Document ID: FAA-2008-0230-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Rolls-Royce Corporation AE 3007A1E and AE 1107C Turbofan/Turboshaft Engines
Posted Date: 2008-06-11T04:00Z

[Federal Register: June 11, 2008 (Volume 73, Number 113)]
[Proposed Rules]               
[Page 33025-33027]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr11jn08-17]                         

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================

[[Page 33025]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0230; Directorate Identifier 2007-NE-24-AD]
RIN 2120-AA64

 
Airworthiness Directives; Rolls-Royce Corporation AE 3007A1E and 
AE 1107C Turbofan/Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Rolls-Royce Corporation (RRC) AE 3007A1E and AE 1107C turbofan/
turboshaft engines. This proposed AD would require removal from service 
of certain 2nd stage, 3rd stage, and 4th stage compressor wheels, 
compressor cone shaft assemblies, and 1st to 2nd-stage turbine spacers, 
at new, reduced, published life limits. This proposed AD results from 
RRC applying an updated lifing methodology to the affected parts. We 
are proposing this AD to prevent low-cycle-fatigue (LCF) failure of the 
parts listed in Table 1 of this proposed AD, which could result in an 
uncontained engine failure and damage to the aircraft.

DATES: We must receive any comments on this proposed AD by August 11, 
2008.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     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.
    You can get the service information identified in this proposed AD 
from Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206; e-
mail: indy.pubs.services@rolls-royce.com; telephone (317) 230-3774; fax 
(317) 230-8084.

FOR FURTHER INFORMATION CONTACT: Michael Downs, Aerospace Engineer, 
Chicago Aircraft Certification Office, Small Airplane Directorate, FAA, 
2300 E. Devon Ave., Des Plaines, IL 60018; telephone (847) 294-7870; 
fax (847) 294-7834.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2008-0230; Directorate 
Identifier 2007-NE-24-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://
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).

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.

Discussion

    RRC was seeking to increase the LCF lives of the compressor wheels 
used in AE 3007A1E and AE 1107C turbofan/turboshaft engines, by 
applying an updated lifing methodology. However, their engine testing 
and evaluation revealed that some of the compressor wheels experienced 
crack initiation in the dovetail slots. RRC found that these parts were 
likely to fail within their published lives, and that that failure 
presented an unacceptable compromise to safety. As a result, RRC 
decreased the published life limits of the compressor wheels, and also 
recalculated and decreased the published life of certain compressor 
cone shaft assemblies and 1st-to-2nd stage turbine spacers. We reviewed 
RRC's testing results and reached the same conclusion. These 
conditions, if not corrected, could lead to LCF failure of the parts 
listed in Table 1 of this proposed AD, which could result in an 
uncontained engine failure and damage to the aircraft.

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. We are proposing this AD, which would require 
removal from service of the parts listed in Table 1 of this proposed 
AD, at new, reduced, published life limits.

Costs of Compliance

    We estimate that this proposed AD would affect 220 AE 3007A1E 
turbofan engines installed on aircraft of U.S. registry. The proposed 
action does not impose any additional labor costs since it will be 
performed at engine overhaul. Required parts would cost about $100,000 
per engine. Based on these figures, we estimate the total cost of the 
proposed AD to U.S. operators to be $22,000,000.

[[Page 33026]]

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 AD:
    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 regulatory evaluation of the estimated costs to 
comply with this proposed AD. 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 
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.

Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

Rolls-Royce Corporation (Formerly Allison Engine Company, Inc.): 
Docket No. FAA-2008-0230; Directorate Identifier 2007-NE-24-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by August 11, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce Corporation (RRC) AE 3007A1E 
and AE 1107C turbofan/turboshaft engines, with the following parts 
in Table 1 installed, as applicable:

                                Table 1.--Affected Parts and Reduced Life Limits
----------------------------------------------------------------------------------------------------------------
                                                                                                    New reduced
                                                                                                  published life
                   Engine                                 Part name                  Part No.        limit, in
                                                                                                   flight cycles
----------------------------------------------------------------------------------------------------------------
AE 3007A1E.................................  2nd Stage Compressor Wheel.........        23050752          15,200
                                             3rd Stage Compressor Wheel.........        23065303          13,300
AE 1107C...................................  2nd Stage Compressor Wheel.........        23050752          11,400
                                             2nd Stage Compressor Wheel.........        23084157          11,400
                                             3rd Stage Compressor Wheel.........        23065303           6,200
                                             3rd Stage Compressor Wheel (serial         23065303           5,000
                                              numbers L72422, L72475, L72505,
                                              L130704, L130829, L130830,
                                              L138218, L138226, L138621,
                                              L206084, L206163).
                                             3rd Stage Compressor Wheel.........        23084158           6,200
                                             4th Stage Compressor Wheel.........        23050754          14,900
                                             4th Stage Compressor Wheel.........        23071259          14,900
                                             4th Stage Compressor Wheel.........        23084159          14,900
                                             Compressor Cone Shaft Assembly.....        23050728           2,900
                                             Compressor Cone Shaft Assembly.....        23070729           2,900
                                             1st to 2nd-Stage Turbine Spacer....        23065300           9,500
----------------------------------------------------------------------------------------------------------------

    AE 3007A1E turbofan engines are installed on, but not limited 
to, EMBRAER EMB-135BJ and EMB-145XR airplanes. AE 1107C turboshaft 
engines are U.S. type-certificated and are installed on, but not 
limited to, certain U.S. military aircraft.

Unsafe Condition

    (d) This AD results from RRC applying an updated lifing 
methodology to the affected parts. We are issuing this AD to prevent 
low-cycle-fatigue failure of the parts listed in Table 1 of this AD, 
which could result in an uncontained engine failure and damage to 
the aircraft.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within 5 days after the effective date of this AD, 
unless the actions have already been done.
    (f) Remove from service the parts listed in Table 1 of this AD, 
at the new, reduced, published life limits specified in Table 1 of 
this AD.

Alternative Methods of Compliance

    (g) The Manager, Chicago Aircraft Certification Office, 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

    (h) RRC Alert Service Bulletin (ASB) No. AE 3007A-A-72-346, 
dated May 1, 2007; Service Bulletin No. AE 1107C-A-72-086, Revision 
2, dated January 28, 2008; and ASB No. AE 1107C-A-72-089, dated 
January 28, 2008, also pertain to the subject of this AD.
    (i) Contact Michael Downs, Aerospace Engineer, Chicago Aircraft 
Certification Office, Small Airplane Directorate, FAA, 2300 E. Devon 
Ave., Des Plaines, IL 60018; telephone (847) 294-7870; fax (847) 
294-7834, for more information about this AD.

[[Page 33027]]

    Issued in Burlington, Massachusetts, on June 5, 2008.
Robert G. Mann,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E8-13056 Filed 6-10-08; 8:45 am]

BILLING CODE 4910-13-P