[Federal Register Volume 64, Number 164 (Wednesday, August 25, 1999)]
[Rules and Regulations]
[Pages 46259-46262]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-21954]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-179-AD; Amendment 39-11267; AD 99-18-01]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-700 and -800 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing Model 737-700 and -800 series
airplanes, that currently requires revising the Airplane Flight Manual
(AFM) to prohibit operation of the airplane under certain conditions;
repetitive inspections of the tab mast fitting of the elevator tab
assemblies to detect cracking; an elevator tab freeplay check; and
corrective actions, if necessary. That AD also provides for optional
terminating action for certain repetitive inspections, and requires
installing an additional fastener on the elevator tab mast fitting,
which terminates the AFM revision and extends certain repetitive
inspection intervals. This amendment continues to require certain
actions, and revises and adds certain other requirements. This
amendment is prompted by a report of a severe vibration incident on a
Boeing Model 737-800 series airplane; inspection revealed fracturing of
the elevator tab mast fitting and excessive freeplay in the elevator
tab. The actions specified in this AD are intended to prevent loss of
controllability of the airplane due to excessive freeplay in the
elevator tab or a free tab.
DATES: Effective September 9, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 9, 1999.
Comments for inclusion in the Rules Docket must be received on or
before October 25, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-179-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: Gregory L. Schneider, Aerospace
Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue,
SW., Renton, Washington 98055-4056; telephone (425) 227-2028; fax (425)
227-1181.
SUPPLEMENTARY INFORMATION: On June 22, 1999, the FAA issued AD 99-13-
51, amendment 39-11213 (64 FR 34976, June 30, 1999), applicable to
certain Boeing Model 737-700 and -800 series airplanes, to require
revising the Airplane Flight Manual (AFM) to prohibit operation of the
airplane under certain conditions; repetitive inspections of the tab
mast fitting of the elevator tab assemblies to detect cracking; an
elevator tab freeplay check; and corrective actions, if necessary. That
AD also provides for optional terminating action for certain repetitive
inspections. In addition, that AD requires installing an additional
fastener on the elevator tab mast fitting, which terminates the AFM
revision and extends certain repetitive inspections. That action was
prompted by a report of a severe vibration incident on a Boeing Model
737-800 series airplane; inspection revealed fracturing of the elevator
tab mast fitting and excessive freeplay in the elevator tab. The
actions required by that AD are intended to prevent reduced
controllability of the airplane due to excessive freeplay in the
elevator tab or a free tab.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the FAA has reviewed and approved
the following new service information:
Boeing Alert Service Bulletin 737-55A1068, Revision 1,
dated June 11, 1999, describes procedures similar to those described in
the original issue of that alert service bulletin, as cited in AD 99-
13-51. However, Revision 1 adds a close visual inspection (detailed
visual inspection) of the elevator tab mast fitting and revises certain
part numbers and references due to typographical errors in the original
issue of the alert service bulletin.
Boeing Service Bulletin 737-55-1063, dated July 1, 1999,
describes procedures for replacing a cracked elevator tab mast fitting
with a new, improved fitting. Such replacement eliminates the need for
repetitive
[[Page 46260]]
inspections of the elevator tab mast fittings.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of this same type design, this AD
supersedes AD 99-13-51 to continue to require revising the AFM to
prohibit operation of the airplane under certain conditions; repetitive
inspections of the tab mast fitting of the elevator tab assemblies to
detect cracking; an elevator tab freeplay check; and corrective
actions, if necessary. This AD also continues to provide for optional
terminating action only for certain repetitive inspections; and
installing an additional fastener on the elevator tab mast fitting,
which terminates the AFM revision and extends certain repetitive
inspection intervals. This amendment also provides optional terminating
action for the requirements of this AD.
It should be noted that, except as otherwise provided for in the
AFM emergency procedures, this AD prohibits the deployment of the
spoilers at speeds in excess of 310 knots indicated airspeed (IAS) with
speed brakes extended. This AD also prohibits the operation of the
airplane above FL 390. The FAA recognizes that under emergency
circumstances, as specified in the AFM, it might become necessary to
deploy spoilers in excess of 310 knots IAS. In that event, this AD
requires accomplishment of the high frequency eddy current (HFEC) and
detailed visual inspections of the elevator tab mast fittings and of
the check of the tabs for freeplay, prior to further flight after
landing.
