
[Federal Register: January 7, 2010 (Volume 75, Number 4)]
[Proposed Rules]               
[Page 950-952]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07ja10-14]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-1249; Directorate Identifier 2009-NM-100-AD]
RIN 2120-AA64

 
Airworthiness Directives; The Boeing Company Model 777 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Model 777 airplanes. This proposed AD would require inspecting 
the bolt, nut, and downstop of the slat track assembly to determine if 
the bolt, nut, or stops are missing and to determine if the thread 
protrusion of the bolt from the nut is within specified limits and 
parts are correctly installed, and related investigative and corrective 
actions if necessary. For certain airplanes, this proposed AD would 
also require inspecting the slat cans at the outboard slat number 3 and 
12 outboard main track locations for holes and wear damage, and 
corrective actions if necessary; and replacing the downstop hardware 
for the outboard slats number 3 and 12 outboard and inboard main track 
locations. This proposed AD results from a report of a hole in the 
inboard main track slat can for outboard slat number 12 on a Model 777 
airplane. The hole was caused when the bolt securing the downstop 
migrated out of the fitting and contacted the slat can. We are 
proposing this AD to detect and correct damage to the outboard slat 
main track slat cans, which can allow fuel leakage into the fixed wing 
leading edge in excess of the capacity of the draining system. Excess 
fuel leakage could result in an uncontained fire.

DATES: We must receive comments on this proposed AD by February 22, 
2010.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; 
Internet https://www.myboeingfleet.com. You may review copies of the 
referenced service information at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information 
on the availability of this material at the FAA, call 425-227-1221 or 
425-227-1152.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
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 Office (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Duong Tran, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6452; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2009-1249; 
Directorate Identifier 2009-NM-100-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because 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 we 
receive about this proposed AD.

Discussion

    We have received a report of a hole in the inboard main track slat 
can for outboard slat number 12 on a Model 777 airplane. The hole was 
caused when the bolt securing the downstop migrated out of the fitting 
and contacted the slat can. Each outboard slat main track has a 
downstop attached to the aft end of the slat track assembly. The 
downstop consists of two fittings that are secured to the track with a 
bolt and nut. The main tracks travel through holes in the front spar 
web when the slat is retracted. In areas of the wing where fuel is 
stored, a slat can is installed on the fuel side of the spar to 
surround the main track and contain the fuel. It is believed that the 
locking element of the nut was not fully engaged, and the nut securing 
the bolt backed off and allowed the bolt to migrate out of the fitting 
and contact the slat can. In addition, in production it was discovered 
that a downstop was contacting the weld on a slat can at the outboard 
main track location on slat numbers 3 and 12. This contact could cause 
wear damage and eventually a hole in the slat can. This condition, if 
not corrected, could result in fuel leakage into the fixed wing leading 
edge in excess of the capacity of the draining system. Fuel leakage 
could result in an uncontained fire.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 777-57A0064, dated 
March 26, 2009. The service bulletin describes procedures for doing a 
detailed inspection of the slat main track stop hardware to determine 
if the bolt, nut, or stops are missing and to determine if the thread 
protrusion of the

[[Page 951]]

bolt from the nut is within specified limits. For airplanes on which 
hardware is missing or the thread protrusion is not within limits, the 
service bulletin describes procedures for doing applicable related 
investigative and corrective actions. These related investigative 
actions include measuring torque of the nuts of the slat main track 
stop hardware, and doing a detailed inspection of the slat can inside 
of the slat can for holes and gouges. The corrective actions include 
repairing or replacing the slat can and replacing the slat main track 
stop hardware.
    The service bulletin also describes procedures for Group 2 
airplanes for doing a detailed inspection of the slat cans at the 
outboard slat number 3 and 12 outboard main track locations for holes 
and wear damage, and corrective actions if necessary; and for replacing 
the downstop hardware for the outboard slats number 3 and 12 outboard 
and inboard main track locations. The corrective actions include 
replacing the slat main track stop hardware, and repairing or replacing 
the slat can.
    The service bulletin specifies that the compliance time for the 
detailed inspections and the replacement is within 6 months after the 
issue date of the service bulletin. The compliance times for the 
related investigative actions range between before further flight and 
within 1,125 days or 6,000 flight cycles after the issue date of the 
service bulletin (whichever occurs first), depending on whether 
hardware is missing or whether damage is within the specified limits. 
The compliance times for the corrective actions range between before 
further flight and within 1,125 days after wear damage is found, 
depending on the severity of the damage.

