[Federal Register Volume 68, Number 19 (Wednesday, January 29, 2003)]
[Rules and Regulations]
[Pages 4367-4369]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-1815]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-307-AD; Amendment 39-13025; AD 2003-03-01]
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 reviewing the airplane 
maintenance records to determine whether an engine has been removed 
from the airplane since the airplane was manufactured. For airplanes on 
which an engine has been removed, this action requires an inspection of 
the aft engine mount to determine if the center link assembly is 
correctly installed, and follow-on actions if necessary. This action 
also prohibits installation of an engine unless the aft engine mount is 
inspected and the center link assembly is found to be installed 
correctly. This action is necessary to prevent increased structural 
loads on the aft engine mount, which could result in failure of the aft 
engine mount and consequent separation of the engine from the airplane. 
This action is intended to address the identified unsafe condition.

DATES: Effective February 13, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 13, 2003.
    Comments for inclusion in the Rules Docket must be received on or 
before March 31, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-307-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 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-307-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 this AD 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: Sue Lucier, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2186; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports indicating that 
operators found that the center link assembly for the aft engine mount 
was reversed on several Model 737-700 series airplanes and one Model 
737-800 series airplane. Investigation revealed that the center link 
assembly had been reversed during re-assembly after overhaul of the 
airplane engine. Because of the nearly symmetrical design of this 
assembly, it is susceptible to being reversed during installation. 
Reversal of the center link assembly increases the structural load on 
the aft engine mount. This condition, if not corrected, could result in 
failure of the aft engine mount and consequent separation of the engine 
from the airplane.
    The design of the center link assembly for the aft engine mount is 
common to

[[Page 4368]]

all Model 737-600, -700, -700C, -800, and -900 series airplanes. 
Therefore, Model 737-600, -700C, and -900 series airplanes may be 
subject to the same unsafe condition revealed on the Model 737-700 and 
-800 series airplanes.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-71A1462, Revision 1, dated November 7, 2002. That service bulletin 
describes procedures for a one-time general visual inspection to 
determine if the center link assembly of the aft engine mount is 
correctly installed, and follow-on actions if necessary. If the center 
link assembly is incorrectly installed, follow-on actions include:
    [sbull] Removing the assembly and installing it correctly;
    [sbull] Performing a detailed inspection of the engine mounting 
lugs and engine turbine rear frame for cracking, yielding, buckling, or 
wear damage; and
    [sbull] Performing a detailed inspection of the hardware for the 
aft engine mount (including the center link assembly, right link 
assembly, aft mount hanger assembly, and link pins) for cracking, 
yielding, buckling, or wear damage.
    Accomplishment of the 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 is 
being issued to prevent increased structural loads on the aft engine 
mount, which could result in failure of the aft engine mount and 
consequent separation of the engine from the airplane. This AD requires 
a one-time review of the airplane maintenance records to determine if 
an engine has been removed since the airplane's date of manufacture. 
For any engine that has been removed since the airplane's date of 
manufacture, this AD requires accomplishment of the actions specified 
in the service bulletin described previously, except as discussed under 
the heading, ``Differences Between This AD and the Service Bulletin.'' 
This AD also prohibits installation of an engine unless the aft engine 
mount is inspected and the center link assembly is found to be 
installed correctly.

Differences Between This AD and the Service Bulletin

    Operators should note that, while the service bulletin's 
effectivity is limited to certain airplane line numbers, this AD is 
applicable to all Boeing Model 737-600, -700, -700C, -800, and -900 
series airplanes. The design of the center link assembly of the aft 
engine mount on all of these airplanes is the same. Therefore, all of 
these airplanes may be subject to the same unsafe condition. This issue 
has been coordinated with Boeing, and Boeing concurs with making this 
AD applicable to all Boeing Model 737-600, -700, -700C, -800, and -900 
series airplanes.
    Operators should note that the service bulletin specifies that the 
engine manufacturer may be contacted for instructions for repair of any 
cracking, yielding, buckling, or wear damage that is found. However, 
this AD requires the repair of those conditions to be accomplished per 
a method approved by the FAA, or per data meeting the type 
certification basis of the airplane approved by a Boeing Company 
Designated Engineering Representative who has been authorized by the 
FAA to make such findings. Alternatively, this AD allows replacement of 
the subject parts with new parts per the airplane maintenance manual.
    Operators also should note that, although the Accomplishment 
Instructions of the referenced service bulletin describe procedures for 
reporting certain findings to the airplane manufacturer, this AD does 
not include such a requirement.

