
[Federal Register: April 21, 2008 (Volume 73, Number 77)]
[Rules and Regulations]               
[Page 21242-21244]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21ap08-12]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0049; Directorate Identifier 2007-NM-168-AD; 
Amendment 39-15478; AD 2008-08-24]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-600, -700, -700C, -
800, and -900 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 certain 
Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. 
This AD requires replacing the drain tube assemblies and support clamps 
on the aft fairing of the engine struts. This AD results from reports 
of failure of the drain tube assembly and clamp on the aft fairings of 
an engine strut. We are issuing this AD to prevent failure of the

[[Page 21243]]

drain tube assemblies and clamps on the aft fairings of the of the 
engine struts. Such a failure could allow leaked flammable fluids in 
the drain systems to discharge on to the heat shields of the aft 
fairings of the engine struts, which could result in an undetected and 
uncontrollable fire.

DATES: This AD is effective May 27, 2008.
    The Director of the Federal Register approved the incorporation by 
reference 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: Samuel Spitzer, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6510; 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 
certain Boeing Model 737-600, -700, -700C, -800, and -900 series 
airplanes. That NPRM was published in the Federal Register on October 
17, 2007 (72 FR 58773). That NPRM proposed to require replacing the 
drain tube assemblies and support clamps on the aft fairings of the 
engine struts.

Comments

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

Support for the NPRM

    Boeing supports the NPRM.

Request for Revision of Compliance Time

    The Air Transport Association (ATA), on behalf of a member, 
American Airlines, requests that the compliance time specified in 
paragraph (f) of the NPRM be revised from 60 to 72 months. The ATA 
states that the operators' routine maintenance schedules may not allow 
for accomplishment of the proposed replacement on affected aircraft 
within the proposed compliance time, and thus operators would incur 
additional costs associated with special scheduling.
    We do not agree with the commenter's request to extend the 
compliance time. In developing an appropriate compliance time for this 
action, we considered the urgency associated with the subject unsafe 
condition, the availability of required parts, and the practical aspect 
of accomplishing the required replacement within a period of time that 
corresponds to the normal scheduled maintenance for most affected 
operators. However, according to the provisions of paragraph (g) of the 
final rule, we may approve requests to adjust the compliance time if 
the request includes data that prove that the new compliance time would 
provide an acceptable level of safety.

Request To Change the Work Hours of the ``Costs of Compliance'' Section

    The ATA also requests that the work hours specified in the ``Costs 
of Compliance'' section of the NPRM be changed from 4 to 10.5 work 
hours. The ATA states that Boeing Special Attention Service Bulletin 
737-54-1043, dated May 2, 2007 (referred to as the appropriate source 
of service information for accomplishing the proposed actions in the 
NPRM), includes 7 work hours for open and close access. The ATA states 
that such a change will provide a better representation of the time 
included in the service bulletin.
    We do not agree with the ATA's request to increase the work hours 
specified in the ``Costs of Compliance'' section of the NPRM. That 
section describes only the direct costs of the specific actions 
required by this AD. Based on the best data available, the manufacturer 
provided the number of work hours (four) necessary to do the required 
actions. This number represents the time necessary to perform only the 
actions actually required by this AD. We recognize that, in doing the 
actions required by an AD, operators might incur incidental costs in 
addition to the direct costs. The cost analysis in AD rulemaking 
actions, however, typically does not include incidental costs such as 
the time required to gain access and close up, time necessary for 
planning, or time necessitated by other administrative actions. Those 
incidental costs, which might vary significantly among operators, are 
almost impossible to calculate. Therefore, we have made no change to 
the AD in this regard.

Clarification of Replacement

    For clarification purposes, we have revised paragraph (f) from: 
``Within 60 months after the effective date of this AD, remove the 
drain tube assemblies and support clamps on the aft fairing of the 
struts of engine number 1 and engine number 2. These are to be replaced 
with new drain tube assemblies and clamps * * *'' to: ``Within 60 
months after the effective date of this AD, replace the drain tube 
assemblies and support clamps on the aft fairing of the struts of 
engine number 1 and engine number 2 with new drain tube assemblies and 
clamps * * *'' to provide consistency of terminology.

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 change described previously. We also determined that 
this change will not increase the economic burden on any operator or 
increase the scope of the AD.

Costs of Compliance

    There are about 2,058 airplanes of the affected design in the 
worldwide fleet. This AD affects about 721 airplanes of U.S. registry. 
The actions take about 4 work hours per airplane, at an average labor 
rate of $80 per work hour. Required parts cost about $2,351 per 
airplane. Based on these figures, the estimated cost of this AD for 
U.S. operators is $1,925,791, or $2,671 per airplane.

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

[[Page 21244]]

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:

2008-08-24 Boeing: Amendment 39-15478. Docket No. FAA-2007-0049; 
Directorate Identifier 2007-NM-168-AD.

Effective Date

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

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, -800, 
and -900 series airplanes, certificated in any category; as 
identified in Boeing Special Attention Service Bulletin 737-54-1043, 
dated May 2, 2007.

Unsafe Condition

    (d) This AD results from reports of failure of the drain tube 
assembly and support clamp on the aft fairing of an engine strut. We 
are issuing this AD to prevent failure of the drain tube assemblies 
and clamps on the aft fairings of the engine struts. Such a failure 
could allow leaked flammable fluids in the drain systems to 
discharge on to the heat shields of the aft fairings of the engine 
struts, which could result in an undetected and uncontrollable fire.

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.

Replacement

    (f) Within 60 months after the effective date of this AD, 
replace the drain tube assemblies and support clamps on the aft 
fairing of the struts of engine number 1 and engine number 2 with 
new drain tube assemblies and clamps, in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-54-1043, dated May 2, 2007.

Alternative Methods of Compliance (AMOCs)

    (g)(1) The Manager, Seattle Aircraft Certification Office, 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.

Material Incorporated by Reference

    (h) You must use Boeing Special Attention Service Bulletin 737-
54-1043, dated May 2, 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 8, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-8328 Filed 4-18-08; 8:45 am]

BILLING CODE 4910-13-P
