AD 2001-06-15

[Federal Register Volume 66, Number 63 (Monday, April 2, 2001)]
[Rules and Regulations]
[Pages 17487-17490]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-7733]



[[Page 17487]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-312-AD; Amendment 39-12162; AD 2001-06-15]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, -700C, and 
-800 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 737-600, -700, -700C, and -800 
series airplanes, that requires inspections of the fasteners in the 
elevator balance panel assemblies to detect various discrepancies; and 
corrective actions, if necessary. This amendment is prompted by a 
report that an elevator balance panel was found disconnected from the 
horizontal stabilizer due to the improper installation of fasteners 
during production. The actions specified by this AD are intended to 
prevent jamming, restricting, or binding of the elevator control 
surfaces due to loose or missing fasteners, which could make the 
movement of the elevator difficult and decrease aerodynamic control of 
the airplane.

DATES: Effective May 7, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 7, 2001.

ADDRESSES: 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 Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 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: Scott Fung, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1221; fax (425) 227-1181.

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 737-600, -
700, and -800 series airplanes was published in the Federal Register on 
September 18, 2000 (65 FR 56266). That action proposed to require 
inspections of the fasteners in the elevator balance panel assemblies 
to detect various discrepancies; and corrective actions, if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Several comments were received from a 
single commenter, and due consideration has been given to these 
comments.

Request To Reference New Service Bulletin

    The commenter requests that the FAA revise the proposed rule to 
reference Boeing Service Bulletin 737-55A1064, Revision 1, dated 
December 7, 2000, as the appropriate source of service information for 
the actions required by this AD. (The proposed rule referenced the 
original issue of Boeing Service Bulletin 737-55A1064, dated October 
15, 1998, as the appropriate source of service information.) The 
commenter points out that Revision 1 of the service bulletin clarifies 
some accomplishment instructions in the original issue of the service 
bulletin.
    The FAA concurs with the commenter's request to revise the proposed 
rule to reference Revision 1 of the service bulletin. The FAA finds 
that the procedures described in Revision 1 are essentially similar to 
those described in the original issue, though some information has been 
clarified. In addition, Revision 1 specifies procedures for disposition 
of certain repair conditions that were omitted in the original issue. 
(This omission was described in the preamble of the proposed rule as a 
difference between the proposed rule and the service bulletin.)
    The FAA concurs with the commenter's request to reference Revision 
1 of the service bulletin in this final rule, and has revised 
paragraphs (a) and (b) of the final rule accordingly. Also, because the 
procedures are essentially the same as the original issue, the FAA has 
included a new ``Note 2'' in the final rule (and renumbered subsequent 
notes accordingly) to state that actions accomplished per the original 
issue of the service bulletin before the effective date of this AD are 
acceptable for compliance with this AD.

Request To Revise Repetitive Interval in Paragraph (a)(1)

    The commenter also requests that the FAA revise the repetitive 
interval stated in paragraph (a)(1) of the proposed rule to be 
consistent with the interval provided in the service bulletin. 
Paragraph (a)(1) states a repetitive interval of 250 flight hours, 
which applies if no discrepancies (inadequate grip length; gaps between 
the bolt head, washer, and structures; missing fasteners) are found 
during the inspection in paragraph (a). For this same condition, 
paragraph 1.E. ``Compliance'' in the service bulletin, states a 
repetitive interval of 250 flight cycles.
    The FAA concurs with the commenter's request to revise the 
compliance time in paragraph (a)(1) from 250 flight hours to 250 flight 
cycles. The FAA's intent was for the repetitive intervals in this AD to 
correspond to those in the service bulletin for airplanes on which no 
discrepancies were found. Paragraph (a)(1) of this final rule has been 
revised accordingly.

Request To Revise Compliance Time in Paragraph (b)

    The commenter requests that the FAA revise the compliance time 
stated in paragraph (b) to be consistent with the compliance time given 
in the service bulletin. Paragraph (b) specifies accomplishment of the 
actions in that paragraph at intervals not to exceed 3,000 flight 
cycles or 18 months after the effective date of this AD, whichever 
occurs later. The commenter points out that the service bulletin 
specifies a compliance time of 3,000 flight cycles or 18 months, 
whichever is first. The commenter states that the alternatives given in 
the service bulletin are intended to ensure that these requirements are 
done in a timely manner on airplanes that have a low number of flight 
cycles.
    The FAA concurs with the commenter's request. It was the FAA's 
intent for the compliance time in paragraph (b) to correspond to that 
provided in the service bulletin. However, paragraph (b) in the 
proposal inadvertently specified ``whichever occurs later,'' when it 
should have said ``whichever occurs first.'' Also, though the proposed 
rule stated a compliance time of 3,000 flight cycles or 18 months after 
the effective date of this AD, the service bulletin provides a 
compliance time of 3,000 flight cycles or 18 months (whichever is 
first) after the first inspection of the fasteners. The FAA finds that 
the compliance time specified

[[Page 17488]]

in the service bulletin, though it is somewhat longer than the 
compliance time stated in the proposed rule, is adequate to ensure the 
continued safety of the affected airplanes and to ensure that the 
actions required by paragraph (b) of this AD will be completed in a 
timely manner. Paragraph (b) in this final rule has been revised 
accordingly.

