DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0015; Project Identifier AD-2022-01281-T]
RIN 2120-AA64

Airworthiness Directives; AVOX System Inc. (formerly Scott
Aviation) Oxygen Cylinder and Valve Assemblies; and Oxygen Valve
Assemblies

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2022-04-09, which applies to certain AVOX System Inc. (formerly Scott
Aviation) oxygen cylinder and valve assemblies; and oxygen valve
assemblies; installed on but not limited to various transport
airplanes. AD 2022-04-09 requires an inspection of the oxygen valve
assemblies, and oxygen cylinder and valve assemblies, to determine the
serial number; for certain assemblies and parts, a detailed inspection
of the gap between the bottom of the packing retainer and top of the
valve body on the assemblies; and replacement of assemblies having
unacceptable gaps. Since the FAA issued AD 2022-04-09, the agency
determined additional assemblies and parts are affected by the unsafe
condition. This proposed AD would require an inspection of the oxygen
valve assemblies, and oxygen cylinder and valve assemblies, to
determine the serial number of the valve, cylinder, and entire
assembly. For assemblies and parts with certain serial numbers, this
proposed AD would require a detailed inspection for correct spacing of
the gap between the bottom of the packing retainer and top of the valve
body on the assemblies, and replacement of assemblies having
unacceptable gaps. This proposed AD would also limit the installation
of affected parts under certain conditions. The FAA is proposing this
AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by March 13,
2023.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to 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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-0015; or in person at Docket Operations between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD
docket contains this NPRM, any comments received, and other
information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
For service information identified in this NPRM, contact
AVOX Systems Inc., 225 Erie Street, Lancaster, NY 14086; telephone 716-
683-5100; internet safranaerosystems.com.
You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200 South
216th St., Des Moines, WA. For information on the availability of this
material at the FAA, call 206-231-3195.

FOR FURTHER INFORMATION CONTACT: Elizabeth Dowling, Aerospace Engineer,
Mechanical Systems and Administrative Services Section, FAA, New York
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2023-0015; Project Identifier
AD-2022-01281-T'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
the proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each
substantive verbal contact received about this proposed AD.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
Elizabeth Dowling, Aerospace Engineer, Mechanical Systems and
Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; email
9-avs-nyaco-cos@faa.gov. Any commentary that the FAA receives that is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.

Background

The FAA issued AD 2022-04-09, Amendment 39-21951 (87 FR 10958,
February 28, 2022) (AD 2022-04-09), for certain AVOX System Inc.
(formerly Scott Aviation) oxygen cylinder and valve assemblies, and
oxygen valve assemblies, installed on but not limited to various
transport airplanes. AD 2022-04-09 was prompted by reports of cylinder
and valve assemblies having oxygen leakage from the valve assembly vent
hole, caused by the absence of a guide that maintains appropriate
spacing between certain parts. AD 2022-04-09 requires an inspection of
the oxygen valve assemblies, and oxygen cylinder and valve assemblies,
to determine the serial number of the valve, cylinder, and entire
assembly. For assemblies and parts with certain serial numbers, AD
2022-04-09 requires a detailed inspection for correct spacing of the
gap between the bottom of the packing retainer and top of the valve
body on the assemblies, and replacement of assemblies having
unacceptable gaps. The agency issued AD 2022-04-09 to address oxygen
leakage from the cylinder, which could result in decreased or
insufficient oxygen supply during a depressurization event; and heating
or flow friction, which could cause an ignition event in the valve
assembly.

Actions Since AD 2022-04-09 Was Issued

Since the FAA issued AD 2022-04-09, the agency determined
additional assemblies and parts are affected by the unsafe condition.
New service information has been issued that expands the population of
discrepant parts, providing more serial numbers for which to inspect.

FAA's Determination

The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.

Related Service Information Under 1 CFR Part 51

The FAA reviewed the following service information, which describes
procedures for an inspection to determine the serial numbers of the
oxygen cylinder and valve assemblies, and the oxygen valve assemblies,
a detailed inspection for correct spacing of the gap between the bottom
of the packing retainer and top of the valve body on the assemblies,
parts marking, inspection report, and return of parts to the
manufacturer. These documents are distinct since they apply to
different assembly part numbers.
AVOX Systems Inc. Alert Service Bulletin 10015804-35-01,
Revision 03, dated June 7, 2021.
AVOX Systems Inc. Alert Service Bulletin 10015804-35-02,
Revision 03, dated March 11, 2022.
AVOX Systems Inc. Alert Service Bulletin 10015804-35-03,
Revision 03, dated June 18, 2021.
This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in the ADDRESSES section.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified
in the service information described previously. This proposed AD would
limit the installation of affected parts under certain conditions and
require returning the affected parts and sending the inspection results
to the manufacturer.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 3,034 oxygen cylinder and valve assemblies, and oxygen valve
assemblies, installed on various transport category airplanes of U.S.
registry. The FAA estimates the following costs to comply with this
proposed AD:

Estimated Costs

The FAA estimates the following costs to do any necessary follow-on
actions that would be required based on the results of the inspection.
The FAA has no way of determining the number of aircraft that might
need these actions:

On-Condition Costs

* The FAA has received no definitive data on the parts cost for the
on-condition replacements.

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this proposed AD may be covered under warranty, thereby reducing the
cost impact on affected operators.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, completing and reviewing the collection of
information. All responses to this collection of information are
mandatory. Send comments regarding this burden estimate or any other
aspect of this collection of information, including suggestions for
reducing this burden to: Information Collection Clearance Officer,
Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX
76177-1524.

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.
The FAA is 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

The FAA has 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) Would not affect intrastate aviation in Alaska, and
(3) Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, 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 FAA amends Sec. 39.13 by:

a. Removing Airworthiness Directive (AD) 2022-04-09, Amendment 39-21951
(87 FR 10958, February 28, 2022), and

b. Adding the following new AD: