E6-9446. Airworthiness Directives; CFM International CFM56-5 and -5B Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for CFM International CFM56-5 and -5B series turbofan engines. That AD currently requires exhaust gas temperature (EGT) harness replacement or the establishment of an EGT baseline and trend monitoring. That AD also requires replacement, if necessary, of certain EGT harnesses and EGT couplings as soon as a slow and continuous EGT drift downward is noticed after the effective date of that AD. This proposed AD would require the same actions but for an increased population of affected EGT harnesses. This proposed AD results from CFM International adding subsequently certified engine models to the list of engines that could have affected harnesses installed. We are proposing this AD to prevent unexpected deterioration of critical rotating engine parts due to higher than desired engine operating EGTs.

DATES:

We must receive any comments on this proposed AD by August 15, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD:

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-NE-49-AD, 12 New England Executive Park, Burlington, MA 01803.
• By fax: [phone].
• By e-mail: [e-mail].

Contact CFM International, Technical Publications Department, 1 Neumann Way, Cincinnati, OH 45215; telephone [phone]; fax [phone] for the service information identified in this proposed AD.

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:

James Rosa, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone [phone]; fax [phone].

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. 2001-NE-49-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 verbally, 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.

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

On January 13, 2003, we issued AD 2003-02-04, Amendment 39-13020 (68 FR 3171, January 23, 2003). That AD requires the establishment of an EGT baseline and trend monitoring using the System for Analysis of Gas Turbine Engines (SAGE), or equivalent. The baseline and trend monitoring is used as an option to EGT harness replacement. That AD also requires replacement, if necessary, of certain EGT harnesses and EGT couplings as soon as a slow and continuous EGT drift downward is noticed after the effective date of that AD. That condition, if not corrected, could result in unexpected deterioration of critical rotating engine parts due to higher than desired engine operating EGTs.

Actions Since AD 2003-02-04 Was Issued

Since AD 2003-02-04 was issued, CFM International added subsequently certified engine models, CFM56-5B3/P1, CFM56-5B3/2P1, CFM56-5B4/P1, and CFM56-5B4/2P1, to the list of engines that could have affected harnesses installed, and increased the population of affected EGT harnesses.

Special Flight Permits Paragraph Removed

Paragraph (e) of the current AD, AD 2003-02-04, contains a paragraph pertaining to special flight permits. Even though this proposed rule does not contain a similar paragraph, we have made no changes with regard to the use of special flight permits to operate the airplane to a repair facility to do the work required by this AD. In July 2002, we published a new Part 39 that contains a general authority regarding special flight permits and airworthiness directives. See Docket No. FAA-2004-8460, Amendment 39-9474 (69 FR 47998, July 22, 2002). Thus, when we now supersede ADs we will not include a specific paragraph on special flight permits unless we want to limit the use of that general authority granted in section 39.23.

Relevant Service Information

We reviewed and approved the technical contents of CFM International Service Bulletin (SB) No. CFM56-5B S/B 77-0008, Revision 3, dated April 4, 2005, and SB No. CFM56-5 S/B 77-0020, Revision 3, dated April 4, 2005. Those SBs list affected EGT harnesses and EGT couplings by serial number (SN). The lists cover an expanded population from the lists in the original SBs. Those SBs also specify applicable engine manual sections for referencing replacement procedures.

FAA's Determination and Requirements of the Proposed AD

Since an unsafe condition has been identified that is likely to exist or develop on other CFM International CFM56-5 and -5B series turbofan engines of the same type design, this proposed AD would require:

• EGT harness replacement or the establishment of an EGT baseline and trend monitoring.
• Replacement if necessary, of certain EGT harnesses and EGT couplings as soon as a slow and continuous EGT drift downward is noticed after the effective date of the proposed AD.

Costs of Compliance

About 730 engines installed on airplanes of U.S. registry would be affected by this proposed AD. We estimate it would take about one workhour per engine to perform the proposed actions, and that the average labor rate is $80 per work hour. Required parts would cost about $15,958 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $11,707,740. CFM International has indicated that this figure might be reduced depending upon warranty agreements.