Request To Revise Paragraph (b)(3)

    The commenter requests that the FAA revise paragraph (b)(3) of the 
proposed rule to remove the requirement to install a new nut plate ``in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or in accordance with data meeting the 
type certification basis of the airplane approved by a Boeing Company 
Designated Engineering Representative (DER) who has been authorized by 
the Manager, Seattle ACO, to make such findings.'' The commenter states 
that replacement of worn nut plates with new nut plates is a standard 
maintenance procedure, and requiring replacement of nut plates as 
specified in paragraph (b)(3) of the proposal would place an undue 
burden on operators by forcing them to request an alternative method of 
compliance for a standard maintenance operation.
    The FAA concurs with the commenter's request to revise paragraph 
(b)(3) of the proposal, and has revised that paragraph accordingly in 
this final rule. However, the FAA finds that it is necessary to clarify 
its intention. As stated before, the FAA noted in the ``Differences 
Between Proposed Rule and Service Bulletin'' section of the preamble of 
the proposal that the service bulletin did not specify procedures for 
disposition of certain repair conditions. The FAA intended to include 
the instruction to repair per a method approved by the FAA or per data 
approved by a Boeing Company DER to provide for conditions where the 
service bulletin did not include instructions. However, this 
instruction was inappropriately placed into paragraph (b)(3) of the 
proposed rule, so that it applied to replacement of the nut plate, 
rather than other repair conditions.
    As described above, since the issuance of the proposed AD, Revision 
1 of the service bulletin has been issued to specify procedures for 
disposition of certain repair conditions that were omitted in the 
original issue. While the procedures in the service bulletin specify to 
contact Boeing for repair procedures, the FAA finds it necessary to 
require such repairs to be done per a method approved by the FAA, or 
per data approved by a Boeing Company DER. Accordingly, the reference 
to repairing per the FAA or per data approved by a Boeing Company DER 
has been moved from its location in paragraph (b)(3) of the proposal to 
a new paragraph (b)(5) in this final rule. Because the FAA clearly 
expressed its intent in the proposed rule to include such a provision 
in this AD, the FAA finds that this change results in no additional 
burden on operators, and may in fact be relieving to certain operators, 
because the original issue of the service bulletin did not provide 
repair procedures.

Explanation of Additional Change to Paragraph (b)

    For certain conditions, paragraphs (a)(1) and (a)(2) of the 
proposed rule refer to the accomplishment of the requirements of 
paragraph (b) ``prior to further flight.'' However, paragraph (b) of 
the proposal includes a separate compliance time. The FAA finds that, 
without clarification, these two compliance times could be potentially 
confusing for operators. Therefore, the FAA has revised paragraph (b) 
of this final rule to include the provision ``Except as provided by 
paragraphs (a)(1) and (a)(2) of this AD,'' to restrict the compliance 
time for paragraph (b) for those operators that accomplish paragraph 
(b) ``prior to further flight'' per paragraph (a)(1) or (a)(2).

Explanation of Change to Applicability

    For clarification, the FAA has revised the applicability of this 
final rule to specifically identify Boeing Model 737-700C series 
airplanes. While the service bulletin does not specify that Model 737-
700C series airplanes are subject to the actions in the service 
bulletin, the list of affected line numbers includes the line numbers 
of certain Model 737-700C series airplanes.

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 123 Model 737-600, -700, -700C, and -800 
series airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 52 airplanes of U.S. registry will be affected by this 
AD, that it will take approximately 11 work hours per airplane 
(including access and close-up hours) to accomplish the required 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the cost impact of this AD on U.S. operators is 
estimated to be $34,320, or $660 per airplane.
    The cost impact figure discussed above is 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

    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:

[[Page 17489]]

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:

2001-06-15  Boeing: Amendment 39-12162. Docket 99-NM-312-AD.

