DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0992 Project Identifier MCAI-2022-00173-R;
Amendment 39-22229; AD 2022-23-02]
RIN 2120-AA64

Airworthiness Directives; Bell Textron Canada Limited (Type
Certificate Previously Held by Bell Helicopter Textron Canada Limited)
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 99-23-18,
AD 2005-03-07, AD 2013-12-07, and AD 2014-04-07, which applied to
certain Bell Helicopter Textron Canada (now Bell Textron Canada
Limited) Model 407 helicopters. AD 99-23-18 required revising the life
limits for certain parts, replacing each part that had exceeded its
life limit, and revising the Airworthiness Limitation Section (ALS) of
the existing maintenance manual. AD 2005-03-07 required establishing a
maximum accumulated Retirement Index Number (RIN) count for certain
crosstube assemblies and revising the ALS of the existing maintenance
manual. AD 2013-12-07 required inspecting the tailboom assembly for a
crack, loose rivet, or other damage and depending on the inspection
results, replacing certain parts. AD 2014-04-07 required preflight
checking, repetitively inspecting for a crack in certain tailbooms,
modifying and re-identifying certain tailbooms, installing an improved
horizontal stabilizer assembly, and revising the ALS of the existing
maintenance manual. Since the FAA issued those ADs, a report was
received of a crack on the tailboom lower skin due to fatigue damage
and new and more restrictive airworthiness limitations have been
issued. This AD was prompted by a report of a crack on the tailboom
lower skin due to fatigue damage and the issuance of new and more
restrictive airworthiness limitations. This AD requires incorporating
into existing maintenance records requirements (airworthiness
limitations) as specified in the ALS service information. The FAA is
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective January 3, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 3,
2023.

ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2022-0992; 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 final rule, any comments received, and other
information. The address for Docket Operations is U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
Material Incorporated by Reference:
For service information identified in this final rule,
contact Bell Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel,
Quebec J7J 1R4, Canada; telephone 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. It is also available at
regulations.gov under Docket No. FAA-2022-0992.