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 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. 2001-NE-49-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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-13020 (68 FR 3171, January 23, 2003), and by adding a new airworthiness directive to read as follows:

CFM International: Docket No. 2001-NE-49-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by August 15, 2006.

Affected ADs

(b) This AD supersedes AD 2003-02-04, Amendment 39-13020.

Applicability

(c) This AD applies to CFM International CFM56-5 and -5B series turbofan engines:

(1) With an exhaust gas temperature (EGT) upper harness part number (P/N) CA170-00, with a serial number (SN):

(i) Listed in Table 1, Table 4, or Table 5 of CFM56 Service Bulletin (SB) No. CFM56-5B S/B 77-0008, Revision 3, dated April 4, 2005, or

(ii) Listed in Table 1 or Table 4 of CFM56 SB No. CFM56-5 S/B 77-0020, Revision 3, dated April 4, 2005.

(2) With an EGT lower harness P/N CA171-00, with a SN:

(i) Listed in Table 2, Table 4, or Table 5 of CFM56 SB No. CFM56-5B S/B 77-0008, Revision 3, dated April 4, 2005; or

(ii) Listed in Table 2 or Table 4 of CFM56 SB No. CFM56-5 S/B 77-0020, Revision 3, dated April 4, 2005.

(3) With an EGT coupling P/N CA172-02 with a SN:

(i) Listed in Table 3, Table 4, or Table 5 of CFM56 Service Bulletin (SB) No. CFM56-5B S/B 77-0008, Revision 3, dated April 4, 2005, or

(ii) Listed in Table 3 or Table 4 of CFM56 SB No. CFM56-5 S/B 77-0020, Revision 3, dated April 4, 2005.

(4) These engines are installed on, but not limited to Airbus Industrie A318, A319, A320, and A321 airplanes.

Unsafe Condition

(d) This AD results from CFM International adding subsequently certified engine models, CFM56-5B3/P1, CFM56-5B3/2P1, CFM56-5B4/P1, and CFM56-5B4/2P1, to the list of engines that could have affected harnesses installed, and increasing the population of affected EGT harnesses. We are issuing this AD to prevent unexpected deterioration of critical rotating engine parts due to higher than desired engine operating EGTs.

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) If an EGT harness or EGT coupling has a serial number that is followed by the letter “W”, no further action is required for that part.

(g) For affected EGT harnesses and EGT couplings identified using paragraph (c) of this AD, with fewer than 3,000 engine flight hours-since-installation, do the following:

(1) Replace affected EGT harnesses and EGT couplings, not being trend monitored, with serviceable parts within 500 flight hours after the effective date of this AD; or

(2) After the effective date of this AD:

(i) Review the smooth data EGT trend via the System for Analysis of Gas Turbine Engines (SAGE), or equivalent, since the affected components were first installed on the current engine.

(ii) Continue this trend monitoring for the affected EGT harnesses and EGT couplings to ensure that the system does not show a minimum of 30 °C downward (i.e. cooler) indication, or more, without a corresponding change in other associated engine parameters such as N1 (LPT rotor speed), N2 (HPT rotor speed), and fuel flow.

(iii) Provided that there is sufficient, actual EGT margin to do so, replace the EGT harnesses and EGT couplings within 100 flight hours after they have been determined to be defective.

(iv) Continue to monitor the EGT indications for 3,000 engine flight hours since the first installation on the current engine.

Terminating Action

(h) Any of the following three conditions is terminating action for the trend monitoring requirements specified in paragraphs (g)(2)(i) through (g)(2)(iv) of this AD:

(1) Replacing an EGT harness and EGT coupling with a serviceable part, or

(2) Replacing an EGT harness and EGT coupling with an EGT harness and EGT coupling that has a letter “W” following the SN, or

(3) Accumulating 3,000 engine flight hours on an EGT harness and EGT coupling.

Alternative Methods of Compliance

(i) 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

(j) Airworthiness directive No. F-2003-001 R2, dated June 8, 2005, which is from the Direction Generale de L'Aviation Civile airworthiness authority for France, also addresses the subject of this AD.

Issued in Burlington, Massachusetts, on June 12, 2006.

Thomas A. Boudreau,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.