DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0232; Project Identifier MCAI-2023-00353-R]
RIN 2120-AA64

Airworthiness Directives; Bell Textron Canada Limited Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Bell Textron Canada Limited Model 407 helicopters. This
proposed AD was prompted by a report that a certain part-numbered fuel
system standpipe assembly (standpipe) may have sharp edges at the
interval weld joints due to a quality escape during the manufacturing
process. This proposed AD would require inspecting certain fuel system
parts and, depending on the inspection results, taking corrective
actions and performing a fuel quantity gauging system calibration.
Depending on the results of the fuel quantity gauging system
calibration, this proposed AD would require performing additional
corrective action and repeating the fuel quantity gauging system
calibration. The FAA is proposing this AD to address the unsafe
condition on these products.

DATES: The FAA must receive comments on this NPRM by April 5, 2024.

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-2024-0232; 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
Bell Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec
J7J 1R4, Canada; phone 1-450-437-2862 or 1-800-363-8023; fax 1-450-433-
0272; email productsupport@bellflight.com; or at bellflight.com/support/contact-support.
You may view this service information at the FAA, Office
of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room
6N 321, Fort Worth, TX 76177. For information on the availability of
this material at the FAA, call (817) 222-5110.

FOR FURTHER INFORMATION CONTACT: Michael Hughlett, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (817) 222-5889; email: michael.hughlett@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-2024-0232; Project Identifier
MCAI-2023-00353-R'' 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
this 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 NPRM.

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
Michael Hughlett, Aviation Safety Engineer, FAA, 1600 Stewart Avenue,
Suite 410, Westbury, NY 11590; phone: (817) 222-5889; email:
michael.hughlett@faa.gov. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.

Background

Transport Canada, which is the aviation authority for Canada,
issued Transport Canada AD CF-2023-11, dated February 23, 3023
(Transport Canada AD CF-2023-11), to correct an unsafe condition on
Bell Textron Canada Limited Model 407 helicopters, serial numbers 54832
through 54931, 54933 through 54939, and 54942 through 54954. Transport
Canada advises that, due to a quality escape, standpipe part number (P/
N) 407-062-032-103 may have been delivered with sharp edges at the
internal weld joints.
Accordingly, Transport Canada AD CF-2023-11 requires a one-time
inspection of standpipe P/N 407-062-032-103 for sharp edges, and
depending on the inspection results, reworking the standpipe. Transport
Canada AD CF-2023-11 also requires inspecting certain parts of the fuel
quantity harness assembly (harness assembly) for damage. Depending on
the inspection results, Transport Canada AD CF-2023-11 requires
contacting Bell for disposition results of the harness assembly and
replacing any unserviceable harness assembly.
You may examine the Transport Canada AD in the AD docket at
regulations.gov under Docket No. FAA-2024-0232.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Bell Alert Service Bulletin 407-21-124, dated
February 1, 2022, which specifies procedures for a one-time visual
inspection of the internal joint welds of standpipe P/N 407-062-032-
103. If there are any sharp edges, this service information specifies
rework procedures, which include deburring the sharp edges, removing
all residue, and applying a chemical film. This service information
also specifies procedures to remove and inspect the harness assembly
connectors for any damage to the electrical pins and inspect the
insulation tubing and wires for any cracks and chafing.
Additionally, this service information specifies if any damage is
found, contacting product support engineering and submitting certain
information. Finally, this service information specifies instructions
for various fuel procedures and checks.
The FAA also reviewed Fuel Quantity Gauging System, DMC-407-A-95-
65-10-01A-273A-A, Issue 002, dated June 2, 2022, of Bell Model 407
Maintenance Manual, BHT-407-MM, Issue No. 014, dated December 12, 2023,
which specifies procedures for a fuel quantity gauging system
calibration procedure and inspecting the fuel quantity display
information.
This material is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in ADDRESSES.

FAA's Determination

These helicopters have been approved by the aviation authority of
Canada and are approved for operation in the United States. Pursuant to
the FAA's bilateral agreement with Canada, Transport Canada has
notified the FAA of the unsafe condition described in its AD. The FAA
is proposing this AD after determining that the unsafe condition
described previously is likely to exist or develop on other helicopters
of the same type design.

Proposed AD Requirements in This NPRM

This proposed AD would require, with the standpipe removed,
inspecting its interior for any sharp edges on each internal weld
joint. If there are any sharp edges on any weld joint, this proposed AD
would require deburring the edges, ensuring not to exceed a certain
depth into the tube. This proposed AD would then require removing all
sanding residue and applying a chemical film to any bare metal
surfaces. This proposed AD would also require, with the harness
assembly removed, inspecting the harness assembly connectors for any
mechanical damage and corrosion to the electrical pins, and inspecting
the insulation tubing and wires of the harness assembly for any crack
and chafing. Depending on these results, this proposed AD would require
replacing the harness assembly.
If the harness assembly was required to be replaced as a result of
the proposed AD requirements, this proposed AD would require performing
a fuel quantity gauging system calibration. Depending on the
calibration results, this proposed AD would require replacing the
harness assembly and repeating the fuel quantity gauging system
calibration.

Differences Between This Proposed AD and the Transport Canada AD

Transport Canada AD CF-2023-11 requires contacting Bell for
disposition instructions if damage is found on the harness assembly,
whereas this proposed AD would require removing an affected harness
assembly from service and replacing it with an airworthy harness
assembly.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 51 helicopters of U.S. Registry. Labor rates are estimated at
$85 per work-hour. Based on these numbers, the FAA estimates the
following costs to comply with this proposed AD.
Inspecting the interior of the standpipe would take approximately 1
work-hour for an estimated cost of $85 per helicopter and $4,335 for
the U.S. fleet.
Inspecting the harness assembly connectors, insulation tubing, and
wiring would take approximately 1 work-hour for an estimated cost of
$85 per helicopter and $4,335 for the U.S. fleet.
If required, deburring, cleaning, and applying a chemical film to
each affected weld joint would take approximately 0.5 work-hour for an
estimated cost of $43 per weld joint.
If required, replacing an affected harness assembly would take
approximately 1 work-hour and parts would cost approximately $1,071 for
an estimated cost of $1,156 per harness replacement.
If required, performing a fuel quantity gauging system calibration
would take approximately 10 work-hours for an estimated cost of $850
per procedure.
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this
proposed AD may be covered under warranty, thereby reducing the cost
impact on affected operators.

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 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 this 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 adding the following new airworthiness
directive: