[Federal Register Volume 65, Number 166 (Friday, August 25, 2000)]
[Rules and Regulations]
[Pages 51750-51752]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-21615]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-288-AD; Amendment 39-11878; AD 2000-17-04]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, and -200C 
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 certain Boeing Model 737-100, -200, and -200C series 
airplanes. This action requires repetitive inspections to detect 
discrepancies in the upper and lower skins of the fuselage lap joint, 
and repair, if necessary. This action is necessary to detect and 
correct such discrepancies, which could result in sudden fracture and 
failure of a lap joint and rapid decompression of the airplane 
fuselage.

DATES: Effective September 11, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 11, 2000.
    Comments for inclusion in the Rules Docket must be received on or 
before October 24, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-288-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-288-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    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

[[Page 51751]]

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: Scott Fung, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-1221; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received a report indicating in-
flight rapid decompression of a Boeing Model 737 series airplane. 
Investigation revealed that the skin above the forward entry door was 
separated at the stringer S-4R lap joint, with a 28-inch tear running 
along the lap joint. The skin was bent back at the upper edge of the 
stringer at S-5R and formed a rectangular opening that progressed from 
body station (BS) 328 to BS 300. Further investigation revealed that 
numerous scratches on the skin of the lap joint had initiated fatigue 
cracks and subsequent tearing of the skin. Fatigue cracking and 
corrosion in other lap joints were also detected at various locations 
on the airplane. The airplane had accumulated 78,198 flight cycles and 
77,115 flight hours. The FAA also has received reports of similar 
damage (corrosion and cracking) to certain lap joints on other Model 
737 series airplanes. Such discrepancies, if not corrected, could 
result in sudden fracture and failure of a lap joint and rapid 
decompression of the airplane fuselage.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-53A1224, dated August 17, 2000, which describes procedures for 
inspections (initial and repetitive eddy current and detailed visual) 
to detect discrepancies (i.e., cracks, pillowing, corrosion, 
delamination, or loose or missing fasteners) in the upper and lower 
skins of the fuselage lap joint, and repair of any discrepancies.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Boeing Model 737 series airplanes of the same 
type design, this AD is being issued to detect discrepancies in the 
upper and lower skins of the fuselage lap joint. This AD requires 
repetitive inspections to detect discrepancies of the upper and lower 
skins of the fuselage lap joint, and repair, if necessary. The actions 
are required to be accomplished in accordance with the alert service 
bulletin described previously, except as discussed below.

Difference Between Alert Service Bulletin and This AD

    Operators should note that, although the alert service bulletin 
specifies that the manufacturer may be contacted for disposition of 
certain repair conditions, this AD requires the repair of those 
conditions to be accomplished in accordance with a method approved by 
the FAA, 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 FAA to make 
such findings.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised that it currently is considering developing a modification that 
will positively address the unsafe condition addressed by this AD. 
Should this modification be developed, approved, and available, the FAA 
may consider additional 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.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the AD is 
being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 2000-NM-288-AD.'' The postcard will be date stamped 
and returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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.

[[Page 51752]]

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 adding the following new 
airworthiness directive:

2000-17-04  Boeing: Amendment 39-11878. Docket 2000-NM-288-AD.

    Applicability: Model 737-100, -200, and -200C series airplanes, 
line numbers 1 through 291 inclusive, 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 detect and correct discrepancies in the upper and lower skins 
of the fuselage lap joint, which could result in sudden fracture and 
failure of a lap joint and rapid decompression of the airplane 
fuselage, accomplish the following:

Initial and Repetitive Inspections

    (a) Perform the applicable (initial and repetitive) inspections 
as specified in Figures 1 through 4 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1224, dated 
August 17, 2000, to detect discrepancies (i.e., cracks, pillowing, 
corrosion, delamination, or loose or missing fasteners) in the upper 
and lower skins of the fuselage lap joint. Perform the inspections 
at the applicable times specified in Tables 1 and 2 of Section 1.E. 
``Compliance'' of the alert service bulletin, in accordance with the 
alert service bulletin; except that where Table 1 specifies a 
compliance time of ``airplane flight cycles at time of service 
bulletin release,'' this AD requires a compliance time of ``airplane 
flight cycles as of the effective date of this AD.''

Repair

    (b) Prior to further flight, repair any discrepancies detected 
during any inspection required by this AD in accordance with Boeing 
Alert Service Bulletin 737-53A1224, dated August 17, 2000. If any 
discrepancies are detected and the alert service bulletin specifies 
that the manufacturer may be contacted for disposition of certain 
repairs, prior to further flight, repair in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA; 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.

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, Seattle ACO, FAA. 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 2: 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 
Secs. 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) Except as provided by paragraph (b) of this AD, the 
inspections and repair shall be done in accordance with Boeing Alert 
Service Bulletin 737-53A1224, dated August 17, 2000. 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.

Effective Date

    (f) This amendment becomes effective on September 11, 2000.

    Issued in Renton, Washington, on August 18, 2000.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-21615 Filed 8-24-00; 8:45 am]
BILLING CODE 4910-13-U