
[Federal Register: February 25, 2008 (Volume 73, Number 37)]
[Proposed Rules]               
[Page 9970-9971]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25fe08-15]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0242; Directorate Identifier 2007-NE-51-AD]
RIN 2120-AA64

 
Airworthiness Directives; General Electric Company CF6-80C2 and 
CF6-80E1 Series Turbofan Engines

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for General Electric Company (GE) CF6-80C2 and CF6-80E1 series turbofan 
engines. This proposed AD would require replacement of all clevis pins 
installed on the thrust reverser central drive units and upper and 
lower actuators, or replacement of pins that fail an on-wing rebound 
hardness test. This proposed AD results from failure of a thrust 
reverser during landing due to unapproved clevis pins being installed. 
The failure was due to lack of clevis pin hardness. We are proposing 
this AD to prevent thrust reverser failure, which could lead to damage 
to the thrust reverser and airplane.

DATES: We must receive any comments on this proposed AD by April 25, 
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.

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: (781) 238-7133, 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-2007-0242; Directorate 
Identifier 2007-NE-51-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

    In January 2007, an MD-11 airplane landed with one actuator on a 
thrust reverser inoperative. When a single actuator is inoperative, the 
thrust reversers are designed to continue normal operation until the 
next inspection. Upon landing, the thrust reversers deployed and two of 
the clevis pins failed on the thrust reverser with one actuator 
inoperative. These failures caused a transcowl to separate from the 
thrust reverser damaging the thrust reverser and airplane, and causing 
the transcowl to become hazardous debris on the runway. Investigation 
revealed that:
     The lower actuator on the affected thrust reverser had 
failed some time before the incident; and
     Of the three thrust reverser central drive unit clevis 
pins affected, one clevis pin was found sheared in half, with part of 
the pin still in place in the rod-end bearing and clevis. The pin was 
an unapproved part, made of carbon steel alloy, which had too low a 
strength and hardness for this application.
     One of the clevis pins remained installed, and was found 
to be an approved part clevis pin and with the correct hardness of 31 
to 38 Rockwell Hardness (C Scale).
     The third clevis pin was not found.

This condition, if not corrected, could result in thrust reverser 
failure, which could lead to damage to the thrust reverser and 
airplane.

[[Page 9971]]

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 
replacement of all clevis pins installed on the thrust reverser central 
drive units and upper and lower actuators, or replacement of pins that 
fail a rebound hardness test.

Costs of Compliance

    We estimate that this proposed AD would affect 802 CF6-80C2 series 
turbofan engines installed on airplanes of U.S. registry. We also 
estimate that it would take about one work-hour per engine to perform 
the proposed rebound hardness test and three work-hours per engine to 
replace the six pins. The average labor rate is $80 per work-hour. Pins 
cost about $144 per pin. If all pins are replaced, we estimate the 
total cost of the proposed AD to U.S. operators to be $949,568. CF6-
80E1 series turbofan engines are not currently installed on U.S. 
registered airplanes, so we did not estimate any cost for them.

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, 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:

General Electric Company: Docket No. FAA-2007-0242; Directorate 
Identifier 2007-NE-51-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by April 25, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-80C2 
and CF6-80E1 series turbofan engines. These engines are installed 
on, but not limited to, Airbus A300-600/R/F, A310-200/-300, and 
A330-200/-300 airplanes, Boeing 747-300/-400/-400ER, and 767-200/-
200ER/-300/-300ER/-400ER airplanes, and MD-11 airplanes.

Unsafe Condition

    (d) This AD results from failure of a thrust reverser during 
landing due to unapproved clevis pins being installed. The failure 
was due to lack of clevis pin hardness. We are issuing this AD to 
prevent thrust reverser failure, which could lead to damage to the 
thrust reverser and airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within 18 months or 4,500 flight hours after the 
effective date of this AD, whichever occurs first, unless the 
actions have already been done.
    (f) Replace the six clevis pins installed on the thrust reverser 
central drive units and actuators with clevis pins that pass the 
hardness test identified in paragraphs (g)(1) through (g)(4) below; 
or
    (g) Perform a rebound hardness test of installed thrust reverser 
central drive unit and actuator clevis pins as follows:
    (1) Remove any corrosion from the head of the pin.
    (2) Perform the rebound hardness test on the head of the clevis 
pin.
    (3) If the hardness measured is outside of the range of 31 to 38 
Rockwell Hardness (C Scale), replace the clevis pin with an approved 
part clevis pin.
    (4) If the hardness measured is within the range of 31 to 38 
Rockwell Hardness (C Scale), and the pin has no visible defects, the 
clevis pin can remain in service, as allowed per the engine 
maintenance manual.
    (5) Perform the steps in paragraphs (g)(1) through (g)(4) to all 
six clevis pins on the thrust reverser.

Install Approved Part Clevis Pins

    (h) After the effective date of this AD, do not install any 
thrust reverser central drive unit and actuator clevis pins that do 
not pass the hardness test of paragraphs (g)(1) through (g)(4) 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) Contact Christopher Richards, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
Christopher.richards@faa.gov; telephone: (781) 238-7133, fax: (781) 
238-7199, for more information about this AD.

    Issued in Burlington, Massachusetts, on February 15, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E8-3463 Filed 2-22-08; 8:45 am]

BILLING CODE 4910-13-P
