Document ID: FAA-2006-24261-0008
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; General Electric Company Aircraft Engines (GEAE) CT7-8A Turboshaft Engines
Posted Date: 2008-03-19T04:00Z

[Federal Register: March 19, 2008 (Volume 73, Number 54)]
[Proposed Rules]               
[Page 14731-14733]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19mr08-26]                         

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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.

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[[Page 14731]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24261; Directorate Identifier 2006-NE-12-AD]
RIN 2120-AA64

 
Airworthiness Directives; General Electric Company Aircraft 
Engines (GEAE) CT7-8A Turboshaft Engines

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

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for certain GEAE CT7-8A turboshaft engines. That AD 
currently requires initial and repetitive inspections of the electrical 
chip detectors for the No. 3 bearing. This proposed AD would require 
removing certain GEAE CT7-8A turboshaft engines within 6,200 cycles-
since-new. This proposed AD results from investigation for the root 
causes of two failures of the No. 3 bearing. We are proposing this AD 
to prevent failure of the No. 3 bearing due to contamination by 
Aluminum Oxide, which could result in a possible dual in-flight 
shutdown of the engines.

DATES: We must receive any comments on this proposed AD by May 19, 
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.
    Contact General Electric Aircraft Engines CT7 Series Turboprop 
Engines, 1000 Western Ave., Lynn, MA 01910; telephone (781) 594-3140, 
fax (781) 594-4805, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Christopher Richards, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; e-
mail: christopher.j.richards@faa.gov; telephone (731) 238-7133; fax 
(781) 238-7199.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2006-24261; 
Directorate Identifier 2006-NE-12-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 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://www.regulations.gov.

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

    The FAA proposes to amend 14 CFR part 39 by superseding AD 2006-06-
51, Amendment 39-14566 (71 FR 19627, April 17, 2006). That AD requires:
     Within 25 hours time-in-service after the effective date 
of that AD, inspecting the electrical chip detector assembly.
     Staggering the inspection intervals so the chip detectors 
on both engines on the same helicopter are not inspected at the same 
time.
     Thereafter, within 25 hours time-since-last inspection, 
performing a repetitive inspection, and
     If the chip detector assembly contains any bearing 
material, replacing the engine.
    That AD was the result of two failures of the No. 3 bearing in GEAE 
CT7-8A turboshaft engines. That condition, if not corrected, could 
result in a possible dual in-flight shutdown of the engines.

Actions Since AD 2006-06-51 Was Issued

    Since we issued that AD, GEAE has developed new procedures for 
flushing Aluminum Oxide hard particle contamination from the air cavity 
of the engine structure's front frame after the manufacturing process 
and for assembling the No. 3 bearing to the engine. Based on that new 
flushing procedure, we are proposing to:
     Delete the requirements to inspect the electrical chip 
detector, and
     Require removing any engine that has a serial number (SN) 
listed in Table 1 of this proposed AD unless the front frame was 
flushed and the No. 3 bearing replaced, and
     Prohibit installing any engine that has a SN listed in 
Table 1 of this proposed AD unless the front frame was flushed and the 
No. 3 bearing replaced.

Relevant Service Information

    We have reviewed and approved the technical contents of GEAE 
Service Bulletin (SB) CT7-8 S/B 72-0017, dated

[[Page 14732]]

October 18, 2007, that describes procedures for flushing the engine 
front frame and replacing the No. 3 bearing.

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. For that reason, we are proposing this AD, 
which would require removing certain GEAE CT7-8A turboshaft engines, 
listed by SN in this proposed AD, from service within 6,200 cycles-
since-new, and, after the effective date of the proposed AD, would 
prohibit installing certain GEAE CT7-8A turboshaft engines, listed by 
SN in this proposed AD.

Costs of Compliance

    We estimate that this proposed AD would affect 29 engines installed 
on helicopters of U.S. registry. We also estimate that it would take 
about 66.0 work-hours per engine to perform the proposed actions, and 
that the average labor rate is $80 per work-hour. Required parts would 
cost about $3,476 per engine. Based on these figures, we estimate the 
total cost of the proposed AD to U.S. operators to be $253,924

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. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

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 removing Amendment 39-14566 (71 FR 
19627, April 17, 2006) and by adding a new airworthiness directive to 
read as follows:

General Electric Company Aircraft Engines: Docket No. FAA-2006-
24261; Directorate Identifier 2006-NE-12-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by May 19, 
2008.

Affected ADs

    (b) This AD supersedes AD 2006-06-51, Amendment 39-14566.

Applicability

    (c) This AD applies to General Electric Company Aircraft Engines 
(GEAE) CT7-8A turboshaft engines that have a serial number (SN) 
listed in Table 1 of this AD. These engines are installed on, but 
not limited to, Sikorsky S92 helicopters.

               Table 1.--Affected Engines by Serial Number
------------------------------------------------------------------------

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

-----------------------Engine Serial No.--------------------------------
------------------------------------------------------------------------
          947205              947228               947254
          947206              947230               947255
          947207              947232               947256
          947208              947233               947258
          947209              947235               947260
          947210              947238               947261
          947211              947240               947262
          947212              947241               947263
          947214              947242               947265
          947215              947243               947266
          947217              947244               947274
          947218              947245               947277
          947219              947247               947278
          947220              947248               947279
          947221              947249               947280
          947223              947250               947284
          947225              947253               947285
------------------------------------------------------------------------

Unsafe Condition

    (d) This AD results from investigation for the root causes of 
two failures of the No. 3 bearing. We are issuing this AD to prevent 
failure of the No. 3 bearing due to contamination by Aluminum Oxide, 
which could result in a possible dual in-flight shutdown of the 
engines.

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.
    (f) No further action is required if:
    (1) Your engine has an SN that is not listed in Table 1 of this 
AD, or
    (2) Your engine has an SN listed in Table 1 of this AD, but the 
engine log specifies that the front frame was flushed and the No. 3 
bearing was replaced.

Engines With SNs Listed in Table 1 of This AD

    (g) For engines with an SN listed in Table 1 of this AD, within 
6,200 cycles-since-new, remove engine from service.

Installation Prohibition

    (h) After the effective date of this AD, do not install any 
engine that has an SN listed in Table 1 of this AD unless the front 
frame was flushed and the No. 3 bearing was replaced. GEAE Service 
Bulletin (SB) CT7-8 S/B 72-0017, dated October 18, 2007, contains 
information on flushing the front frame and replacing the No. 3 
bearing.

Alternative Methods of Compliance

    (i) The Manager, Engine Certification Office, FAA, 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

    (j) GEAE SB No. CT7-8 S/B 72-0017, dated October 18, 2007, 
pertains to the subject of this AD.
    (k) Contact Christopher Richards, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park,

[[Page 14733]]

Burlington, MA 01803; e-mail: christopher.j.richards@faa.gov; 
telephone (731) 238-7133; fax (781) 238-7199, for more information 
about this AD.

    Issued in Burlington, Massachusetts, on March 12, 2008.
Robert J. Ganley,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E8-5492 Filed 3-18-08; 8:45 am]

BILLING CODE 4910-13-P