Airworthiness Directives; Boeing Model 737-100, -200, -200C, and -300 Series Airplanes

[Federal Register Volume 70, Number 171 (Tuesday, September 6, 2005)]
[Rules and Regulations]
[Pages 52899-52902]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-17461]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18877; Directorate Identifier 2002-NM-340-AD; 
Amendment 39-14248; AD 2005-18-08]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, and 
-300 Series Airplanes

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 737-100, -200, -200C, and -300 series airplanes. 
This AD requires repetitive detailed inspections to detect 
discrepancies of the retaining pin lugs on the support fitting of the 
main landing gear (MLG) beam, and rework of the support fitting, or 
replacement of the fitting if necessary. This AD is prompted by reports 
of discrepancies of the lugs. We are issuing this AD to prevent 
separation of the support beam of the MLG from the rear spar, which 
could cause cracking of the MLG support fitting and a consequent leak 
in the wing fuel tank or collapse of the MLG.

DATES: This AD becomes effective October 11, 2005.
    The incorporation by reference of certain publications listed in 
the AD is approved by the Director of the Federal Register as of 
October 11, 2005.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    Docket: The AD docket contains the proposed AD, comments, and any 
final disposition. 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 U.S. 
Department of Transportation, 400 Seventh Street, SW., room PL-401, 
Washington, DC. This docket number is FAA-2004-18877; the directorate 
identifier for this docket is 2002-NM-340-AD.

FOR FURTHER INFORMATION CONTACT: Robert C. Hardwick, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6457; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with an AD for certain Boeing Model 737-100, -200, -200C, and -300 
series airplanes. That action, published in the Federal Register on 
August 17, 2004 (69 FR 51017), proposed to require repetitive detailed 
inspections to detect discrepancies of the retaining pin lugs on the 
support fitting of the main landing gear (MLG) beam, and rework of the 
support fitting or replacement of the fitting if necessary.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
submitted on the proposed AD.

Agreement With the Proposed AD

    One commenter, the manufacturer, agrees with the proposed AD.

Conditional Agreement With the Proposed AD

    One commenter, an operator, agrees with the proposed AD provided 
that there are adequate parts available if the discrepant condition is 
found.
    The FAA agrees that adequate availability of parts is necessary. We

[[Page 52900]]

have received no information from the manufacturer concerning a 
possible delay in availability of parts. In the event there is a delay 
in the availability of parts, an operator may request approval for an 
alternative method of compliance as specified in paragraph (k)(1) of 
this AD.

Request for Clarification of Paragraph (g) of the Proposed AD

    One commenter, an operator, requests additional information and 
clarification regarding the reference in paragraph (g)(2) of the 
proposed AD to replacing the fittings in accordance with the 
Accomplishment Instructions, Part III--Fitting Replacement, of Boeing 
Service Bulletin 737-57-1216, Revision 2, dated May 6, 1999. The 
commenter notes that, in certain situations, those Accomplishment 
Instructions instruct the operator to install a self-locking nut to 
secure the support pin of the MLG support beam. However, the commenter 
advises that installing a self-locking nut would be in conflict with AD 
2002-02-08 (67 FR 6372, February 12, 2002).
    We agree that clarification of paragraph (g)(2) of the AD is 
necessary in order to prevent a conflict between the requirements of 
this AD and AD 2002-02-08. Therefore, we have added further information 
to paragraph (g)(2) of the AD to specify that, if operators choose to 
accomplish the corrective action specified in paragraph (g)(2) of the 
AD, replacing the fitting in accordance with the Accomplishment 
Instructions, Part III--Fitting Replacement, of Boeing Service Bulletin 
737-57-1216, Revision 2, dated May 6, 1999, must also include replacing 
the retaining bolt, self-locking nut, and associated hardware of the 
support beam for the MLG with a new bolt, castellated nut, and new 
hardware; in accordance with Boeing Service Bulletin 737-57A1260, 
Revision 2, dated October 18, 2001.

