
[Federal Register: May 21, 2008 (Volume 73, Number 99)]
[Rules and Regulations]               
[Page 29407-29410]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21my08-5]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29069; Directorate Identifier 2007-NM-176-AD; 
Amendment 39-15525; AD 2008-11-03]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-100, -200, and -200C 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Boeing Model 737-100, -200, and -200C series airplanes. This AD 
requires revising the FAA-approved maintenance inspection program to 
include inspections that will give no less than the required damage 
tolerance rating for each structural significant item (SSI), doing 
repetitive inspections to detect cracks of all SSIs, and repairing 
cracked structure. This AD results from a report of incidents involving 
fatigue cracking in transport category airplanes that are approaching 
or have exceeded their design service objective. We are issuing this AD 
to maintain the continued structural integrity of the entire fleet of 
Model 737-100, -200, and -200C series airplanes.

DATES: This AD is effective June 25, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 25, 
2008.
    The Director of the Federal Register approved the incorporation by 
reference of Boeing Document D6-37089, ``Supplemental Structural 
Inspection Document for Model 737-100/200/200C Airplanes,'' Revision E, 
dated May 2007, as listed in this AD, on May 27, 2008 (73 FR 21237, 
April 21, 2008).

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6440; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
all Boeing Model 737-100, -200, and -200C series airplanes. That NPRM 
was published in the Federal Register on August 31, 2007 (72 FR 50294). 
That NPRM proposed to require revising the FAA-approved maintenance 
inspection program to include inspections that will give no less than 
the required damage tolerance rating for each structural significant 
item (SSI), doing repetitive inspections to detect cracks of all SSIs, 
and repairing cracked structure.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received from the one commenter.

Request To Allow Alternative Inspections for Previously Repaired/
Altered Structure

    Boeing requests that the NPRM be revised to include a provision for 
alternative inspections when a repair area prohibits operators from 
doing the inspections required by paragraph (i) of the NPRM. Boeing 
requests that the initial alternative inspection be done within 12 
months after the repair is discovered during the initial inspection 
required by paragraph (i) of the NPRM. Boeing points out that a similar 
provision was provided in paragraph (e) of AD 98-11-04 R1, amendment 
39-10984 (64 FR 987, January 7, 1999). Boeing states that including 
such a provision will assist operators.
    We agree. We have added a new paragraph (j) to this AD (and 
reidentified subsequent paragraphs) that provides for alternative 
inspections to those in paragraph (i) of this AD.

Request To Clarify Certain Sections of the Preamble of the NPRM

    Boeing requests that certain sections in the preamble of the NPRM 
be clarified for the following reasons:
    1. Boeing states that Advisory Circular (AC) No. 91-56, 
``Supplemental Structural Inspection Program for Large Transport 
Category Airplanes,'' dated May 6, 1981, applies to airplanes certified 
under the fail-safe and fatigue requirements of Civil Air Regulations 
(CAR) 4b or part 25 of the Federal Aviation Regulations (14 CFR part 
25), not damage tolerance structural requirements as stated in the 
Issuance of Advisory Circular (AC) section.
    2. Boeing notes that the Other Relevant Rulemaking section 
identifies the strut as one of the affected SSIs for Model 737-100, -
200, and -200C series airplanes. Boeing states that those airplanes do 
not have an engine strut.

[[Page 29408]]

    3. Boeing states that Boeing Document D6-37089, ``Supplemental 
Structural Inspection Document for Model 737-100/200/200C Airplanes,'' 
Revision E, dated May 2007 (referred to in the NPRM as an appropriate 
source of service information for the required actions), does not 
describe procedures for repairing cracked structure, as specified in 
the Relevant Service Information section.
    We partially agree. We agree with Boeing that the identified 
sections should be clarified. However, we find that no change to the 
final rule is necessary, since the identified sections of the NPRM do 
not reappear in the final rule.

Explanation of Change to Reported Incidents

    We have revised the AD to specify that this AD results from a 
report of incidents involving fatigue cracking only.

Explanation of Change to Costs of Compliance

    The requirements for the baseline structure of Model 737-100, -200, 
and -200C series airplanes are currently described in 14 CFR 
121.1109(c)(1) and 129.109(b)(1), not in 14 CFR 121.370(a) and 129.16 
as indicated in the third paragraph of the Cost of Compliance section 
of the NPRM. Therefore, we have revised the Costs of Compliance section 
of the AD accordingly.

