Airworthiness Directives; Boeing Model 777-200 Series Airplanes, 75428-75430 [05-24243]

Download as PDF 75428 Federal Register / Vol. 70, No. 243 / Tuesday, December 20, 2005 / Proposed Rules by removing amendment 39–11097 (64 FR 15298, March 31, 1999) and adding the following new airworthiness directive (AD): Boeing: Docket No. FAA–2005–23358; Directorate Identifier 2005–NM–206–AD. Comments Due Date (a) The FAA must receive comments on this AD action by February 3, 2006. Affected ADs (b) This AD supersedes AD 99–07–12. Applicability (c) This AD applies to Boeing Model 747– 100, 747–100B, 747–100B SUD, 747–200B, 747–300, 747–400, 747–400D, and 747SR series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747–53A2408, Revision 1, dated April 4, 2002. Unsafe Condition (d) This AD results from reports indicating that fatigue cracks were found in lower lobe frames on the left side of the fuselage. We are issuing this AD to detect and correct fatigue cracking of certain lower lobe fuselage frames, which could lead to fatigue cracks in the fuselage skin, and consequent rapid decompression of the airplane. 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. Restatement of the Requirements of AD 99– 07–12, With Additional Information for Group 2 Airplanes Initial Inspections (f) For airplanes on which the initial detailed internal inspection of the Section 46 lower lobe frames required by paragraph (f)(2) or (i)(2) of AD 2005–20–30, amendment 39–14327, has not been accomplished: Perform a detailed visual inspection to detect cracking of the lower lobe fuselage frames from Body Station 1820 to Body Station 2100, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747–53A2408, dated April 25, 1996; or Boeing Alert Service Bulletin 747–53A2408, Revision 1, dated April 4, 2002; as applicable; at the later of the applicable times specified in paragraph (f)(1), (f)(2), or (f)(3) of this AD. (1) For all airplanes: Prior to the accumulation of 15,000 total flight cycles; or (2) For Group 1 airplanes identified in Revision 1 of the service bulletin: Within 1,500 flight cycles or 18 months after May 5, 1999 (the effective date of AD 99–07–12), whichever occurs first. (3) For Group 2 airplanes identified in Revision 1 of the service bulletin: Within 1,500 flight cycles or 18 months after the effective date of this AD, whichever occurs first. Note 1: Paragraph (f)(2) or (i)(2) of AD 2005–20–30 requires a detailed inspection to detect cracks in the Section 46 lower lobe frames, in accordance with Boeing Service VerDate Aug<31>2005 15:07 Dec 19, 2005 Jkt 208001 Bulletin 747–53–2349, Revision 2, dated April 3, 2003. The initial inspection is required prior to the accumulation of 22,000 total flight cycles; or within 1,000 flight cycles after June 11, 1993 (the effective date of AD 93–08–12, amendment 39–8559), or November 16, 2005 (the effective date of AD 2005–20–30), depending on previous inspections accomplished; whichever occurs later. Note 2: For the purposes of this AD, a detailed inspection is: ‘‘An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.’’ Repetitive Inspections Flight Standards Certificate Holding District Office. (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 an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who 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. (4) AMOCs approved previously in accordance with AD 99–07–12, amendment 39–11097, are approved as AMOCs for the corresponding provisions of this AD. Issued in Renton, Washington, on December 13, 2005. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05–24242 Filed 12–19–05; 8:45 am] BILLING CODE 4910–13–P (g) If no cracking is detected during the inspection required by paragraph (f) of this AD, repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles. DEPARTMENT OF TRANSPORTATION Corrective Actions Federal Aviation Administration (h) If any cracking is detected during any inspection required by paragraph (f) of this AD, prior to further flight, accomplish paragraphs (h)(1) and (h)(2) of this AD: (1) Within 20 inches of the crack location on the frame, perform a detailed inspection of the adjacent structure to detect cracking. If any cracking is detected during any detailed inspection done in accordance with paragraph (f) or (h)(1) of this AD, prior to further flight, repair in accordance with paragraph (h)(1)(i) or (h)(1)(ii) of this AD, as applicable. (i) For Group 1 airplanes: Using a method approved in accordance with the procedures specified in paragraph (j) of this AD. The Boeing 747 Structural Repair Manual, Subject 53–10–04, Figure 67 or 90, is one approved method. (ii) For Group 2 airplanes: Using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (2) Repeat the inspection required by paragraph (f) of this AD thereafter at intervals not to exceed 3,000 flight cycles. 