E9-14815. Airworthiness Directives; General Electric Company CF6-50C Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to revise an existing airworthiness directive (AD) for General Electric Company (GE) CF6-50C series turbofan engines. That AD currently requires reworking certain forward fan stator cases and installing a fan module secondary containment shield. This proposed AD would require the same actions but would eliminate a certain service bulletin from the compliance method. This proposed AD results from a review that shows that only one of the service bulletins referenced in the original AD is applicable as a compliance method. We are proposing this AD revision to prevent uncontained fan blade failures, which can result in separation of airplane hydraulic lines, damage to critical airplane systems, and possible loss of airplane control.

DATES:

We must receive any comments on this proposed AD by August 24, 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: [phone].

FOR FURTHER INFORMATION CONTACT:

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

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-2006-24171; Directorate Identifier 2006-NE-08-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 [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

On May 22, 2007, we issued AD 2007-11-18, Amendment 39-15075 (72 FR 30249, May 31, 2007). That AD requires reworking certain forward fan stator cases and installing a fan module secondary containment shield. That AD resulted from reports of uncontained fan blade failures. That condition, if not corrected, could result in separation of airplane hydraulic lines, damage to critical airplane systems, and possible loss of airplane control due to uncontained fan blade failures.

Actions Since AD 2007-11-18 Was Issued

Since AD 2007-11-18 was issued, we determined that we don't need GE Service Bulletin No. CF6-50 S/B 72-0986, Revision 2, dated March 21, 2007, applicable to DC-10 series aircraft, in order to satisfy our corrective action requirements. Accordingly, this proposed AD deletes this SB as a required corrective action.

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 this reason, we are proposing this AD revision, which would require reworking certain forward fan stator cases and installing a fan module secondary containment shield on Airbus A300 series airplanes, and would eliminate GE Service Bulletin No. CF6-50 S/B 72-0986, Revision 2, dated March 21, 2007. The proposed AD would require that you do the rework and installations using GE Service Bulletin No. CF6-50 S/B 72-0985, Revision 2, dated March 21, 2007 only.

Costs of Compliance

We estimate that this AD would affect 40 CF6-50C series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 2.5 work hours per engine to perform the actions, and that the average labor rate is $80 per work hour. Required parts would cost about $9,451 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $386,040.

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. 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
• Incorporation by reference
• 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-15075 (72 FR 30249, May 31, 2007), and by adding a new airworthiness directive, to read as follows:

General Electric Company: Docket No. FAA-2006-24171; Directorate Identifier 2006-NE-08-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by August 24, 2009.

Affected ADs

(b) This AD revises AD 2007-11-18, Amendment 39-15075.

Applicability

(c) This AD applies to General Electric Company (GE) CF6-50C, CF6-50C1, CF6-50C2, and CF6-50C2R turbofan engines, with a forward fan stator case, part number (P/N) 9064M53G04, G05, G06, G07, G08, G09, G10, G12, or G13, or P/N 9173M37G01, G02, G03, G04, G05, or G06 installed. These engines are installed on, but not limited to, Airbus A300, McDonnell Douglas DC-10 series, and DC-10-30F (KC-10A, KDC-10) airplanes.

Unsafe Condition

(d) This AD revision results from a review that shows that only one of the service bulletins referenced in the original AD is applicable as a compliance method. We are issuing this AD to prevent uncontained fan blade failures, which can result in separation of airplane hydraulic lines, damage to critical airplane systems, and possible loss of airplane control.

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) At the next engine shop visit after the effective date of this AD, but no later than June 30, 2010, rework the forward fan stator case and install the fan module secondary containment shield.

(1) For engines on Airbus 300 series airplanes, use paragraph 3, Accomplishment Instructions, of GE Service Bulletin (SB) No. CF6-50 S/B 72-0985, Revision 2, dated March 21, 2007, to do the rework and installation.

(2) Deleted.

(g) The rework and installation specified in paragraph (f)(1) of this AD can also be done on-wing.

Previous Credit

(h) Previous credit is allowed for fan stator cases reworked and containment shields installed using GE SB No. CF6-50 S/B 72-0985, dated December 2, 1991 or Revision 1, dated September 15, 1998 before the effective date of this AD.

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) European Aviation Safety Agency airworthiness directive 2004-0007, dated December 15, 2004, also addresses the subject of this AD.

(k) Contact James Rosa, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

(l) Contact General Electric Company via Lockheed Martin Technology Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215, telephone [phone], fax [phone], for a copy of the service information referenced in this AD.

Issued in Burlington, Massachusetts, on June 17, 2009.

Carlos Pestana,

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