Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Rolls-Royce plc (RR) models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, RB211-535E4-C, and RB211-22B-02 turbofan engines. That AD currently requires inspecting certain high pressure (HP) turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacing the discs with serviceable parts. This proposed AD would require the same inspections, and would reduce the compliance times for eddy current inspection (ECI) for the RR RB211-22B-02 engines. This proposed AD results from the manufacturer reducing their recommended compliance times for inspections on RB211-22B-02 engines. We are proposing this AD to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by March 31, 2006.

ADDRESSES:

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

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-62-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: (781) 238-7055.
• By e-mail: 9-ane-adcomment@faa.gov.

You can get the service information identified in this proposed AD from Rolls-Royce plc, PO Box 31, Derby, England; telephone: 011 44 1332-249428, fax: 011 44 1332-249223.

You may examine the AD docket, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7178, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2000-NE-62-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

On December 15, 2004, the FAA issued AD 2004-26-03, Amendment 39-13915 (69 FR 77881, December 29, 2004) for RR models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 turbofan engines. That AD requires inspecting certain HP turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacing the discs with serviceable parts.

Actions Since AD 2004-26-03 Was Issued

Since we issued AD 2004-26-03, the Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified us that an unsafe condition might exist on RR model RB211-22B-02 turbofan engines manufactured between 1989 and 1999. The CAA advises that cracks were found in a Trent 800 HP turbine disc attributable to machining anomalies during new manufacture. The RB211-22B-02 HP turbine is similar in design to the Trent 800, manufactured at the same facility and with the same tooling. This proposed AD would require inspection of certain HP turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacement with serviceable parts. We are reducing the inspection schedules required by AD 2004-26-03, for the high risk discs installed on model RB211-22B-02 engines. This AD retains the same inspection schedules, currently required for RR models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75 turbofan engines that were in AD 2004-26-03. The actions specified in this proposed AD are intended to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

Bilateral Airworthiness Agreement

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 CAA has kept the FAA informed of the situation described above. We have examined the findings of the CAA, 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.

Relevant Service Information

We have reviewed and approved the technical contents of RR ASB RB.211-72-AE717, dated January 21, 2005, that describes procedures for inspecting the RB211-22B disk for cracks. The CAA classified this service bulletin as mandatory and issued AD G-2005-0003, dated January 24, 2005, in order to ensure the airworthiness of these RR RB211-22 turbofan engines in the U.K.

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. Therefore, we are proposing this AD, which would require the same inspections specified in AD 2004-26-03, but would reduce the compliance times for the model RB211-22B engine to:

• Within 500 cycles-in-service (CIS) after January 1, 2005 or before accumulating 11,000 cycles-since-new (CSN), whichever occurs first, on engines with more than 9,000 CSN on January 1, 2005, and
• Before accumulating 9,500 CSN or at the next shop visit after the effective date of this proposed AD, whichever occurs first, on engines with more than 1,500 CSN but fewer than 9,001 CSN on January 1, 2005.

The proposed AD would require that you do these actions using the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect six RR RB211-22B engines installed on airplanes of U.S. registry. We also estimate that it would take about 4.0 work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. There are no required parts. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,560.

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 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. 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 summary of the costs to comply with this proposal and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2000-NE-62-AD” in your request.

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.