[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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