Request for Credit for Accomplishing Certain Service Bulletins

    One commenter, an operator, requests that the original issue, dated 
December 17, 1992, and Revision 1, dated September 23, 1993, of Boeing 
Service Bulletin 737-57-1216 be approved as acceptable for terminating 
the requirements of the proposed AD. The commenter states that the 
original issue and Revision 1 provide procedures for replacing the 
fitting that are essentially the same as those in Revision 2, which is 
cited as the appropriate service information in paragraph (g)(2) of the 
proposed AD.
    We agree with the commenter for the reason stated and have revised 
paragraph (g)(2) of the AD accordingly.

Request To Clarify Paragraph (j) of the Proposed AD

    One commenter, an operator, requests that the fittings acceptable 
for installation be stated in a more definite manner than ``a new 
lug.'' The commenter suggests that paragraph (j) of the proposed AD be 
revised to specify a part number or serial number, rather than just ``a 
new lug.'' The commenter also requests that the inspection and rework 
instructions of paragraph (j) of the proposed AD be more specific.
    We agree that clarifying the intent of the words ``new lug'' is 
necessary. Although the inspection requirements of this AD are intended 
to detect cracking of ``the retaining pin lugs of the support fitting 
of the MLG, or elongation of a bolt hole in a lug,'' the corrective 
actions of paragraph (g) of this AD require reworking or replacing the 
fittings. We specify reworking or replacing the fittings, rather than 
the lugs, since the lugs are not available as individual replacement 
parts. The intent and purpose of paragraph (j) of this AD is to specify 
that any lug must be inspected and the fitting reworked or replaced, as 
applicable, except for those fittings that previously have been 
reworked or replaced, in accordance with paragraph (g) of this AD. We 
have revised paragraph (j) of the AD accordingly. We do not, however, 
agree that the inspection and rework instructions of paragraph (j) of 
the AD need to be more specific. The requirements of paragraph (j) of 
the AD indicate multiple actions that are clearly encompassed by 
stating ``in accordance with this AD,'' rather than to specify each 
action that has already been stated in previous paragraphs of the AD.

Changes to Delegation Authority

    Boeing has received a Delegation Option Authorization (DOA). We 
have revised this final rule to delegate the authority to approve an 
alternative method of compliance for any repair required by this AD to 
the Authorized Representative for the Boeing DOA Organization rather 
than the Designated Engineering Representative (DER).

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been submitted, and determined that air safety and 
the public interest require adopting the AD with the changes described 
previously. We have determined that these changes will neither increase 
the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 1,670 airplanes worldwide of the affected design 
and 668 airplanes of U.S. registry. The required actions take about 2 
work hours per airplane, at an average labor rate of $65 per work hour. 
Based on these figures, the estimated cost of the required actions for 
U.S. operators is $86,840, or $130 per airplane, per inspection cycle.
    The rework, if accomplished, will take about 24 work hours per 
airplane to accomplish at an average labor rate of $65 per work hour. 
Required parts will cost about $1,006 per airplane. Based on these 
figures, the cost impact of the rework provided by this AD is estimated 
to be $2,566 per airplane.
    The replacement of the support fitting of the MLG beam, if 
accomplished, will take about 128 work hours per airplane to accomplish 
at an average labor rate of $65 per work hour. Required parts will cost 
between $4,540 and $5,271 per airplane. Based on these figures, the 
cost impact of the replacement provided by this AD is estimated to be 
between $12,860 and $13,591 per airplane.
    The replacement of the support fitting and installation of a 
special bushing of the MLG beam (for Group 9 and Group 10 airplanes), 
if accomplished, will take about 144 work hours per airplane to 
accomplish at an average labor rate of $65 per work hour. Required 
parts will cost about $5,081 per airplane. Based on these figures, the 
cost impact of this replacement and installation is estimated to be 
$14,441 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.

[[Page 52901]]

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD 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.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2005-18-08 Boeing: Amendment 39-14248. Docket No. FAA-2004-18877; 
Directorate Identifier 2002-NM-340-AD.

Effective Date

    (a) This AD becomes effective October 11, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-100, -200, -200C, and -
300 series airplanes, certificated in any category; line numbers 1 
through 1670 inclusive.

Unsafe Condition

    (d) This AD was prompted by reports of discrepancies of the lugs 
on the support fitting of the main landing gear (MLG) beam. We are 
issuing this AD to prevent separation of the support beam of the MLG 
from the rear spar, which could cause cracking of the MLG support 
fitting and a consequent leak in the wing fuel tank or collapse of 
the MLG.

