Federal Aviation Administration (FAA), Department of Transportation (DOT).
Notice of proposed rulemaking (NPRM).
The FAA proposes to adopt a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211-524 and -535 series turbofan engines. This proposed AD would require initial and repetitive fluorescent penetrant inspections (FPI) and borescope inspections of the high pressure (HP) compressor stage 1 and 2 rotor discs for cracks. This proposed AD results from reports of low-cycle-fatigue cracks found at overhaul in the interface weld between the HP compressor stage 1 and 2 rotor disc. We are proposing this AD to prevent uncontained engine failure and damage to the airplane.
We must receive any comments on this proposed AD by November 28, 2006.
Use one of the following addresses to comment on this proposed AD.
- DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
- Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
- Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.
- Fax: (202) 493-2251.
- Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Contact Rolls-Royce plc, PO Box 31, Derby, England, DE248BJ; telephone: 011-44-1332-242424; fax: 011-44-1332-249936 for the service information identified in this proposed AD.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine And Propeller Directorate, 12 New England Executive Park; Burlington, MA 01803; telephone (781) 238-7178; fax (781) 238-7199.End Further Info End Preamble Start Supplemental Information
We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2006-24325; Directorate Identifier 2006-NE-10-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.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 DMS Web site, anyone can find and read the comments in any of our dockets. This includes 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) or you may visit http://dms.dot.gov.
Examining the AD Docket
You may examine the docket that contains the proposal, any comments received, and any final disposition in person at the DMS Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.
The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified us that an unsafe condition might exist on certain RR RB211-524 and -535 series turbofan engines. The CAA advises that during overhaul inspections of HP compressor stage 1 and 2 rotors, low-cycle-fatigue cracks were identified. The cracks ran in an axial direction in the region of the interface weld between the HP compressor stage 1 and 2 rotor discs. If allowed to spread, the cracks could result in uncontained engine failure and damage to the airplane.
Relevant Service Information
We have reviewed and approved the technical contents of RR Alert Service Bulletin (ASB) No. RB.211-72-AE359, dated November 17, 2005. That ASB describes FPI and borescope inspections for cracks in HP compressor stage 1 and 2 rotor discs. The CAA classified this ASB as mandatory and issued airworthiness directive G-2005-0028 R1, dated October 18, 2005, in order to ensure the airworthiness of these engines in the United Kingdom.
FAA's Determination and Requirements of the Proposed AD
These RR RB211-524 and -535 series turbofan engines are manufactured in the United Kingdom. They are 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. In keeping with this bilateral airworthiness agreement, the CAA kept us informed of the situation described above. We have examined the CAA's findings, 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. For this reason, we are proposing this AD, which would require starting at the next engine shop visit, initial and repetitive FPI and borescope inspections of the HP Start Printed Page 57450compressor stage 1 and 2 rotor discs for cracks. The proposed AD would require you to use the service information described previously to perform these actions.
These actions are interim actions and we may take further rulemaking actions in the future.
Costs of Compliance
We estimate that this proposed AD would affect 884 RB211-524 and -535 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 2 work-hours per engine to perform the proposed inspections, and that the average labor rate is $80 per work-hour. Based on these figures, we estimate the total cost to U.S. operators of performing one inspection on all of the engines, to be $141,440.
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.
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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
The Proposed Amendment
Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The FAA amends § 39.13 by adding the following new airworthiness directive:
Rolls-Royce plc: Docket No. FAA-2006-24325; Directorate Identifier 2006-NE-10-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by November 28, 2006.
(c) This AD applies to the following Rolls-Royce plc (RR) RB211-524 and -535 series turbofan engines:
These engines are installed on, but not limited to, Boeing 747, 757, 767, Lockheed L-1011, and Tupolev Tu204 airplanes.
(d) This AD results from reports of low-cycle fatigue cracks found at overhaul in the interface weld between the high pressure (HP) compressor stage 1 and 2 rotor discs. We are issuing this AD to prevent uncontained engine failure and damage to the airplane.
(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 and Repetitive Inspections
(f) At the next engine shop visit, but no later than 30 days after the effective date of this AD, perform an initial fluorescent penetrant inspection (FPI) and borescope inspection of the HP compressor stage 1 and 2 rotor discs for cracks.
(g) Thereafter, at every engine shop visit, perform repetitive FPIs and borescope inspections of HP compressor stage 1 and 2 rotor discs for cracks.
(h) Use paragraphs 3.A.(1) through 3.A.(4)(o) of the Accomplishment Instructions of RR Alert Service Bulletin (ASB) No. RB.211-72-AE359, Revision 1, dated November 17, 2005, to do the inspections.
(i) Accept or reject as necessary, HP compressor stage 1 and 2 rotor discs using inspection criteria paragraphs 3.A.(5)(a) through 3.A.(5)(f) of the Accomplishment Instructions of RR ASB No. RB.211-72-AE359, Revision 1, dated November 17, 2005.
(j) For the purpose of this AD, an engine shop visit is defined as anytime the HP compressor stage 1 and 2 rotor discs are removed from the HP compressor stage 3 disc.
(k) Within 10 days, report inspection findings of cracks to the RR local field service office representative. The Office of Management and Budget has approved the reporting requirements specified in paragraph 3.A.(6)(b) of the Accomplishment Instructions of RR ASB No. RB.211-72-AE359, Revision 1, dated November 17, 2005, and assigned OMB control number 2120-0056.
Alternative Methods of Compliance
(l) 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. Start Printed Page 57451
(m) Civil Aviation Authority airworthiness directive No. G-2005-0028 R1, dated October 18, 2005, also addresses the subject of this AD.
Issued in Burlington, Massachusetts, on September 25, 2006.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.
[FR Doc. E6-16047 Filed 9-28-06; 8:45 am]
BILLING CODE 4910-13-P