[Federal Register: January 14, 2008 (Volume 73, Number 9)]
[Proposed Rules]
[Page 2195-2197]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14ja08-18]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0011; Directorate Identifier 2007-NM-203-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757 Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Boeing Model 757 airplanes. This proposed AD would require
an inspection to determine the manufacturer and manufacture date of the
oxygen masks in the passenger service units and the lavatory and
attendant box assemblies, and corrective action if necessary. This
proposed AD results from a report that several passenger masks with
broken in-line flow indicators were found following a mask deployment.
We are proposing this AD to prevent the in-line flow indicators of the
passenger oxygen masks from fracturing and separating, which could
inhibit oxygen flow to the masks and consequently result in exposure of
the passengers and cabin attendants to hypoxia following a
depressurization event.
DATES: We must receive comments on this proposed AD by February 28,
2008.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov.
Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
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 proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Susan Letcher, Aerospace Engineer,
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; telephone (425) 917-6474; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2008-0011;
Directorate Identifier 2007-NM-203-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov
, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.
Discussion
We have received a report indicating that several passenger masks
with broken in-line flow indicators were found following a mask
deployment on a Boeing Model 777-200 series airplane. Operators
subsequently found several more broken in-line flow indicators after
examining the oxygen mask assemblies on other Model 777 series
airplanes and on Model 747-400 series airplanes. Investigation revealed
that certain flow indicators are weaker and can fracture because of
internal residual stresses caused by the flow indicator joint
[[Page 2196]]
design and manufacturing processes. Fractures cause the in-line flow
indicator to separate and consequently prevent oxygen flow to the mask
during an emergency. This condition, if not corrected, could result in
exposure of the passengers and cabin attendants to hypoxia following a
depressurization event.
The oxygen masks on certain Model 777 airplanes and Model 747-400
series airplanes have the same flow indicators as those installed on
certain Model 757 airplanes. Therefore, the Model 757 airplanes may be
subject to the identified unsafe condition.
Relevant Service Information
We have reviewed Boeing Special Attention Service Bulletin 757-35-
0028, dated April 9, 2007. The service bulletin describes procedures
for doing a general visual inspection to determine the manufacturer and
manufacture date of the oxygen masks in the passenger service units
(PSUs) and the lavatory and attendant box assemblies. The service
bulletin also describes procedures for doing the corrective action if
necessary and other specified action. The corrective action is to
repair any B/E Aerospace oxygen mask assembly with a manufacturing date
after January 1, 2002, and before March 1, 2006. The service bulletin
also specifies that as an alternative to doing the repair (rework), the
oxygen mask assembly may be replaced with a new oxygen mask.
Boeing Special Attention Service Bulletin 757-35-0028 refers to B/E
Aerospace Service Bulletin 174080-35-01, dated February 6, 2006; and
Revision 1, dated May 1, 2006; as additional sources of service
information for repairing the oxygen mask assembly. B/E Aerospace
Service Bulletin 174080-35-01 describes procedures for modifying the
oxygen mask assembly by replacing the flow indicator, part number (P/N)
118023-02, with an improved flow indicator, P/N 118023-12. B/E
Aerospace Service Bulletin 174080-35-01 also specifies that, as an
alternative to modifying the oxygen mask, operators may replace the
oxygen mask with a new oxygen mask having the improved flow indicator.
Accomplishing the actions specified in the service information is
intended to adequately address the unsafe condition.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other airplanes
of this same type design. For this reason, we are proposing this AD,
which would require accomplishing the actions specified in the service
information described previously.
Clarification Between the Proposed AD and Service Bulletin
Although Boeing Special Attention Service Bulletin 757-35-0028
specifies to repair the oxygen mask assembly, the intent of the service
bulletin is to replace it with either a new or modified oxygen mask
assembly having an improved flow indicator. Therefore, this proposed AD
would require replacing the oxygen mask assembly with a new or modified
oxygen mask assembly having an improved flow indicator.
Costs of Compliance
There are about 1,035 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 640 airplanes of
U.S. registry. The proposed actions would take about 20 work hours per
airplane, for an average of 240 oxygen masks per airplane, at an
average labor rate of $80 per work hour. Based on these figures, the
estimated cost of the proposed AD for U.S. operators is $1,024,000, or
$1,600 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
We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 the proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the 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.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket. See the
ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
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]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2008-0011; Directorate Identifier 2007-NM-
203-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by February
28, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 757-200, -200CB, -200PF, and
-300 series airplanes, certificated in any category; as identified
in Boeing Special Attention Service Bulletin 757-35-0028, dated
April 9, 2007.
Unsafe Condition
(d) This AD results from a report that several passenger masks
with broken in-line flow indicators were found following a mask
deployment. We are issuing this AD to prevent the in-line flow
indicators of the passenger oxygen masks from fracturing and
separating, which could inhibit oxygen flow to the masks and
consequently result in exposure of the passengers and cabin
attendants to hypoxia following a depressurization event.
[[Page 2197]]
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.
Inspection and Corrective/Other Specified Actions if Necessary
(f) Within 60 months after the effective date of this AD, do a
general visual inspection to determine the manufacturer and
manufacture date of the oxygen masks in the passenger service units
and the lavatory and attendant box assemblies, and do the applicable
corrective action, by accomplishing all of the applicable actions
specified in the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 757-35-0028, dated April 9, 2007; except
where the service bulletin specifies repairing the oxygen mask
assembly, replace it with a new or modified oxygen mask assembly
having an improved flow indicator. The corrective action and other
specified action must be done before further flight.
Note 1: The service bulletin refers to B/E Aerospace Service
Bulletin 174080-35-01, dated February 6, 2006; and Revision 1, dated
May 1, 2006; as additional sources of service information for
modifying the oxygen mask assembly by replacing the flow indicator
with an improved flow indicator.
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.
Issued in Renton, Washington, on December 21, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-376 Filed 1-11-08; 8:45 am]
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