[Federal Register Volume 86, Number 244 (Thursday, December 23, 2021)]
[Proposed Rules]
[Pages 72891-72894]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-27622]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1074; Project Identifier MCAI-2021-00447-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 429 helicopters. This 
proposed AD was prompted by reports of failed rivets between the 
tailboom skin and the tail rotor (TR) gearbox support assembly. This 
proposed AD would require visually inspecting the external surface of 
the TR gearbox support assembly, borescope inspecting or visually 
inspecting the inside of the tailboom for certain conditions, and 
performing a tactile inspection. Depending on the results of the 
inspections, this proposed AD would require removing certain rivets 
from service or repairing gaps in accordance with FAA-approved methods. 
This proposed AD would also require repeating these inspections within 
certain intervals. 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 February 7, 
2022.

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 https://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: Deliver to Mail address between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, 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 [email protected]; or at https://www.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.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No.

[[Page 72892]]

FAA-2021-1074; 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, the Transport Canada AD, any comments received, and 
other information. The street address for Docket Operations is listed 
above.

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 [email protected].

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-2021-1074; Project Identifier 
MCAI-2021-00447-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 
https://www.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 
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 [email protected]. 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, has 
issued Canadian AD CF-2021-15, dated April 14, 2021 (Transport Canada 
AD CF-2021-15), to correct an unsafe condition for Bell Textron Canada 
Limited Model 429 helicopters, serial numbers (S/N) 57001 and 
subsequent. Transport Canada advises of multiple in-service reports of 
failed rivets at the joint between the tailboom skin and the TR gearbox 
support assembly part number (P/N) 429-034-701-101 or P/N 429-035-705-
101. Transport Canada states that in-service reports also revealed a 
quality escape resulted in a gapping condition between the tailboom 
skin and the TR gearbox support fitting at some locations around the 
joint, and that rivets of inadequate grip length have been installed at 
the affected joint. This condition, if not addressed, could result in 
progressive deterioration of the joint structural integrity, detachment 
of the TR gearbox support assembly and loss of control of the 
helicopter.
    Accordingly, Transport Canada AD CF-2021-15 requires for certain 
serial-numbered helicopters an initial visual inspection of the rivets 
at the TR gearbox support assembly for signs of failed rivets or 
inadequate grip length. Transport Canada AD CF-2021-15 also requires, 
for all serial-numbered helicopters defined in the applicability, 
repeating the initial visual inspection at intervals not to exceed 400 
hours air time or 12 months, whichever occurs first. Transport Canada 
AD CF-2021-15 also requires repair or replacement of affected parts if 
discrepancies are found. Transport Canada considers its AD an interim 
action and states that further AD action may follow.

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, its 
technical representative, has notified the FAA of the unsafe condition 
described in its AD. The FAA is proposing this AD after evaluating all 
known relevant information and determining that the unsafe condition 
described previously is likely to exist or develop on other helicopters 
of these same type designs.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Bell Alert Service Bulletin 429-19-47, Revision B, 
dated January 27, 2021 (ASB 429-19-47). This service information 
specifies procedures for an initial and repetitive general visual 
inspections and detailed inspections of the affected rivets at the 
joint between the tailboom skin and the TR gearbox support assembly. 
This service information also specifies procedures for replacing the 
affected rivets and repairing the gaps in accordance with an approved 
Bell structural repair scheme.
    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

    For Model 429 helicopters with S/N 57002 through 57210 inclusive 
and S/N 57212 and subsequent that, as of the effective date of this AD, 
have accumulated less than 300 total hours time-in-service (TIS), 
before accumulating 400 total hours TIS; or for helicopters with S/N 
57002 through 57210 inclusive and S/N 57212 and subsequent that, as of 
the effective date of this AD, have replaced certain part-numbered TR 
gearbox support assemblies and the helicopter has accumulated less than 
300 total hours TIS since the replacement of the TR gearbox support 
assembly, before accumulating 400 total hours TIS since the 
replacement, this proposed AD would require visually inspecting the 
external surface of the TR gearbox support assembly for any rivet heads 
that have separated from their tail, measuring any gaps, and before 
further flight, removing affected rivets from service or repairing gaps 
in accordance with FAA-approved methods.
    This proposed AD would also require either borescope inspecting or 
using a light source and mirror to visually inspect each rivet inside 
the tailboom for missing rivet tails, rivet tails not resting against 
the tailboom skin, and any rivet tails resting at the bottom of the 
tailboom. Depending on the inspection results, this proposed AD would 
require, before further flight, additional inspections or removing 
certain parts from service. This proposed AD would require performing a 
tactile inspection of certain rivets

