[Federal Register Volume 64, Number 229 (Tuesday, November 30, 1999)]
[Rules and Regulations]
[Pages 66765-66767]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30946]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-332-AD; Amendment 39-11445; AD 99-25-02]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-100, -200, -300, -400,
and -500 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 737-100, -200, -300, -400, and -500
series airplanes. This action requires a one-time inspection to verify
correct installation of the fastener that connects the input rod of the
spoiler mixer mechanism to the torque tube crank, and corrective
actions, if necessary. For certain airplanes, this action requires
replacement of the nut, bolt, and cotter pin that connects the input
rod of the spoiler mixer mechanism to the torque tube crank with a new
or serviceable nut, bolt, and cotter pin. This amendment is prompted by
reports indicating numerous discrepancies in the installation of the
fastener that connects the input rod of the spoiler mixer mechanism to
the torque tube crank. The actions specified in this AD are intended to
prevent the linkage between the ratio changer input rod and the aft
aileron control quadrant from becoming disconnected, which could result
in reduced controllability of the airplane.
DATES: Effective December 15, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of December 15, 1999.
Comments for inclusion in the Rules Docket must be received on or
before January 31, 2000.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-332-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
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: Robert C. Jones, Aerospace Engineer,
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue
SW., Renton, Washington 98055-4056; telephone (425) 227-1118; fax (425)
227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received reports indicating
numerous discrepancies in the installation of the fastener that
connects the input rod of the spoiler mixer mechanism to the torque
tube crank on Boeing Model 737-100, -200, -300, -400, and -500 series
airplanes. These discrepancies include the use of incorrect hardware,
the lack of secondary means of retention, and the incorrect (inverted)
installation of the bolt. Additionally, the airplane manufacturer has
indicated that the torque values specified, in a previously issued
service bulletin, for the nut and bolt of the fastener in the spoiler
mixer mechanism were too high. The previously specified torque values
could cause the nut and bolt to fail, which could result in a
disconnection of the linkage between the ratio changer input rod and
the aft aileron control quadrant. This condition, if not corrected,
could result in reduced controllability of the airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
737-27A1213, Revision 1, dated May 21, 1998, which describes procedures
for a one-time visual inspection to verify
[[Page 66766]]
correct installation of the fastener that connects the input rod of the
spoiler mixer mechanism to the torque tube crank, and corrective
actions, if necessary. The corrective actions involve either re-
installation of the existing fastener, or replacement of the fastener
with a new or serviceable fastener.
For certain airplanes on which the initial issue of the alert
service bulletin has been accomplished, the alert service bulletin
describes procedures for replacement of the nut, bolt, and cotter pin
that connects the input rod of the spoiler mixer mechanism to the
torque tube crank with a new or serviceable nut, bolt, and cotter pin.
Accomplishment of the actions specified in the alert 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 the linkage between the ratio changer input rod
and the aft aileron control quadrant from becoming disconnected, which
could result in reduced controllability of the airplane. The actions
are required to be accomplished in accordance with the alert service
bulletin described previously, except as discussed below. This AD also
requires that operators report certain results of the one-time
inspections to the FAA.
Differences Between AD and Alert Service Bulletin
Operators should note that the Boeing alert service bulletin
recommends that the inspection to verify correct installation of the
fastener that connects the input rod of the spoiler mixer mechanism to
the torque tube crank be performed at the operator's earliest
maintenance opportunity. However, the FAA has determined that such an
interpretive compliance time may not address the identified unsafe
condition in a timely manner. In developing appropriate compliance
times for this AD, the FAA considered not only the manufacturer's
recommendation, but the degree of urgency associated with addressing
the subject unsafe condition, the average utilization of the affected
fleet, the accessibility of the area to be inspected, the time
necessary to accomplish the inspection (approximately 1 hour), and the
time necessary to accomplish the replacement (approximately 1 hour). In
light of all these factors, the FAA finds that inspecting to verify
correct installation of the fastener in the spoiler mixer mechanism
within a 90-day compliance time is warranted, in that it represents an
appropriate interval of time allowable for affected airplanes to
continue to operate without compromising safety.
Operators also should note that the Boeing alert service bulletin
specifies the effectivity to be Boeing Model 737-100, -200, -300, -400,
and -500 series airplanes having line numbers 1 through 2681. However,
the FAA has determined that this effectivity would not address all the
affected airplanes on which the identified unsafe condition is likely
to exist or develop. Therefore, the applicability of this AD includes
all Boeing Model 737-100, -200, -300, -400, and -500 series airplanes.
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.
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 99-NM-332-AD.'' The postcard will be date stamped and
returned to the commenter.
Regulatory Impact
The regulations adopted herein will not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
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.
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.
[[Page 66767]]
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
99-25-02 Boeing: Amendment 39-11445. Docket 99-NM-332-AD.
Applicability: All Model 737-100, -200, -300, -400, and -500
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 (c) 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 the linkage between the ratio changer input rod and
the aft aileron control quadrant from becoming disconnected, which
could result in reduced controllability of the airplane; accomplish
the following:
Detailed Visual Inspection
(a) Within 90 days after the effective date of this AD,
accomplish the actions required by paragraph (a)(1) or (a)(2) of
this AD, as applicable, in accordance with Boeing Alert Service
Bulletin 737-27A1213, Revision 1, dated May 21, 1998.
(1) For airplanes on which Boeing Alert Service Bulletin 737-
27A1213, dated April 23, 1998, has not been accomplished: Perform a
one-time detailed visual inspection to verify correct installation
of the fastener that connects the input rod of the spoiler mixer
mechanism to the torque tube crank, in accordance with Revision 1 of
the alert service bulletin.
Note 2: 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.''
(i) If the fastener that connects the input rod of the spoiler
mixer mechanism to the torque tube crank is installed correctly, no
further action is required by this AD.
(ii) If the fastener that connects the input rod of the spoiler
mixer mechanism to the torque tube crank is not installed correctly,
prior to further flight, either re-install the existing fastener, or
install a new or serviceable fastener, in accordance with Revision 1
of the alert service bulletin.
(2) For airplanes on which Boeing Alert Service Bulletin 737-
27A1213, dated April 23, 1998, has been accomplished: Replace the
nut, bolt, and cotter pin that connects the input rod of the spoiler
mixer mechanism to the torque tube crank with a new or serviceable
nut, bolt, and cotter pin in accordance with Revision 1 of the alert
service bulletin.
Reporting Requirement
(b) Within 10 days after accomplishing the actions required by
paragraph (a)(1) of this AD, submit a report of any findings of
fasteners that connect the input rod of the spoiler mixer mechanism
to the torque tube crank that require corrective action to the
Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington
98055-4056; fax (425) 227-1181. 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
(c) 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, 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 3: 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
(d) 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
(e) The actions shall be done in accordance with Boeing Alert
Service Bulletin 737-27A1213, Revision, 1, dated May 21, 1998. 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.
(f) This amendment becomes effective on December 15, 1999.
Issued in Renton, Washington, on November 22, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-30946 Filed 11-29-99; 8:45 am]
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