

[Federal Register: January 2, 2008 (Volume 73, Number 1)]
[Proposed Rules]               
[Page 75-77]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02ja08-17]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0037; Directorate Identifier 2007-NE-41-AD]
RIN 2120-AA64

 
Airworthiness Directives; Rolls-Royce Deutschland Ltd. & Co. KG. 
(RRD) TAY 650-15 Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. 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 states the following:

    Strip results from some of the engines listed in the 
applicability section of this directive revealed excessively 
corroded low pressure turbine discs 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 AD is 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.

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

DATES: We must receive comments on this proposed AD by February 1, 
2008.

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: (202) 493-2251.

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 (800) 647-5527) 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: Jason Yang, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803;

[[Page 76]]

e-mail: jason.yang@faa.gov; telephone (781) 238-7747; fax (781) 238-
7199.

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 we 
receive about this proposed AD.

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2006-0288, dated September 15, 2006, to correct 
an unsafe condition for the specified products. The EASA AD states:

    Strip results from some of the engines listed in the 
applicability section of this directive revealed excessively 
corroded low pressure turbine discs 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 AD is 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.

    You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    RRD has issued Alert Service Bulletin No. TAY-72-A1524, Revision 1, 
dated September 1, 2006. 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

    This product has been approved by the aviation authority of 
Germany, and is approved for operation in the United States. Under this 
bilateral airworthiness agreement, the EASA has kept the FAA informed 
of the situation described above. We have examined the findings of the 
EASA, 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.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about two engines installed on airplanes of U.S. registry. 
We also estimate that it would take about 1.0 work-hours per product to 
inspect the disk, and that the average labor rate is $80 per work-hour. 
If corrosion is found, we estimate that it would take about 2.0 work-
hours to replace the disk. Required parts would cost about $40,000 per 
product. Based on these figures, we estimate the total cost of the 
proposed AD to U.S. operators to be $80,480. Our cost estimate is 
exclusive of possible warranty coverage.

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, 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.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  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 February 1, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to RRD TAY 650-15 turbofan engines that have 
a serial number listed in Table 1 of this AD, and low pressure 
turbine module M05300AA installed. These engines are installed on, 
but not limited to, Fokker F28 Mark 0100 airplanes.

         Table 1.--Affected TAY 650-15 Engines by Serial Number
------------------------------------------------------------------------
                       Engine serial number
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17251
17255
17256
17273
17275
17280
17281
17282
17300
17301
17327
17332
17365
17393
17437
17443
17470
17520

[[Page 77]]


17521
17523
17539
17542
17556
17561
17562
17563
17580
17581
17612
17618
17635
17637
17645
17661
17686
17699
17701
17702
17736
17737
17738
17739
17741
17742
17808
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Reason

    (d) Strip results from some of the engines listed in the 
applicability section of this directive revealed excessively 
corroded low pressure turbine discs 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 AD is 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.
    We are proposing this AD to detect corrosion that could cause 
stage 2 or stage 3 disk of the low pressure 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, 
and thereafter at intervals not exceeding 11,700 FC of the engine, 
inspect the low pressure turbine discs stage 2 and stage 3 for 
corrosion in accordance with Rolls-Royce Deutschland Non-
Modification Alert Service Bulletin TAY-72-A1524, Revision 1.
    (2) For engines 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 paragraph 
(e)(1) of this directive, corrosion is found, replace the affected 
parts using the rejection criteria described in the Rolls-Royce TAY 
650 Engine Manual--E-TAY-3RR.

Other FAA AD Provisions

    (f) Alternative Methods of Compliance (AMOCs): 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

    (g) Refer to EASA Airworthiness Directive 2006-0288, dated 
September 15, 2006, and RRD Alert Service Bulletin TAY-72-A1524, 
Revision 1, dated September 1, 2006, for related information.
    (h) Contact Jason Yang, Aerospace Engineer, Engine Certification 
Office, FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; e-mail: jason.yang@faa.gov; 
telephone (781) 238-7747; fax (781) 238-7199, for more information 
about this AD.

    Issued in Burlington, Massachusetts, on December 26, 2007.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E7-25457 Filed 12-31-07; 8:45 am]

BILLING CODE 4910-13-P
