
[Federal Register: May 2, 2008 (Volume 73, Number 86)]
[Rules and Regulations]               
[Page 24151-24153]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02my08-7]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0046; Directorate Identifier 2007-NM-173-AD; 
Amendment 39-15496; AD 2008-09-15]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 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, -200C, -300, -400, and -500 series 
airplanes. This AD requires repetitive inspections for any cracking of 
or damage to the left side and right side flight deck No. 2, No. 4, and 
No. 5 windows and corrective actions if necessary. This AD results from 
reports of in-flight departure and separation of the flight deck 
windows. We are issuing this AD to detect and correct cracking in the 
vinyl interlayer or damage to the structural inner glass panes of the 
flight deck No. 2, No. 4, and No. 5 windows, which could result in loss 
of a window and rapid loss of cabin pressure. Loss of cabin pressure 
could cause crew communication difficulties or crew incapacitation.

DATES: This AD is effective June 6, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of June 6, 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: Wayne Lockett, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6447; 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, -200C, -300, -400, and -500 series 
airplanes. That NPRM was published in the Federal Register on October 
17, 2007 (72 FR 58766). That NPRM proposed to require repetitive 
inspections for any cracking of or damage to the left side and right 
side flight deck No. 2, No. 4, and No. 5 windows and corrective actions 
if necessary.

Changes Made to This AD

    We have deleted paragraph (h)(4) of the NPRM and added a new 
paragraph (h) to this AD specifying that installation of metallic 
window blanks at cockpit eyebrow windows No. 4 and No. 5 in accordance 
with Supplemental Type Certificate (STC) ST01630SE terminates the 
initial and repetitive inspections for the flight deck No. 4 and No. 5 
windows required by paragraph (f) of this AD. Incorporation of STC 
ST01630SE is considered a terminating action, not an alternative method 
of compliance (AMOC), since an AMOC can only be issued after an AD has 
been issued. We have also reidentified the AMOC paragraph of the NPRM 
as paragraph (i) in this AD.

Comments

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

Support for the NPRM

    Boeing and Continental Airlines support the NPRM.

Request to Expand Applicability

    North Star Aerospace states that the affected window panels are 
also installed on Boeing Model 707 and 727 airplanes and Model 737-600, 
-700, -800, and -900 series airplanes, and that it has witnessed 
failure of the windows on these airplanes. North Star Aerospace 
believes the inspections should be extended to include all airplanes 
equipped with window panels having part numbers (P/Ns) 5-89355-( ), 5-
89357-( ), and 5-89358-( ).
    We infer the commenter requests that we revise the applicability to 
add Model 707 and 727 airplanes and Model 737-600, -700, -800, and -900 
series airplanes. Since the affected windows are interchangeable, we 
agree that the windows might be installed on all Model 707, 727, and 
737 airplanes. However, we do not agree to expand the applicability of 
this AD, since we have issued separate rulemaking actions to address 
the unsafe condition on Model 707 and 727 airplanes and Model 737-600, 
-700, -800, and -900 series airplanes. Please refer to Docket Nos. FAA-
2007-0264, FAA-2007-0265, and FAA-2007-0263, respectively, at http://
www.regulations.gov. No change to this AD is necessary in this regard.

Request To Revise the Compliance Time

    Continental Airlines requests that we revise the compliance time 
for the initial inspection of the flight deck No. 2 window to within 36 
months or 7,500 flight hours, whichever occurs first, after the window 
installation. Continental Airlines states that the NPRM, which proposes 
to require the initial inspection within 24 months after the effective 
date of this AD regardless of the age or flight time of the window, 
unnecessarily penalizes operators who proactively inspect and replace 
the No. 2 window before the AD is issued. Continental Airlines also 
states that, according to the wording in the NPRM, a window replaced 
one day before the effective date of the AD would need to be re-
inspected within 24 months, but a window inspected and replaced one day 
after the effective date of the AD would not need to be re-inspected 
until 36 months or 7,500 window flight hours, whichever is first.
    We do not agree to revise the compliance time for the initial 
inspection of the flight deck No. 2 window. According to paragraph (e) 
of this AD, an operator is responsible for having the actions required 
by this AD performed within the compliance times specified, unless the 
actions have already been done. If the initial inspection of the No. 2 
window was done before the effective date of this AD in accordance with 
Boeing Alert Service Bulletin 737-56A1023, dated May 24, 2007, then the 
initial inspection does not need to be accomplished again; only the 
repetitive inspections would need to be accomplished in accordance with 
the service bulletin at the applicable

[[Page 24152]]

interval specified in the service bulletin. If the initial and 
repetitive inspections of the No. 2 window are done before the 
effective date of this AD, but are not done in accordance with the 
service bulletin, then those inspections are not acceptable for 
compliance with this AD unless an AMOC is issued for those prior 
inspections. Under the provisions of paragraph (i) of this AD, we will 
consider requests for approval of an AMOC if sufficient data are 
submitted to substantiate that prior inspections incorporate similar 
criteria to what is provided for in the service bulletin. Therefore, no 
change to this AD is necessary in this regard.

