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Proposed Rule

Airworthiness Directives; General Electric Company CF6-80C2 Series Turbofan Engines

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Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for General Electric Company (GE) CF6-80C2 series turbofan engines with certain thrust reverser ballscrew gearbox assembly adjustable-length end actuators installed. This proposed AD would require initial visual inspections and repetitive replacements of the 3/8-inch rod-ends installed on the thrust reverser ballscrew gearbox assembly adjustable-length end actuators, along with optional terminating action to those repetitive replacements. This proposed AD would also require initial visual inspections and replacements, if necessary, of the other hardware connecting the thrust reverser transcowls to the engine. This proposed AD results from reports of four failures of rod-ends on certain thrust reverser ballscrew gearbox assembly adjustable-length end actuators, leading to partial or complete separation of the transcowl from the engine and airplane during thrust reversal. We are proposing this AD to prevent loss of thrust control, asymmetric thrust, increased stopping distance, and possibly hazardous debris on the runway, which could result in unsafe landings.

DATES:

We must receive any comments on this proposed AD by May 15, 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.
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FOR FURTHER INFORMATION CONTACT:

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

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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-2009-0018; Directorate Identifier 2009-NE-01-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

Since January 2007, we received reports of four GE CF6-80C2 series turbofan engine thrust reverser transcowls separating from the engine and airplane during thrust reverser deployment while landing. Investigation has revealed that the 3/8-inch adjustable rod-ends on the adjustable-length end actuators can fail in fatigue. When a rod-end fails, additional load is put on the thrust reverser system center drive unit (CDU). This additional load can cause the CDU clevis bracket fasteners to fail or the CDU clevis pin to lose its retaining capability, both causing separation of the transcowl from the engine and airplane. This condition, if not corrected, could result in loss of thrust control, asymmetric thrust, increased stopping distance, and possibly hazardous debris on the runway, which could result in unsafe landings.

Relevant Service Information

We have reviewed and approved the technical contents of Middle River Aircraft Systems Alert Service Bulletin (ASB) No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009. That ASB describes procedures for inspecting ballscrew gearbox assembly adjustable-length end actuator 3/8-inch rod-ends and torsion arms, clevis fasteners, clevis pins, and clevis pin retaining clips. That ASB also describes procedures for replacing broken rod-ends, worn, damaged, or deformed torsion arms, loose clevis fasteners, clevis pins that do not meet wear limits, and loose clip retainer nuts and bolts.Start Printed Page 11044

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 initial and repetitive replacements of the 3/8-inch rod-ends installed on the thrust reverser ballscrew gearbox assembly adjustable-length end actuators, along with optional terminating action to those repetitive replacements. The proposed AD would also require an initial visual inspection and replacement if necessary, of the other hardware that connects the thrust reverser transcowl to the engine. The proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

We estimate that this proposed AD would affect 750 GE CF6-80C2 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 1.5 work-hours per engine to perform the proposed inspection, 0.8 work-hour per engine to perform the proposed rod-end replacement, and 24 work-hours per engine to perform the proposed clevis bracket replacement. The average labor rate is $80 per work-hour. Required rod-ends would cost about $168 per engine. We estimate that 75 engines would require clevis bracket replacement. Required replacement clevis brackets and associated labor would cost about $826,500. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,090,500.

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.

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List of Subjects in 14 CFR Part 39

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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:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

General Electric Company: Docket No. FAA-2009-0018; Directorate Identifier 2009-NE-01-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by May 15, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to General Electric Company (GE) CF6-80C2 series turbofan engines with thrust reverser ballscrew gearbox assembly adjustable-length end actuators having 3/8-inch rod-end, part number (P/N) KBE6-59, MS21242S06, M81935/1-6, B15946-13, or 15946000-13, installed. These engines are installed on, but not limited to, Airbus A300-600/R/F and A310-200/300, and Boeing 747-200B/300/400/400D/400F, 767-200/300/300F/400ER, and MD-11 airplanes.

Exemption

(d) GE CF6-80C2 series turbofan engines that have completed the initial compliance actions in Middle River Aircraft Systems (MRAS) Alert Service Bulletin (ASB) No. CF6-80C2 S/B 78A1162, dated December 30, 2008, or ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009:

(1) Are allowed to take credit for accomplishing paragraphs (g) and (h) of this AD; however

(2) All 3/8-inch rod-ends, including those on engines which satisfy paragraph (d) of this AD, are subject to the replacement requirements in paragraph (i) of this AD.

