[Federal Register Volume 64, Number 31 (Wednesday, February 17, 1999)]
[Rules and Regulations]
[Pages 7774-7777]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3750]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-16-AD; Amendment 39-11047; AD 99-04-22]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727, 727-100, 727-200, 
727C, 727-100C, and 727-200F 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 727, 727-100, 727-200, 727C, 727-
100C, and 727-200F series airplanes. This action requires repetitive 
inspections to detect cracking of the lower skin panel at the lower row 
of fasteners in certain lap joints of the fuselage, and repair, if 
necessary. This amendment also provides for optional terminating action 
for certain repetitive inspections. This amendment is prompted by a 
report of fatigue cracking in the lower skin panel at the lower row of 
fasteners of the fuselage lap joints. The actions specified in this AD 
are intended to detect and correct such fatigue cracking, which could 
result in sudden fracture and failure of the lower skin lap joints, and 
rapid decompression of the airplane.

DATES: Effective March 4, 1999.
    The incorporation by reference of certain publications, as listed 
in the regulations, was approved previously by the Director of the 
Federal Register as of June 23, 1998 (63 FR 27455, May 19, 1998).
    Comments for inclusion in the Rules Docket must be received on or 
before April 19, 1999.


[[Page 7775]]


ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-16-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056.
    The service information referenced in the rule 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: Walt Sippel, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2774; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received a report indicating 
that a 20-inch crack was detected in the lower skin panel of the 
fuselage on a Boeing Model 727 series airplane, between body station 
(BS) 540 and BS 560 common to stringer S26L, at the lower row of 
fasteners in the lap joint. This type of cracking was determined to be 
the result of multiple site fatigue damage in the lap joint lower 
fastener row.
    Further investigation revealed multiple site fatigue damage 
(approximately 80 cracks) in the stringer S-4R lap joint of the lower 
fastener row of the lower skin panel. The lower skin is 0.040-inch 
thick at both of these lap joint locations. Three out of the four 
airplanes inspected were found with such damage at the stringer S-4R 
lap joint; one of the airplanes had accumulated approximately 55,430 
total flight cycles. Preliminary results of the investigation revealed 
that the cracking had initiated at approximately 40,000 total flight 
cycles.
    Such fatigue cracking, if not detected and corrected, could result 
in sudden fracture and failure of the lower skin lap joints, and rapid 
decompression of the airplane.

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 detect and correct fatigue cracking of the lower skin 
at the lower row of fasteners in certain lap joints of the fuselage. 
This AD requires repetitive inspections to detect cracking of the lower 
skin panel at the lower row of fasteners in certain lap joints of the 
fuselage, and repair, if necessary. This AD also provides for optional 
terminating action for certain repetitive inspections.
    In the context of other AD's affecting lap joints, the FAA has 
become aware that, in many cases, operators have accomplished repairs 
or alterations to the lap joints that make it impossible to accomplish 
inspections required by the AD's. Yet, in some cases, the operators 
have not obtained approval for alternative methods of compliance (AMOC) 
for those inspections. Therefore, the FAA has added a paragraph to this 
AD that requires that, before such a repair or alteration can be 
accomplished, approval for an AMOC must be obtained.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

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-16-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 7776]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

99-04-22  Boeing: Amendment 39-11047. Docket 99-NM-16-AD.

    Applicability: All Model 727, 727-100, 727-200, 727C, 727-100C, 
and 727-200F 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 (g) 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 detect and correct fatigue cracking in the lower skin panel 
at the lower row of fasteners of the fuselage lap joints, which 
could result in sudden fracture and failure of the lap joints, and 
rapid decompression of the airplane; accomplish the following:
    (a) Except as provided by paragraph (e) of this AD: At the later 
of the times specified in paragraphs (a)(1) and (a)(2) of this AD, 
perform an external detailed visual inspection to detect cracking in 
the lower skin panels at the lower row of fasteners of the fuselage 
lap joints at the following associated body stations (BS). 
Thereafter, repeat the inspection at intervals not to exceed 50 
flight cycles until the requirements of either paragraph (c) or (d) 
of this AD are accomplished.