FOR FURTHER INFORMATION CONTACT: Andrea Jimenez, Aerospace Engineer,
COS Program Management Section, Operational Safety Branch, Compliance &
Airworthiness Division, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY
11590; telephone (516) 228-7330; email andrea.jimenez@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 99-23-18, Amendment 39-11414 (64 FR 61784,
November 15, 1999) (AD 99-23-18), AD 2005-03-07, Amendment 39-13963 (70
FR 7016, February 10, 2005) (AD 2005-03-07), AD 2013-12-07, Amendment
39-17485 (78 FR 38546, June 27, 2013) (AD 2013-12-07), and AD 2014-04-
07, Amendment 39-17766 (79 FR 35481, June 23, 2014) (AD 2014-04-07).
AD 99-23-18 applied to all Bell Helicopter Textron Canada (now Bell
Textron Canada Limited) Model 407 helicopters. AD 99-23-18 was prompted
by an engineering evaluation of additional flight test data, which
resulted in redefining the service life for certain parts and revising
the ALS of the existing maintenance manual. AD 99-23-18 required
revising the life limits for certain parts, and replacing each part
that had exceeded its life limit with an airworthy part. AD 99-23-18
also required revising the ALS of the existing maintenance manual to
reflect these new life limits and annotating the component history card
or equivalent record with the revised life limits.
AD 2005-03-07 applied to Bell Helicopter Textron Canada (now Bell
Textron Canada Limited) Model 407 helicopters with certain part-
numbered landing gear crosstube assemblies installed. AD 2005-03-07 was
prompted by fatigue testing, analysis, and evaluation by the
manufacturer that determined that run-on landings impose a high stress
on landing gear or crosstubes and may cause cracking in the area above
the skid tube saddle. AD 2005-03-07 required establishing a component
history card or equivalent record, converting accumulated run-on
landings to an accumulated RIN count, and establishing a maximum
accumulated RIN for certain crosstube assemblies. AD 2005-03-07 also
required replacing any crosstube assembly before it exceeds the maximum
RIN life limit and revising the ALS of the existing maintenance manual
to reflect this new life limit.
AD 2013-12-07 applied to Bell Helicopter Textron Canada (now Bell
Textron Canada Limited) Model 407 helicopters with certain part-
numbered tailboom assemblies installed. AD 2013-12-07 was prompted by a
stress analysis of the tailboom skin that revealed that
high-stress-concentration areas are susceptible to skin cracking. AD
2013-12-07 required, for certain tailboom assemblies, inspecting the
tailboom assembly for a crack or inspecting for a crack around each
fastener and above the edge of the upper stabilizer support. AD 2013-
12-07 also required, for certain tailboom assemblies, inspecting the
tailboom assembly for a crack by using either a 10X or higher power
magnifying glass, or by eddy current inspecting.
Additionally, AD 2013-12-07 required inspecting the tailboom
assembly for a crack, loose rivet, or other damage, and depending on
the inspection results, replacing the tailboom assembly with an
airworthy part.
AD 2014-04-07 applied to Bell Helicopter Textron Canada (now Bell
Textron Canada Limited) Model 407 helicopters serial numbers (S/Ns)
53000 through 53475, with certain part-numbered tailbooms installed. AD
2014-04-07 was prompted by additional reports of cracked tailboom
skins. AD 2014-04-07 required for certain part-numbered tailbooms that
have not been modified, conducting daily preflight checks of the
tailboom for a crack; and for certain tailbooms, visually inspecting
the tailboom for a crack using a 10X or higher power magnifying glass,
modifying and re-identifying certain part-numbered tailbooms, and
installing an improved horizontal stabilizer assembly. AD 2014-04-07
also required, for certain part-numbered tailbooms, after the
modification, establishing a component history card or equivalent
record, and revising the existing ALS of the maintenance manual to
reflect a new life limit.
Additionally, AD 2014-04-07 required, for certain part-number
tailbooms, daily visual inspections of the tailboom for a crack, and
using a 10X or higher power magnifying glass, inspecting each tailboom
for a loose rivet, crack, skin corrosion, or any other damage.
Depending on the inspection results, AD 2014-04-07 required corrective
actions, including, if there is a crack, replacing the tailboom
assembly.
The NPRM published in the Federal Register on August 15, 2022 (87
FR 50005). The NPRM was prompted by Transport Canada AD CF-2021-34,
dated October 22, 2021 (Transport Canada AD CF-2021-34), issued by
Transport Canada, which is the aviation authority for Canada, to
correct an unsafe condition for Bell Textron Canada Limited Model 407
helicopters, S/N 53000 through 53900, 53911 through 54166, and 54300
and subsequent. Transport Canada advises of a report of a crack on the
tailboom lower skin due to fatigue damage, which could affect the
structural integrity of the tailboom. Transport Canada advises that
Bell Textron Canada Limited issued a revision to the ALS, which adds a
new inspection zone for tailboom assemblies to address the unsafe
condition. Accordingly, Transport Canada AD CF-2021-34 requires
compliance with Bell BHT-407-MPI, Chapter 04, ALS, Issue 3, dated June
21, 2021, of Bell Model 407 Maintenance Planning Information, PMC-407-
97499-01000-00, Issue No. 005, dated July 6, 2022 (BHT-407-MPI, ALS
Issue 3), which includes maintenance tasks and life limits for the
tailboom and other parts. The FAA is issuing this AD to address the
unsafe condition on these products.
You may examine the Transport Canada AD in the AD docket at
regulations.gov under Docket No. FAA-2022-0992.

Relationship Between AD 99-23-18, AD 2005-03-07, AD 2013-12-07, AD
2014-04-07, and This AD

AD 99-23-18 and AD 2005-03-07 were prompted by unsafe conditions
not related to the tailboom crack that prompted this AD. However, the
actions required to address the unsafe conditions in AD 99-23-18 and AD
2005-03-07 are included in BHT-407-MPI, ALS Issue 3. Therefore, the FAA
is superseding AD 99-23-18, AD 2005-03-07, AD 2013-12-07, and AD 2014-
04-07, in order to reduce the burden on operators by requiring
compliance with a single AD in lieu of multiple FAA ADs.
AD 99-23-18 required reducing the life limit for drive ring set
part number (P/N) 406-010-126-107 from 49,000 RIN to 48,000 RIN, and
replacing each part that has exceeded its life limit. BHT-407-MPI, ALS
Issue 3 states the life limit for drive ring set P/N 406-010-126-107 is
100,000 RIN.
AD 2005-03-07 required establishing a maximum accumulated RIN for
certain crosstube assemblies of 5,000 RIN and replacing any crosstube
assembly before it exceeds the maximum accumulated RIN. BHT-407-MPI,
ALS Issue 3 adds an additional life limit to certain part-numbered
crosstube assemblies of 2,500 landings or 5,000 RIN.
AD 2013-12-07 required for certain part-numbered tailboom
assemblies and with certain hours TIS, inspecting the tailboom assembly
for a crack. AD 2013-12-07 also required either inspecting using a 10X
or higher power magnifying glass and thereafter repeating that
inspection or eddy current inspecting and thereafter repeating the eddy
current inspection. Additionally, AD 2013-12-07 required inspecting the
tailboom assembly for a loose rivet, crack, or other damage.
BHT-407-MPI, ALS Issue 3 adds tailboom assembly P/N 407-530-013-105
and successive dash numbers, and also specifies for tailboom assembly
P/N 407-530-013-105 and successive dash numbers and P/N 407-030-801-201
and successive dash numbers, inspecting for a crack; and for certain
tailbooms inspecting using a 10X magnifying glass inspection method, or
eddy current inspecting; and for certain tailboom assemblies,
inspecting for a crack either with a daily visual inspection or with a
10X magnifying glass inspection method. Additionally, BHT-407-MPI, ALS
Issue 3 specifies additional inspection zones, intervals, and criteria.
AD 2014-04-07 required modifying and re-identifying certain part-
numbered tailbooms, and for these re-identified tailbooms, establishing
a retirement life of 5,000 hours TIS, daily checks for a crack, and
recurring inspections using a 10X or higher power magnifying glass for
a loose rivet, a crack, skin corrosion, or other damage. BHT-407-MPI,
ALS Issue 3 specifies for tailboom P/N 407-530-014-101 and successive
dash numbers, and P/N 407-030-801-107 and successive dash numbers,
daily and recurring inspections for a crack. BHT-407-MPI, ALS Issue 3
also revises the inspection areas.