Request for an AMOC for a Parts Manufacturer Approval (PMA) Equivalent 
Part

    Continental Airlines states that the FAA has approved a new, 
improved flight deck No. 2 window designed by GKN Aerospace 
Transparency Systems, under PMA Holder No. PQ1250NM, Supplement 10, 
dated September 17, 2007. Continental Airlines states that the new, 
improved No. 2 window was designed to prevent the premature failure of 
the window, and that new, improved window addresses the unsafe 
condition of the NPRM. Continental Airlines, therefore, requests that 
we add a new AMOC paragraph to this AD, which would exempt the new, 
improved No. 2 window from the required inspections.
    We do not agree to allow the PMA equivalent No. 2 window as an AMOC 
to the required inspections. Although the window has been approved as a 
PMA equivalent part, the commenter has not provided data showing that 
the PMA equivalent window is not susceptible to the same vinyl 
interlayer cracking. However, under the provisions of paragraph (i) of 
this AD, we will consider requests for approval of an AMOC if 
sufficient data are submitted to substantiate that the design change 
would provide an acceptable level of safety. No change to this AD is 
necessary in this regard.

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 2,685 airplanes of the affected design in the 
worldwide fleet. This AD affects about 799 airplanes of U.S. registry. 
The required inspections take about 2 work hours per airplane, at an 
average labor rate of $80 per work hour. Based on these figures, the 
estimated cost of the AD for U.S. operators is $127,840, or $160 per 
airplane, per inspection cycle.

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:

2008-09-15 Boeing: Amendment 39-15496. Docket No. FAA-2007-0046; 
Directorate Identifier 2007-NM-173-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective June 6, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 737-100, -200, -200C, -
300, -400, and -500 series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from reports of in-flight departure and 
separation of flight deck windows. We are issuing this AD to detect 
and correct cracking in the vinyl interlayer or damage to the 
structural inner glass panes of the flight deck No. 2, No. 4, and 
No. 5 windows, which could result in loss of a window and rapid loss 
of cabin pressure. Loss of cabin pressure could cause crew 
communication difficulties or crew incapacitation.

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.

Repetitive Inspections and Replacement

    (f) At the applicable times specified in Tables 1, 2, and 3 of 
paragraph 1.E. of Boeing Alert Service Bulletin 737-56A1023, dated 
May 24, 2007, except as provided by paragraph (g) of this AD: Do the 
internal and external detailed inspections for any cracking of or 
damage to the left side and right side flight deck No. 2, No. 4, and 
No. 5 windows and do the applicable corrective actions before 
further flight, by accomplishing all of the applicable actions 
specified in the Accomplishment Instructions of the service 
bulletin. Repeat the inspections thereafter at the applicable 
interval specified in paragraph 1.E. of the service bulletin.

Exception to Compliance Times

    (g) Where Tables 1, 2, and 3 of paragraph 1.E. of Boeing Alert 
Service Bulletin 737-56A1023, dated May 24, 2007, specify counting 
the compliance time from ``* * * the date on this service 
bulletin,'' this AD requires counting the compliance time from the 
effective date of this AD.

[[Page 24153]]

Optional Terminating Action

    (h) Installation of metallic window blanks at cockpit eyebrow 
windows No. 4 and No. 5 in accordance with Supplemental Type 
Certificate ST01630SE terminates the initial and repetitive 
inspections for the flight deck No. 4 and No. 5 windows required by 
paragraph (f) of this AD. All other applicable actions required by 
paragraph (f) of this AD must be fully complied with.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office (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 must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD.

Material Incorporated by Reference

    (j) You must use Boeing Alert Service Bulletin 737-56A1023, 
dated May 24, 2007, to do the actions required by this AD, unless 
the AD specifies otherwise.
    (1) 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.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (3) 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 18, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-9312 Filed 5-1-08; 8:45 am]

BILLING CODE 4910-13-P