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we evaluated all relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs. This proposed AD would require accomplishing the actions 
specified in the service information described previously.

Costs of Compliance

    We estimate that this proposed AD would affect 129 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                 Table--Estimated Costs
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                                                                                                                 Number of
                                                          Average                                                  U.S.-
                  Action                    Work hours   labor rate     Parts           Cost per product         registered           Fleet cost
                                                          per hour                                               airplanes
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Inspection for Group 1 airplanes.........           39          $80           $0  $3,120 per inspection cycle.          127  $396,240 per inspection
                                                                                                                              cycle.
Inspection for Group 2 airplanes.........           55           80            0  $4,400 per inspection cycle.            2  $8,800 per inspection
                                                                                                                              cycle.
Replacement for Group 2 airplanes........            8           80        9,267  $9,907......................            2  $19,814.
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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 this 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. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA 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 AD:

The Boeing Company: Docket No. FAA-2009-1249; Directorate Identifier 
2009-NM-100-AD.

Comments Due Date

    (a) We must receive comments by February 22, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to The Boeing Company Model 777-200, -200LR, 
-300, and -300ER airplanes, certificated in any category; as 
identified in Boeing Alert Service Bulletin 777-57A0064, dated March 
26, 2009.

Subject

    (d) Air Transport Association (ATA) of America Code 57: Wings.

[[Page 952]]

Unsafe Condition

    (e) This AD results from a report of a hole in the inboard main 
track slat can for outboard slat number 12 on a Model 777 airplane. 
The Federal Aviation Administration is issuing this AD to detect and 
correct damage to the outboard slat main track slat cans, which can 
allow fuel leakage into the fixed wing leading edge in excess of the 
capacity of the draining system. Excess fuel leakage could result in 
an uncontained fire.

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.

Inspect the Slat Track Stop Hardware and Measure the Torque of the Slat 
Main Track Stop Hardware

    (g) At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 777-57A0064, dated 
March 26, 2009, except as required by paragraph (h) of this AD: Do 
the applicable actions specified in paragraphs (g)(1) and (g)(2) of 
this AD.
    (1) For all airplanes: Do a detailed inspection of the slat main 
track stop hardware to determine if the bolt, nut, or stops are 
missing and to determine if the thread protrusion of the bolt from 
the nut is within specified limits, and do all applicable related 
investigative and corrective actions, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 777-
57A0064, dated March 26, 2009. Do all applicable related 
investigative and corrective actions at the applicable time 
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 777-57A0064, dated March 26, 2009, except as required by 
paragraph (h) of this AD.
    (2) For airplanes identified as Group 2 airplanes in Boeing 
Alert Service Bulletin 777-57A0064, dated March 26, 2009: Do a 
detailed inspection of the slat cans at the outboard slat number 3 
and 12 outboard main track locations for holes and wear damage and 
all applicable corrective actions, and replace the downstop hardware 
for the outboard slats number 3 and 12 outboard and inboard main 
track locations. Do all applicable corrective actions at the 
applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009.

Exception to the Service Bulletin

    (h) Where Boeing Alert Service Bulletin 777-57A0064, dated March 
26, 2009, specifies a compliance time after the date on the service 
bulletin, this AD requires compliance within the specified 
compliance time after the effective date of this AD.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. Send information to 
ATTN: Duong Tran, Aerospace Engineer, Airframe Branch, ANM-120S, 
FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., 
Renton, Washington 98057-3356; telephone (425) 917-6452; fax (425) 
917-6590. Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-
Requests@faa.gov.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that has been authorized by the Manager, Seattle ACO, to make 
those findings. For a repair method to be approved, the repair must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.

    Issued in Renton, Washington, on December 23, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-31431 Filed 1-6-10; 8:45 am]
BILLING CODE 4910-13-P