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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the AD is 
being requested.
    [sbull] 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-307-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 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.

[[Page 4369]]

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:

2003-03-01 Boeing: Amendment 39-13025. Docket 2002-NM-307-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 (g) 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 increased structural loads on the aft engine mount, 
which could result in failure of the aft engine mount and consequent 
separation of the engine from the airplane, accomplish the 
following:

Review of Maintenance Records

    (a) Within 90 days after the effective date of this AD, review 
the airplane maintenance records to determine whether either engine 
has been removed since the airplane's date of manufacture. If 
neither engine has been removed since the airplane's date of 
manufacture, no further action is required by this paragraph.

Inspection To Determine if Center Link Assembly is Installed Correctly

    (b) For any installed engine that is found to have been removed 
from the airplane since the airplane's date of manufacture: Within 
90 days after the effective date of this AD, do a one-time general 
visual inspection to determine if the center link assembly of the 
aft engine mount is installed correctly, per the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-71A1462, Revision 
1, dated November 7, 2002. If the center link assembly is installed 
correctly, as specified in the service bulletin, no further action 
is required by paragraphs (b), (c), or (d) of this AD for that 
engine. However, paragraph (f) of this AD continues to apply.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Follow-on and Corrective Actions

    (c) For any center link assembly that is found installed 
incorrectly during the inspection required by paragraph (b) of this 
AD: Before further flight, do the actions in paragraphs (c)(1), 
(c)(2), and (c)(3) of this AD, per the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-71A1462, Revision 1, dated 
November 7, 2002, except that it is not necessary to submit a report 
of findings to the airplane manufacturer.
    (1) Remove the center link assembly and install it correctly.
    (2) Perform a detailed inspection of the engine mounting lugs 
and engine turbine rear frame for cracking, yielding, buckling, or 
wear damage.
    (3) Perform a detailed inspection of the hardware for the aft 
engine mount; including the center link assembly, right link 
assembly, aft mount hanger assembly, and link pins; for cracking, 
yielding, buckling, or wear damage.

    Note 3: 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.''

Repair

    (d) If any cracking, yielding, buckling, or wear damage is found 
during the inspections required by paragraphs (c)(2) and (c)(3) of 
this AD: Before further flight, replace the discrepant part with a 
new or serviceable part per the applicable section of the airplane 
maintenance manual, or repair per a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO), FAA; or per data 
meeting the type certification basis of the airplane approved by a 
Boeing Company Designated Engineering Representative who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved, the approval must specifically 
reference this AD.

Credit for Actions Accomplished Previously

    (e) Inspections and correction of the installation of the center 
link assembly accomplished before the effective date of this AD per 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-71A1462, dated August 29, 2002, are acceptable for compliance 
with the requirements of paragraphs (b) and (c) of this AD.

Parts Installation

    (f) As of the effective date of this AD, no person may install 
an engine on any airplane unless the inspection specified by 
paragraph (b) of this AD is accomplished and the center link 
assembly of the aft engine mount is found to be installed correctly.

Alternative Methods of Compliance

    (g) 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 ACO. 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 4: 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

    (h) Special flight permits may be issued in accordance with 
sections 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

    (i) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Alert Service Bulletin 737-71A1462, 
Revision 1, dated November 7, 2002. 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

    (j) This amendment becomes effective on February 13, 2003.

    Issued in Renton, Washington, on January 21, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-1815 Filed 1-28-03; 8:45 am]
BILLING CODE 4910-13-P