Interim Action
This is considered to be interim action. The FAA is currently
considering requiring the currently optional terminating action
(replacement of the elevator tab mast fitting with a new, improved
fitting). However, the planned compliance time for the replacement is
sufficiently long so that notice and opportunity for prior public
comment will be practicable.
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-179-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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-11213 (64 FR
34976, June 30, 1999), and by adding a new airworthiness directive
(AD), amendment 39-11267, to read as follows:
99-18-01 Boeing: Amendment 39-11267. Docket 99-NM-179-AD.
Supersedes AD 99-13-51, Amendment 39-11213.
Applicability: Model 737-700 and -800 series airplanes having
line numbers 1 through 190, 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 (j) 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 loss of controllability of the airplane due to
excessive freeplay in the elevator tab or a free tab, accomplish the
following:
Airplane Flight Manual (AFM) Revision Required by AD 99-13-51
(a) Within 24 clock hours after July 6, 1999 (the effective date
of AD 99-13-51, amendment 39-11213), revise the Limitations Section
of the FAA-approved
[[Page 46261]]
AFM to include the following information. This may be accomplished
by inserting a copy of this AD into the AFM.
``Do not operate the airplane at speeds in excess of 310 knots
indicated airspeed (IAS) with speed brakes extended. Do not operate
the airplane above FL 390.''
Action in Event of Speed Brake Deployment
(b) In the event of deployment of the speed brakes at speeds in
excess of 310 knots IAS, prior to further flight after landing,
accomplish the requirements of paragraph (c) of this AD.
Inspection and Check Required by AD 99-13-51
(c) Within 10 days after July 6, 1999, perform a high frequency
eddy current (HFEC) inspection of the elevator tab mast fitting of
the left and right elevator tab assembly to detect cracking, and a
one-time elevator tab freeplay check to detect freeplay of the
elevator tab, in accordance with Boeing Alert Service Bulletin 737-
55A1068, dated June 9, 1999, or Revision 1, dated June 11, 1999.
(1) If no cracking is found in the elevator tab mast fitting,
repeat the HFEC inspection thereafter at intervals not to exceed 15
days, until accomplishment of the actions required by paragraph (g)
of this AD. After the effective date of this AD, only the HFEC and
detailed visual inspection required by paragraph (f) of this AD
shall be accomplished.
(2) If any cracking is found in the elevator tab mast fitting,
prior to further flight, accomplish the requirements of paragraph
(h) of this AD.
(3) If any freeplay is found that is outside the limits
specified in the alert service bulletin, prior to further flight,
perform corrective actions in accordance with the alert service
bulletin.
Note 2: Boeing Alert Service Bulletin 737-55A1068, dated June 9,
1999, references Boeing Model 737-600/-700/-800 Maintenance Manual
(AMM), Subjects 27-09-91, 27-31-00, and 51-21-99; 737 Nondestructive
Test (NDT) Manual D6-37239, Part 6, Subject 55-00-00; 737 Structural
Repair Manual (SRM) Subject 51-20-81; and Operations Manual Service
Bulletin D6-27370-TBC (``Elevator Tab Operational Limitations''),
dated June 10, 1999; as additional sources of service information to
accomplish certain requirements of this AD.
New AFM Revision
(d) Within 24 clock hours after the effective date of this AD,
revise the Limitations Section of the FAA-approved AFM to include
the following information. This may be accomplished by inserting a
copy of this AD into the AFM. Following accomplishment of this AFM
revision, remove the AFM revision required by paragraph (a) of this
AD from the Limitations Section of the FAA-approved AFM.
``Except as otherwise provided for in the AFM emergency
procedures, do not operate the airplane at speeds in excess of 310
knots indicated airspeed (IAS) with speed brakes extended. Do not
operate the airplane above FL 390.''
Action in Event of Speed Brake Deployment
(e) In the event of deployment of the speed brakes at speeds in
excess of 310 knots IAS, prior to further flight after landing,
accomplish the requirements of paragraph (f) of this AD.