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) Prior to the accumulation of 15,000 total flight cycles, or 
within 3,000 flight cycles after the effective date of this AD, 
whichever occurs later: Perform a detailed inspection to detect 
cracking of the retaining pin lugs of the support fitting of the MLG 
beam, or elongation of a bolt hole in a lug, in accordance with the 
Accomplishment Instructions, Part I: Inspection, of Boeing Special 
Attention Service Bulletin 737-57-1267, dated August 8, 2002. If no 
cracked lug or elongated bolt hole is found, repeat the inspection 
thereafter at intervals not to exceed 12,000 flight cycles, until 
the actions specified in paragraph (h) of this AD are accomplished.

    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 
mirrors magnifying lenses, etc. may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Corrective Action

    (g) If any cracked lug or elongated bolt hole is found during 
any inspection required by paragraph (f) of this AD, before further 
flight, do paragraph (g)(1) or (g)(2) of this AD.
    (1) Rework the fitting in accordance with the Accomplishment 
Instructions, Part II: Rework, of Boeing Special Attention Service 
Bulletin 737-57-1267, dated August 8, 2002.
    (2) Replace the fitting in accordance with the Accomplishment 
Instructions, Part III--Fitting Replacement, of Boeing Service 
Bulletin 737-57-1216, Revision 2, dated May 6, 1999, and install a 
retaining bolt, castellated nut, and cotter pin in accordance with 
Boeing Service Bulletin 737-57A1260, Revision 2, dated October 18, 
2001. Replacing the fitting in accordance with the Accomplishment 
Instructions, Part III--Fitting Replacement, of Boeing Service 
Bulletin 737-57-1216, dated December 17, 1992, or Revision 1, dated 
September 23, 1993; and replacing the retaining bolt, self-locking 
nut, and associated hardware of the support beam for the MLG with a 
new bolt, castellated nut, and new hardware; in accordance with 
Boeing Service Bulletin 737-57A1260, Revision 2, dated October 18, 
2001; prior to the effective date of this AD are acceptable methods 
of compliance with the requirements of this paragraph.

Optional Terminating Action

    (h) Reworking or replacing the fitting in accordance with 
paragraph (g)(1) or (g)(2) of this AD constitutes terminating action 
for the inspections required by paragraph (f) of this AD.

Repair

    (i) If any cracking is found during any inspection required by 
this AD, and the service bulletin specifies to contact Boeing for 
appropriate action: Before further flight, repair in accordance with 
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 an Authorized Representative (AR) for 
the Boeing DOA Organization 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.

Parts Installation

    (j) As of the effective date of this AD: With the exception of a 
new support fitting of the MLG; (i.e., a fitting that has been 
reworked or replaced as required by paragraph (g) of this AD), all 
retaining pin lugs of the support fitting, and bolt holes of the 
lugs must be inspected in accordance with this AD before being 
installed on any airplane.

Alternative Methods of Compliance (AMOCs)

    (k)(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 corrective actions per data meeting the type certification 
basis of the airplane approved by a Boeing DOA Organization AR 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 reference this AD.

Material Incorporated by Reference

    (l) You must use Boeing Special Attention Service Bulletin 737-
57-1267, dated August 8, 2002; Boeing Service Bulletin 737-57-1216, 
Revision 2, dated May 6, 1999; and Boeing Service Bulletin 737-
57A1260, Revision 2, dated October 18, 2001; as applicable, to 
perform the actions that are required by this AD, unless the AD 
specifies otherwise. The Director of the Federal Register approves 
the incorporation by reference of these documents in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. To get copies of the service 
information, contact Boeing Commercial Airplanes, P.O. Box 3707, 
Seattle, Washington 98124-2207. To view an AD docket, go to the 
Docket Management Facility, U.S. Department of Transportation, 400 
Seventh Street, SW., room PL-401, Nassif Building, Washington, DC. 
To review copies of the service information, go to the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at the NARA, call (202) 741-6030, or 
go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.


[[Page 52902]]


    Issued in Renton, Washington, on August 24, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-17461 Filed 9-2-05; 8:45 am]
BILLING CODE 4910-13-P

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