E6-6737. Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Tay 650-15 and Tay 651-54 Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Rolls-Royce Deutschland Ltd & Co KG (RRD) Tay 650-15 turbofan engines. That AD currently establishes cyclic life limits for certain part number (P/N) stage 1 high pressure turbine (HPT) discs and stage 1 (LPT) discs operating under certain flight plan profiles. This proposed AD would add Tay 651-54 turbofan engines to the applicability. This proposed AD would also require removing certain stage 1 HPT discs and stage 1 LPT discs at reduced cyclic life limits using a drawdown schedule. This proposed AD results from RRD updating their low-cycle-fatigue (LCF) analysis for stage 1 HPT discs and stage 1 LPT discs and reducing their cyclic life limits. We are proposing this AD to prevent cracks leading to turbine 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 July 3, 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. 99-NE-61-AD, 12 New England Executive Park, Burlington, MA 01803.
• By fax: [phone].
• By e-mail: [e-mail].

You can get the service information identified in this proposed AD from Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11, 15872 Blankenfelde-Mahlow, Germany, telephone [phone]; fax [phone].

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:

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 “AD Docket No. 99-NE-61-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 April 7, 2000, we issued AD 2000-08-01, Amendment 39-11687 (65 FR 20714, April 18, 2000). That AD establishes Tay 650-15 cyclic life limits for stage 1 HPT discs, P/N JR32013 and P/N JR33838, and stage 1 LPT discs, P/N JR32318A operating under certain flight plan profiles. The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified us that an unsafe condition may exist on Tay 650-15 and Tay 651-54 turbofan engines. The LBA advises that the current cyclic life limits for stage 1 HPT discs, P/N JR32013 and P/N JR33838, installed in Tay 650-15 and Tay 651-54 turbofan engines are too high.

Actions Since AD 2000-08-01 Was Issued

Since AD 2000-08-01 was issued, RRD updated their LCF analysis for stage 1 HPT discs, P/N JR32013 and P/N JR33838, and stage 1 LPT discs, P/N JR32318A, installed in Tay 650-15 and Tay 651-54 turbofan engines. Rolls-Royce Deutschland issued service information based on the LCF analysis.

Special Flight Permits Paragraph Removed

Paragraph (d) of the current AD, AD 2000-08-01, contains a paragraph pertaining to special flight permits. Even though this proposed AD does not contain a similar paragraph, we have made no changes with regard to the use of special flight permits to operate the airplane to a repair facility to do the work required by this proposed AD. In July 2002, we published a new part 39 that contains a general authority regarding special flight permits and airworthiness directives; see Docket No. FAA-2004-8460, Amendment 39-9474 (69 FR 47998, July 22, 2002). Thus, when we now supersede ADs we will not include a specific paragraph on special flight permits unless we want to limit the use of that general authority granted in section 39.23.

Relevant Service Information

We have reviewed and approved the technical contents of RRD Alert Service Bulletin (ASB) No. Tay-72-A1676, Revision 1, dated August 16, 2005, that contains updated cyclic life limits. That ASB also describes procedures for calculating and re-establishing the achieved cyclic life of discs that have been exposed to different flight plans. That ASB also contains cyclic life limit drawdown schedules for discs in engine flight plan profiles B, C, and D. The LBA classified this ASB as mandatory. With European Aviation Safety Agency approval, the LBA issued AD No. D-2005-252R1, dated August 31, 2005, to ensure the airworthiness of these Tay 650-15 and Tay 651-54 turbofan engines in Germany.

Bilateral Agreement Information

These engine models are manufactured in Germany and 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 has kept the FAA informed of the situation described above. We have examined the findings of the LBA, 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.

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, for Tay 650-15 and Tay 651-54 engines:

• Calculating and re-establishing the achieved cyclic life of stage 1 HPT discs, P/N JR32013 and P/N JR33838, and stage 1 LPT discs, P/N JR32318A, that have been exposed to different flight plans; and
• Removing those stage 1 HPT discs and stage 1 LPT discs operated under engine flight plans A, B, C, and D at reduced cyclic life limits, using a drawdown schedule for certain discs and profiles.

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 50 Tay 650-15 and Tay 651-54 turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about one workhour per engine to calculate and re-establish the achieved cyclic life for a disc, and that the average labor rate is $80 per workhour. We estimate that the prorated cost of the life reduction per engine would be $15,000. Based on these figures, we estimate that if all of the engines required calculating and re-establishing achieved cyclic life, the total cost of the proposed AD to U.S. operators would be $752,000.

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 by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 99-NE-61-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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-11687 (65 FR 20714, April 18, 2000) and by adding a new airworthiness directive, to read as follows:

Rolls-Royce Deutschland Ltd & Co KG (formerly Rolls-Royce plc): Docket No. 99-NE-61-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by July 3, 2006.

Affected ADs

(b) This AD supersedes AD 2000-08-01, Amendment 39-11687.

