[Federal Register Volume 69, Number 186 (Monday, September 27, 2004)]
[Rules and Regulations]
[Pages 57632-57636]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-21271]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-90-AD; Amendment 39-13804; AD 2004-19-10]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 737-100, -200, -200C, -300, -400, 
and -500 series airplanes, that requires repetitive inspections for 
corrosion and cracking of the pivot hinge pins of the horizontal 
stabilizer, certain follow-on inspections, and replacement of the hinge 
pins with new or serviceable pins if necessary. This action is 
necessary to prevent failure of the outer and inner hinge pins due to 
corrosion or cracking, which could allow the pins to migrate out of the 
joint and result in intermittent movement of the horizontal stabilizer 
structure and consequent loss of controllability of the airplane. This 
action is intended to address the identified unsafe condition.

DATES: Effective November 1, 2004.
    The incorporation by reference of a certain publication listed in 
the regulations is approved by the Director of the Federal Register as 
of November 1, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

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.

[[Page 57633]]


SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes was published in the 
Federal Register on December 8, 2003 (68 FR 68301). That action 
proposed to require repetitive inspections for corrosion and cracking 
of the pivot hinge pins of the horizontal stabilizer, certain follow-on 
inspections, and replacement of the hinge pins with new or serviceable 
pins if necessary.

Clarification of Changes to the Proposed AD

    Although paragraph (a) of the proposed AD specifies repetitive 
inspections, paragraph (a)(1) specifies that if the hinge pins are 
serviceable, ``no further action is required.'' We have removed the 
phrase ``no further action is required by this paragraph'' from 
paragraph (a)(1) of the proposed AD to clarify that the repetitive 
inspections are still required.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Comments That Resulted in a Change to the Proposed AD

Requests To Add Certain Repair Approvals

    Two commenters request that paragraphs (b)(6), (d)(6), (f)(6), and 
(h)(6) of the proposed AD be revised to add an additional method of 
repair. The proposed AD specifies that, for a pin found corroded in an 
area that is not threaded or in a thread relief radius, operators must 
repair, before further flight, per a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO). Both commenters request 
that a method of repair, such as pin replacement, be provided as an 
additional repair approval prior to releasing the AD. The commenters 
request such an additional method of repair approval in order to 
preclude the possibility of long delays in obtaining approval of a 
repair from the Manager, Seattle ACO.
    Another commenter requests that the same paragraphs discussed in 
the previous paragraph be revised to allow operators to obtain repair 
approval from a Boeing Company Designated Engineering Representative 
(DER), who has been authorized by the Manager, Seattle ACO, to make 
such findings.
    The FAA agrees with the commenters that those additional methods of 
repair approval may be provided for in this AD. Therefore, we have 
revised paragraphs (b)(6), (d)(6), (f)(6), and (h)(6) of the final rule 
accordingly.

Requests To Clarify Certain Inspections

    One commenter requests that we revise paragraphs (b) and (f) of the 
proposed rule to specify that the inspections required by those 
paragraphs can be accomplished per either Part 2 or Part 3 of the 
service bulletin. The commenter states that the hinge pin (outer) and 
pin insert (inner) can be removed at the same time from the airplane as 
an assembly. The commenter concludes that, in the case of the Model 
737-200 series airplanes, the only difference is whether to perform the 
magnetic particle inspection of the outer pin when the outer pin is 
already out. Additionally, the commenter states that, although the Part 
3 inspection is more comprehensive than the Part 2 inspection, it 
implicitly satisfies the requirement. Another commenter requests that 
the FAA clarify if operators are given the choice of using either Part 
2 or Part 3, and if so, are both inspections still required at the same 
compliance times specified in the proposed AD.
    We agree with the commenters that clarification for paragraphs (b) 
and (f) is necessary. We have revised those paragraphs to specify that 
the required inspections may be accomplished per the procedures 
specified in either Part 2 or Part 3 of the Accomplishment Instruction 
of the specified service bulletin. We point out, however, that the 
repetitive inspection intervals specified for paragraphs (c) and (g) of 
the AD remain the same as specified in the proposed rule, regardless of 
whether the inspections are performed per Part 2 or Part 3 of the 
Accomplishment Instructions of the service bulletin.

