[Federal Register: March 30, 2007 (Volume 72, Number 61)]
[Proposed Rules]
[Page 15073-15075]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30mr07-20]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-27740; Directorate Identifier 2006-NM-290-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800
and -900 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 adopt a new airworthiness directive (AD)
for certain Boeing Model 737-600, -700, -700C, -800 and -900 series
airplanes. This proposed AD would require an inspection of the fillet
sealant at the inboard and outboard sides of the receptacles in the
wheel wells of the main landing gear, and related investigative/
corrective actions if necessary. This proposed AD results from reports
of in-production airplanes with missing or insufficient fillet sealant
around the receptacles at the disconnect bracket. We are proposing this
AD to prevent corrosion damage due to missing or insufficient fillet
sealant. Such corrosion could result in insufficient electrical bonding
between the connectors and the disconnect bracket, and consequent loss
of the shielding that protects the wire bundles from lightning,
electromagnetic interference (EMI), and high intensity radiated field
(HIRF). Loss of lightning, EMI, and HIRF protection at those
receptacles could cause failure of multiple electrical systems and
subsequent loss of several critical control systems that are necessary
for safe flight. In addition, a lightning strike could cause arcing in
the fuel tank; this potential ignition source, in combination with
flammable fuel vapors, could result in a fuel tank explosion and
consequent loss of the airplane.
DATES: We must receive comments on this proposed AD by May 14, 2007.
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.
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: Binh Tran, Aerospace Engineer, Systems
and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone
(425) 917-6485; 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-2007-
27740; Directorate Identifier 2006-NM-290-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
We have received a report indicating that 333 Boeing Model 737-600,
-700, -700C, -800 and -900 series airplanes in the production factory
had missing or insufficient fillet sealant around the receptacles in
the wheel wells of the main landing gear (MLG). Missing or insufficient
fillet sealant could result in corrosion damage, and consequent
insufficient electrical bonding between the connectors and the
disconnect bracket. The loss of electrical bonding could result in loss
of the shielding that protects the wire bundles from lightning,
electromagnetic interference (EMI), and high intensity radiated field
(HIRF). The loss of lightning, EMI, and HIRF protection at those
receptacles could cause multiple electrical systems failures. Those
failures could result in the loss of several critical control systems
that are necessary for safe flight.
[[Page 15074]]
In addition, a lightning strike could cause arcing in the fuel tank;
this potential ignition source, in combination with flammable fuel
vapors, could result in a fuel tank explosion and consequent loss of
the airplane.
Relevant Service Information
We have reviewed Boeing Special Attention Service Bulletin 737-24-
1169, dated December 15, 2006. The service bulletin describes
procedures for a detailed inspection of the fillet sealant at the
inboard and outboard sides of the receptacles in the MLG wheel wells.
For airplanes on which the sealant is missing or otherwise
insufficient, the service bulletin describes the following related
investigative and corrective actions:
An additional detailed inspection to detect signs of
corrosion damage of the connector and receptacle;
Cleaning of any corrosion-free connector;
Cleaning of any receptacle that has corrosion damage on
less than 20 percent of the total surface area of the receptacle
flange;
Replacement (with a new part having the same part number)
of any receptacle that has corrosion on more than 20 percent of the
total surface area of the receptacle flange;
Replacement of corroded connectors with connectors
identified in the service bulletin; and
Application of fillet sealant around the receptacles.
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 333 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.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Number of U.S.-
Work hours Average labor Cost per registered Fleet cost
rate per hour airplane airplanes
----------------------------------------------------------------------------------------------------------------
1........................................... $80 $80 118 $9,440
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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 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-2007-27740; Directorate Identifier 2006-NM-
290-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by May 14,
2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 737-600, -700, -700C, -800
and -900 series airplanes; certificated in any category; as
identified in Boeing Special Attention Service Bulletin 737-24-1169,
dated December 15, 2006.
Unsafe Condition
(d) This AD results from reports of in-production airplanes with
missing or insufficient fillet sealant around the receptacles
installed in the wheel wells of the main landing gear (MLG). We are
issuing this AD to prevent corrosion damage due to missing or
insufficient fillet sealant. Such corrosion could result in
insufficient electrical bonding between the connectors and the
disconnect bracket, and consequent loss of the shielding that
protects the wire bundles from lightning, electromagnetic
interference (EMI), and high intensity radiated field (HIRF). Loss
of lightning, EMI, and HIRF protection at those receptacles could
cause failure of multiple electrical systems and subsequent loss of
several critical control systems that are necessary for safe flight.
In addition, a lightning strike could cause arcing in the fuel tank;
this potential ignition source, in combination with flammable fuel
vapors, could result in a fuel tank explosion and consequent loss of
the airplane.
[[Page 15075]]
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.
Inspection
(f) Within 24 months after the effective date of this AD,
perform a detailed inspection to determine if there is sufficient
fillet sealant at the inboard and outboard sides of the receptacles
in the MLG wheel wells, in accordance with the Accomplishment
Instructions of Boeing Special Attention Service Bulletin 737-24-
1169, dated December 15, 2006. Do all applicable related
investigative and corrective actions before further flight in
accordance with the service bulletin.
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 March 23, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-5907 Filed 3-29-07; 8:45 am]
BILLING CODE 4910-13-P