AD 2003-08-01 ACTIVE

The FAA is adopting a new airworthiness directive (AD) for certain serial numbers (SNs) of Rolls-Royce Deutschland Ltd. & Co KG (RRD) Model Tay 650-15 turbofan engines. This action requires initial and repetitive visual inspections of low pressure (LP) turbine stage 2 rotor discs and LP turbine stage 3 rotor discs on certain SNs of engines, for corrosion. This AD is prompted by reports of excessive corrosion found during disc inspection. The actions specified in this AD are intended to prevent uncontained LP turbine stage 2 rotor disc or LP turbine stage 3 rotor disc failure due to excessive corrosion, and damage to the airplane.

Final rule; request for comments.

Federal Aviation Administration (FAA), Airworthiness Directive (AD) 2003-08-01, Docket No. 2003-NE-06, Amendment 39-13112, Rolls-Royce Deutschland Ltd. & Co KG, Subject: Initial and Repetitive Visual Inspections of Low Pressure (LP) Turbine Stage 2 Rotor Discs and LP Turbine Stage 3 Rotor Discs

Effective Date

(a) This AD becomes effective May 20, 2003.

Affected ADs

(b) None.

Applicability

(c) This AD is applicable to Rolls-Royce Deutschland Ltd. & Co KG (RRD) Model Tay 650-15 turbofan engines with low pressure (LP) turbine stage 2 rotor discs, part number (P/N) JR32319, and LP turbine stage 3 rotor discs, P/N JR32320A, that have a serial number (SN) listed in Table 1 of this AD. These engines are installed on, but not limited to Fokker F.28 Mark 0100 airplanes. Table 1 follows:

Table 1.--Disc SNs

Last known engine SN
LP turbine
stage 2 rotor
disc, part No.
JR32319,
SNs
LP turbine stage 3 rotor disc, part No.
JR32320A, SNs
17251
1725517256
17273
17275
EETM1355
DETM19039
SETM11283
PETM718
DETM17343
DETM1853/A
DETM19007
SETM15065
DETM14896/A
DETM17546
17280
17281
17282
17300
17301
17327
17332
17365
17393
17437
17563
17618
EETM1808
DETM19036
EETM2163
SETM12109
DETM18772
EETM2510
SETM20088
SETM15166
DETM17083
EETM19304
EETM4414
EETM5010
SETM14410
DETM18999
DETM3703/A
SETM11379
DETM18348
DETM15404/A
SETM21297
SETM15188
DETM16860
DETM19008
DETM15583/A
DETM9588/A

Unsafe Condition

(d) This AD was prompted by reports of excessive corrosion found during LP turbine stage 2 rotor disc and LP turbine stage 3 rotor disc inspection. The actions specified in this AD are intended to prevent uncontained LP turbine stage 2 rotor disc or LP turbine stage 3 rotor disc failure due to excessive corrosion, and damage to the airplane.

Compliance

(e) Compliance with this AD is required as indicated, unless already done.

Visual Inspections

(f) Perform an initial visualinspection of the LP turbine stage 2 rotor disc and LP turbine stage 3 rotor disc for corrosion within 11,700 cycles-in-service (CIS) after the effective date of this AD. Information on performing visual inspections can be found in RRD engine manual task 72-52-23-200-000 and task 72-52-24-200-000 respectively.

Discs That Fail Inspection

(g) Before further flight, do the following for discs that fail inspection:

(1) Replace any LP turbine stage 2 rotor discs and LP turbine stage 3 rotor discs found with corrosion pits beyond repairable limits. Information on repairable limits may be found in RRD Engine Manual Task 72-52-23-200-000 and Task 72-52-24-200-000 respectively.

(2) Repair any LP turbine stage 2 rotor discs and LP turbine stage 3 rotor discs found with corrosion pits within repairable limits. Information on repairable limits may be found in RRD Engine Manual Task 72-52-23-200-000 and Task 72-52-24-200-000 respectively.

