Airworthiness Directives: CFM International S.A. Model CFM56 Turbofan Engines

Federal Register: November 26, 2008 (Volume 73, Number 229)

Proposed Rules

Page 71951-71952

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr26no08-27

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 14 CFR Part 39

Docket No. FAA-2008-1245; Directorate Identifier 2008-NE-27-AD

RIN 2120-AA64

Airworthiness Directives; CFM International S.A. Model CFM56

Turbofan 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 CFM International S.A. CFM56-2, CFM56-3, CFM56-5A, CFM56-5B, CFM56- 5C, and CFM56-7B series turbofan engines with certain part number (P/N) and serial number (SN) high-pressure compressor (HPC) 4-9 spools installed. This proposed AD would require removing certain HPC 4-9 spools listed by P/N and SN in this proposed AD. This proposed AD results from reports of certain HPC 4-9 spools that Propulsion

Technology LLC (PTLLC) improperly repaired and returned to service. We are proposing this AD to prevent cracking of the HPC 4-9 spool, which could result in possible uncontained failure of the spool and damage to the airplane.

DATES: We must receive any comments on this proposed AD by January 26, 2009.

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.

FOR FURTHER INFORMATION CONTACT: Stephen K. Sheely, Aerospace Engineer,

Engine Certification Office, FAA, Engine & Propeller Directorate, 12

New England Executive Park, Burlington, MA 01803; e-mail: stephen.k.sheely@faa.gov; telephone (781) 238-7750; fax (781) 238-7199.

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-2008-1245; Directorate

Identifier 2008-NE-27-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

We have received reports of life-limited parts (LLPs) HPC 4-9 spools that PTLLC, repair station certificate No. XZ4R084M, improperly repaired and returned to service. Our investigation found some areas of the seal tooth plasma coating that were thicker than allowed by the

CFM56 engine overhaul limits. The investigation also found:

Seal tooth plasma overspray between the seal teeth, which is not permitted by the engine overhaul manual, and

Cracks that were missed during the fluorescent penetrant inspection.

These conditions, if not corrected, could cause cracking of the HPC 4-9 spool, which could result in possible uncontained failure of the spool and damage to the airplane.

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 removing certain HPC 4-9 spools that have a P/N and SN listed in Table 1 of this proposed AD before accumulating 8,900 cycles since repair at

PTLLC or within 1,100 cycles from the effective date of this AD, whichever occurs later.

Costs of Compliance

We estimate that this proposed AD would affect 26 engines installed on airplanes of U.S. registry. We also estimate that it would take about 410 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 $227,500 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $6,767,800.

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.

Page 71952

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:

CFM International S.A.: Docket No. FAA-2008-1245; Directorate

Identifier 2008-NE-27-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by January 26, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to CFM International S.A. CFM56-2, CFM56-3,

CFM56-5A, CFM56-5B, CFM56-5C, and CFM56-7B series turbofan engines with a high-pressure compressor (HPC) 4-9 spool that has a part number (P/N) and serial number (SN) specified in Table 1 of this AD, installed. These engines are installed on, but not limited to,

Airbus A319, A320, and A340 airplanes and Boeing 737 airplanes.

Table 1--HPC 4-9 Spools by P/N and SN

HPC 4-9 Spool P/N

HPC 4-9 Spool SN

9513M93G08................................ MPON1641 1590M29G01................................ GWN0087D 1590M29G01................................ GWN00MG2 1590M29G01................................ GWN011LG 1590M29G01................................ GWN01285 1590M29G01................................ GWN021JC 1590M29G01................................ GWNFY923 1590M29G01................................ GWNFY824 1590M29G01................................ GWNPA756 1590M29G01................................ GWNPG015 1590M29G01................................ GWNWC515 1590M29G01................................ GWNWR523 1590M29G01................................ GWNWT631 1590M29G01................................ GWNYC495 1588M89G03................................ GWN03K1R 1588M89G03................................ GWN03N61 1588M89G03................................ GWN03N6C 1588M89G03................................ GWN040L9 1588M89G03................................ GWN0468N 1588M89G03................................ GWN05AMO 1277M97G02................................ GWNE1298 1277M97G02................................ GWNE1564 1277M97G02................................ GWNJ7891 1277M97G02................................ GWNT4187 9513M93G11................................ GWNB3373 1358M94G01................................ GWNU0169

Unsafe Condition

(d) This AD results from reports of certain HPC 4-9 spools that

Propulsion Technology LLC (PTLLC) improperly repaired and returned to service. We are issuing this AD to prevent cracking of the HPC 4- 9 spool, which could result in possible uncontained failure of the spool 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.

Removing the HPC 4-9 Spool

(f) Remove HPC 4-9 spools from service that have a P/N and S/N listed in Table 1 of this AD before accumulating 8,900 cycles since repair at PTLLC or within 1,100 cycles from the effective date of this AD, whichever occurs later.

Installation Prohibition

(g) After the effective date of this AD, do not install any engine with an HPC 4-9 spool that has a P/N and SN specified in

Table 1 of this AD.

Alternative Methods of Compliance

(h) The Manager, Engine 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

(i) Contact Stephen K. Sheely, Aerospace Engineer, Engine

Certification Office, FAA, Engine & Propeller Directorate, 12 New

England Executive Park, Burlington, MA 01803; e-mail: stephen.k.sheely@faa.gov; telephone (781) 238-7750; fax (781) 238- 7199, for more information about this AD.

Issued in Burlington, Massachusetts, on November 18, 2008.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft

Certification Service.

FR Doc. E8-28055 Filed 11-25-08; 8:45 am

BILLING CODE 4910-13-P