2010-10739. Airworthiness Directives; Rolls-Royce Deutschland Ltd. & Co. KG (RRD) Models Tay 650-15 and Tay 651-54 Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede an existing airworthiness directive (AD) for Tay 650-15 turbofan engines. That AD currently requires initial and repetitive inspections of the low-pressure (LP) turbine discs stage 2 and stage 3 for corrosion, on certain Tay 650-15 serial number engines. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Strip results from some of the engines listed in the applicability section of this AD revealed excessively corroded low-pressure turbine disks stage 2 and stage 3. The corrosion is considered to be caused by the environment in which these engines are operated. Following a life assessment based on the strip findings it is concluded that inspections for corrosion attack are required. The action specified by this European Aviation Safety Agency (EASA) AD 2008-0122 was intended to avoid a failure of a low-pressure turbine disk stage 2 or stage 3 due to potential corrosion problems which could result in uncontained engine failure and damage to the airplane. It has been later realized that the same unsafe condition could potentially occur on more serial numbers for the Tay 650-15 engines and on the Tay 651-54 engines. This AD, superseding EASA AD 2008-0122, retaining its requirements, is therefore issued to expand the Applicability in adding further engine serial numbers for the Tay 650-15 engines and in adding the Tay 651-54 engines.

We are proposing this AD to detect corrosion that could cause the stage 2 or stage 3 disk of the LP turbine to fail and result in an uncontained failure of the engine.

DATES:

We must receive comments on this proposed AD by June 21, 2010.

ADDRESSES:

You may send comments by any of the following methods:

• 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, Dahlwitz, 15827 Blankenfelde-Mahlow, Germany; phone: 011 49 (0) 33-7086-1883; fax: 011 49 (0) 33-7086-3276, for the service information identified in this proposed AD.

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 (phone: [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Tara Chaidez, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; phone: [phone]; fax: [phone].

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-2007-0037; Directorate Identifier 2007-NE-41-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 based on 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).

Discussion

On October 8, 2009, the FAA issued AD 2009-22-01 (Amendment 39-16052 (74 FR 55121, October 27, 2009), which superseded AD 2008-10-14 (Amendment 39-15521, 73 FR 29405, May 21, 2008). AD 2009-22-01 requires initial and repetitive inspections of the LP turbine discs stage 2 and stage 3 for corrosion on 79 engines by serial number. That AD was the result of MCAI issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. That condition, if not corrected, could result in the stage 2 or stage 3 disk of the LP turbine to fail and result in an uncontained failure of the engine.

Since AD 2009-22-01 was issued, RRD identified 14 additional Tay 650-15 engines by serial number that require the same inspections. RRD also expanded the applicability to all Tay 651-54 engines. EASA, which is the Technical Agent for the Member States of the European Community, has issued EASA AD 2010-0060R1, dated April 14, 2010. That MCAI extends the applicability to include the 14 additional Tay 650-15 engine serial numbers and Tay 651-54 engines for inspections. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Rolls-Royce Deutschland has issued Alert Service Bulletin No. TAY-72-A1524, Revision 3, dated March 24, 2010. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

These products have been approved by the United Kingdom (UK), and are approved for operation in the United States. Pursuant to our bilateral agreement with the UK, they have notified us of the unsafe condition described in the MCAI ADs, and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. This proposed AD would require initial and repetitive eddy current inspections of HP turbine discs.

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about three Tay 651-54 engines installed on airplanes of U.S. registry. We also estimate that it would take about three work-hours per engine to comply with this proposed AD. The average labor rate is $85 per work-hour. Required parts would cost about $40,000 per engine. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $120,765.

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 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 this 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. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

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 adding the following new AD:

Rolls-Royce Deutschland Ltd & Co KG (RRD) (formerly Rolls-Royce plc, Derby, England): Docket No. FAA-2007-0037; Directorate Identifier 2007-NE-41-AD.

Comments Due Date

(a) We must receive comments by June 21, 2010.

Affected Airworthiness Directives (ADs)

Affected ADs

(b) This AD supersedes AD 2009-22-01, Amendment 39-16052.

Applicability

(c) This AD applies to:

(1) RRD model Tay 650-15 turbofan engines that have a serial number listed in Table 1, Table 2, or Table 3 of this AD;

(2) All model Tay 651-54 turbofan engines; and

(3) Engines with a low-pressure (LP) turbine module M05300AA installed.