Repetitive Visual Inspections

(h) Perform repetitive visual inspections of the LP turbine stage 2 rotor disc and LP turbine stage 3 rotor disc for corrosion within every 11,700 cycles-since-last inspection. Information on performing visual inspections can be found in RRD Engine Manual Task 72-52-23-200-000 and Task 72-52-24-200-000 respectively.

(i) Disposition discs that fail inspection as specified in paragraph (g) of this AD.

Alternative Methods of Compliance

(j) The Manager, Engine Certification Office, FAA, is authorized to approve alternative methods of compliance for this AD in accordance with 14 CFR 39.19.

Material Incorporated by Reference

(k) None.

Related Information

(l) LBA airworthiness directive 2002-287, dated October 17, 2002, also addresses the subject of this AD.

The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified the FAA that an unsafe condition may exist on certain SNs of RRD Model Tay 650-15 turbofan engines. The LBA advises that the LP turbine stage 2 rotor discs and LP turbine stage 3 rotor discs of seventeen Tay 650-15 turbofan engines have been found to have excessive corrosion. RRD has determined that this excessive corrosion is the result of the specific environment in which these engines operate. This AD requires initial and repetitive visual inspections for corrosion of low pressure (LP) turbine stage 2 rotor discs and LP turbine stage 3 rotor discs on certain SNs of engines. Because disc deterioration may already have begun, repetitive inspections are also required if any affected disc is removed from the corrosive environment and put in service in a noncorrosive environment. The actions specified in this AD are intended to prevent uncontained LP turbine stage2 rotor disc or LP turbine stage 3 rotor disc failure due to excessive corrosion, and damage to the airplane.

Relevant Service Information

The LBA issued AD 2002-287, dated October 17, 2002, in order to assure the airworthiness of these RRD Model Tay 650-15 turbofan engines in Germany.

FAA's Determination and Requirements of This AD

Although none of these affected disc SNs are used on any airplanes that are registered in the United States, the possibility exists that these disc SNs could be installed into engines used on airplanes that are registered in the United States in the future. Since an unsafe condition has been identified that is likely to exist or develop on other RRD Tay 650-15 turbofan engines of the same type design, this AD is being issued to prevent uncontained LP turbine stage 2 rotor disc or LP turbine stage 3 rotor disc failure due to excessive corrosion, and damage to the airplane. For engine SNs 17251, 17255, 17256, 17273, 17275, 17280, 17281, 17282, 17300, 17301, 17327, 17332, 17365, 17393, 17437, 17563, and 17618, this AD requires initial and repetitive visual inspections of LP turbine stage 2 rotor discs and LP turbine stage 3 rotor discs for corrosion.

Bilateral Airworthiness Agreement

This engine model is manufactured in Germany, and is type certificated for operation in the United States under the provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the LBA has kept the FAA informed of the situation described above. The FAA has 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.

Immediate Adoption of This AD

Since none of these affected engine SNs are used on any airplanes that are registered in the United States, notice and opportunity for prior public comment are unnecessary. Therefore, a situation exists that allows the immediate adoption of this regulation.

Changes to 14 CFR Part 39--Effect on the AD

On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs our AD system. This regulation now includes material that relates to special flight permits, alternative methods of compliance, and altered products. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include "AD Docket No. 2003-NE-06-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 rule that might suggest a need to modify it. If a person contacts us through a nonwritten communication, and that contact relates to a substantive part of this 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 AD in light of those comments.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications with you. You may get more information about plain language at http://frwebgate.access.gpo.gov/cgi- bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.plainlangu age.gov.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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 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 summary of the costs to comply with this AD 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. 2003-NE-06-AD" in your request.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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:

Use one of the following addresses to submit comments on this AD:

By mail: The Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-NE-06-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

By fax: (781) 238-7055.

By e-mail: 9-ane-adcomment@faa.gov

You may get the service information referenced in this AD from Rolls-Royce Deutschland Ltd & Co KG, Eschenweg 11, D-15827 Dahlewitz, Germany, telephone +49 (0) 33-7086-1768; fax +49 (0) 33-7086-3356.

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.

James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7176; fax (781) 238-7199.