2011-27512. Airworthiness Directives; Rolls-Royce plc (RR) RB211-535 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede an existing airworthiness directive (AD) that applies to all RR RB211-535E4-37, -535E4-B-37, -535E4-B-75, and -535E4-C-37 turbofan engines. The existing AD currently requires performing initial and repetitive visual and fluorescent penetrant inspections (FPI) of the low-pressure (LP) turbine stage 1, 2, and 3 discs to detect cracks in the discs. Since we issued that AD, we determined that the definition of shop visit is too restrictive in the existing AD. This proposed AD would continue to require those inspections and would change the definition of a shop visit to be less restrictive. We are proposing this AD to correct the definition of shop visit, and to detect cracks in the LP turbine stage 1, 2, and 3 discs, which could result in an uncontained release of LP turbine blades and damage to the airplane.

DATES:

We must receive comments on this proposed AD by December 27, 2011.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• 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: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: [phone], fax: [phone]; or e-mail: http://www.rolls-royce.com/​contact/​civil_​team.jsp,, or download the publication from https://www.aeromanager.com. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781-238-7125.

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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Alan Strom, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: [phone]; fax: [phone]; e-mail: [e-mail].

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-2009-0994; Directorate Identifier 2009-NE-39-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 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 proposed AD.

Discussion

On May 20, 2011, we issued AD 2011-11-08, Amendment 39-16707 (76 FR 30529, May 26, 2011), for all RR RB211-535E4-37, -535E4-B-37, -535E4-B-75, and -535E4-C-37 turbofan engines. That AD requires performing an initial FPI on the LP turbine stage 1, 2, and 3 discs at the next engine shop inspection after the effective date of that AD. That AD also requires repetitive inspections at each engine shop visit after accumulating 1,500 cycles since last inspection of the LP turbine stage 1, 2, and 3 discs. That AD resulted from several findings of cracking at the firtrees of LP turbine discs. We issued that AD to detect cracks in the LP turbine stage 1, 2, and 3 discs, which could result in an uncontained release of LP turbine blades and damage to the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2011-11-08, Amendment 39-16707 (76 FR 30529, May 26, 2011), we found that the definition of “shop visit” in the AD is too restrictive, in that it would require operators to inspect more often than required to ensure safety.

Costs of Compliance

We estimate that this proposed AD would affect about 588 RB211-535 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 30 work-hours per product to comply with this proposed AD. The average labor rate is $85 per work-hour. No parts are required. Based on these figures, we estimate the cost of this proposed AD on U.S. operators to be $1,499,400.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined that the definition of shop visit is too restrictive, and to correct the unsafe condition described previously. This condition is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This AD requires accomplishing the same requirements as AD 2011-11-08 (76 FR 30529, May 26, 2011), except the definition of shop visit has been redefined.

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),

(3) Will not affect intrastate aviation in Alaska, and

(4) 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.

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 FAA 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 airworthiness directive (AD) 2011-11-08, Amendment 39-16707 (76 FR 30529, May 26, 2011), and adding the following new AD:

Rolls-Royce plc: Docket No. FAA-2009-0994; Directorate Identifier 2009-NE-39-AD.

(a) Comments Due Date

The FAA must receive comments on this AD action by December 27, 2011.

(b) Affected ADs

This AD supersedes AD 2011-11-08, Amendment 39-16707 (76 FR 30529, May 26, 2011).

(c) Applicability

This AD applies to Rolls-Royce plc RB211-535E4-37, -535E4-B-37, -535E4-B-75, and -535E4-C-37 turbofan engines.

(d) Unsafe Condition

This AD was prompted by our determination that the definition of “shop visit” in the existing AD is too restrictive, in that it would require operators to inspect more often than required to ensure safety. We are issuing this AD to correct the definition of shop visit, and to detect cracks in the low-pressure (LP) turbine stage 1, 2, and 3 discs, which could result in an uncontained release of LP turbine blades and damage to the airplane.

(e) Compliance

Comply with this AD within the compliance times specified, unless already done.

(1) Initial Inspection Requirements

At the next engine shop visit after the effective date of this AD, perform a visual and a fluorescent penetrant inspection (FPI) of the LP turbine stage 1, 2, and 3 discs.

(2) Repeat Inspection Requirements

At each engine shop visit after accumulating 1,500 cycles since the last inspection of the LP turbine stage 1, 2 and 3 discs, repeat the inspections specified in paragraph (e)(1) of this AD.

(3) Remove Cracked Discs

If you find cracks, remove the disc from service.

(f) Definitions

For the purpose of this AD, an “engine shop visit” is induction of an engine into the shop for any purpose where:

(1) All the blades are removed from the high-pressure (HP) compressor discs and the HP turbine disc, or

(2) All the blades are removed from the intermediate pressure turbine disc.

(g) Alternative Methods of Compliance (AMOCs)

The Manager, Engine Certification Office, FAA may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request.

(h) Related Information

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

(2) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2009-0244, dated November 9, 2009, and Rolls-Royce plc Alert Service Bulletin No. RB.211-72-AG272 for related information. Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: [phone], fax: [phone]; or e-mail: http://www.rollsroyce.com/​contact/​civil_​team.jsp,, for a copy of this service information or download the publication from https://www.aeromanager.com.

Issued in Burlington, Massachusetts, on October 18, 2011.

Peter A White,

Manager, Engine & Propeller Directorate, Aircraft Certification Service.