[Federal Register Volume 68, Number 156 (Wednesday, August 13, 2003)]
[Proposed Rules]
[Pages 48326-48327]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-20573]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-19-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation (formerly 
Allison Engine Company) AE 3007A1, AE 3007A1/1, AE 3007A1/3, AE 3007A3, 
AE 3007A1E, and AE 3007A1P 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 Rolls-Royce Corporation (formerly Allison Engine Company) AE 
3007A1, AE 3007A1/1, AE 3007A1/3, AE 3007A3, AE 3007A1E, and AE 3007A1P 
turbofan engines, with 1st to 2nd stage turbine spacers, part number 
(P/N) 23069627, 23070989, 23072849, or 23075364 installed. This 
proposed AD would reduce the life limit for 1st to 2nd stage turbine 
spacer, part number (P/N) 23072849, to a certain lower life limit, 
based on engine model. This proposed AD would also require a one-time 
fluorescent penetrant inspection (FPI) of 1st to 2nd stage turbine 
spacers P/Ns 23069627, 23070989, 23072849, and 23075364 before reaching 
the spacer life limit, within specified cycles-since-new (CSN), and 
would require replacement of the spacer if found cracked, or with bent 
or missing aft tangs. This proposed AD is prompted by a report that 
during a scheduled inspection, aft pilot tangs on a 1st to 2nd stage 
turbine spacer were found bent and cracked. The actions specified in 
this proposed AD are intended to prevent 1st to 2nd stage turbine 
spacer failure, leading to uncontained turbine failure, engine 
shutdown, and damage to the airplane.

DATES: We must receive any comments on this proposed AD by October 14, 
2003.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
    [sbull] By mail: Federal Aviation Administration (FAA), New England 
Region, Office of the Regional Counsel, Attention: Rules Docket No. 
2003-NE-19-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
    [sbull] By fax: (781) 238-7055.
    [sbull] By e-mail: [email protected].
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA.

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

SUPPLEMENTARY INFORMATION:

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 ``AD Docket No. 2003-NE-19-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 proposed 
AD. If a person contacts us through a nonwritten communication, and 
that contact relates to a substantive part of this proposed 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 
proposed 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 that affect you. You may get more information about 
plain language at http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Discussion

    The FAA has been made aware that during a scheduled engine 
inspection, aft pilot tangs on a 1st to 2nd stage turbine spacer were 
found cracked and bent. The manufacturer has determined that the cause 
of the cracking and bending is due to a tight interference fit between 
the 2nd stage high pressure turbine wheel and the 1st to 2nd stage 
turbine spacer, and a fillet radius on the aft tangs, that is too 
small. The manufacturer is making design changes to decrease the 
interference fit of a replacement 1st to 2nd stage turbine spacer. The 
manufacturer has reduced the original life limit for spacer part number 
23072849. The manufacturer is also requesting FPI of this spacer P/N 
23072849 and three other related spacers P/Ns 23069627, 23070989, and 
23075364. This action is considered interim and future AD action may be 
taken based on inspection results and replacement part availability.

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. Therefore, we are proposing this AD, which 
would reduce the 20,000 CSN life limit for the replacement 1st to 2nd 
stage turbine spacer, P/N 23072849, to 13,100 CSN for engine models AE 
3007A1/1, AE 3007A1/3, AE 3007A1, and AE 3007A3, and to 12,900 CSN for 
engine models AE 3007A1E and AE 3007A1P. This proposed AD would also 
require a one-time FPI of 1st to 2nd stage turbine spacers P/Ns 
23069627, 23070989, 23072849, and 23075364 before reaching the spacer 
life limit, within specified CSN, and would require replacement of 
spacers if found cracked, or with bent or missing aft tangs.

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

    On July 10, 2002, we published a new version of 14 CFR part 39 (67 
FR 47997, July 22, 2002), which governs the FAA's AD system. This 
regulation now includes material that relates to altered products, 
special flight permits, and alternative methods of compliance. 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.

