Airworthiness Directives; Boeing Model 737-200, -200C, -300, -400, and -500 Series Airplanes

[Federal Register Volume 68, Number 131 (Wednesday, July 9, 2003)]
[Rules and Regulations]
[Pages 40759-40761]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-17432]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-165-AD; Amendment 39-13225; AD 2003-14-06]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200, -200C, -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 certain Boeing Model 737-200, -200C, -300, -400, and -
500 series airplanes. This action requires repetitive inspections for 
cracking of certain lap splices, and corrective action if necessary. 
This action is necessary to detect and correct fatigue cracks in the 
lap joints and consequent rapid decompression of the airplane. This 
action is intended to address the identified unsafe condition.

DATES: Effective July 14, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 14, 2003.
    Comments for inclusion in the Rules Docket must be received on or 
before September 8, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-165-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 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. 2003-NM-165-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 or 2000 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 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: Duong Tran, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6452; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: The FAA recently received a report of a 
significant number of cracks along the fuselage skin lap joint on a 
Boeing Model 737-300 series airplane with 35,710 total flight cycles. 
During scheduled maintenance, fatigue cracks were found on a lap joint 
of the skin that extends from aft of the flight deck to the wing front 
spar just above the passenger windows. Some of the cracks linked up to 
form a 10-inch crack. The premature cracks were attributed to 
delaminated skin doublers. Improper processing during phosphoric 
anodize application of the skin panel is the cause of the delaminated 
skin doublers. This condition, if not corrected, could result in 
fatigue cracks in the lap joints and consequent rapid decompression of 
the airplane.
    The improperly processed panels were installed on certain airplanes 
during manufacturing and were available to the remaining airplanes as 
spare parts. Therefore, Model 737-200, -200C, -300, -400, and -500 
series airplanes may be subject to the identified unsafe condition.

Related Rulemaking Activity

    We have issued several ADs to require inspections of lap joints; 
however, those inspections are not required until various times defined 
in those ADs, which are substantially longer than the compliance time 
threshold of this AD such that those compliance times do not provide a 
sufficient level of safety to address the identified unsafe condition.
    In addition, on June 26, 2003, we issued a supplemental notice of 
proposed rulemaking, Rules Docket No. 98-NM-11-AD (68 FR 39485, July 2, 
2003). That proposed AD would apply to certain Boeing Model 737 series

[[Page 40760]]

airplanes including those affected by this AD, and would require, among 
other things, repetitive inspections for cracking of the same bonded 
skin panels addressed in this AD to detect delamination of the skin 
doublers (tear straps) from the skin panels. That proposed AD would 
require accomplishment of the actions specified in Boeing Service 
Bulletin 737-53-1179, Revision 2, dated October 25, 2001.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Service Bulletin 737-53-1179, 
Revision 2, dated October 25, 2001. That service bulletin describes 
procedures for, among other things, a one-time internal inspection for 
discrepancies (including cracks, corrosion, and delamination of skin 
doublers) of the lap joints on both sides of the airplane, and repair 
of any cracking found.

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 registered 
in the United States, this AD requires repetitive external detailed 
inspections for cracks of the fuselage skin at the upper row of 
fasteners on all the lap joints from body station (BS) 259 to BS 1016. 
Inspection of the lap joints underneath the wing-to-body fairing is not 
required by this AD. This AD also provides for optional terminating 
action for the repetitive inspections. This optional terminating action 
consists of the one-time internal inspection described in the service 
bulletin discussed previously.

Difference Between Proposed Rule and Service Bulletin

    Although the service bulletin specifies that operators may contact 
the manufacturer for disposition of certain repair conditions, this AD 
requires operators to repair those conditions per a method approved by 
the FAA, or per 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

    We consider this AD interim action. As stated previously, we have 
issued a related proposed AD that is intended to require, among other 
things, additional inspections defined in Boeing Service Bulletin 737-
53-1179. This new AD provides for those additional inspections as 
optional terminating action for the repetitive inspections required by 
this AD. However, the planned compliance time for additional 
inspections would allow enough time to provide notice and opportunity 
for prior public comment on the merits of the modification.