Inspections and Check
Note 3: Accomplishment of the initial HFEC inspection and check
required by paragraph (c) of this AD, prior to the effective date of
this AD, in accordance with Boeing Alert Service Bulletin 737-
55A1068, dated June 9, 1999, is considered acceptable for compliance
with the HFEC inspection, detailed visual inspection, and one-time
freeplay check required by paragraph (f) of this AD.
(f) Within 10 days after the effective date of this AD, perform
an HFEC inspection and a detailed visual inspection of the elevator
tab mast fittings of the left and right elevator tab assemblies to
detect cracking, and a one-time elevator tab freeplay check to
detect freeplay of the elevator tabs, in accordance with Boeing
Alert Service Bulletin 737-55A1068, Revision 1, dated June 11, 1999.
Accomplishment of these actions terminates the inspections and
checks required by paragraph (c) of this AD.
(1) If no cracking is found in any elevator tab mast fitting,
repeat the HFEC and detailed visual inspections thereafter at
intervals not to exceed 15 days, until accomplishment of the actions
required by paragraph (g) of this AD.
(2) If any cracking is found in any elevator tab mast fitting,
prior to further flight, accomplish the replacement action required
by paragraph (h) of this AD.
(3) If any freeplay is found in any elevator tab, which is
outside the limits specified in the alert service bulletin, prior to
further flight, perform corrective actions in accordance with the
alert service bulletin.
Note 4: 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.''
Note 5: Boeing Alert Service Bulletin 737-55A1068, Revision 1,
dated June 11, 1999, references Boeing Model 737-600/-700/-800
Maintenance Manual (AMM), Subjects 27-09-91, 27-31-00, 27-31-34, and
51-21-99; 737 Nondestructive Test (NDT) Manual D6-37239, Part 6,
Subject 51-00-00; 737 Structural Repair Manual (SRM) Subjects 51-20-
01, 51-20-07, and 51-21-99; and 737-600/-700/-800 Operations Manual
Service Bulletin ``Elevator Tab Operational Limitations''; as
additional sources of service information to accomplish certain
requirements of this AD.
Time-Limited Modification
(g) Within 90 days after July 6, 1999, install an additional
high-strength fastener on the elevator tab mast fitting in
accordance with Boeing Alert Service Bulletin 737-55A1068, dated
June 9, 1999, or Boeing Alert Service Bulletin 737-55A1068, Revision
1, dated June 11, 1999. Accomplishment of this modification
constitutes terminating action for the requirements of paragraphs
(b), (c), and (e) of this AD. Following accomplishment of the
installation, the AFM revision required by paragraphs (a) and (d) of
this AD may be removed from the AFM. Following accomplishment of the
installation, repeat the HFEC and detailed visual inspection
required by paragraph (f) of this AD thereafter at intervals not to
exceed 90 days, until accomplishment of paragraph (h) of this AD.
Optional Terminating Action
(h) Replacement of the elevator tab mast fittings with new,
improved tab mast fittings, in accordance with Boeing Service
Bulletin 737-55-1063, dated July 1, 1999, constitutes terminating
action for the requirements of this AD.
Spares
(i) As of the effective date of this AD, no person shall install
an elevator tab mast fitting, part number (P/N) 183A8400-1 or
183A8400-2, on any airplane.
Alternative Methods of Compliance
(j) 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 Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. 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 6: 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
(k) 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
(l) Except as provided by paragraphs (a), (b), (e), and (f) of
this AD, the actions shall be done in accordance with the following
service information, as applicable:
(1) The incorporation by reference of Boeing Alert Service
Bulletin 737-55A1068, Revision 1, dated June 11, 1999, and Boeing
Service Bulletin 737-55-1063, dated July 1, 1999, as applicable, was
approved by the Director of the Federal Register in accordance with
5 U.S.C. 552(a) and 1 CFR part 51.
(2) The incorporation by reference of Boeing Alert Service
Bulletin 737-55A1068, dated June 9, 1999, was approved previously by
the Director of the Federal Register as of July 6, 1999 (64 FR
34976, June 30, 1999).
(3) Copies may be obtained from Boeing Commercial Airplane
Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may
[[Page 46262]]
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.
(m) This amendment becomes effective on September 9, 1999.
Issued in Renton, Washington, on August 18, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-21954 Filed 8-24-99; 8:45 am]
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