy Flight Profile Monitoring”. We are proposing this AD to prevent stage 5 and 6 disc crack initiation and propagation that might lead to uncontained disc failure and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by June 26, 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].

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-2009-1369; Directorate Identifier 2003-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 July 23, 2003, we issued AD 2003-15-06, Amendment 39-13249 (68 FR 44610, July 30, 2003). That AD requires removal from service of HP compressor rotor rear stage 5 and 6 discs and cone shafts, P/Ns FK25230 and FK27899, before reaching newly reduced life limits. The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (U.K.), had notified the FAA that an unsafe condition may exist on Rolls-Royce plc RB211 Trent 875, Trent 877, Trent 884, Trent 892, Trent 892B, and Trent 895 turbofan engines. The CAA advised that three HP compressor rotor rear stage 5 and 6 discs and cone shafts, P/Ns FK25230 and FK27899, were found with crack indications in the stage 5 and 6 blade loading slots, during overhaul inspection. The manufacturer's analysis had not yet been able to identify the root cause of these cracks, or to fully explain the crack propagation rate. As a result of the analysis, a new lower life limit of 7,500 cycles-since-new had been assigned by the manufacturer to these HP compressor rotor rear stage 5 and 6 discs and cone shafts. This condition, if not corrected, could result in stage 5 and 6 disc crack initiation and propagation that might lead to uncontained disc failure and damage to the airplane.

Actions Since AD 2003-15-06 Was Issued

Since AD 2003-15-06 was issued, Rolls-Royce plc has further reduced the lives of HP compressor rotor rear stage 5 and 6 discs and cone shafts, P/Ns FK25230 and FK27899, and changed the life calculating method to use “Standard Duty Cycles” with “Multiple Flight Profile Monitoring” and “Flight Cycles” with “Heavy Flight Profile Monitoring”.

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, the European Aviation Safety Agency (EASA) kept us informed of the situation described above. We have examined the findings of 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 changing the life calculating method to use “Standard Duty Cycles” with “Multiple Flight Profile Monitoring” and “Flight Cycles” with “Heavy Flight Profile Monitoring”, and reducing the lives of the affected parts to 5,000 “Standard Duty Cycles” or 5,000 Flight cycles”, respectively.

Costs of Compliance

We estimate that this proposed AD would affect 94 Rolls-Royce plc RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent 895-17 turbofan engines installed on airplanes of U.S. registry. Removal of these HP compressor rotor rear stage 5 and 6 discs and cone shafts would not impose any additional labor costs if performed at the time of scheduled engine overhaul. The prorated life loss is about $225,000 per engine. Based on these figures, we estimate the cost of this proposed AD on U.S. operators to be $21,150,000.

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
• 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 39-13249 (68 FR 44610, July 30, 2003) and by adding a new airworthiness directive, to read as follows:

Rolls-Royce plc: Docket No. FAA-2009-1369; Directorate Identifier 2003-NE-03-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by June 26, 2009.

Affected ADs

(b) This AD supersedes AD 2003-15-06, Amendment 39-13249.

Applicability

(c) This AD applies to Rolls-Royce plc RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent 895-17 turbofan engines with high pressure (HP) compressor rotor rear stage 5 and 6 discs and cone shafts, part numbers (P/Ns) FK25230 and FK27899 installed. These engines are installed on, but not limited to, Boeing 777 series airplanes.

Unsafe Condition

(d) This AD results from Rolls-Royce plc reducing the lives of these parts and changing the life calculating method to use “Standard Duty Cycles” with “Multiple Flight Profile Monitoring”, and “Flight Cycles” with “Heavy Flight Profile Monitoring”. We are issuing this AD to prevent stage 5 and 6 disc crack initiation and propagation that might lead to uncontained disc 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.

(f) For operators using “Multiple Flight Profile Monitoring” (Flight Profiles “A” through “F”), remove HP compressor rotor rear stage 5 and 6 discs and cone shafts from service at or before accumulating 5,000 “Standard Duty Cycles”. Information on “Multiple Flight Profile Monitoring” can be found in the Aircraft Maintenance Manual, Chapter 70-01-10.

(g) For operators using “Heavy Flight Profile Monitoring”, remove HP compressor rotor rear stage 5 and 6 discs and cone shafts from service at or before accumulating 5,000 “Flight Cycles”. Information on “Heavy Flight Profile Monitoring” can be found in the Aircraft Maintenance Manual, Chapter 70-01-10.

Alternative Methods of Compliance

(h) 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

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

(j) European Aviation Safety Agency AD 2007-0004, dated January 8, 2007, also addresses the subject of this AD.

(k) Rolls-Royce plc Alert Service Bulletin No. RB.211-72-AE082, Revision 7, dated June 18, 2008, pertains to the subject of this AD. Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, UK, telephone [phone]; fax [phone], for a copy of this service information.

(l) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of the Aircraft Maintenance Manual referenced in this AD.

Issued in Burlington, Massachusetts, on April 17, 2009.

Peter A. White,

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