[[Page 72893]]

identified in the applicable service information and depending on the 
inspection results, removing rivets from service before further flight.
    For Model 429 helicopters with S/N 57002 through 57210 inclusive 
and S/N 57212 and subsequent that are not identified in paragraph 
(g)(1) of this AD, this proposed AD would require, within 100 hours TIS 
after the effective date of this AD, performing the visual inspection 
of the TR gearbox support assembly, visually inspecting or borescope 
inspecting each rivet inside the tailboom, performing the tactile 
inspection, and accomplishing the applicable corrective actions 
described previously.
    For Model 429 helicopters S/N 57002 through 57210 inclusive and S/N 
57212 and subsequent this proposed AD would require, within 400 hours 
TIS after the initial inspections required by this proposed AD, as 
applicable to your helicopter, and thereafter at intervals not to 
exceed 400 hours TIS, performing the visual inspection of the TR 
gearbox support assembly, visually inspecting or borescope inspecting 
each rivet inside the tailboom, performing the tactile inspection, and 
accomplishing the applicable corrective actions described previously.
    For Model 429 helicopters S/N 57001 and 57211, this proposed AD 
would require, within 400 hours TIS after the effective date of this 
proposed AD and thereafter at intervals not to exceed 400 hours TIS, 
performing the visual inspection of the TR gearbox support assembly, 
visually inspecting or borescope inspecting each rivet inside the 
tailboom, performing the tactile inspection, and accomplishing the 
applicable corrective actions described previously.

Differences Between This Proposed AD and the Transport Canada AD

    Transport Canada AD CF-2021-15 requires replacing any rivets, and 
repairing any gaps that exceed 0.005 in (0.127 mm), in accordance with 
an approved Bell structural repair scheme, and submitting certain 
information to the manufacturer, whereas this proposed AD would require 
removing the rivets from service and repairing the gaps using an FAA-
approved method instead. Transport Canada AD CF-2021-15 requires 
replacing any rivets if any gaps are 0.005 in (0.127mm) or less, 
whereas this proposed AD would require removing the rivets from 
service.
    Transport Canada AD CF-2021-15 also requires for certain serial-
numbered helicopters that have accumulated less than 300 hours air 
time, or have replaced a certain part-numbered TR gearbox support 
assembly and have accumulated less than 300 hours air time since the 
replacement, within 100 hours air time or 6 months upon reaching 300 
hours air time, whichever occurs first, performing the visual 
inspection of the TR gearbox support assembly, visually inspecting or 
borescope inspecting each rivet inside the tailboom, performing the 
tactile inspection, and accomplishing the applicable corrective actions 
described previously, whereas this proposed AD would require these 
actions for certain helicopters before accumulating 400 total hours TIS 
and for certain other helicopters, before the helicopter accumulates 
400 total hours TIS since the replacement of a certain part-numbered TR 
gearbox support assembly.
    Additionally, Transport Canada AD CF-2021-15 requires for certain 
serial-numbered helicopters that have accumulated 300 hours air time or 
more, or have replaced a certain part-numbered TR gearbox support 
assembly and have accumulated 300 hours air time or more since the 
replacement, within 100 hours air time or 6 months, whichever occurs 
first, performing the visual inspection of the TR gearbox support 
assembly, visually inspecting or borescope inspecting each rivet inside 
the tailboom, performing the tactile inspection, and accomplishing the 
applicable corrective actions described previously, whereas this 
proposed AD would require these actions within 100 hours TIS after the 
effective date of this AD.
    Finally, Transport Canada AD CF-2021-15 requires repeating the 
visual inspection of the TR gearbox support assembly, the visual 
inspection or borescope inspection of each rivet inside the tailboom, 
performing the tactile inspection, and accomplishing the applicable 
corrective actions described previously at intervals not to exceed 400 
hours air time or 12 months, whichever occurs first, whereas this 
proposed AD would require for certain serial-numbered helicopters, the 
repetitive inspections to occur within 400 hours TIS after the 
effective date of this AD, and thereafter at intervals not to exceed 
400 hours TIS.

Interim Action

    The FAA considers this proposed AD would be an interim action. Once 
final action has been identified, the FAA might consider further 
rulemaking.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 120 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.
    Visually inspecting the surface of the TR gearbox support assembly 
would take about 0.5 work-hour for an estimated cost of $43 per 
inspection and $5,160 for the U.S. fleet per inspection.
    If required, replacing any affected rivets would take about 1 work-
hour and parts would cost about $110 per rivet for an estimated cost of 
$195 per rivet replacement.
    If required, measuring gaps would take about 0.5 work-hour for an 
estimated cost of $43 per helicopter.
    If required, repairing any gaps would take up to about 1 work-hour 
for an estimated cost of up to $85 per repair.
    Visually inspecting or borescope inspecting the inside of the 
tailboom would take about 0.5 work-hour for an estimated cost of $43 
per inspection and $5,160 for the U.S. fleet per inspection.
    Performing a tactile inspection would take about 0.5 work-hour for 
an estimated cost of $43 per inspection and $5,160 for the U.S. fleet 
per inspection.

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, I certify this proposed regulation:

[[Page 72894]]

    (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

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 airworthiness 
directive:

Bell Textron Canada Limited: Docket No. FAA-2021-1074; Project 
Identifier MCAI-2021-00447-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by February 7, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bell Textron Canada Limited Model 429 
helicopters, serial numbers (S/N) 57001 and subsequent, certificated 
in any category.