These engines are installed on, but not limited to, Fokker F.28 Mark 0070 and 0100 airplanes, Boeing 727 airplanes modified in accordance with Supplemental Type Certificate No. SA8472SW, and Gulfstream G-IV airplanes.

Table 1—Affected Tay 650-15 Engines by Serial Number (Carried Forward From AD 2008-10-14 and AD 2009-22-01)

Engine serial number
17251	17561
17255	17562
17256	17563
17273	17580
17275	17581
17280	17612
17281	17618
17282	17635
17300	17637
17301	17645
17327	17661
17332	17686
17365	17699
17393	17701
17437	17702
17443	17736
17470	17737
17520	17738
17521	17739
17523	17741
17539	17742
17542	17808
17556

Table 2—Affected Tay 650-15 Engines by Serial Number (Carried Forward From AD 2009-22-01)

Engine serial number
17249	17522
17303	17534
17358	17535
17370	17536
17425	17538
17426	17540
17433	17541
17438	17552
17445	17553
17446	17585
17460	17613
17474	17723
17478	17724
17490	17740
17491	17759
17517	17760
17518	17807

Table 3—Affected Tay 650-15 Engines by Serial Number (Added New in This AD)

Engine serial number
17344	17707
17360	17716
17376	17718
17413	17719
17537	17731
17694	17756
17698	17757

Reason

(d) Strip results from some of the engines listed in the applicability section of this AD revealed excessively corroded low-pressure turbine disks stage 2 and stage 3. The corrosion is considered to be caused by the environment in which these engines are operated. Following a life assessment based on the strip findings it is concluded that inspections for corrosion attack are required. The action specified by this European Aviation Safety Agency (EASA) AD 2008-0122 was intended to avoid a failure of a low-pressure turbine disk stage 2 or stage 3 due to potential corrosion problems which could result in uncontained engine failure and damage to the airplane. It has been later realized that the same unsafe condition could potentially occur on more serial numbers for the Tay 650-15 engines and on the Tay 651-54 engines. This AD, superseding EASA AD 2008-0122, retaining its requirements, is therefore issued to expand the Applicability in adding further engine serial numbers for the Tay 650-15 engines and in adding the Tay 651-54 engines. We are issuing this AD to detect corrosion that could cause the stage 2 or stage 3 disk of the LP turbine to fail and result in an uncontained failure of the engine.

Actions and Compliance

(e) Unless already done, do the following actions.

(1) Prior to accumulating 11,700 flight cycles (FC) since new of disk life, and thereafter at intervals not exceeding 11,700 FC of disk life, inspect the LP turbine disks stage 2 and stage 3 for corrosion using RRD Alert Service Bulletin (ASB) No. TAY-72-A1524, Revision 3, dated March 24, 2010.

(2) For engines with disk life that already exceed 11,700 FC on the effective date of this AD, perform the inspection within 90 days after the effective date of this AD.

(3) When, during any of the inspections as required by paragraphs (e)(1) and (e)(2) of this AD, corrosion is found, replace the affected parts. RRD TAY 650 Engine Manual—E-TAY-3RR, Tasks 72-52-23-200-000 and 72-52-24-200-000, and RRD TAY 651 Engine Manual—E-TAY-5RR, Tasks 72-52-23-200-000 and 72-52-24-200-000, contain guidance on performing the inspection for corrosion and rejection criteria.

Previous Credit

(f) Initial inspections done before the effective date of this AD on LP turbine disks stage 2 and stage 3 listed in Table 1 and Table 2 of this AD using RRD ASB No. TAY-72-A1524, Revision 1, dated September 1, 2006, or Revision 2, dated June 13, 2008, comply with the initial inspection requirements specified in this AD.

Alternative Methods of Compliance (AMOCs)

(g) The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(h) Refer to EASA AD 2010-060R1, dated April 14, 2010, for related information. Contact Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11, Dahlwitz, 15827 Blankenfelde-Mahlow, Germany; phone: 011 49 (0) 33-7086-1883; fax: 011 49 (0) 33-7086-3276, for a copy of the service information referenced in this AD.

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

Issued in Burlington, Massachusetts, on April 29, 2010.

Peter A. White,

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