[Federal Register Volume 70, Number 106 (Friday, June 3, 2005)]
[Proposed Rules]
[Pages 32534-32537]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-11051]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21346; Directorate Identifier 2005-NM-031-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 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 all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. This proposed AD would require operators to examine the 
airplane's maintenance records to determine if the main landing gear 
(MLG) has been overhauled and if Titanine JC5A (also known as Desoto 
823E508) corrosion-inhibiting compound (``C.I.C.'') was used during the 
overhaul. For airplanes for which the maintenance records indicate that 
further action is necessary, or for airplanes on which C.I.C. JC5A may 
have been used during manufacture, this proposed AD would require a 
one-time detailed inspection for discrepancies of certain components of 
the MLG, and corrective action if necessary. This proposed AD is 
prompted by twelve reports of severe corrosion on one or more of three 
components of the MLG. We are proposing this AD to prevent collapse of 
the MLG, or damage to hydraulic tubing or the aileron control cables, 
which could result in possible departure of the airplane from the 
runway and loss of control of the airplane.

DATES: We must receive comments on this proposed AD by July 18, 2005.

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.
     By 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.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., room PL-
401, on the plaza level of the Nassif Building, Washington, DC. This 
docket number is FAA-2005-

[[Page 32535]]

21346; the directorate identifier for this docket is 2005-NM-031-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 under ADDRESSES. Include ``Docket No. FAA-2005-21346; 
Directorate Identifier 2005-NM-031-AD'' in the subject line 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 submitted 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 can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    You can 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 DMS receives them.

Discussion

    We have received twelve reports of severe corrosion on one or more 
of the following three components of the main landing gear (MLG) on the 
affected airplanes: The trunnion pin, the actuator beam, and the tee-
bolt fitting. The manufacturer analyzed the corrosion and found that 
JC5A, a corrosion-inhibiting compound (C.I.C.), was used on the 
components. JC5A has been found to decompose in the presence of 
moisture. The decomposition can make chemical by-products that damage 
the primer, which is the primary protection for the titanium-cadmium 
(Ti-Cad) plating on the components. The Ti-Cad plating protects the 
base metal against corrosion.
    Corrosion can cause a fracture of the trunnion pin or the actuator 
beam bolts. If the inboard end of the trunnion pin becomes 
disconnected, the side strut and reaction link will not be stable. 
Further, if the tee fitting attach bolt assembly fractures, the drag 
strut could become unstable. Either of these conditions could result in 
MLG collapse, and departure of the airplane from the runway.
    Fractures in the trunnion pin or the actuator beam bolts can cause 
the actuator to move outboard during gear retraction. This outboard 
movement could damage the hydraulic tubing or the aileron control 
cables and could cause the flightcrew to lose control of the airplane.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 737-32A1367, Revision 1, 
dated December 23, 2004. The service bulletin describes procedures for 
a one-time detailed inspection for discrepancies (damage to the finish, 
indications of corrosion or pitting) of components of the MLG. These 
MLG components are the trunnion pins, the actuator beam bolts, the tee-
bolt fitting, and certain adjacent parts indicated in the service 
bulletin. The airplanes to be inspected are those on which JC5A was 
applied during manufacture, or those on which JC5A was applied when the 
MLG was overhauled. The service bulletin does not include an inspection 
of the trunnion pins on Model 737-400 series airplanes due to the 
unique configuration of the Model 737-400.
    If no discrepancy is found during the inspection, the service 
bulletin states that no more work is necessary.
    If any discrepancy is found during the inspection, the service 
bulletin describes procedures for corrective action. The corrective 
action includes doing one of the following:
     For parts that have finish damage without corrosion or 
pitting, applying a new protective finish.
     For parts with corrosion or pitting, repair by removing 
the corrosion or pitting from the part, and applying a new protective 
finish, or replace the part with a serviceable part.
     For parts with corrosion or pitting that cannot be made 
serviceable after removing the corrosion or pitting, contact the 
manufacturer.
    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. Therefore, we are proposing this AD, which 
would require the actions specified in the service bulletin, except as 
discussed under ``Differences Between the Proposed AD and the Service 
Bulletin.''

Differences Between the Proposed AD and the Service Bulletin

    The service bulletin specifies that you may contact the 
manufacturer for instructions on how to repair certain conditions, but 
this proposed AD would require you to repair those conditions in one of 
the following ways:
     Using a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Delegation Option Authorization Organization whom we 
have authorized to make those findings.
    The service bulletin specifies additional compliance times after 
the original airplane delivery date; this proposed AD would require 
compliance within the specified compliance time after the date of 
issuance of the original standard Airworthiness Certificate or the date 
of issuance of the original Export Certificate of Airworthiness.
    Although the service bulletin does not specify when to accomplish 
any necessary corrective actions, this proposed AD would require 
operators to do these corrective actions before further flight after 
the inspection.