14 CFR Part 39 Optional Terminating Inspection (i) Accomplishment of the initial detailed inspection of the Section 46 lower lobe frames required by paragraph (f)(2) or (i)(2) of AD 2005–20–30 constitutes terminating action for the requirements of this AD only for airplanes identified in Boeing Alert Service Bulletin 747–53A2408, Revision 1, dated April 4, 2002, as Group 1 airplanes. Alternative Methods of Compliance (AMOCs) (j)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. (2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA PO 00000 Frm 00006 Fmt 4702 Sfmt 4702 [Docket No. FAA–2005–23357; Directorate Identifier 2005–NM–207–AD] RIN 2120–AA64 Airworthiness Directives; Boeing Model 777–200 Series Airplanes Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). AGENCY: SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 777–200 series airplanes. This proposed AD would require installing a new washer between the lower wing surface and the jam nut of the sump drain valve assembly. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent energy from a lightning strike on the bushing for the sump drain valve from arcing to the inside of the center fuel tank wall, which could create an ignition source in the fuel tank and result in a fuel tank explosion. DATES: We must receive comments on this proposed AD by February 3, 2006. ADDRESSES: Use one of the following addresses to submit comments on this proposed AD. • DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically. • Government-wide rulemaking Web site: Go to http://www.regulations.gov E:\FR\FM\20DEP1.SGM 20DEP1 Federal Register / Vol. 70, No. 243 / Tuesday, December 20, 2005 / Proposed Rules and follow the instructions for sending your comments electronically. • Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, room PL–401, Washington, DC 20590. • Fax: (202) 493–2251. • Hand Delivery: Room PL–401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124–2207, for the service information identified in this proposed AD. FOR FURTHER INFORMATION CONTACT: Margaret Langsted, Aerospace Engineer, Propulsion Branch, ANM–140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055–4056; telephone (425) 917–6500; fax (425) 917–6590. SUPPLEMENTARY INFORMATION: Comments Invited We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number ‘‘FAA–2005–23357; Directorate Identifier 2005–NM–207–AD’’ at the beginning 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:// dms.dot.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 that web site, anyone can find and read the comments in any of our dockets, including 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 DOT’s complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477–78), or you may visit http:// dms.dot.gov. Examining the Docket You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except VerDate Aug<31>2005 15:07 Dec 19, 2005 Jkt 208001 Federal holidays. The Docket Management Facility office (telephone (800) 647–5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them. Discussion The FAA has examined the underlying safety issues involved in recent fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, we issued a regulation titled ‘‘Transport Airplane Fuel Tank System Design Review, Flammability Reduction and Maintenance and Inspection Requirements’’ (67 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 (‘‘SFAR 88,’’ Amendment 21–78, and subsequent Amendments 21–82 and 21–83). Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources in the fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews. In evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: Single failures, single failures in combination with another latent failure condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action. PO 00000 Frm 00007 Fmt 4702 Sfmt 4702 75429 We have determined that the actions identified in this AD are necessary to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane. We have received a report indicating that small gaps may be present between the bushing of the sump drain valve and the lower wing surface in the center fuel tank, on certain Boeing Model 777–200 series airplanes. If a lightning strike occurs on the bushing, arcs can go across the small gaps between the bushing and the lower wing surface, and into the inside of the fuel tank wall. The bushing does not have an engineered bond path to the wing surface. In addition, the layer of sealant between the bushing and the inner surface of the fuel tank could be too thin to contain the energy in the arcs. This condition, if not corrected, could create an ignition source in the center fuel tank and result in a fuel tank explosion. Relevant Service Information We have reviewed Boeing Special Attention Service Bulletin 777–28– 0045, dated September 1, 2005. The service bulletin describes procedures for installing a new washer between the lower wing surface and the jam nut of the sump drain valve assembly. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. 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 airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously. Costs of Compliance There are about 88 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 22 airplanes of U.S. registry. The proposed actions would take about 4 work hours per airplane, at an average labor rate of $65 per work hour. Required parts would cost about $360 per airplane. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $13,640, or $620 per airplane. Authority for This Rulemaking Title 49 of the United States Code specifies the FAA’s authority to issue E:\FR\FM\20DEP1.SGM 20DEP1 75430 Federal Register / Vol. 70, No. 243 / Tuesday, December 20, 2005 / Proposed Rules 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. § 39.13 [Amended] DEPARTMENT OF TRANSPORTATION 2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD): Boeing: Docket No. FAA–2005–23357; Directorate Identifier 2005–NM–207–AD. Comments Due Date (a) The FAA must receive comments on this AD action by February 3, 2006. Affected ADs (b) None. Applicability Unsafe Condition 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 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. We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. (d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent energy from a lightning strike on the bushing for the sump drain valve from arcing to the inside of the center fuel tank wall, which could create an ignition source in the fuel tank and result in a fuel tank explosion. Air transportation, Aircraft, Aviation safety, 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: 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. Installation (f) Within 60 months after the effective date of this AD, install a new washer between the lower wing surface and the jam nut of the sump drain valve assembly in both wings, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777–28–0045, dated September 1, 2005. Alternative Methods of Compliance (AMOCs) (g)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. (2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. Issued in Renton, Washington, on December 13, 2005. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05–24243 Filed 12–19–05; 8:45 am] BILLING CODE 4910–13–P Authority: 49 U.S.C. 106(g), 40113, 44701. VerDate Aug<31>2005 15:07 Dec 19, 2005 Jkt 208001 PO 00000 Frm 00008 14 CFR Part 39 [Docket No. 2003–NM–198–AD] RIN 2120–AA64 Airworthiness Directives; McDonnell Douglas Model DC–9–10, –20, –30, –40, and –50 Series Airplanes; Model DC– 9–81 (MD–81), –82 (MD–82), –83 (MD– 83), and –87 (MD–87) Airplanes; and Model MD–88 Airplanes Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Supplemental notice of proposed rulemaking; reopening of comment period. AGENCY: (c) This AD applies to Boeing Model 777– 200 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 777–28–0045, dated September 1, 2005. Regulatory Findings List of Subjects in 14 CFR Part 39 Federal Aviation Administration Fmt 4702 Sfmt 4702 SUMMARY: This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC–9–10, –20, –30, –40, and –50 series airplanes; Model DC–9– 81 (MD–81), –82 (MD–82), –83 (MD–83), and –87 (MD–87) airplanes; and Model MD–88 airplanes. That proposed AD would have required repetitive inspections and functional tests of the static port heater assemblies, an inspection of the static port heaters and insulators, and corrective actions if necessary. This new action revises the proposed AD by adding repetitive inspections of the static port heaters and insulators and revising the functional test of the static port heater. The actions specified by this new proposed AD are intended to prevent an electrical short of the static port heater from sparking and igniting the insulation blanket adjacent to the static port heater, which could result in smoke and/or fire in the cabin area. This action is intended to address the identified unsafe condition. DATES: Comments must be received by January 17, 2006. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM–114, Attention: Rules Docket No. 2003–NM– 198–AD, 1601 Lind Avenue, SW., Renton, Washington 98055–4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227–1232. Comments may also be sent via the Internet using the following address: 9-anmnprmcomment@faa.gov. Comments sent via fax or the Internet must contain ‘‘Docket No. 2003–NM–198–AD’’ in the subject line and need not be submitted E:\FR\FM\20DEP1.SGM 20DEP1