(d) Subject

    Joint Aircraft Service Component (JASC) Code: 5302, Rotorcraft 
tail boom.

(e) Unsafe Condition

    This AD was prompted by reports of failed rivets between the 
tailboom skin and the tail rotor (TR) gearbox support assembly. The 
FAA is issuing this AD to detect failed rivets and rivets with 
inadequate grip length. The unsafe condition, if not addressed, 
could result in deterioration of the joint structural integrity, 
detachment of the TR gearbox support assembly, and loss of 
helicopter control.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) As of the effective date of this AD, for Model 429 
helicopters S/N 57002 through 57210 inclusive and S/N 57212 and 
subsequent that have accumulated less than 300 total hours time-in-
service (TIS), before accumulating 400 total hours TIS; or for Model 
429 helicopters S/N 57002 through 57210 inclusive and S/N 57212 and 
subsequent that have replaced the TR gearbox support assembly part 
number (P/N) 429-034-701-101 or P/N 429-035-705-101 and the 
helicopter has accumulated less than 300 total hours TIS since the 
replacement of the TR gearbox support assembly, before accumulating 
400 total hours TIS since the replacement:
    (i) Visually inspect the external surface of the TR gearbox 
support assembly for any rivet heads that have separated from their 
tail. If there are any rivet heads that have separated from their 
tail, before further flight, measure any gaps between the TR gearbox 
support assembly and the tailboom skin by following the 
Accomplishment Instructions, Part I, paragraphs 9.b. through 9.d of 
Bell Alert Service Bulletin 429-19-47, Revision B, dated January 27, 
2021 (ASB 429-19-47 Rev B).
    (A) If there are no gaps or if any gap measures less than 0.005 
in (0.127 mm), before further flight, remove the rivets from 
service.
    (B) If there are any gaps that are equal to or exceed 0.005 in 
(0.127 mm), before further flight, repair the gaps in accordance 
with an FAA-approved method, and remove the rivets from service.
    (ii) Borescope inspect or use a light source and mirror to 
visually inspect each rivet inside the tailboom for any missing 
rivet tails, any rivet tails resting at the bottom of the tailboom, 
and any rivet tails not resting against the tailboom skin.
    (A) If there are any missing rivet tails, or any rivet tails 
resting at the bottom of the tailboom, before further flight, 
measure any gaps between the TR gearbox support assembly and the 
tailboom skin by following the Accomplishment Instructions, Part I, 
paragraphs 9.b. through 9.d of ASB 429-19-47 Rev B, and perform the 
corrective actions specified in paragraphs (g)(1)(i)(A) or (B) of 
this AD as applicable.
    (B) If there are any rivet tails not resting against the 
tailboom skin before further flight, remove the rivets from service.
    (iii) Perform a tactile inspection of the rivets identified in 
Figure 1 of ASB 429-19-47 Rev B, by pulling on each rivet tail with 
pliers or pulling by hand. If any rivet does not come out when 
pulled with pliers or when pulled by hand, before further flight, 
remove the rivet from service.
    (2) For Model 429 helicopters S/N 57002 through 57210 inclusive 
and S/N 57212 and subsequent that are not identified in paragraph 
(g)(1) of this AD, within 100 hours TIS after the effective date of 
this AD, perform the actions as specified in paragraph (g)(1)(i) 
through (iii) of this AD.
    (3) For Model 429 helicopters S/N 57002 through 57210 inclusive 
and S/N 57212 and subsequent, within 400 hours TIS after the initial 
inspections required by paragraph (g)(1) or (2) of this AD, as 
applicable to your helicopter, and thereafter at intervals not to 
exceed 400 hours TIS, accomplish the actions required by paragraphs 
(g)(1)(i) through (iii) of this AD.
    (4) For Model 429 helicopters S/N 57001 and 57211, within 400 
hours TIS after the effective date of this AD, and thereafter at 
intervals not to exceed 400 hours TIS, accomplish the actions 
required by paragraphs (g)(1)(i) through (iii) of this AD.

(h) Credit for Previous Actions

    This paragraph provides credit for the actions specified in 
paragraphs (g)(1) and (2) of this AD, if those actions were 
performed before the effective date of this AD using Bell Alert 
Service Bulletin 429-19-47, Revision A, dated November 2, 2020, or 
Bell Alert Service Bulletin 429-19-47, dated August 28, 2019.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, International Validation Branch, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the International Validation Branch, send 
it to the attention of the person identified in paragraph (j)(1) of 
this AD. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    (1) For more information about this AD, 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 [email protected].
    (2) For service information identified in this AD, 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 [email protected]; or at https://www.bellflight.com/support/contact-support. You may view this 
referenced 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.
    (3) The subject of this AD is addressed in Transport Canada AD 
CF-2021-15, dated April 14, 2021. You may view the Transport Canada 
AD on the internet at https://www.regulations.gov in Docket No. FAA-
2021-1074.

    Issued on December 15, 2021.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-27622 Filed 12-22-21; 8:45 am]
BILLING CODE 4910-13-P