Comments That Resulted in No Change to the Proposed AD

Requests To Extend the Compliance Time

    One commenter requests that the initial compliance time of ``within 
90 days after the effective date of this AD'' for the detailed 
inspection specified by paragraph (a) of the proposed AD be extended to 
180 days. The commenter states that the additional time is necessary to 
obtain spare parts. The commenter notes that revising the initial 
inspection compliance time to 180 days would be consistent with the 
180-day interval for the repetitive inspections. Another commenter 
requests that the compliance times for the inspections per Part 3 be 
extended to 15,000 flight hours or 96 months for Model 737-200 series 
airplanes and 18,000 flight hours or 96 months for the Model 737-400 
series airplanes. The commenter states that those compliance times 
would coincide with its ``D'' check and ``SI'' check intervals.
    Two commenters request that the compliance times specified in the 
proposed AD be adjusted to allow for anticipated part shortages. The 
commenters both note that replacement hinge pins that may have to be 
replaced are ``under management control by Boeing.'' One commenter 
explains that ``under management control'' means there is a very 
limited supply of spare hinge pins to support industry inspections.
    Another commenter requests that the flight-hour intervals specified 
in paragraphs (d) and (h) of the proposed AD be increased from 12,000 
flight hours and 16,000 flight hours, respectively, to 15,000 flight 
hours and 18,000 flight hours, respectively. The commenter specifies 
that such an extension would coincide with its normal schedule for 
heavy maintenance. The commenter provided no further justification for 
such extension of the repetitive inspection intervals.
    We do not agree with the commenters' requests. We have determined 
that the identified unsafe condition warrants a compliance time of 
``within 90 days after the effective date of the AD.'' We note that the 
manufacturer recommends a compliance time of ``within 90 days of the 
release of the service bulletin release date,'' which was December 6, 
2001. We have been informed by Boeing that parts should be available. 
If a shortage of the supply of hinge pins does occur, paragraph (j) of 
this AD provides affected operators the opportunity to apply for an 
alternative method of compliance (AMOC) and to present data to justify 
the adjustment of compliance times.
    We also do not agree with the commenters' request to extend the 
threshold compliance times for accomplishment of the requirements of 
Part 3 of the Boeing alert service bulletin. No technical justification 
was provided to substantiate this request.

Request To Delay Issuance of the Final Rule

    One commenter notes that Boeing Alert Service Bulletin 737-55A1077 
Information Notice (IN) 01, dated September 11, 2003, was not 
referenced in the proposed AD. The commenter states that the IN has 
revised wording of

[[Page 57634]]

the original service bulletin to correct certain errors. The commenter 
points out that having such differences between the proposed AD and the 
new service information could create confusion and potential compliance 
problems. The commenter requests revision of Boeing Service Bulletin 
737-55A1077 by the manufacturer and approval by the FAA prior to the 
release of the AD.
    We do not agree with the commenter's request. The IN was a minor 
clarification that has already been addressed by this AD as noted in 
the ``Differences'' section in the preamble of the notice of proposed 
rulemaking (NPRM). Delaying this action until after the release and 
approval of the manufacturer's planned service bulletin is not 
warranted. We have determined that the inspections must be conducted to 
ensure continued operational safety. When a new revision of the service 
bulletin has been developed, we will review that revision and consider 
approving it as an alternative method of compliance with the 
requirements of this AD.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 3,132 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,250 airplanes of U.S. 
registry will be affected by this AD, that it will take approximately 1 
work hour per airplane to accomplish the detailed inspection specified 
in paragraph (a) of this AD, and that the average labor rate is $65 per 
work hour. Since the requirements of paragraph (a) of this AD apply to 
the total affected fleet, the cost impact of the inspections required 
by paragraph (a) of this AD on U.S. operators is estimated to be 
$81,250, or $65 per airplane, per inspection cycle.
    It will take approximately 6 work hours per airplane, per 
inspection, to accomplish the detailed and magnetic particle 
inspections described in Part 2 of the Accomplishment Instructions of 
the specified alert service bulletin. We estimate that if all airplanes 
were required to accomplish those inspections, the estimated cost 
impact of the affected airplanes will be $487,500 or $390 airplane, per 
inspection cycle.
    It will take approximately 12 work hours per airplane, per 
inspection, to accomplish the detailed and magnetic particle 
inspections described in Part 3 of the Accomplishment Instructions of 
the specified alert service bulletin. We estimate that if all airplanes 
were required to accomplish those inspections, the estimated cost 
impact of the affected airplanes will be $975,000, or $780 per 
airplane, per inspection cycle.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

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.
    For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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

0
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

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. Section 39.13 is amended by adding the following new airworthiness 
directive:

Boeing: Amendment 39-13804. Docket 2003-NM-90-AD.

