[Federal Register Volume 71, Number 113 (Tuesday, June 13, 2006)]
[Proposed Rules]
[Pages 34026-34028]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-9174]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25000; Directorate Identifier 2006-NM-096-AD]
RIN 2120-AA64


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

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to revise an existing airworthiness directive 
(AD) that applies to certain Boeing Model 737-600, -700, -700C, and -
800 series airplanes. The existing AD currently requires inspecting/
measuring the length of the attachment fasteners between the nacelle 
support fittings and the lower wing skin panels, and related 
investigative/corrective actions if necessary. This proposed AD would 
correct errors found in the existing AD. This proposed AD results from 
detection of those inadvertent errors. We are proposing this AD to 
prevent inadequate fastener clamp-up, which could result in cracking of 
the fastener holes, cracking along the lower wing skin panels, fuel 
leaking from the wing fuel tanks onto the engines, and possible fire.

DATES: We must receive comments on this proposed AD by July 28, 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 and follow the instructions for sending your 
comments electronically.

[[Page 34027]]

     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 service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6440; 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 docket number ``Docket No. 
FAA-2006-25000; Directorate Identifier 2006-NM-096-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 a docket, 
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 the 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

    On November 10, 2005, we issued AD 2005-24-03, amendment 39-14383 
(70 FR 70713, November 23, 2005), for certain Boeing Model 737-600, -
700, -700C, and -800 series airplanes. That AD requires inspecting/
measuring the length of the attachment fasteners between the nacelle 
support fittings and the lower wing skin panels, and related 
investigative/corrective actions if necessary. That AD resulted from a 
report from the manufacturer that in production, during the 
installation of certain attachment fasteners for the nacelle support 
fittings, only one washer was installed instead of two. We issued that 
AD to prevent inadequate fastener clamp-up, which could result in 
cracking of the fastener holes, cracking along the lower wing skin 
panels, fuel leaking from the wing fuel tanks onto the engines, and 
possible fire.

Actions Since Existing AD Was Issued

    Since we issued AD 2005-24-03, inadvertent errors were found in the 
existing AD. Those errors include no grace period provided in 
paragraphs (f)(1) and (f)(2) of the existing AD; and incorrect 
airplanes referred to for accomplishing the requirements specified in 
paragraphs (f)(1) and (f)(2).

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 revise AD 2005-24-03 and would retain the requirements of 
the existing AD. In addition, we have included a grace period of 12 
months in paragraphs (f)(1) and (f)(2) of this proposed AD. We also 
have limited the airplanes referred to in paragraph (f)(1) to Model 
737-700 series airplanes only (no other airplanes modified by the 
supplemental type certificate (STC) are affected by those 
requirements). We have changed the airplanes referred to in paragraph 
(f)(2) of the existing AD to ``all other airplanes,'' and removed the 
STC reference in that paragraph.

Costs of Compliance

    There are about 751 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD. The requirements that 
were previously required by AD 2005-24-03 are retained in this proposed 
AD and add no additional economic burden. The current costs are 
repeated for the convenience of affected operators, as follows:

                                                 Estimated Costs
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                                                                                         Number of
                                               Average                       Cost per      U.S.-
            Action               Work hours   labor rate       Parts         airplane    registered   Fleet cost
                                               per hour                                  airplanes
----------------------------------------------------------------------------------------------------------------
Inspection/Measurement........           12          $65  Nominal........         $780          302     $235,560
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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.

[[Page 34028]]

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 place 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 
removing amendment 39-14383 (70 FR 70713, November 23, 2005), and 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-25000; Directorate Identifier 2006-NM-
096-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 28, 
2006.

Affected ADs

    (b) This AD revises AD 2005-24-03.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, and -
800 series airplanes; line numbers 1 through 761 inclusive, except 
for line numbers 596, 683, 742, 749, 750, 751, 754, 755, 759, and 
760; certificated in any category.

Unsafe Condition

    (d) This AD results from a determination that errors were 
inadvertently included in the existing AD. We are issuing this AD to 
prevent inadequate fastener clamp-up, which could result in cracking 
of the fastener holes, cracking along the lower wing skin panels, 
fuel leaking from the wing fuel tanks onto the engines, and possible 
fire.

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 Requirements In AD 2005-24-03

Inspection/Measurement and Related Investigative and Corrective Actions

    (f) At the applicable time specified in paragraph (f)(1) or 
(f)(2) of this AD: Inspect/measure the length of certain attachment 
fasteners between the lower wing skin panels and the nacelle support 
fittings. Do the inspection/measurement, and all applicable related 
investigative and corrective actions, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 737-57-1275, 
Revision 1, dated August 18, 2005, except as provided by paragraph 
(g) of this AD.
    (1) For Model 737-700 series airplanes modified by Supplemental 
Type Certificate (STC) ST00830SE as of December 28, 2005 (the 
effective date of AD 2005-24-03): Accomplish the actions at the 
later of the times specified in paragraphs (f)(1)(i) and (f)(1)(ii) 
of this AD.
    (i) Prior to the accumulation of 25,000 total flight hours or 
25,000 total flight cycles, whichever is first.
    (ii) Within 12 months after December 28, 2005.
    (2) For all other airplanes: Accomplish the actions at the later 
of the times specified in paragraphs (f)(2)(i) and (f)(2)(ii) of 
this AD.
    (i) Prior to the accumulation of 30,000 total flight hours or 
30,000 total flight cycles, whichever is first.
    (ii) Within 12 months after December 28, 2005.
    (g) If accomplishing a corrective action as required by 
paragraph (f) of this AD, and the service bulletin specifies to 
contact Boeing for repair information: Before further flight, do the 
repair using a method approved in accordance with paragraph (i) of 
this AD.

Actions Accomplished According to Previous Issue of Service Bulletin

    (h) Actions accomplished before December 28, 2005, in accordance 
with Boeing Service Bulletin 737-57-1275, dated September 4, 2003, 
are considered acceptable for compliance with the corresponding 
action specified in 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.
    (2) AMOCs approved previously in accordance with AD 2005-24-03, 
amendment 39-14383, are approved as AMOCs for the corresponding 
provisions of this AD.
    (3) Before using any AMOC approved in accordance with 14 CFR 
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (4) 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, and the approval must specifically refer to this 
AD.

    Issued in Renton, Washington, on June 5, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-9174 Filed 6-12-06; 8:45 am]
BILLING CODE 4910-13-P