[Federal Register: June 11, 2009 (Volume 74, Number 111)]
[Rules and Regulations]
[Page 27691-27693]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr11jn09-6]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-1364; Directorate Identifier 2008-NM-103-AD;
Amendment 39-15928; AD 2009-12-05]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-300, -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 certain
Boeing Model 737-300, -400, and -500 series airplanes. This AD requires
modifying the control power wiring of the normal supply fan and the low
flow sensor for the equipment cooling system of the electronic flight
instrument system (EFIS). This AD results from a report of loss of both
the normal EFIS cooling supply and the indication of EFIS cooling loss
due to a single failure of the battery bus, causing eventual power-down
of the EFIS displays; the standby attitude indication is also powered
by this battery bus. We are issuing this AD to prevent loss of all
attitude indications from both the standby indicator and EFIS displays,
which could decrease the ability of the flightcrew to maintain the safe
flight and landing of the airplane.
DATES: This AD is effective July 16, 2009.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of July 16,
2009.
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1, fax 206-766-5680; e-mail me.boecom@boeing.com;
Internet https://www.myboeingfleet.com.
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: Suk Jang, Aerospace Engineer, Systems
and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone
(425) 917-6511; 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 737-300, -400, and -500 series airplanes. That
NPRM was published in the Federal Register on January 12, 2009 (74 FR
1153). That NPRM proposed to require modifying the control power wiring
of the normal supply fan and the low flow sensor for the equipment
cooling system of the electronic flight instrument system (EFIS).
Comments
We gave the public the opportunity to participate in developing
this AD. We considered the comments received.
Supportive Comments
Boeing and Continental Airlines support the actions in the NPRM.
Request To Add an Alternate Method of Compliance
Lufthansa German Airlines asks that we add a method acceptable for
compliance with the corresponding requirements of the NPRM. Lufthansa
notes that, as specified in paragraphs (f), (g)(1), and (g)(2) of the
NPRM, actions done in accordance with Boeing Alert Service Bulletin
737-21A1156, Revision 1, dated October 23, 2007; or Boeing Alert
Service Bulletin 737-21A1156, dated June 20, 2006; are acceptable for
compliance. Lufthansa adds that these actions prevent loss of all
attitude indications from both the standby indicator and EFIS displays
in case of battery bus failure. (The following is a clarification of
the commenter's description of acceptable sources of service
information specified in this AD: Boeing Alert Service Bulletin 737-
21A1156, Revision 2, dated December 11, 2008, is the source of service
information referred to in the NPRM for accomplishing the specified
actions. Actions done previously in accordance with Boeing Alert
Service Bulletin 737-21A1156, Revision 1, dated October 23, 2007; or
Boeing Alert Service Bulletin
[[Page 27692]]
737-21A1156, dated June 20, 2006 (for Groups 1 and 2 airplanes
identified in Boeing Alert Service Bulletin 737-21A1156, Revision 1),
are acceptable for compliance with the corresponding requirements of
this AD.)
Lufthansa asks that we consider another method to address this
unsafe condition, which is to append an abnormal procedure task to the
flight crew operations manual in case of battery bus failure to specify
setting the equipment cooling switch to alternate if the battery bus
fails. This would allow the alternate supply fan to still cool the EFIS
displays and prevent them from failing.
We disagree with the commenter's request to add this additional
method of compliance to the AD requirements. The identified unsafe
condition is loss of all attitude indications from both the standby
indicator and EFIS displays, which could decrease the ability of the
flightcrew to maintain the safe flight and landing of the airplane.
Although we recognize the commenter's suggestion provides some safety
mitigation for the unsafe condition, the inherently unsafe design of
the EFIS cooling system must be corrected to ensure that flightcrews
are equipped with attitude indications. Therefore, after the
modification of the control power wiring of the EFIS cooling system is
done, revising the flightcrew operations manual is not necessary and is
not acceptable as an alternate method of compliance to this AD. We have
made no change to the AD 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 as proposed.