    Applicability: Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes having line numbers 1 through 3132 inclusive; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the outer and inner hinge pins due to 
corrosion or cracking, which could allow the pins to migrate out of 
the joint and result in intermittent movement of the horizontal 
stabilizer structure and consequent loss of controllability of the 
airplane, accomplish the following:
    (a) For all airplanes: Within 90 days after the effective date 
of this AD, perform a detailed inspection of the pivot hinge pin 
joints for corrosion and, with hand pressure, check for movement of 
the hinge pins within the joints of the horizontal stabilizer, per 
Part 1 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin (ASB) 737-55A1077, dated December 6, 2001. Repeat the 
detailed inspections and check at intervals not to exceed 180 days 
until the initial inspection specified in paragraph (b), (d), (f), 
or (h) of this AD, as applicable, is performed.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive 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.''

    (1) If no corrosion is found, and if the hinge pins cannot be 
moved with hand pressure, the hinge pins are serviceable.
    (2) If any pin can be moved with hand pressure, before further 
flight, remove and inspect both pins on the left and right sides and 
perform follow-on corrective actions per Part 3 of the 
Accomplishment Instructions of the ASB.
    (3) If any corrosion is found, before further flight, remove and 
perform a detailed inspection of the pin(s) per Figure 2 (inner pin) 
or Figure 3 (inner and outer pins), as applicable, of the 
Accomplishment Instructions of the ASB; and perform follow-on 
corrective actions, per the Accomplishment Instructions of the ASB.
    (b) For Models 737-100, -200, and 200C series airplanes: Within 
3,000 flight hours or

[[Page 57635]]

24 months after the effective date of this AD, whichever occurs 
first, perform a detailed inspection and magnetic particle 
inspection for corrosion and cracking of the horizontal stabilizer 
hinge pins, per Part 2 or Part 3 of the Accomplishment Instructions 
of Boeing ASB 737-55A1077, dated December 6, 2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (b)(3) 
and (b)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is damage free, before further flight, 
replace the outer pin with a new or serviceable pin, per the 
Accomplishment Instructions of the ASB.
    (3) If an outer pin is cracked in the area that includes the 
straight shank or the head, before further flight, replace both the 
inner and outer pins with new or serviceable pins, per the 
Accomplishment Instructions of the ASB.
    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pins with new or 
serviceable pins, per the Accomplishment Instructions of the ASB.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin, per the 
Accomplishment Instructions of the ASB.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, accomplish the requirements of paragraph (b)(6)(i) 
or (b)(6)(ii) of this AD.
    (i) Replace the pin with a new or serviceable pin, per the ASB.
    (ii) 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 FAA to make such findings. For a repair method to 
be approved, the approval must specifically reference this AD.
    (c) For Models 737-100, -200, -200C series airplanes: 
Thereafter, repeat the inspections required by paragraph (b) of this 
AD at the times specified in paragraph (c)(1) or (c)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, repeat the 
inspection at intervals not to exceed 6,000 flight hours or 48 
months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
grease (Mastinox 6856K), repeat the inspections at intervals not to 
exceed 3,000 flight hours or 24 months, whichever occurs first.
    (d) For Models 737-100, -200, and -200C series airplanes: Within 
12,000 flight hours or 96 months after the effective date of this 
AD, whichever occurs first, perform a detailed inspection and 
magnetic particle inspection for corrosion and cracking of the 
horizontal stabilizer hinge pins, per Part 3 of the Accomplishment 
Instructions of Boeing ASB 737-55A1077, dated December 6, 2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (d)(3) 
and (d)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is damage free, before further flight, 
replace the outer pin with a new or serviceable pin, per the 
Accomplishment Instructions of the ASB.
    (3) If an outer pin is cracked in the area that includes the 
straight shank and the head, before further flight, replace both the 
inner and outer pins with new or serviceable pins, per the 
Accomplishment Instructions of the ASB.
    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pins with new or 
serviceable pins, per the Accomplishment Instructions of the ASB.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin, per the 
Accomplishment Instructions of the ASB.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, accomplish the actions specified in paragraph 
(d)(6)(i) or (d)(6)(ii) of this AD.
    (i) Replace the pin with a new or serviceable pin, per the ASB.
    (ii) 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 FAA to make such findings. For a repair method to 
be approved, the approval must specifically reference this AD.
    (e) For Models 737-100, -200, -200C series airplanes: 
Thereafter, repeat the inspections required by paragraph (d) of this 
AD at the times specified in paragraph (e)(1) or (e)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, thereafter, 
repeat the inspections at intervals not to exceed 12,000 flight 
hours or 96 months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
grease (Mastinox 6856K), thereafter, repeat the inspections at 
intervals not to exceed 6,000 flight hours or 48 months, whichever 
occurs first.
    (f) For Model 737-300, -400, and -500 series airplanes: Within 
4,000 flight hours or 24 months from the effective date of this AD, 
whichever occurs first, perform a detailed inspection and magnetic 
particle inspection for corrosion and cracking of the horizontal 
stabilizer hinge pins, per Part 2 or Part 3 of the Accomplishment 
Instructions of Boeing ASB 737-55A1077, dated December 6, 2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (f)(3) 
and (f)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is free of damage, before further flight, 
replace the outer pin with a new or serviceable pin, per the 
Accomplishment Instructions of the ASB.
    (3) If an outer pin is cracked in the area that includes the 
straight shank or the head, before further flight, replace both the 
inner and outer pins with new or serviceable pins, per the 
Accomplishment Instructions of the ASB.
    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pins with new or 
serviceable pins, per the Accomplishment Instructions of the ASB.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin, per the 
Accomplishment Instructions of the ASB.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, accomplish the actions of paragraph (f)(6)(i) or 
(f)(6)(ii) of this AD.
    (i) Replace the pin with a new or serviceable pin, per the ASB.
    (ii) 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 FAA to make such findings. For a repair method to 
be approved, the approval must specifically reference this AD.
    (g) For Model 737-300, -400, and -500 series airplanes: 
Thereafter, repeat the inspections required by paragraph (f) of this 
AD at the times specified in paragraph (g)(1) or (g)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, thereafter, 
repeat the inspections at intervals not to exceed 8,000 flight hours 
or 48 months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
(Mastinox 6856K), repeat the inspections at intervals not to exceed 
4,000 flight hours or 24 months, whichever occurs first.
    (h) For Model 737-300, -400, and -500 series airplanes: Within 
16,000 flight hours or 96 months from the effective date of this AD, 
whichever occurs first, perform a detailed inspection and magnetic 
particle inspection for corrosion or cracking of the horizontal 
stabilizer hinge pins per Part 3 of the Accomplishment Instructions 
of Boeing ASB 737-55A1077, dated December 6, 2001.
    (1) If no corrosion or cracking is found, before further flight, 
reinstall the pin unless the condition of the other pin in that 
joint requires that both pins be replaced. (See paragraphs (h)(3) 
and (h)(4) of this AD.)
    (2) If an outer pin is cracked in the area that includes the 
tapered shank, the adjacent thread relief radius, or the threaded 
end, but the inner pin is damage free, before further flight, 
replace the outer pin with a new or serviceable pin.
    (3) If an outer pin is cracked in the area that includes the 
straight shank or the head, before further flight, replace both the 
inner and outer pin with new or serviceable pins.

