[Federal Register Volume 69, Number 191 (Monday, October 4, 2004)]
[Proposed Rules]
[Pages 59148-59151]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-22192]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19157; Directorate Identifier 2004-NE-30-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Deutschland (RRD) (Formerly 
Rolls-Royce plc) Tay 650-15 Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain RRD Tay 650-15 series turbofan engines. This proposed AD 
would require inspection of the high pressure compressor (HPC) shaft 
and high pressure turbine (HPT) shaft for spline flank wear. This 
proposed AD results from a number of occurrences of excessive HPC shaft 
and HPT shaft

[[Page 59149]]

spline flank wear discovered during on-wing and in-shop inspections. We 
are proposing this AD to prevent spline disengagement resulting in an 
overspeed event, which could lead to an uncontained engine failure and 
possible damage to the airplane.

DATES: We must receive any comments on this proposed AD by December 3, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    You can get the service information identified in this proposed 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 comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7178; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

    We have implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, we post new AD actions on the DMS 
and assign a DMS docket number. We track each action and assign a 
corresponding Directorate identifier. The DMS docket No. is in the form 
``Docket No. FAA-200X-XXXXX.'' Each DMS docket also lists the 
Directorate identifier (``Old Docket Number'') as a cross-reference for 
searching purposes.

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19157; 
Directorate Identifier 2004-NE-30-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://dms.dot.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 
DMS Web site, anyone can find and read the comments in any of our 
dockets, including 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) or you 
may visit http://dms.dot.gov.
    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 that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received, and any final disposition in person at the DMS Docket Offices 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office (telephone (800) 647-5227) is located on 
the plaza level of the Department of Transportation Nassif Building at 
the street address stated in ADDRESSES. Comments will be available in 
the AD docket shortly after the DMS receives them.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified us that an unsafe 
condition might exist on certain RRD Tay 650-15 series turbofan 
engines. The CAA advises that the spline flanks on the HPC shaft and 
HPT shaft may be developing excessive wear. The amount of wear is 
directly related to the amount of relative movement between the HPC and 
an immobilized HPT. You can detect wear by inspecting the engine to 
determine the amount of relative movement between the HPC and an 
immobilized HPT. On-wing and in-shop inspections found excessive spline 
flank wear on HPC shafts and HPT shafts that incorporated Service 
Bulletin (SB) No. TAY-72-1327 (hard coated abutment face) and HPC 
shafts and HPT shafts that did not incorporate SB No. TAY-72-1327.

Relevant Service Information

    We have reviewed and approved the technical contents of RRD SB No. 
TAY-72-1485, Revision 2, dated March 21, 2003 that describes procedures 
for inspecting the flanks on the HPC shaft and HPT shaft for wear. The 
CAA classified the initial Rolls-Royce plc (RR) SB as mandatory and 
issued airworthiness directive CAA 001-01-2002, dated January 11, 2002 
in order to ensure the airworthiness of these RR engines in the United 
Kingdom. Subsequently, the certification responsibility was transferred 
to RRD and Revision 1 and Revision 2 were reclassified to 
``Recommended'' by the Luftfahrt-Bundesamt (LBA), which is the aviation 
authority for Germany.

Differences Between This Proposed AD and the Manufacturer's Service 
Information

    The RRD SB No. TAY-72-1485, Revision 2, dated March 21, 2003 
specifies compliance times based on the date of receipt of the SB. We 
have mandated compliance times based on the effective date of this 
proposed AD.
    At initial inspection, if the HPC shaft or HPT shaft has 
accumulated 3,000 flight cycles or more, RRD SB No. TAY-72-1485, dated 
January 11, 2002, specifies compliance within 12 months. At initial 
inspection, if the HPC shaft or HPT shaft has accumulated 3,000 flight 
cycles or more, we specify compliance within six months from the 
effective date of the final rule.

FAA's Determination and Requirements of the Proposed AD

    This engine model, manufactured in Germany, is 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 CAA and LBA have kept us 
informed of the situation described above. We have examined the 
findings of the CAA and LBA, reviewed all available information, and 
determined that AD action is necessary for products

[[Page 59150]]

of this type design that are certificated for operation in the United 
States. We are proposing this AD, which would require inspecting the 
spline flanks on the HPC shaft and HPT shaft for wear. The proposed AD 
would require you to use the service information described previously 
to perform these actions.

Costs of Compliance

    There are about 390 RRD Tay 650-15 series turbofan engines of the 
affected design in the worldwide fleet. We estimate that 172 engines 
installed on airplanes of U.S. registry would be affected by this 
proposed AD. We also estimate that it would take about 4 work hours per 
engine to perform the proposed actions, and that the average labor rate 
is $65 per work hour. Based on these figures, we estimate the total 
cost of the proposed AD to U.S. operators, per inspection cycle, to be 
$44,720. We also estimate, for the HPC shaft of 172 engines to be 
replaced at teardown, with a parts cost of approximately $13,862 per 
shaft, the total cost of the proposed AD to U.S. operators to be 
$2,384,264.

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 at the 
address listed under ADDRESSES.

