
[Federal Register: August 28, 2008 (Volume 73, Number 168)]
[Rules and Regulations]               
[Page 50714-50716]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28au08-6]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0621; Directorate Identifier 2008-NM-015-AD; 
Amendment 39-15653; AD 2008-17-15]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-600, -700, -800, and -
900 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Boeing Model 737-600, -700, -800, and -900 series airplanes. This AD 
requires installing hot short protector (HSP) support brackets and 
equipment for the fuel quantity indicating system (FQIS) fuel 
densitometer and other specified actions as applicable. This AD also 
requires revising the Airworthiness Limitations (AWLs) section of the 
Instructions for Continued Airworthiness to incorporate AWL No. 28-AWL-
07. This AD results from fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent the center tank fuel 
densitometer from overheating and becoming a potential ignition source 
inside the center fuel tank, which, in combination with flammable fuel 
vapors, could result in a center fuel tank explosion and consequent 
loss of the airplane.

DATES: This AD is effective October 2, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of October 2, 
2008.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.

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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Georgios Roussos, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6482; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
certain Boeing Model 737-600, -700, -800, and -900 series airplanes. 
That NPRM was published in the Federal Register on June 9, 2008 (73 FR 
32491). That NPRM proposed to require installing hot short protector 
(HSP) support brackets and equipment for the fuel quantity indicating 
system (FQIS) fuel densitometer and other specified actions as 
applicable. That NPRM proposed to also require revising the 
Airworthiness Limitations (AWLs) section of the Instructions for 
Continued Airworthiness to incorporate AWL No. 28-AWL-07.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the single comment received. Boeing concurs with 
the NPRM.

Change to Final Rule Regarding Later Revisions of Service Information

    We removed all references to the use of ``later revisions'' of the 
applicable service information from this AD to be consistent with FAA 
and Office of the Federal Register policies. We may consider approving 
the use of later revisions of the service information as an alternative 
method of compliance with this AD, as provided by paragraph (k) of this 
AD.

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting the 
AD with the change described previously. We also determined that this 
change will not increase the economic burden

[[Page 50715]]

on any operator or increase the scope of the AD.

Costs of Compliance

    We estimate that this AD affects 13 airplanes of U.S. registry. The 
following table provides the estimated costs, at an average labor rate 
of $80 per work hour, for U.S. operators to comply with this AD.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Number of
                                                                       Cost per        U.S.-
            Action                Work hours           Parts           airplane      registered     Fleet cost
                                                                                     airplanes
----------------------------------------------------------------------------------------------------------------
Installation of HSP support    Up to 16........  Up to $14,698...  Up to $15,978..           13  Up to $207,714
 brackets and equipment.
AWLs revision................  1...............  None............  $80............           13  $1,040
----------------------------------------------------------------------------------------------------------------

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2008-17-15 Boeing: Amendment 39-15653. Docket No. FAA-2008-0621; 
Directorate Identifier 2008-NM-015-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective October 2, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -800, and -
900 series airplanes, certificated in any category; as identified in 
Boeing Alert Service Bulletin 737-28A1221, Revision 1, dated 
November 9, 2007.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections. Compliance with 
these inspections is required by 14 CFR 91.403(c). For airplanes 
that have been previously modified, altered, or repaired in the 
areas addressed by these inspections, the operator may not be able 
to accomplish the inspections described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance (AMOC) 
according to paragraph (k) of this AD. The request should include a 
description of changes to the required inspections that will ensure 
the continued operational safety of the airplane.

Unsafe Condition

    (d) This AD results from fuel system reviews conducted by the 
manufacturer. We are issuing this AD to prevent the center tank fuel 
densitometer from overheating and becoming a potential ignition 
source inside the center fuel tank, which, in combination with 
flammable fuel vapors, could result in a center fuel tank explosion 
and consequent loss of the airplane.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Installation of the Hot Short Protector (HSP)

    (f) Within 60 months after the effective date of this AD, 
install the HSP support brackets and equipment for the fuel quantity 
indicating system (FQIS) fuel densitometer and do all the other 
specified actions as applicable, by accomplishing all of the 
applicable actions specified in the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-28A1221, Revision 1, dated 
November 9, 2007.

Airworthiness Limitations (AWLs) Revision for AWL No. 28-AWL-07

    (g) Concurrently with accomplishing the actions required by 
paragraph (f) of this AD, revise the AWLs section of the 
Instructions for Continued Airworthiness (ICA) by incorporating AWL 
No. 28-AWL-07 of Subsection F, ``AIRWORTHINESS LIMITATIONS--FUEL 
SYSTEM AWLs,'' of Section 9 of the Boeing 737-600/700/800/900 
Maintenance Planning Data (MPD) Document, D626A001-CMR, Revision 
March 2007 R2 (hereafter referred to as ``the MPD'').

No Alternative Critical Design Configuration Control Limitations 
(CDCCLs)

    (h) After accomplishing the action specified in paragraph (g) of 
this AD, no alternative CDCCLs may be used unless the CDCCLs are 
approved as an alternative methods of compliance (AMOC) in 
accordance with the procedures specified in paragraph (k) of this 
AD.

Credit for Actions Done According to Previous Issue of Service Bulletin

    (i) Actions done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 737-28A1221, dated 
January 14, 2007, are acceptable for compliance with the 
requirements of paragraph (f) of this AD.

[[Page 50716]]

Terminating Action for AWLs Revision

    (j) Incorporating AWL No. 28-AWL-07 into the AWLs section of the 
ICA in accordance with paragraph (g)(3) of AD 2008-10-10, amendment 
39-15516, terminates the action required by paragraph (g) of this 
AD.

AMOCs

    (k)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
ATTN: Georgios Roussos, Aerospace Engineer, Systems and Equipment 
Branch, ANM-130S, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone (425) 917-6482; fax (425) 917-6590; has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19.
    (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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

Material Incorporated by Reference

    (l) You must use Boeing Alert Service Bulletin 737-28A1221, 
Revision 1, dated November 9, 2007; and Airworthiness Limitation 28-
AWL-07 of Section 9 of the Boeing 737-600/700/800/900 Maintenance 
Planning Data (MPD) Document, D626A001-CMR, Revision March 2007 R2; 
to do the actions required by this AD, unless the AD specifies 
otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (3) You may review copies of the service information 
incorporated by reference at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal_register/code_of_federal_
regulations/ibr_locations.html.

    Issued in Renton, Washington, on August 12, 2008.
Michael J Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-19367 Filed 8-27-08; 8:45 am]

BILLING CODE 4910-13-P