[[Page 57636]]

    (4) If any cracks are found on an inner pin, before further 
flight, replace both the inner and outer pin with new or serviceable 
pins.
    (5) On any pin, if corrosion is found on a threaded area or in 
the thread relief radius adjacent to the threads, before further 
flight, replace the pin with a new or serviceable pin.
    (6) If any corrosion is found on an area of the pin that is not 
threaded or in a thread relief radius adjacent to threads, before 
further flight, accomplish the actions specified in paragraph 
(h)(6)(i) or (h)(6)(ii) of this AD.
    (i) Replace the pin with a new or serviceable pin, per the ASB.
    (ii) 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 FAA to make such findings. For a repair method to 
be approved, the approval must specifically reference this AD.
    (i) For Model 737-300, -400, and -500 series airplanes: 
Thereafter, repeat the inspections required by paragraph (h) of this 
AD at the times specified in paragraph (i)(1) or (i)(2) of this AD, 
as applicable.
    (1) If BMS 3-27 grease (Mastinox 6856K) is used, thereafter, 
repeat the inspections at intervals not to exceed 16,000 flight 
hours or 96 months, whichever occurs first.
    (2) If BMS 3-33 grease is used as a substitute for BMS 3-27 
(Mastinox 6856K), thereafter, repeat the inspections at intervals 
not to exceed 8,000 flight hours or 48 months, whichever occurs 
first.

Alternative Methods of Compliance

    (j)(1) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office (ACO), FAA, is authorized to approve 
alternative methods of compliance (AMOCs) for this AD.
    (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 a 
Boeing Company Designated Engineering Representative who has been 
authorized by the Manager, Seattle ACO, to make those findings. For 
a repair method to be approved, the approval must specifically 
reference this AD.

Incorporation by Reference

    (k) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 737-55A1077, 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 Airplanes, 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 National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Effective Date

    (l) This amendment becomes effective on November 1, 2004.

    Issued in Renton, Washington, on September 15, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-21271 Filed 9-24-04; 8:45 am]
BILLING CODE 4910-13-P