[Federal Register Volume 67, Number 155 (Monday, August 12, 2002)]
[Rules and Regulations]
[Pages 52396-52398]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-19878]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-148-AD; Amendment 39-12842; AD 2002-16-03]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all Boeing Model 737-600, -700, -700C, -800, and -900 
series airplanes. This action requires determining exposure to runway 
deicing fluids containing potassium formate, and, for certain 
airplanes, repetitive inspections of certain electrical connectors in 
the wheel well of the main landing gear for corrosion, and follow-on 
actions. This action is necessary to prevent such corrosion, which 
could result in incorrect functioning of critical airplane systems 
essential to safe flight and landing of the airplane. This action is 
intended to address the identified unsafe condition.

DATES: Effective August 27, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 27, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before October 11, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-148-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

[[Page 52397]]

via fax to (425) 227-1232. Comments may also be sent via the Internet 
using the following address: [email protected]. Comments sent 
via fax or the Internet must contain ``Docket No. 2002-NM-148-AD'' in 
the subject line and need not be submitted in triplicate. Comments sent 
via the Internet as attached electronic files must be formatted in 
Microsoft Word 97 for Windows or ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

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 98055-4056; telephone 
(425) 227-2890; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports indicating that 
significant corrosion of the electrical connectors located in the main 
wheel well was found on some Boeing Model 737 series airplanes. Those 
airplanes land on runways treated with deicing fluids containing 
potassium formate, which has been determined as the cause of the 
corrosion. Tests conducted by the airplane manufacturer revealed that 
corrosion inhibiting compounds (CIC) can be used to form a shield 
against such corrosion and will not affect the electrical components or 
the systems. Corrosion of the electrical connectors could result in 
incorrect functioning of critical airplane systems essential to safe 
flight and landing of the airplane.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin 737-
24A1148, dated December 6, 2001, which recommends determining if 
airplanes have been exposed to runway deicing fluids containing 
potassium formate (by reviewing airport data on the type of components 
in deicing fluid used at airports that support their operations), and 
follow-on actions. If any airplane has been exposed, the service 
bulletin describes procedures for inspecting the line replaceable unit 
(LRU) electrical connectors (including the contacts and backshells) for 
corrosion. Signs of corrosion are the presence of moisture, corrosion 
pits, or white-colored material buildup on the connectors; black or 
reddish discoloration on the contacts; or loss of the olive-drab 
conversion coating on the backshells. The follow-on actions include 
cleaning the LRU connectors and applying CIC if no corrosion is found; 
and, if corrosion is found, replacing the LRU with a new LRU and 
applying CIC. The service bulletin also recommends an operational test 
of the affected systems after doing the applicable actions. 
Accomplishment of the inspections and follow-on actions specified in 
the service bulletin is intended to adequately address the identified 
unsafe condition.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD 
requires accomplishment of the actions specified in the service 
bulletin described previously, except as discussed below.

Differences Between Service Information and This AD

    The service bulletin specifies an examination of the electrical 
connectors in the wheel well of the main landing gear for corrosion. 
For the purposes of this AD, we have determined that the procedures in 
the service bulletin constitute a ``detailed inspection.'' Note 2 of 
this AD defines such an inspection.
    The service bulletin specifies that no work is necessary for 
airplanes that have not been exposed to runways using deicing fluids 
containing potassium formate (this is determined by reviewing airport 
data, as specified previously). We have concluded that such airplanes, 
although not presently using those runways, could use them in the 
future due to changes in routes. Therefore, this AD requires operators 
of those airplanes to repeat the data review every 12 months.
    The service bulletin states that airplane exposure to runway 
deicing fluids containing potassium format may be determined by 
reviewing airport data on the type of components in the deicing fluid 
used. This AD specifies that the determination be made in accordance 
with a review of the airport data, rather than specifying the 
determination in accordance with the service bulletin.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the AD is 
being requested.
     Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-148-AD.'' The postcard will be date stamped 
and returned to the commenter.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is

[[Page 52398]]

determined that this final rule does not have federalism implications 
under Executive Order 13132.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new 
airworthiness directive:

2002-16-03  Boeing: Amendment 39-12842. Docket 2002-NM-148-AD.

    Applicability: All Model 737-600, -700, -700C, -800, and -900 
series airplanes, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent corrosion of the electrical connectors and contacts 
in the wheel well of the main landing gear (MLG), which could result 
in incorrect functioning of critical airplane systems essential to 
safe flight and landing of the airplane, accomplish the following:

Determination of Exposure/Inspections/Follow-On Actions

    (a) Within 90 days after the effective date of this AD, do the 
requirements specified in either paragraph (a)(1) or (a)(2) of this 
AD.
    (1) Determine airplane exposure to runway deicing fluids 
containing potassium formate by reviewing airport data on the type 
of components in the deicing fluid used at airports that support 
airplane operations.
    (i) For airplanes that have not been exposed: Repeat the 
requirements in paragraph (a)(1) of this AD at least every 12 
months.
    (ii) For airplanes that have been exposed: Before further 
flight, do a detailed inspection of the line replaceable unit (LRU) 
electrical connectors (including the contacts and backshells) in the 
wheel well of the MLG for corrosion (the presence of moisture, 
corrosion pits, or white-colored material buildup), per Boeing Alert 
Service Bulletin 737-24A1148, dated December 6, 2001. Repeat the 
detailed inspection at least every 12 months.

    Note 2: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (2) Do a detailed inspection of the LRU electrical connectors 
(including the contacts and backshells) in the wheel well of the MLG 
for corrosion (the presence of moisture, corrosion pits, or white-
colored material buildup), per the service bulletin. Repeat the 
detailed inspection at least every 12 months.
    (b) Before further flight after doing any inspection specified 
in paragraph (a)(1)(ii) or (a)(2) of this AD, as applicable; do the 
requirements specified in paragraphs (b)(1), (b)(2), and (b)(3) of 
this AD, as applicable, per Boeing Alert Service Bulletin 737-
24A1148, dated December 6, 2001.
    (1) If no corrosion is found, clean the LRU connector.
    (2) If any corrosion is found, replace the LRU connector with a 
new connector.
    (3) Apply D5026NS corrosion inhibiting compound, or equivalent, 
to the affected areas.

Alternative Methods of Compliance

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished.

Incorporation by Reference

    (e) Except as provided by paragraph (a)(1) of this AD: The 
actions shall be done in accordance with Boeing Alert Service 
Bulletin 737-24A1148, dated December 6, 2001. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, 
Seattle, Washington 98124-2207. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (f) This amendment becomes effective on August 27, 2002.

    Issued in Renton, Washington, on July 29, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-19878 Filed 8-9-02; 8:45 am]
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