Unsafe Condition

(e) This AD results from reports of four failures of rod-ends on certain thrust reverser ballscrew gearbox assembly adjustable-length end actuators, leading to partial or complete separation of the transcowl from the engine and airplane during thrust reversal. We are issuing this AD to prevent loss of thrust control, asymmetric thrust, increased stopping distance, and possibly hazardous debris on the runway, which could result in unsafe landings.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Visual Inspection and Fastening Hardware Replacements

(g) Within 500 flight cycles after the effective date of this AD, do the following:

(1) Inspect all translating cowl clevis pin retaining clips and associated fastening hardware, including those on the center drive unit (CDU), to ensure they are properly assembled and securely fastened in place. If a retaining clip is not completely covering the clevis pin and firmly attached to the clevis, remove and replace the fastening hardware. Use paragraphs 3.B.(2)(b) and 3.B.(2)(c) of MRAS ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009, to do the inspections.

(2) Remove and inspect all clevis pins for physical damage or significant corrosion. Use paragraphs 3.C.(1) through 3.C.(3) of MRAS ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009, to do the removals, inspections, and part disposition as necessary.

(3) Inspect the clevis brackets and four clevis fasteners at each of the clevis brackets (upper, center, and lower) for structural integrity. Use paragraphs 3.F.(1)(a) and 3.F.(1)(b) of MRAS ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009, to do the inspections.

(4) If loose or missing clevis fasteners are found, remove and replace the clevis Start Printed Page 11045fasteners. Use paragraphs 3.F.(2)(a) through 3.F(2)(c) of MRAS ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009, to do the replacements.

Initial Rod-End Replacements

(h) For all 3/8-inch translating cowl adjustable-length actuator rod-ends, P/N KBE6-59, MS21242S06, B15946-13, 15946000-13, or M81935/1-6 having more than 600 flight cycles-since-new on the effective date of this AD, replace them with P/N M81935/1-6, zero time rod-ends within 500 flight cycles after the effective date of this AD. Use paragraphs 3.E.(2) through 3.E.(7) of MRAS ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009, to do the replacements.

Repetitive 3/8-inch Rod-End Replacements

(i) Repetitively replace 3/8-inch translating cowl adjustable-length actuator rod-ends, P/N M81935/1-6, that were installed as specified in paragraph (h) of this AD, before they accumulate 11,000 flight cycles, with a zero time 3/8-inch adjustable-length rod-end, P/N M81935/1-6. Use paragraphs 3.E.(2) through 3.E.(7) of MRAS ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009, to do the replacements.

Optional Terminating Action

(j) As an optional terminating action to the repetitive 3/8-inch rod-end replacements required by this AD, replace the 3/8-inch adjustable rod-ends with either a fixed length rod-end, P/N 3238726-1, -2, or MS9560-08, or a 7/16-inch adjustable rod-end, P/N 3238729-1. Use paragraph 3.E.(1) of MRAS ASB No. CF6-80C2 S/B 78A1162, Revision 1, dated February 13, 2009, to do the replacements.

Installation Prohibition

(k) Rod-ends removed to comply with this AD are not eligible for installation on any aircraft.

Previous Credit

(l) Inspections and replacements and optional terminating action performed before the effective date of this AD using MRAS ASB No. CF6-80C2 S/B 78A1162, dated December 30, 2008, satisfy the required initial actions and optional terminating action of this AD.

Alternative Methods of Compliance

(m) 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

(n) Contact Christopher J. Richards, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: christopher.j.richards@faa.gov; telephone (781) 238-7133; fax (781) 238-7199, for more information about this AD.

(o) Contact Middle River Aircraft Systems, Mail Point 46, 103 Chesapeake Park Plaza, Baltimore, MD 21220, attn: Warranty Support; telephone (410) 682-0094; fax (410) 682-0100, for a copy of the service information identified in this AD.

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Issued in Burlington, Massachusetts, on March 9, 2009.

Francis A. Favara,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.

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[FR Doc. E9-5575 Filed 3-13-09; 8:45 am]

BILLING CODE 4910-13-P