                                                                        Table 1.
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                Model                          Stringer                                                Body station
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727 series airplanes and 727-100      S-4L, S-4R                 259 through 700, and 1009 through 1183.
 series airplanes.
                                      S-10L                      259 through 310.
                                      S-10R                      259 through 360.
                                      S-19L                      259 through 660.
                                      S-19R                      259 through 500.
                                      S-24L, S-24R               259 through 360.
                                      S-26L                      360 through 680.
                                      S-26R                      360 through 500, and 601 through 680.
727-200 series airplanes............  S-4L, S-4R                 259 through 681; 686 through 720E; and 1009 through 1183.
                                      S-10L                      259 through 310.
                                      S-10R                      259 through 360.
                                      S-19L, S19R                259 through 360.
                                      S-24L, S-24R               259 through 360.
                                      S-26L                      360 through 644.
                                      S-26R                      360 through 481, and 486 through 514.
727C series airplanes, 727-100C       S-4L                       259 through 441, and 1080 through 1183.
 series airplanes.
                                      S-4R                       259 through 619, and 1080 through 1183.
                                      S-10L                      259 through 310.
                                      S-10R                      259 through 360.
                                      S-19L                      259 through 441.
                                      S-19R                      259 through 500.
                                      S-24L, S-24R               259 through 360.
                                      S-26L                      360 through 680.
                                      S-26R                      360 through 500, and 601 through 680.
727-200F series airplanes...........  S-4L                       259 through 441, and 1009 through 1183.
                                      S-4R                       259 through 481, and 1009 through 1183.
                                      S-10L                      259 through 310.
                                      S-10R                      259 through 360.
                                      S-19L                      259 through 360.
                                      S-19R                      259 through 520.
                                      S-26L                      486 through 644.
                                      S-26R                      486 through 514.
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    (1) Inspect prior to the accumulation of 40,000 total flight 
cycles.
    (2) Inspect within 50 flight cycles or 15 days after the 
effective date of this AD, whichever occurs first.
    (b) After the effective date of this AD, no person may 
accomplish a repair or alteration that would interfere with the 
accomplishment of the inspection required by paragraph (a) of this 
AD (e.g., covering an affected lap joint), unless an alternative 
method of compliance for that inspection has been approved in 
accordance with the provisions of paragraph (g) of this AD.
    (c) At the latest of the times specified in paragraphs (c)(1), 
(c)(2), and (c)(3) of this AD, perform a low frequency eddy current 
(LFEC) inspection to detect cracking in the lower skin panels at the 
lower row of fasteners of the fuselage lap joints, at the associated 
body stations specified in Table 1. of paragraph (a) of this AD; in 
accordance with Items F-43 and F-43A of Boeing Document No. D6-
48040-1, Volumes 1 and 2, ``Supplemental Structural Inspection 
Document'' (SSID), Revision H, dated June 1994 (hereinafter referred 
to as the ``Boeing Document''). Thereafter, repeat the LFEC 
inspection at intervals not to exceed 600 flight cycles. 
Accomplishment of the LFEC inspection constitutes terminating action 
for the repetitive inspections required by paragraph (a) of this AD.
    (1) Inspect prior to the accumulation of 40,000 total flight 
cycles.
    (2) Inspect within 300 flight cycles or 60 days after the 
effective date of this AD, whichever occurs first.
    (3) Inspect within 600 flight cycles after accomplishing the 
same inspection in accordance with AD 98-11-03, amendment 39-10530.

    Note 2: The provisions of paragraph 1. of Item F-43A of the 
Boeing Document, which give credit for performing the modification 
or repair specified in Figure 4 of Boeing Service Bulletin 727-53-
72, Revision 5, dated June 1, 1989, do not apply to this AD. All lap 
joints specified in this AD are to be inspected whether or not they 
have been modified or repaired previously in accordance with that 
service bulletin.
    Note 3: Accomplishment of the initial LFEC inspection prior to 
the effective date of this AD in accordance with the initial LFEC 
inspection specified in the Boeing Document, is considered 
acceptable for compliance with the initial inspection specified in 
paragraph (c) of this AD.


[[Page 7777]]


    (d) Accomplishment of internal detailed visual and high 
frequency eddy current (HFEC) inspections to detect cracking in the 
lower skin panels at the lower row of fasteners of the fuselage lap 
joints, at the associated body stations specified in Table 1. of 
paragraph (a) of this AD; in accordance with the Boeing Document, 
constitutes terminating action for the repetitive inspection 
requirements of paragraphs (a) and (c) of this AD, provided that the 
internal detailed visual and HFEC inspections are repeated 
thereafter at intervals not to exceed 7,000 flight cycles.

    Note 4: Accomplishment of the internal HFEC inspection prior to 
the effective date of this AD in accordance with the HFEC inspection 
specified in the Boeing Document is considered acceptable for 
compliance with the initial HFEC inspection specified in paragraph 
(d) of this AD, provided that the repetitive inspections in 
paragraph (d) of this AD are accomplished as specified.

    (e) Airplanes on which the inspection required by paragraph (c) 
or (d) of this AD is performed within the compliance time specified 
in paragraph (a) of this AD are not required to accomplish the 
inspection required by paragraph (a).
    (f) If any crack is detected during any inspection required by 
this AD, prior to further flight, perform internal detailed visual 
and HFEC inspections to detect additional cracking in the entire lap 
joint of the lower skin panel where the crack was found, in 
accordance with the Boeing Document, and repair any crack detected 
in accordance with a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate; 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.
    (g) 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 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (h) 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.
    (i) The inspections shall be done in accordance with Boeing 
Document No. D6-48040-1, Volumes 1 and 2, ``Supplemental Structural 
Inspection Document'' (SSID), Revision H, dated June 1994, which 
contains the following list of effective pages:

------------------------------------------------------------------------
                                                                Revision
                                                                  level
                    Page No. shown on page                      shown on
                                                                  page
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List of Active Pages: Pages 1 thru 17.2.......................         H
------------------------------------------------------------------------

(Note: The issue date of Revision H is indicated only on the title 
page; no other page of the document is dated.) This incorporation by 
reference was approved previously by the Director of the Federal 
Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as 
of June 23, 1998 (63 FR 27455, May 19, 1998). 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.
    (j) This amendment becomes effective on March 4, 1999.

    Issued in Renton, Washington, on February 10, 1999.
Ronald T. Wojnar,
Acting Manager,
Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-3750 Filed 2-16-99; 8:45 am]
BILLING CODE 4910-13-U