Costs of Compliance
We estimate that this AD will affect 263 airplanes of U.S.
registry. The following table provides the estimated costs for U.S.
operators to comply with this AD.
Estimated Costs
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Average
Work labor Cost per Number of U.S.-
Action/airplane group hours rate per Parts product registered Fleet cost
hour airplanes
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Groups 1 & 2 modification.......................................... 3 $80 $0 $240 153 $36,720
Group 4 modification............................................... 2 $80 $0 $160 113 $18,080
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Currently, there are no Group 3 airplanes on the U.S. Register.
However, if an affected airplane is imported and placed on the U.S.
Register in the future, the required actions would take about 5 work
hours, at an average labor rate of $80 per work hour. Based on these
figures, we estimate the cost of this AD for Group 3 airplanes to be
$400 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 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:
2009-12-05 Boeing: Amendment 39-15928. Docket No. FAA-2008-1364;
Directorate Identifier 2008-NM-103-AD.
Effective Date
(a) This airworthiness directive (AD) is effective July 16,
2009.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 737-300, -400, and -500
series airplanes, certificated in any category; as identified in
Boeing Alert Service Bulletin 737-21A1156, Revision 2, dated
December 11, 2008.
Unsafe Condition
(d) This AD results from a report of loss of both the normal
electronic flight instrument system (EFIS) cooling supply and the
indication of EFIS cooling loss due to a single failure of the
battery bus, causing eventual power-down of the EFIS displays; the
standby attitude indication is also powered by this battery bus. We
are issuing this AD to prevent loss of all attitude indications from
both the standby indicator and EFIS displays, which could decrease
the ability of the flightcrew to maintain the safe flight and
landing of the airplane.
Compliance
(e) Comply with this AD within the compliance times specified,
unless already done.
Modification
(f) Within 24 months after the effective date of this AD: Modify
the control power
[[Page 27693]]
wiring of the normal supply fan and the low flow sensor for the
equipment cooling system of the EFIS, by doing all the applicable
actions specified in the Accomplishment Instructions of Boeing Alert
Service Bulletin 737-21A1156, Revision 2, dated December 11, 2008.
Credit for Actions Done Using Previous Service Information
(g)(1) Actions done before the effective date of this AD in
accordance with Boeing Alert Service Bulletin 737-21A1156, Revision
1, dated October 23, 2007, are acceptable for compliance with the
corresponding requirements of this AD.
(2) For Groups 1 and 2 airplanes identified in Boeing Alert
Service Bulletin 737-21A1156, Revision 1, dated October 23, 2007:
Actions done before the effective date of this AD in accordance with
Boeing Alert Service Bulletin 737-21A1156, dated June 20, 2006, are
acceptable for compliance with the corresponding requirements of
this AD.
Alternative Methods of Compliance (AMOCs)
(h)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, ATTN: Suk Jang, Aerospace Engineer, Systems and Equipment
Branch, ANM-130S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; telephone (425) 917-6511; fax (425) 917-6590;
has the authority to approve AMOCs for this AD, if requested using
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 principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, or lacking a
principal inspector, your local Flight Standards District Office.
The AMOC approval letter must specifically reference this AD.
Material Incorporated by Reference
(i) You must use Boeing Alert Service Bulletin 737-21A1156,
Revision 2, dated December 11, 2008; 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, Attention: Data & Services Management,
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone
206-544-5000, extension 1, fax 206-766-5680; e-mail
me.boecom@boeing.com; Internet https://www.myboeingfleet.com.
(3) You may review copies of the service information at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington. For information on the availability of this material at
the FAA, call 425-227-1221 or 425-227-1152.
(4) You may also review copies of the service information that
is incorporated by reference 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 June 1, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E9-13304 Filed 6-10-09; 8:45 am]
BILLING CODE 4910-13-P