Applicability

(c) This AD applies to Rolls-Royce Deutschland Ltd & Co KG (RRD) Tay 650-15 and Tay 651-54 turbofan engines with stage 1 high pressure turbine (HPT) discs, part number (P/N) JR32013 and P/N JR33838, and stage 1 low pressure turbine (LPT) discs, P/N JR32318A, installed. These engines are installed on, but not limited to, Fokker Model F.28 Mark 0100, and Boeing 727-100 series airplanes modified in accordance with Supplemental Type Certificate (STC) SA8472SW (727 QF).

Unsafe Condition

(d) This AD results from RRD updating their low-cycle-fatigue (LCF) analysis for stage 1 HPT discs and stage 1 LPT discs and reducing their cyclic life limits. We are issuing this AD to prevent cracks leading to turbine disc failure, which could 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.

(f) Information on the referenced engine flight plan profiles A, B, C, and D can be found in RRD Tay Engine Manual, Section 70-01-10.

Calculating and Re-Establishing Within 30 Days, the Achieved Cyclic Life of a Stage 1 HPT or Stage 1 LPT Disc Previously Exposed to Different Flight Plan(s)

(g) If a stage 1 HPT disc or stage 1 LPT disc was previously exposed to flight plan(s) different than the currently operated flight plan:

(1) You must calculate and re-establish the achieved cyclic life for that disc, within 30 days after the effective date of this AD.

(2) Use paragraphs 3.A. through 3.D.(2)(c) of Accomplishment Instructions of RRD Alert Service Bulletin (ASB) No. Tay-72-A1676, Revision 1, dated August 16, 2005, to calculate and re-establish the achieved cyclic life.

After an Engine Flight Plan Changeover, Calculating and Re-Establishing Within 30 Days, the Achieved Cyclic Life of Stage 1 HPT Discs and Stage 1 LPT Discs

(h) After an engine has a flight plan changeover:

(1) You must calculate and re-establish the achieved cyclic life for the stage 1 HPT disc and stage 1 LPT disc, within 30 days after the flight plan changeover.

(2) Use paragraphs 3.A. through 3.D.(2)(c) of Accomplishment Instructions of RRD ASB No. Tay-72-A1676, Revision 1, dated August 16, 2005, to calculate and re-establish the achieved cyclic life.

Removal of Stage 1 HPT Discs and Stage 1 LPT Discs From Service Tay 650-15 Engine Flight Plan Profile A

(i) Remove from service Tay 650-15 stage 1 HPT discs and stage 1 LPT discs operated under flight plan profile A, before accumulating 23,000 cycles-since-new (CSN), and replace with serviceable parts.

Tay 650-15 Engine Flight Plan Profile B

(j) Remove from service Tay 650-15 stage 1 HPT discs operated under flight plan profile B and replace with serviceable parts:

(1) On or before July 31, 2007, before accumulating 21,000 CSN; and

(2) After July 31, 2007, before accumulating 20,000 CSN.

(k) Remove from service Tay 650-15 stage 1 LPT discs operated under flight plan profile B, before accumulating 21,000 CSN, and replace with serviceable parts.

Tay 650-15 Engine Flight Plan Profile C

(l) Remove from service Tay 650-15 stage 1 HPT discs operated under flight plan profile C and replace with serviceable parts:

(1) On or before August 31, 2006, before accumulating 18,000 CSN; and

(2) After August 31, 2006, but on or before July 31, 2007, before accumulating 15,800 CSN; and

(3) After July 31, 2007, before accumulating 14,700 CSN.

(m) Remove from service Tay 650-15 stage 1 LPT discs operated under flight plan profile C, before accumulating 18,000 CSN, and replace with serviceable parts.

Tay 650-15 Engine Flight Plan Profile D

(n) Remove from service Tay 650-15 stage 1 HPT discs operated under flight plan profile D and replace with serviceable parts:

(1) On or before August 31, 2006, before accumulating 14,250 CSN; and

(2) After August 31, 2006, before accumulating 11,000 CSN.

(o) Remove from service Tay 650-15 stage 1 LPT discs operated under flight plan profile D, before accumulating 14,250 CSN, and replace with serviceable parts.

Tay 651-54 Engines

(p) Remove from service Tay 651-54 stage 1 HPT discs and replace with serviceable parts:

(1) On or before August 31, 2006, before accumulating 14,250 CSN; and

(2) After August 31, 2006, before accumulating 12,600 CSN.

(q) Remove from service Tay 651-54 stage 1 LPT discs before accumulating 20,000 CSN and replace with serviceable parts.

Alternative Methods of Compliance

(r) The Manager, Engine Certification Office, FAA, 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

(s) Luftfahrt-Bundesamt airworthiness directive No. D-2005-252R1, dated August 31, 2005, also addresses the subject of this AD.

Issued in Burlington, Massachusetts, on April 27, 2006.

Francis A. Favara,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.