Clarification of Procedures in the Service Bulletin

    The procedures in the service bulletin state that airplanes must be 
inspected if they have had the MLG overhauled and C.I.C. JC5A was used 
during the last overhaul, or if the airplane was assembled in the 
factory during a time when JC5A was used by the manufacturer as an 
approved substitute C.I.C. Although the service bulletin does not have 
explicit procedures for doing so, this proposed AD would require that

[[Page 32536]]

operators of certain groups of airplanes identified in the service 
bulletin examine airplane maintenance records to determine if the MLG 
has been overhauled and if C.I.C. JC5A has been applied to the MLG 
during overhaul. This AD also would require that operators inspect any 
airplane for which the maintenance records indicate that the MLG was 
overhauled, but for which it is unclear whether or not C.I.C. JC5A was 
used during the overhaul.

Costs of Compliance

    There are about 3,132 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
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                                               Average                              Number of  U.S.-
              Action                 Work     labor rate      Parts      Cost per      registered     Fleet cost
                                     hours     per hour                  airplane      airplanes
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Records examination..............        1          $65   None........       $65              1,748    $113,620
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    For airplanes that require a detailed inspection, we estimate that 
the inspection would take about 3 work hours per airplane to 
accomplish, at an average labor rate of $65 per work hour. Based on 
these figures, we estimate that the detailed inspection would cost 
about $195 per airplane.

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

Boeing: Docket No. FAA-2005-21346; Directorate Identifier 2005-NM-
031-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by July 18, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 737-100, -200, -200C, -
300, -400, and -500 series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD was prompted by twelve reports of severe corrosion 
on one or more of three components of the main landing gear (MLG). 
We are issuing this AD to prevent collapse of the MLG, or damage to 
hydraulic tubing or the aileron control cables, which could result 
in possible departure of the airplane from the runway and loss of 
control 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.

Service Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
32A1367, Revision 1, dated December 23, 2004.

Records Examination and Compliance Times

    (g) For all airplanes: Before the inspection required by 
paragraph (h) of this AD, examine the airplane records to determine 
if the MLG has been overhauled, and, for any overhauled MLG, if JC5A 
corrosion inhibiting compound (C.I.C.) was used on the trunnion pin 
or other parts of the MLG.
    (1) For airplanes identified in the service bulletin as Group 2 
and Group 4: If records indicate conclusively that the MLG has not 
been overhauled, no further action is required by this paragraph or 
paragraph (h) of this AD.
    (2) For airplanes identified in the service bulletin as Group 1, 
Group 2, Group 3, and Group 4: If records indicate conclusively that 
the MLG has been overhauled and that C.I.C. JC5A was not used on the 
trunnion pins or other parts of the MLG during the overhaul, no 
further action is required by this paragraph or paragraph (h) of 
this AD.

Inspection and Corrective Action

    (h) For all airplanes, except as provided by paragraph (g)(1) 
and (g)(2) of this AD: At the applicable compliance time in 
paragraph (h)(1) or (h)(2) of this AD, do a detailed inspection for 
discrepancies of the applicable MLG components specified in the 
service bulletin. Do all applicable corrective actions before 
further flight after the inspection. Do all the actions in 
accordance with the service bulletin, except as required by 
paragraph (i) of this AD.
    (1) For airplanes identified in the service bulletin as Group 1 
and Group 3 for which records indicate conclusively that the MLG has 
not been overhauled: Inspect at the later of the times in paragraph 
(h)(1)(i) and (h)(1)(ii) of this AD.
    (i) Within 48 months after the date of issuance of the original 
Airworthiness

[[Page 32537]]

Certificate or the date of issuance of the original standard Export 
Certificate of Airworthiness, whichever occurs later.
    (ii) Within 6 months after the effective date of this AD.
    (2) For airplanes identified in the service bulletin as Group 1, 
Group 2, Group 3, and Group 4 for which records indicate 
conclusively that the MLG has been overhauled, and for which records 
indicate conclusively that C.I.C. JC5A was used during the last 
overhaul; and for airplanes for which records do not show 
conclusively which C.I.C. compound was used during the last 
overhaul: Inspect at the later of the times in paragraph (h)(2)(i) 
or (h)(2)(ii) of this AD.
    (i) Within 48 months after the landing gear was installed.
    (ii) Within 6 months after the effective date of this AD.

    Note 1: 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.''

Contact ACO or DOA for Certain Corrective Actions

    (i) If any discrepancy is found during any inspection required 
by this AD, and the service bulletin specifies to contact Boeing for 
appropriate action: Before further flight, do the action according 
to a method approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA; or according to data meeting the certification 
basis of the airplane approved by an Authorized Representative for 
the Boeing Delegation Option Authorization Organization (DOA) who 
has been authorized by the Manager, Seattle ACO, to make those 
findings. For a repair method to be approved, the approval must 
specifically refer to this AD.

Use of JC5A Prohibited

    (j) As of the effective date of this AD, no person may use 
C.I.C. JC5A on an MLG component on any airplane.

Actions Done According to Previous Revision of Service Bulletin

    (k) Actions done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 737-32A1367, dated 
August 19, 2004, are considered acceptable for compliance with the 
corresponding action specified in this AD.

Alternative Methods of Compliance (AMOCs)

    (l)(1) The Manager, Seattle 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) 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 DOA 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 May 26, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-11051 Filed 6-2-05; 8:45 am]
BILLING CODE 4910-13-P