[Federal Register Volume 66, Number 102 (Friday, May 25, 2001)]
[Proposed Rules]
[Pages 28850-28851]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-13183]


========================================================================
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.

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


Federal Register / Vol. 66, No. 102 / Friday, May 25, 2001 / Proposed 
Rules

[[Page 28850]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-46]


Airworthiness Directives; Rolls-Royce Corporation (Formerly 
Allison Engine Company) AE 3007 Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The Federal Aviation Administration (FAA) proposes to 
supersede an existing airworthiness directive (AD), applicable to 
certain Rolls-Royce Corporation (formerly Allison Engine Company) AE 
3007 series turbofan engines. That AD currently requires removal of 
certain compressor cone shafts from service before exceeding new cyclic 
life limits and replacement with serviceable parts. This proposal would 
require increasing the cyclic life limit for certain serial numbers of 
new compressor cone shafts, part number (P/N) 23070729, that are used 
on AE3007A1/3 and AE3007A1P engines. This proposal is prompted by 
recent approved changes in engineering and manufacturing processes for 
new compressor cone shafts P/N 23070729. The actions specified by the 
proposed AD are intended to prevent low-cycle fatigue (LCF) failure of 
cone shafts, which could result in an uncontained engine failure and 
damage to the airplane.

DATES: Comments must be received by July 24, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 99-NE-46-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: <a href="/cdn-cgi/l/email-protection#3c05115d5259115d585f5351515952487c5a5d5d12585348125b534a"><span class="__cf_email__" data-cfemail="eed7c38f808bc38f8a8d8183838b809aae888f8fc08a819ac0898198">[email protected]</span></a>. Comments sent via the Internet must contain the 
docket number in the subject line. Comments may be inspected at this 
location between 8 a.m. and 4:30 p.m., Monday through Friday, except 
Federal holidays. This information may be examined 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

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NE-46-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 99-NE-46-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    On April 27, 2000, the FAA issued AD 2000-09-05, Amendment 39-11714 
(65 FR 26121, May 5, 2000), to require removal of certain compressor 
cone shafts from service before exceeding new cyclic life limits, and 
replacement with serviceable parts. That action was prompted by 
additional testing and low-cycle fatigue (LCF) life analysis that 
substantiated lower cyclic lives than originally determined. That 
condition, if not corrected, could result in LCF failure of compressor 
cone shafts, uncontained engine failure, and damage to the airplane. 
Since the issuance of that AD, the manufacturer has made changes to the 
engineering and manufacturing processes for new cone shafts, P/N 
23070729, that increase the cyclic life limit, based on approved FAA 
and Rolls-Royce methodology for establishing cycle life.

FAA's Determination of an Unsafe Condition and Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Rolls-Royce Corporation AE 3007 series 
turbofan engines of this same type design, the proposed AD would revise 
AD 2000-09-05 to require increasing the cyclic life limit for certain 
serial numbers of new compressor cone shafts, part number (P/N) 
23070729, that are used on AE3007A1/3 and AE3007A1P engines.

Economic Impact

    There are approximately 598 engines of the affected design in the 
worldwide fleet. The FAA estimates that 364 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD, that 
it would take approximately 150 work hours per engine to accomplish the 
proposed actions, and that the average labor rate is $60 per work hour. 
Required parts would cost approximately $3,921 per engine. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $4,703,244.

Regulatory Impact

    This proposed rule does not have federalism implications, as 
defined in

[[Page 28851]]

Executive Order 13132, because it 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. Accordingly, 
the FAA has not consulted with state authorities prior to publication 
of this proposed rule.
    For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-11714 (65 FR 
26121, May 5, 2000), and by adding a new airworthiness directive (AD), 
to read as follows:

Rolls-Royce Corporation (formerly Allison Engine Company): Docket 
No. 99-NE-46-AD. Supersedes AD 2000-09-05, Amendment 39-11714.

Applicability

    This AD is applicable to Rolls-Royce Corporation (formerly 
Allison Engine Company) models AE 3007A, AE 3007A1, AE 3007A1/1, AE 
3007A1/2, AE 3007A1/3, AE 3007A1P, and AE 3007C turbofan engines, 
with compressor cone shafts, part numbers (P/Ns) 23050728 and 
23070729, installed. These engines are installed on but not limited 
to EMBRAER EMB-135 and EMB-145 series and Cessna 750 series 
airplanes.

    Note 1: This AD applies to each engine identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For engines that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (h) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

Compliance

    Compliance with this AD is required as indicated, unless already 
done.
    To prevent low-cycle fatigue failure of cone shafts, which could 
result in an uncontained engine failure and damage to the airplane, 
accomplish the following:

Removal From Service

    (a) For Rolls-Royce Corporation model AE 3007A engines, remove 
cone shafts from service prior to accumulating 9,500 cycles-since-
new (CSN) and replace with serviceable parts.
    (b) For Rolls-Royce Corporation model AE 3007C engines, remove 
cone shafts from service prior to accumulating 14,500 CSN and 
replace with serviceable parts.
    (c) For Roll-Royce Corporation models AE 3007A1, AE 3007A1/1, 
and AE 3007A1/2 engines, remove cone shafts from service prior to 
accumulating 7,500 CSN and replace with serviceable parts.
    (d) For Rolls-Royce Corporation model AE 3007A1/3 engines:
    (1) With compressor cone shafts P/N 23070729, serial number (SN) 
MM78599, MM78615, MM78632, MM78650, MM78651, MM78652, MM78653, 
MM78654, MM78655, MM78656, MM78657, MM78658, MM78659, MM78660, 
MM78661, MM78662, MM78663, MM78665 or higher, remove cone shafts 
from service prior to accumulating 9,300 CSN and replace with 
serviceable parts.
    (2) With compressor cone shafts P/N 23050728, or P/N 23070729 
having other than the S/N's listed in paragraph (d)(1) of this AD, 
remove cone shafts from service prior to accumulating 3,500 CSN and 
replace with serviceable parts.
    (e) For Rolls-Royce Corporation AE 3007A1P engines:
    (1) With compressor cone shafts P/N 23070729, SN MM78599, 
MM78615, MM78632, MM78650, MM78651, MM78652, MM78653, MM78654, 
MM78655, MM78656, MM78657, MM78658, MM78659, MM78660, MM78661, 
MM78662, MM78663, MM78665 or higher, remove cone shafts from service 
prior to accumulating 7,300 CSN and replace with serviceable parts.
    (2) With compressor cone shafts P/N 23050728, or P/N 23070729 
having other than the SN's listed in paragraph (e)(1) of this AD, 
remove cone shafts from service prior to accumulating 2,400 CSN and 
replace with serviceable parts.

New Life Limits

    (f) Paragraphs (a), (b), (c), (d) and (e) of this AD establish 
new, lower life limits for cone shafts, P/Ns 23050728 and 23070729.
    (g) Except for the provisions of paragraph (h) of this AD, no 
cone shafts, P/Ns 23050728 and 23070729, may remain in service 
exceeding the life limits established in paragraphs (a), (b), (c), 
(d) and (e) of this AD.

Alternative Method of Compliance

    (h) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Chicago Aircraft Certification 
Office (ACO). Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Chicago ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Chicago ACO.

Special Flight Permits

    (i) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the aircraft to a location where 
the requirements of this AD can be accomplished.

    Issued in Burlington, Massachusetts, on May 18, 2001.
Diane S. Romanosky,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-13183 Filed 5-24-01; 8:45 am]
BILLING CODE 4910-13-P


</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>