Explanation of Editorial Changes

    We have revised the title of Boeing Document D6-37089-1 from 
``Appendix A Model 737-100/200/200C Airplanes'' to ``Supplemental 
Structural Inspection Document Appendix A Model 737-100/200/200C 
Airplanes'' in this AD. In addition, we have revised ``Appendix'' to 
``Appendix A'' in paragraphs (g) and (h) of this AD.

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting the 
AD with the changes described previously. We also determined that these 
changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Costs of Compliance

    There are about 676 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                 Number of U.S.-
            Action                Work hours     Average labor        Cost         registered       Fleet cost
                                                 rate per hour                      airplanes
----------------------------------------------------------------------------------------------------------------
Revision of maintenance        200 per                     $80  $16,000 per                 118  $368,000.
 inspection program.            operator (23                     operator.
                                U.S.
                                operators).
Inspections..................  150 per                      80  $12,000, per                118  $1,416,000 per
                                airplane.                        airplane, per                    inspection
                                                                 inspection                       cycle.
                                                                 cycle.
----------------------------------------------------------------------------------------------------------------

    The number of work hours, as indicated above, is presented as if 
the accomplishment of the actions in this AD is to be conducted as 
``stand alone'' actions. However, in actual practice, these actions for 
the most part will be done coincidentally or in combination with 
normally scheduled airplane inspections and other maintenance program 
tasks. Therefore, the actual number of necessary additional work hours 
will be minimal in many instances. Additionally, any costs associated 
with special airplane scheduling will be minimal.
    Further, compliance with this AD would be a means of compliance 
with the aging airplane safety final rule (AASFR) for the baseline 
structure of Model 737-100, -200, and -200C series airplanes. The AASFR 
requires certain operators to incorporate damage tolerance inspections 
into their maintenance inspection programs. These requirements are 
described in 14 CFR 121.1109(c)(1) and 129.109(b)(1). Accomplishment of 
the actions required by this AD will meet the requirements of these CFR 
sections for the baseline structure. The costs for accomplishing the 
inspection portion of this AD were accounted for in the regulatory 
evaluation of the AASFR.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD 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.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979), and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:


[[Page 29409]]


    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2008-11-03 Boeing: Amendment 39-15525. Docket No. FAA-2007-29069; 
Directorate Identifier 2007-NM-176-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective June 25, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 737-100, -200, and -200C 
series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a report of incidents involving fatigue 
cracking in transport category airplanes that are approaching or 
have exceeded their design service objective. We are issuing this AD 
to maintain the continued structural integrity of the entire fleet 
of Model 737-100, -200, and -200C series airplanes.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Service Information

    (f) The term ``Revision E,'' as used in this AD, means Boeing 
Document D6-37089, ``Supplemental Structural Inspection Document for 
Model 737-100/200/200C Airplanes,'' Revision E, dated May 2007.
    (g) The term ``Appendix A,'' as used in this AD, means Boeing 
Document D6-37089-1 ``Supplemental Structural Inspection Document 
Appendix A Model 737-100/200/200C Airplanes,'' Original Release, 
dated May 2007, of Revision E.

Revision of the FAA-Approved Maintenance Inspection Program

    (h) Before the accumulation of 66,000 total flight cycles, or 
within 12 months after the effective date of this AD, whichever 
occurs later, incorporate a revision into the FAA-approved 
maintenance inspection program that provides no less than the 
required damage tolerance rating (DTR) for each structural 
significant item (SSI) listed in Section 3.0, ``Flap and Support 
Structure (Flap Structure) SSI Information,'' of Appendix A. (The 
required DTR value for each SSI is listed in Appendix A.) The 
revision to the maintenance inspection program must include and must 
be implemented in accordance with the procedures in Section 3.0 of 
Appendix A, and in accordance with the procedures in Section 5.0, 
``Damage Tolerance Rating (DTR) System Application,'' and Section 
6.0, ``SSI Discrepancy Reporting'' of Revision E. Under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), 
the Office of Management and Budget (OMB) has approved the 
information collection requirements contained in this AD and has 
assigned OMB Control Number 2120-0056.

Initial and Repetitive Inspections

    (i) Except as provided by paragraph (j) of this AD: Before the 
accumulation of 66,000 total flight cycles, or within 4,000 flight 
cycles measured from 12 months after the effective date of this AD, 
whichever occurs later, do the applicable initial inspections to 
detect cracks of all SSIs, in accordance with Appendix A. Repeat the 
applicable inspections thereafter at the intervals necessary to 
obtain the required DTR specified in Appendix A.
    (j) For any SSI that has been repaired or altered before the 
effective date of this AD such that the repair or design change 
affects your ability to accomplish the actions required by paragraph 
(i) of this AD: Before further flight, you must request FAA approval 
of an alternative method of compliance (AMOC) in accordance with 
section 39.17 of the Federal Aviation Regulations (14 CFR 39.17), or 
do the actions specified in paragraphs (j)(1) and (j)(2) of this AD 
as an approved means of compliance with the requirements of 
paragraph (i) of this AD.
    (1) At the initial compliance time specified in paragraph (i) of 
the AD, identify each repair or design change to that SSI.
    (2) Within 12 months after the identification of a repair or 
design change required by paragraph (j)(1) of this AD, assess the 
damage tolerance characteristics of each SSI affected by each repair 
or design change to determine the effectiveness of the applicable 
Supplemental Structural Inspection Document (SSID) inspection for 
that SSI and if not effective, incorporate a revision into the FAA-
approved maintenance inspection program to include a damage-
tolerance-based alternative inspection program for each affected 
SSI. Thereafter, inspect the affected structure in accordance with 
the alternative inspection program. The inspection method and 
compliance times (i.e., threshold and repeat intervals) of the 
alternative inspection program must be approved in accordance with 
the procedures specified in paragraph (m) of this AD.

Repair

    (k) If any cracked structure is found during any inspection 
required by paragraph (i) or (j) of this AD, before further flight, 
repair the cracked structure using a method approved in accordance 
with the procedures specified in paragraph (m) of this AD.

Inspection Program for Transferred Airplanes

    (l) Before any airplane that is subject to this AD and that has 
exceeded the applicable compliance times specified in paragraph (i) 
of this AD can be added to an air carrier's operations 
specifications, a program for the accomplishment of the inspections 
required by this AD must be established in accordance with paragraph 
(l)(1) or (l)(2) of this AD, as applicable.
    (1) For airplanes that have been inspected in accordance with 
this AD: The inspection of each SSI must be done by the new operator 
in accordance with the previous operator's schedule and inspection 
method, or the new operator's schedule and inspection method, at 
whichever time would result in the earlier accomplishment for that 
SSI inspection. The compliance time for accomplishment of this 
inspection must be measured from the last inspection accomplished by 
the previous operator. After each inspection has been done once, 
each subsequent inspection must be performed in accordance with the 
new operator's schedule and inspection method.
    (2) For airplanes that have not been inspected in accordance 
with this AD: The inspection of each SSI required by this AD must be 
done either before adding the airplane to the air carrier's 
operations specification, or in accordance with a schedule and an 
inspection method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA. After each inspection has been done 
once, each subsequent inspection must be done in accordance with the 
new operator's schedule.

AMOCs

    (m)(1) The Manager, Seattle ACO, FAA, has the authority to 
approve AMOCs for this AD, if requested in accordance with the 
procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair approval must specifically refer 
to this AD.

Material Incorporated by Reference

    (n) You must use Boeing Document D6-37089, ``Supplemental 
Structural Inspection Document for Model 737-100/200/200C 
Airplanes,'' Revision E, dated May 2007; and Boeing Document D6-
37089-1 ``Supplemental Structural Inspection Document Appendix A 
Model 737-100/200/200C Airplanes,'' Original Release, dated May 
2007; as applicable; to do the actions required by this AD, unless 
the AD specifies otherwise.
    (1) Boeing Document D6-37089-1 contains these errors: Pages REF 
1 and REF 2 of the Reference Section and pages L-19.1 and L-19.2 of 
Section 4.0, as specified in the List of Effective Pages, do not 
exist.
    (2) The Director of the Federal Register approved the 
incorporation by reference of Boeing Document D6-37089-1 
``Supplemental Structural Inspection Document Appendix A Model 737-
100/200/200C Airplanes,'' Original Release, dated May 2007, under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (3) The Director of the Federal Register approved the 
incorporation by reference of Boeing Document D6-37089, 
``Supplemental

[[Page 29410]]

Structural Inspection Document for Model 737-100/200/200C 
Airplanes,'' Revision E, dated May 2007, on May 27, 2008 (73 FR 
21237, April 21, 2008).
    (4) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (5) You may review copies of the service information that is 
incorporated by reference at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal_register/code_of_federal_
regulations/ibr_locations.html.

    Issued in Renton, Washington, on May 7, 2008.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-10977 Filed 5-20-08; 8:45 am]

BILLING CODE 4910-13-P