Changes to 14 CFR Part 39/Effect on the AD

    On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 
47997, July 22, 2002), which governs the FAA's airworthiness directives 
system. The regulation now includes material that relates to altered 
products, special flight permits, and alternative methods of compliance 
(AMOCs). Because we have now included this material in part 39, only 
the office authorized to approve AMOCs is identified in each individual 
AD.

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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the AD is 
being requested.
    [sbull] 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 2003-NM-165-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.

Adoption of the Amendment

0
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:

[[Page 40761]]

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2003-14-60 Boeing: Amendment 39-13225. Docket 2003-NM-165-AD.

    Applicability: Model 737-200, -200C, -300, -400, and -500 series 
airplanes; certificated in any category; line numbers 292 through 
2947 inclusive.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct fatigue cracks in the lap joints and 
consequent rapid decompression of the airplane, accomplish the 
following:

Inspection

    (a) At the applicable time specified in paragraph (a)(1) or 
(a)(2) of this AD: Do an external detailed inspection for cracks of 
the fuselage skin at the upper row of fasteners on all the lap 
joints from body station (BS) 259 to BS 1016. Inspection of the lap 
joints underneath the wing-to-body fairing is not required by this 
paragraph. Repeat the inspection at intervals not to exceed 500 
flight cycles, until the terminating action specified in paragraph 
(b) of this AD has been accomplished.
    (1) For line numbers 611 through 2869 inclusive: Inspect before 
the accumulation of 20,000 total flight cycles on the airplane, or 
within 20 days after the effective date of this AD, whichever occurs 
later.
    (2) For line numbers 292 through 610 inclusive and 2870 through 
2947 inclusive: Inspect before the accumulation of 20,000 total 
flight cycles on the airplane, or within 90 days after the effective 
date of this AD, whichever occurs later.

    Note 1: For the purposes of this AD, a detailed 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.''

Terminating Action

    (b) For airplanes identified in paragraph (a)(1) of this AD, 
accomplishment of the one-time internal inspection for discrepancies 
(including cracks, corrosion, and delamination of the skin doublers) 
of the skin panels, as shown in Table 2 of Figure 2 of the 
Accomplishment Instructions of Boeing Service Bulletin 737-53-1179, 
Revision 2, dated October 25, 2001, terminates the repetitive 
inspection requirements of paragraph (a) of this AD. (For Zone A, an 
internal inspection is required. For Zone B, either an internal or 
external inspection is permissible.)
    (c) For airplanes identified in paragraph (a)(2) of this AD, 
accomplishment of the one-time internal inspection for discrepancies 
of the skin panels, as shown in Table 3 of Figure 2 of the 
Accomplishment Instructions Boeing Service Bulletin 737-53-1179, 
Revision 2, dated October 25, 2001, terminates the repetitive 
inspection requirements of paragraph (a) of this AD. (For Zone A, an 
internal inspection is required. For Zone B, either an internal or 
external inspection is permissible.)

Corrective Action

    (d) If any crack is found during any inspection required by 
paragraph (a), (b), or (c) of this AD: Before further flight, repair 
in accordance with Boeing Service Bulletin 737-53-1179, Revision 2, 
dated October 25, 2001, except as provided by paragraph (e) of this 
AD.
    (e) Where Boeing Service Bulletin 737-53-1179, Revision 2, dated 
October 25, 2001, specifies contacting Boeing for appropriate 
action: Before further flight, repair in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA; or per 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. For a repair method to be approved, the 
approval must specifically reference this AD.

Alternative Methods of Compliance

    (f)(1) In accordance with 14 CFR 39.19, the Manager, Seattle 
ACO, FAA, is authorized to approve alternative methods of compliance 
(AMOCs) for this AD.
    (2) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by a 
Boeing Company Designated Engineering Representative (DER) who has 
been authorized by the Manager, Seattle ACO, to make such findings.

Incorporation by Reference

    (g) Except as otherwise provided in this AD, the actions must be 
done in accordance with Boeing Service Bulletin 737-53-1179, 
Revision 2, dated October 25, 2001. 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

    (h) This amendment becomes effective on July 14, 2003.

    Issued in Renton, Washington, on July 4, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-17432 Filed 7-8-03; 8:45 am]
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