E7-22003. Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (RRD) Dart 528, 529, 532, 535, 542, and 552 Series Turboprop 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 (RRD) Dart 528, 529, 532, 535, 542, and 552 Series turboprop engines. That AD currently requires 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 reworking or replacing the IPT disk if worn beyond acceptable limits. This proposed AD would continue to require those actions. This proposed AD results from us including an incorrect engine model and omitting an engine model from the applicability of the existing AD. 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 January 8, 2008.

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].

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 send 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://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 proposed 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 January 12, 2007, the FAA issued AD 2007-02-07, Amendment 39-14894 (72 FR 2610, January 12, 2007). That AD requires a dimensional inspection of the IPT disk or an ultrasonic inspection of the seal arm contact between the HPT and the IPT disk seal arm and reworking or replacing the IPT disk if worn beyond acceptable limits. That AD was the result of reports of a number of HPT disk failures, some of which resulted in released portions of the HPT disk. That condition, if not corrected, could result in HPT disk failure, which can result in an uncontained engine failure and damage to the airplane.

Actions Since AD 2007-02-07 Was Issued

Since we issued AD 2007-02-07, we found that we listed Dart 555 series turboprop engines, which don't exist, and we omitted Dart 552 series engines from the AD. We are proposing this AD to delete Dart 555 series engines from the applicability paragraph of this proposed AD and to list Dart 552 series turboprop engines in the applicability paragraph of this proposed AD.

Relevant Service Information

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 the Proposed AD and the 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

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. For that reason, we are proposing this AD, which 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 552 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 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

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 39-14894 (72 FR 2610, January 12, 2007) and by adding a new airworthiness directive to read as follows:

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 January 8, 2008.

Affected ADs

(b) This AD supersedes AD 2007-02-17, Amendment 39-14894.

Applicability

(c) This AD applies to Rolls-Royce Deutschland Ltd & Co KG (RRD) Dart 528, 529, 532, 535, 542, and 552 series turboprop 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 us including an incorrect engine model and omitting an engine model from the applicability of the existing AD. 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 High Pressure Turbine (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) For RRD Dart 528, 529, 532, 535, 542 series turboprop engines if wear is outside allowable limits, before June 30, 2007, 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) For RRD Dart 552 series turboprop engines if wear is outside allowable limits, before April 30, 2008, 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.

(iii) 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

(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.

(i) 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]; e-mail: [e-mail], for more information about this AD.

Issued in Burlington, Massachusetts, on November 2, 2007.

Peter A. White,

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