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 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding a new airworthiness directive (AD) to read as follows:

Roll-Royce Deutschland Ltd & Co KG (RRD) (Formerly Rolls-Royce plc): 
Docket No. FAA-2004-19157; Directorate Identifier 2004-NE-30-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by December 
3, 2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to RRD Tay 650-15 series turbofan engines. 
These engines are installed on, but not limited to, Fokker F100 
airplanes.

Unsafe Condition

    (d) This AD results from a number of occurrences of excessive 
high pressure compressor (HPC) and high pressure turbine (HPT) shaft 
spline wear and spline flank wear discovered during on-wing and in-
shop inspections. We are issuing this AD to prevent spline 
disengagement resulting in an overspeed event, which could lead to 
an uncontained engine failure and possible 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.

Initial Visual Inspection of the HPC Shaft and HPT Shaft Splines

    (f) Within the compliance times specified in Table 1 of this AD, 
perform initial inspections of the HPC shaft splines and HPT shaft 
splines of RRD Tay 650-15 series turbofan engines. Use paragraph 
3.A. of Accomplishment Instructions of RRD Service Bulletin (SB) No. 
TAY-72-1485, Revision 2, dated March 21, 2003, to do the 
inspections. Calculate spline wear using Appendix 1, paragraph 4.K., 
of RRD SB No. TAY-72-1485, Revision 2, dated March 21, 2003.

  Table 1.--HPC Shaft Splines and HPT Shaft Splines Inspection Schedule
------------------------------------------------------------------------
           Current shaft life                         Action
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(1) If the HPC shaft or HPT shaft has    Inspect HPC shaft splines and
 accumulated 3,000 cycles-since-new       HPT shaft splines for wear
 (CSN) or more on the effective date of   within six months after the
 this AD.                                 effective date of this AD,
                                          unless previously done.
(2) If the HPC shaft or HPT shaft has    Wait until the HPC shaft or HPT
 accumulated fewer than 3,000 CSN on      shaft has accumulated 3,000
 the effective date of this AD.           flight cycles, then inspect
                                          the HPC shaft splines and HPT
                                          shaft splines for wear within
                                          300 cycles-since-last visual
                                          inspection (CSLI) or remainder
                                          of 12 months from the
                                          effective date of this AD,
                                          whichever is greater.
------------------------------------------------------------------------

    (g) Disposition the HPC shaft, HPT shaft, or engine as specified 
in Table 2 of this AD.

                  Table 2.--Visual Inspection Criteria
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           Inspection limits                       Disposition
------------------------------------------------------------------------
(1) If spline wear is 0.1 inch or        Remove engine from service
 greater.                                 within 50 cycles-since-last
                                          visual inspection CSLI).
(2) If spline wear is greater than or    Remove engine from service
 equal to 0.06 inch but less than 0.1     within 500 CSLI.
 inch.
(3) If spline wear is greater than or    Inspect HPC shaft and HPT shaft
 equal to 0.03 inch but less than 0.06    using the intervals in
 inch..                                   paragraph (h)(1) of this AD.

[[Page 59151]]

 
(4) If spline wear is less than 0.03     Inspect HPC shaft and HPT shaft
 inch.                                    using the intervals in
                                          paragraph (h)(2) of this AD.
------------------------------------------------------------------------

Repetitive Visual Inspection of the HPC Shaft and HPT Shaft Splines

    (h) Perform repetitive inspections of the HPC shaft splines and 
HPT shaft splines of RRD Tay 650-15 series turbofan engines. Use 
paragraph 3.A. of Accomplishment Instructions with Appendix 1 of RRD 
SB No. TAY-72-1485, Revision 2, dated March 21, 2003, to do the 
inspections. Calculate spline wear using Appendix 1, paragraph 4.K., 
of RRD SB No. TAY-72-1485, Revision 2, dated March 21, 2003.
    (1) If wear measured in paragraph (f) of this AD was greater 
than or equal to 0.03 inch but less than 0.06 inch, repetitively 
inspect HPC shaft and HPT shaft within 1,000 cycles-since-last 
visual inspection (CSLI).
    (2) If wear measured in paragraph (f) of this AD was less than 
0.03 inch, repetitively inspect HPC shaft and HPT shaft within 5,500 
CSLI.
    (i) Disposition the HPC shaft, HPT shaft, or engine as specified 
in Table 2 of this AD.

Previous Credit

    (j) Previous credit is allowed for performing the initial 
inspections in paragraph (f) of this AD, that were done using the 
Accomplishment Instructions of one of the following, before the 
effective date of this AD:
    (1) SB No. TAY-72-1485, dated January 11, 2002;
    (2) SB No. TAY-72-1485, Revision 1, dated January 29, 2003; and
    (3) SB No. TAY-72-1485, Revision 2, dated March 21, 2003.

Material Incorporated by Reference

    (k) None.

Related Information

    (l) Civil Aviation Authority (CAA) airworthiness directive 001-
01-2002, dated January 11, 2002, also addresses the subject of this 
AD.

    Issued in Burlington, Massachusetts, on September 24, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-22192 Filed 10-1-04; 8:45 am]
BILLING CODE 4910-13-P