E6-10772. Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Formerly Rolls-Royce, plc.) Dart 528, 529, 532, 535, 542, and 555 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for Rolls-Royce Deutschland Ltd & Co KG (RRD) Dart 528, 529, 532, 535, 542, and 555 series turbofan engines. This proposed AD would require a dimensional inspection of the intermediate pressure turbine (IPT) disk or an ultrasonic inspection of the seal arm contact between the high pressure turbine (HPT) and the IPT disk seal arm and rework or replacement of the IPT disk if wear outside acceptable limits is found. This proposed AD results from reports of a number of HPT disk failures, some of which resulted in portions of the HPT disk being released. We are proposing this AD to prevent HPT disk failure, which can result in an uncontained engine failure and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by September 11, 2006.

ADDRESSES:

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: [phone].
• 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 Deutschland Ltd & Co KG, Eschenweg 11, D-15827 Dahlewitz, Germany; telephone [phone]; fax [phone] for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Jason Yang, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2006-24825; Directorate Identifier 2006-NE-17-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, including 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 Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) 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.

Discussion

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified us that an unsafe condition may exist on RRD Dart 528, 529, 532, 535, 542, and 555 turbofan engines. The LBA advises that since 1972, there have been a number of HPT disk failures on in-service engines, three of which resulted in release of the HPT turbine disk. Fretting between the HPT disk and the IPT disk seal arms caused the release. We are proposing this AD to prevent HPT disk failure, which can result in an uncontained engine failure and damage to the airplane.

We have reviewed and approved the technical contents of RRD DART Service Bulletin (SB) Da72-536, Revision 1, dated August 25, 2003, and SB Da72-538, dated June 10, 2005. SB Da72-536 describes procedures for conducting an ultrasonic inspection to determine if a gap exists between the HPT and IPT disk seal arms. SB Da72-538 describes procedures for a dimensional inspection of the IPT disk and rework or replacement of the IPT disk if wear outside acceptable limits is found. The LBA classified this SB as mandatory and issued airworthiness directive D-2005-197, dated June 30, 2005, in order to ensure the airworthiness of these engines in Germany.

Differences Between This Proposed AD and the Manufacturer's Service Information

Because the service information was developed before the proposed AD, the compliance times permitted to conduct the inspections differ.

FAA's Determination and Requirements of the Proposed AD

These engines, manufactured in the United Kingdom, 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 LBA kept us informed of the situation described above. We have examined the LBA'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. We are proposing this AD, that would require a dimensional inspection of the IPT disk or an ultrasonic inspection of seal arm contact between the HPT and the IPT disk seal arm, and rework or replacement of the IPT disk, if wear outside acceptable limits is found. The proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

We estimate that this proposed AD would affect 30 RRD Dart 528, 529, 532, 535, 542, and 555 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 50 work-hours per engine to perform the proposed actions, and that the average labor rate is $80 per work-hour. Required parts would cost about $50,000 per IPT disk. We estimate that 25 percent, or eight engines, would require IPT disk replacement. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $500,000.

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 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 at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

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:

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 adding the following new airworthiness directive:

Rolls-Royce Deutschland Ltd & Co KG (formerly Rolls-Royce, PLc.): Docket No. FAA-2006-24825; Directorate Identifier 2006-NE-17-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by September 11, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Rolls-Royce Deutschland Ltd & Co KG (RRD) Dart 528, 529, 532, 535, 542, and 555 series turbofan engines. These engines are installed on, but not limited to, Hawker Siddeley, Argosy AW.650, Fairchild Hiller F-27, F-27A, F-27B, F-27F, F-27G, F-27J, FH-227, FH-227B, FH-227C, FH-227D, FH-227E, Fokker F.27 all marks; British Aircraft Corporation Viscount 744, 745D and 810; and Gulfstream G-159 airplanes.

Unsafe Condition

(d) This AD results from reports of a number of high pressure turbine (HPT) disk failures, some of which resulted in portions of the HPT disk being released. We are issuing this AD to prevent HPT disk failure, which can result in an 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.

Intermediate Pressure Turbine (IPT) Disk and HPT/IPT Disk Seal Arm Inspections

(f) Within 60 days after the effective date of the AD, do either of the following:

(1) Perform a dimensional inspection of the IPT disk and repair or replace the IPT disk, if necessary using paragraph 3 of the Accomplishment Instructions of RRD Service Bulletin (SB) Da72-538, dated June 10, 2005; Or

(2) Perform an ultrasonic inspection of the disk seal arm contact between the HPT and the IPT using paragraph 3 of the Accomplishment Instructions of RRD SB Da72-536, Revision 1, dated August 25, 2003.

(i) If wear is outside allowable limits, before December 31, 2006, perform a dimensional inspection and repair or replace the IPT disk, if necessary. Use paragraph 3 of the Accomplishment Instructions of RRD SB Da72-538, dated June 10, 2005.

(ii) If wear is within allowable limits, perform a dimensional inspection of the IPT disk at the next engine shop visit or at next overhaul, whichever occurs first and repair or replace the IPT disk, if necessary, Use paragraph 3 of the Accomplishment Instructions of RRD SB Da72-538, dated June 10, 2005.

Alternative Methods of Compliance (AMOCs)

(g) 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

(h) LBA airworthiness directive D-2005-197, dated June 30, 2005, also addresses the subject of this AD.

Issued in Burlington, Massachusetts, on July 5, 2006.

Francis A. Favara,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.