Costs of Compliance

    There are approximately 1,244 engines of the affected design in the 
worldwide fleet. We estimate that 850 engines installed on airplanes of 
U.S.

[[Page 48327]]

registry would be affected by this proposed AD. We estimate the 
prorated replacement cost of a spacer for engine models AE 3007A1/1, AE 
3007A1/3, AE 3007A1, and AE 3007A3 to be $13,755, and $13,545 for 
engine models AE 3007A1E and AE 3007A1P. We also estimate that 
approximately 45%, or 382, of the 850 domestic engines will require 
replacement spacers. We also estimate that it would take approximately 
1 work hour per engine to perform the proposed inspection, and that the 
average labor rate is $60 per work hour. We also estimate that it would 
take approximately 18 work hours per engine to perform the proposed 
part replacement. Based on these figures, we estimate the total cost of 
the proposed AD to U.S. operators to be $5,649,780.

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 by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 2003-NE-19-AD'' in your request.

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 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: Docket No. 2003-NE-19-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by October 14, 
2003.

Affected ADs

    (b) None.

Applicability

    (c) This AD is applicable to Rolls-Royce Corporation (formerly 
Allison Engine Company) AE 3007A1, AE 3007A1/1, AE 3007A1/3, AE 
3007A3, AE 3007A1E, and AE 3007A1P turbofan engines, with 1st to 2nd 
stage turbine spacer part number (P/N) 23069627, 23070989, 23072849, 
or 23075364 installed. These engines are installed on, but not 
limited to, EMBRAER EMB-135 and EMB-145 series airplanes.

Unsafe Condition

    (d) This AD was prompted by a report that during a scheduled 
inspection, aft pilot tangs were found bent and cracked on a 1st to 
2nd stage turbine spacer. The actions specified in this AD are 
intended to prevent 1st to 2nd stage turbine spacer failure, leading 
to uncontained turbine failure, engine shutdown, and 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.

1st to 2nd Stage Turbine Spacer Life Limits

    (f) 1st to 2nd stage turbine spacer life limits are as follows:
    (1) For P/N 23072849, the newly established life limit is:
    (i) 13,100 cycles-since-new (CSN) for engine models AE 3007A1/1, 
AE 3007A1/3, AE 3007A1, AE 3007A3; and
    (ii) 12,900 CSN for engine models AE 3007A1E and AE 3007A1P.
    (2) For P/Ns 23069627, 23070989, and 23075364, the life limits 
are unchanged.

Inspection

    (g) After the effective date of this AD, perform a one-time 
fluorescent penetrant inspection (FPI) of the 1st to 2nd stage 
turbine spacer P/Ns 23069627, 23070989, 23072849, and 23075364 and 
replace spacer if cracked or if aft pilot tangs are bent or missing, 
with a new or serviceable 1st to 2nd stage turbine spacer, using the 
following compliance criteria:
    (1) For an engine inducted into the shop for any reason, if the 
spacer has accumulated 3,000 CSN or more.
    (2) For installed engines, if the spacer has accumulated more 
than 9,300 CSN, inspect before accumulating an additional 500 
cycles-in-service, or before accumulating 4,200 cycles-since-last 
FPI, whichever is more, but do not exceed the spacer life limit in 
paragraph (f) of this AD.
    (3) For installed engines, if the spacer has accumulated 9,300 
or less CSN, inspect before accumulating 9,800 CSN, or before 
accumulating 4,200 cycles-since-last FPI, whichever is more, but do 
not exceed the spacer life limit in paragraph (f) of this AD.

Alternative Methods of Compliance

    (h) Alternative methods of compliance must be requested in 
accordance with 14 CFR part 39.19, and must be approved by the 
Manager, Chicago Aircraft Certification Office, FAA.

Related Information

    (i) The subject of this AD is addressed in Rolls-Royce 
Corporation alert service bulletin No. AE 3007A-A-72-265, Revision 
1, dated April 10, 2003.

    Issued in Burlington, Massachusetts, on August 7, 2003.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 03-20573 Filed 8-12-03; 8:45 am]
BILLING CODE 4910-13-P