[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]
BILLING CODE 4910-13-P