Discussion of Final Airworthiness Directive

Comments

The FAA received no comments on the NPRM or on the determination of
the costs.

Conclusion

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, its
technical representative, has notified the FAA of the unsafe condition
described in its AD. The FAA reviewed the relevant data and determined
that air safety requires adopting this AD as proposed. Accordingly, the
FAA is issuing this AD to address the unsafe condition on these
helicopters. This AD is adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed BHT-407-MPI, ALS Issue 3, which specifies certain
actions and associated thresholds and
intervals, including life limits and maintenance tasks. These
requirements (airworthiness limitations) include new inspection zones
and new maintenance tasks (e.g., inspections for cracks) with new
compliance times.
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 ADDRESSES.

ADs Mandating Airworthiness Limitations

The FAA has previously mandated airworthiness limitations by
mandating each airworthiness limitation task (e.g., inspections and
replacements (life limits)) as an AD requirement or issuing ADs that
require revising the ALS of the existing maintenance manual or
instructions for continued airworthiness to incorporate new or revised
inspections and life limits. This AD, however, requires operators to
incorporate into maintenance records required by 14 CFR 91.417(a)(2) or
135.439(a)(2), as applicable for your rotorcraft, the requirements
(airworthiness limitations) identified in the ALS service information,
as described previously. The FAA does not intend this as a substantive
change. For these ADs, the ALS requirements for operators are the same
but are complied with differently. Requiring the incorporation of the
new ALS requirements into the existing maintenance records, rather than
requiring individual ALS tasks (e.g., repetitive inspections and
replacements), requires operators to record AD compliance once after
updating the maintenance records, rather than after every time the ALS
task is completed.

Differences Between This AD and the Transport Canada AD or the Service
Information

Transport Canada AD CF-2021-34 does not supersede any previously
issued Transport Canada ADs, whereas this AD supersedes FAA AD 99-23-
18, AD 2005-03-07, AD 2013-12-07, and AD 2014-04-07. The airworthiness
limitations specified in Transport Canada AD CF-2021-34 encompass the
requirements of AD 99-23-18, AD 2005-03-07, AD 2013-12-07, and AD 2014-
04-07.
Additionally, Transport Canada AD CF-2021-34 is applicable to
certain serial-numbered Bell Textron Canada Limited Model 407
helicopters, whereas this AD is applicable to all serial-numbered Model
407 helicopters.
The service information specifies replacing each component before
exceeding the applicable airworthiness life limit, accomplishing all
applicable maintenance tasks within the defined thresholds and
intervals, and performing the specified corrective action(s) if a
defect is found during the inspection, whereas this AD requires
incorporating requirements (airworthiness limitations) into existing
maintenance records within 30 days after the effective date of this AD.

Costs of Compliance

The FAA estimates that this AD affect 791 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 AD.
Incorporating requirements (airworthiness limitations) into
existing maintenance records takes about 2 work-hours for an estimated
cost of $170 per helicopter and $134,470 for the U.S. fleet.

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 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) Will not affect intrastate aviation in Alaska, 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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 99-23-18, Amendment 39-11414 (64 FR
61784, November 15, 1999); Airworthiness Directive 2005-03-07,
Amendment 39-13963 (70 FR 7016, February 10, 2005); Airworthiness
Directive 2013-12-07, Amendment 39-17485 (78 FR 38546, June 27, 2013);
and Airworthiness Directive 2014-04-07, Amendment 39-17766 (79 FR
35481, June 23, 2014); and

b. Adding the following new airworthiness directive: