[Federal Register Volume 73, Number 77 (Monday, April 21, 2008)]
[Rules and Regulations]
[Pages 21237-21240]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-8320]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29029; Directorate Identifier 2007-NM-175-AD; 
Amendment 39-15477; AD 2008-08-23]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200C 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 737-200C 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 737-200C 
series airplanes.

DATES: This AD is effective May 27, 2008.
    The Director of the Federal Register approved the incorporation by 
reference

[[Page 21238]]

of a certain publication listed in this AD as of May 27, 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 737-200C series airplanes. That NPRM was published in 
the Federal Register on August 23, 2007 (72 FR 48243). 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 specified in paragraph (h) 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 (h). 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 (i) to this AD (and 
reidentified subsequent paragraphs) that provides alternative 
inspections to those in paragraph (h) 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, 2001, 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.
    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 the 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 agree with Boeing that the identified sections could be 
clarified. For the first two items we agree with Boeing's statements. 
On the third item, while the document does not specify individual 
repair procedures for each specific SSI, it does specify that all 
repairs must be approved. However, no change has been made to the final 
rule 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 737-200C 
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.

Conclusion

    We reviewed the relevant data, considered the comments 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 49 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        1,000, per                  $80  $80,000 per                   9  $240,000.
 inspection program.            operator (3                      operator.
                                U.S.
                                operators).
Inspections..................  500 per                      80  $40,000, per                  9  $360,000, per
                                airplane.                        airplane, per                    inspection
                                                                 inspection                       cycle.
                                                                 cycle.
----------------------------------------------------------------------------------------------------------------


[[Page 21239]]

    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 will be a means of compliance with 
the aging airplane safety final rule (AASFR) for the baseline structure 
of Model 737-200C series airplanes. The AASFR final rule 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 final rule.

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:

    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:

2008-08-23 Boeing: Amendment 39-15477. Docket No. FAA-2007-29029; 
Directorate Identifier 2007-NM-175-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective May 27, 2008.

Affected ADs

    (b) Accomplishing the actions required by paragraph (g) and the 
initial inspections required by paragraph (h) of this AD ends the 
requirements of AD 98-11-04 R1, amendment 39-10984, for Model 737-
200C series airplanes only. Operators of Model 737-100 and -200 
series airplanes must continue to do the actions required by AD 98-
11-04 R1.

Applicability

    (c) This AD applies to all Boeing Model 737-200C 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 737-200C 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.

Revision of the FAA-Approved Maintenance Inspection Program

    (g) At the applicable time specified in Table 1 of this AD, 
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 
Revision E. (The required DTR value for each SSI is listed in 
Revision E.) The revision to the maintenance inspection program must 
include and must be implemented 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 of 1980 (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.

  Table 1.--Compliance Time for Revising Maintenance Inspection Program
------------------------------------------------------------------------
     For airplanes with SSIs--                 Compliance time
------------------------------------------------------------------------
(1) Affected by the cargo           Before the accumulation of 46,000
 configuration.                      total flight cycles, or within 12
                                     months after the effective date of
                                     this AD, whichever occurs later.
(2) Not affected by the cargo       Before the accumulation of 66,000
 configuration.                      total flight cycles, or within 12
                                     months after the effective date of
                                     this AD, whichever occurs later.
------------------------------------------------------------------------


[[Page 21240]]

Initial and Repetitive Inspections

    (h) Except as provided by paragraph (i) of this AD: At the 
applicable time specified in Table 2 of this AD, do the applicable 
initial inspections to detect cracks of all SSIs, in accordance with 
Revision E. Repeat the applicable inspections thereafter at the 
intervals specified in Section 3.0, ``Implementation'' of Revision 
E.

            Table 2.--Compliance Time for Initial Inspections
------------------------------------------------------------------------
     For airplanes with SSIs--                 Compliance time
------------------------------------------------------------------------
(1) Affected by the cargo           Before the accumulation of 46,000
 configuration.                      total flight cycles, or within
                                     4,000 flight cycles measured from
                                     12 months after the effective date
                                     of this AD, whichever occurs later.
(2) Not affected by the cargo       Before the accumulation of 66,000
 configuration.                      total flight cycles, or within
                                     4,000 flight cycles measured from
                                     12 months after the effective date
                                     of this AD, whichever occurs later.
------------------------------------------------------------------------

    (i) 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 
(h) of this AD: 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), at the initial 
compliance time specified in paragraph (h) of the AD; or do the 
actions specified in paragraphs (i)(1) and (i)(2) of this AD, at the 
times specified in those paragraphs, as an approved means of 
compliance with the requirements of paragraph (h) of this AD.
    (1) At the initial compliance time specified in paragraph (h) 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 (i)(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 
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 (l) of this AD.

Repair

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

Inspection Program for Transferred Airplanes

    (k) Before any airplane that is subject to this AD and that has 
exceeded the applicable compliance times specified in paragraph (h) 
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 
(k)(1) or (k)(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.

Alternative Methods of Compliance (AMOCs)

    (l)(1) The Manager, Seattle ACO 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

    (m) You must use Boeing Document D6-37089, ``Supplemental 
Structural Inspection Document for Model 737-100/200/200C 
Airplanes,'' Revision E, dated May 2007, to do the actions required 
by this AD, unless the AD specifies otherwise.
    (1) The document contains the following errors:
    (i) Pages 2.0.3 and 2.0.4, Revision D, of Section 2.0 and pages 
F-14.5, Revision D, and F-14.6, Revision Blank, of Section 8.2 
exist; but are not specified in the List of Effective Pages.
    (ii) Pages 7.0.43 through 7.0.46 inclusive of Section 7.0 and 
pages W.34.1 and W.34.2 of Section 11.1, as specified in the List of 
Effective Pages, do not exist.
    (iii) The List of Effective Pages specifies incorrect revision 
levels for certain pages; the revision levels specified on each page 
are correct.
    (iv) None of the pages are dated. The issue date for each 
revision is specified in the Revision Highlights section.
    (2) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (3) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (4) You may review copies of the service information 
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 April 8, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-8320 Filed 4-18-08; 8:45 am]
BILLING CODE 4910-13-P