Agencies

[Federal Register Volume 70, Number 243 (Tuesday, December 20, 2005)]
[Proposed Rules]
[Pages 75428-75430]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-24243]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-23357; Directorate Identifier 2005-NM-207-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 Series Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 777-200 series airplanes. This proposed AD 
would require installing a new washer between the lower wing surface 
and the jam nut of the sump drain valve assembly. This proposed AD 
results from fuel system reviews conducted by the manufacturer. We are 
proposing this AD to prevent energy from a lightning strike on the 
bushing for the sump drain valve from arcing to the inside of the 
center fuel tank wall, which could create an ignition source in the 
fuel tank and result in a fuel tank explosion.

DATES: We must receive comments on this proposed AD by February 3, 
2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://
www.regulations.gov

[[Page 75429]]

and follow the instructions for sending your comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Margaret Langsted, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6500; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2005-
23357; Directorate Identifier 2005-NM-207-AD'' at the beginning 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://
dms.dot.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 
that web site, anyone can find and read the comments in any of our 
dockets, including 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 DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://
dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    The FAA has examined the underlying safety issues involved in 
recent fuel tank explosions on several large transport airplanes, 
including the adequacy of existing regulations, the service history of 
airplanes subject to those regulations, and existing maintenance 
practices for fuel tank systems. As a result of those findings, we 
issued a regulation titled ``Transport Airplane Fuel Tank System Design 
Review, Flammability Reduction and Maintenance and Inspection 
Requirements'' (67 FR 23086, May 7, 2001). In addition to new 
airworthiness standards for transport airplanes and new maintenance 
requirements, this rule included Special Federal Aviation Regulation 
No. 88 (``SFAR 88,'' Amendment 21-78, and subsequent Amendments 21-82 
and 21-83).
    Among other actions, SFAR 88 requires certain type design (i.e., 
type certificate (TC) and supplemental type certificate (STC)) holders 
to substantiate that their fuel tank systems can prevent ignition 
sources in the fuel tanks. This requirement applies to type design 
holders for large turbine-powered transport airplanes and for 
subsequent modifications to those airplanes. It requires them to 
perform design reviews and to develop design changes and maintenance 
procedures if their designs do not meet the new fuel tank safety 
standards. As explained in the preamble to the rule, we intended to 
adopt airworthiness directives to mandate any changes found necessary 
to address unsafe conditions identified as a result of these reviews.
    In evaluating these design reviews, we have established four 
criteria intended to define the unsafe conditions associated with fuel 
tank systems that require corrective actions. The percentage of 
operating time during which fuel tanks are exposed to flammable 
conditions is one of these criteria. The other three criteria address 
the failure types under evaluation: Single failures, single failures in 
combination with another latent failure condition(s), and in-service 
failure experience. For all four criteria, the evaluations included 
consideration of previous actions taken that may mitigate the need for 
further action.
    We have determined that the actions identified in this AD are 
necessary to reduce the potential of ignition sources inside fuel 
tanks, which, in combination with flammable fuel vapors, could result 
in fuel tank explosions and consequent loss of the airplane.
    We have received a report indicating that small gaps may be present 
between the bushing of the sump drain valve and the lower wing surface 
in the center fuel tank, on certain Boeing Model 777-200 series 
airplanes. If a lightning strike occurs on the bushing, arcs can go 
across the small gaps between the bushing and the lower wing surface, 
and into the inside of the fuel tank wall. The bushing does not have an 
engineered bond path to the wing surface. In addition, the layer of 
sealant between the bushing and the inner surface of the fuel tank 
could be too thin to contain the energy in the arcs. This condition, if 
not corrected, could create an ignition source in the center fuel tank 
and result in a fuel tank explosion.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 777-28-
0045, dated September 1, 2005. The service bulletin describes 
procedures for installing a new washer between the lower wing surface 
and the jam nut of the sump drain valve assembly. Accomplishing the 
actions specified in the service information is intended to adequately 
address the unsafe condition.

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 airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the service 
information described previously.

Costs of Compliance

    There are about 88 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 22 airplanes of 
U.S. registry. The proposed actions would take about 4 work hours per 
airplane, at an average labor rate of $65 per work hour. Required parts 
would cost about $360 per airplane. Based on these figures, the 
estimated cost of the proposed AD for U.S. operators is $13,640, or 
$620 per airplane.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue

[[Page 75430]]

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 
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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

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 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

    Boeing: Docket No. FAA-2005-23357; Directorate Identifier 2005-
NM-207-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by February 
3, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200 series airplanes, 
certificated in any category; as identified in Boeing Special 
Attention Service Bulletin 777-28-0045, dated September 1, 2005.

Unsafe Condition

    (d) This AD results from fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent energy from a 
lightning strike on the bushing for the sump drain valve from arcing 
to the inside of the center fuel tank wall, which could create an 
ignition source in the fuel tank and result in a fuel tank 
explosion.

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.

Installation

    (f) Within 60 months after the effective date of this AD, 
install a new washer between the lower wing surface and the jam nut 
of the sump drain valve assembly in both wings, in accordance with 
the Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 777-28-0045, dated September 1, 2005.

Alternative Methods of Compliance (AMOCs)

    (g)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

    Issued in Renton, Washington, on December 13, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-24243 Filed 12-19-05; 8:45 am]
BILLING CODE 4910-13-P