    Applicability: Model 737-600, -700, -700C, and -800 series 
airplanes, as listed in Boeing Alert Service Bulletin 737-55A1064, 
Revision 1, dated December 7, 2000; 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 (d) 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 jamming, restricting, or binding of the elevator 
control surfaces due to loose or missing fasteners; which could make 
the movement of the elevator difficult and decrease aerodynamic 
control of the airplane; accomplish the following:

Inspections of Fasteners, and Corrective Action, if Necessary

    (a) Within 250 flight hours or 30 days after the effective date 
of this AD, whichever occurs first, perform a detailed visual 
inspection of the fasteners in the elevator balance panel to detect 
inadequate grip length, gaps between the bolt head, washer, and 
structure, and missing fasteners, in accordance with paragraph 3.A. 
of the Accomplishment Instructions of Boeing Service Bulletin 737-
55A1064, Revision 1, dated December 7, 2000.

    Note 2: Accomplishment of the actions specified in Boeing 
Service Bulletin 737-55A1064, dated October 15, 1998, prior to the 
effective date of this AD is acceptable for compliance with the 
applicable actions required by this AD.


    Note 3: For the purposes of this AD, a detailed visual 
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.''

    (1) If adequate grip length is detected, if no gap is detected, 
and if no fastener is missing, repeat the inspection thereafter at 
intervals not to exceed 250 flight cycles until the requirements of 
paragraph (b) of this AD have been accomplished; or prior to further 
flight, accomplish the actions specified in paragraph (b) of this 
AD.
    (2) If inadequate grip length is detected, if any gap is 
detected, or if any fastener is missing, prior to further flight, 
accomplish the actions specified in paragraph (b) of this AD.

Inspection and Corrective Actions, if Necessary

    (b) Except as provided by paragraphs (a)(1) and (a)(2) of this 
AD, within 3,000 flight cycles or 18 months after the first 
inspection in accordance with paragraph (a) of this AD, whichever 
occurs first: Perform a detailed visual inspection to detect missing 
fasteners at the locations specified in Figure 2 of Boeing Service 
Bulletin 737-55A1064, Revision 1, dated December 7, 2000, to detect 
inadequate grip length, and to determine the locking torque of the 
nut plates specified in Figure 2 of the service bulletin. These 
actions shall be done in accordance with paragraph 3.B. (``Fastener 
Inspection and Replacement'') of the Accomplishment Instructions of 
Boeing Service Bulletin 737-55A1064, Revision 1. Accomplishment of 
the inspection constitutes terminating action for the repetitive 
inspection requirements of paragraph (a)(1) of this AD.
    (1) If no loose (i.e., minimum locking torque of nut plate not 
achieved) fastener is detected, if no fastener is missing, and if 
adequate grip length is found, no further action is required by this 
paragraph.
    (2) If any fastener with an inadequate grip length is found, 
prior to further flight, replace the fastener with a new fastener in 
accordance with the service bulletin; and perform a detailed visual 
inspection of adjacent elevator and horizontal stabilizer structure 
to detect damage. If any damage is found on adjacent elevator or 
horizontal stabilizer structure, prior to further flight, repair or 
replace the damaged structure or component in accordance with the 
service bulletin.
    (3) If any nut plate is found to have inadequate locking torque, 
prior to further flight, install a new nut plate.
    (4) If any fastener is missing, prior to further flight, install 
a new fastener in accordance with the service bulletin; and perform 
a detailed visual inspection of adjacent elevator and horizontal 
stabilizer structure to detect damage. If any damage is found on 
adjacent elevator or horizontal stabilizer structure, prior to 
further flight, repair or replace the damaged structure or component 
in accordance with the service bulletin.
    (5) Where the service bulletin specifies to contact Boeing for 
repair procedures or does not specify repair procedures, before 
further flight, repair in accordance with a method approved by the 
Manager, Seattle Aircraft Certification Office (ACO), FAA; or in 
accordance with 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 by the 
Manager, Seattle ACO, as required by this paragraph, the Manager's 
approval letter must specifically reference this AD.

Reporting Requirement

    (c) Within 10 days after accomplishing any inspection required 
by paragraphs (a) and (b)--not including paragraph (b)(2)--of this 
AD, submit a report of the inspection results (positive findings 
only) to the Manager, Seattle Manufacturing Inspection District 
Office, ANM-108S, 2500 East Valley Road, Suite C-2, Renton, WA 
98055-4056; fax (425) 227-1159. Information collection requirements 
contained in this regulation have been approved by the Office of 
Management and Budget (OMB) under the provisions of the Paperwork 
Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been 
assigned OMB Control Number 2120-0056.

Alternative Methods of Compliance

    (d) 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

    (e) 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

    (f) Except as provided by paragraph (b)(5) of this AD, the 
actions shall be done in accordance with Boeing Service Bulletin 
737-55A1064, Revision 1, dated December 7, 2000. 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

    (g) This amendment becomes effective on May 7, 2001.


[[Page 17490]]


    Issued in Renton, Washington, on March 23, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-7733 Filed 3-30-01; 8:45 am]
BILLING CODE 4910-13-U