[Federal Register Volume 86, Number 111 (Friday, June 11, 2021)]
[Rules and Regulations]
[Pages 31089-31092]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-12229]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0185; Project Identifier MCAI-2020-00265-R; 
Amendment 39-21581; AD 2021-11-19]
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 adopting a new airworthiness directive (AD) for 
Bell Textron Canada Limited (type certificate previously held by Bell 
Helicopter Textron Canada Limited) (Bell) Model 505 helicopters. This 
AD was prompted by the discovery of a gap between the transmission 
restraint assembly aft attachment hardware lower washer and mating 
airframe truss assembly (truss assembly) clevis lower lug. This AD 
requires inspecting the transmission restraint aft attachment hardware 
installation for a gap and corrective action depending on the 
inspection results. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective July 16, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain document listed in this AD as of July 16, 2021.

ADDRESSES: For service information identified in this final rule, 
contact Bell Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, 
Quebec J7J1R4; telephone 450-437-2862 or 800-363-8023; fax 450-433-
0272; or at https://www.bellcustomer.com. You may view the referenced 
service information at the FAA, Office of the Regional Counsel, 
Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 
76177. Service information that is incorporated by reference is also 
available at https://www.regulations.gov by searching for and locating 
Docket No. FAA-2021-0185.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0185; 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, the 
Transport Canada AD, any comments received, and other information. The 
street 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.

FOR FURTHER INFORMATION CONTACT: Matt Fuller, AD Program Manager, 
General Aviation & Rotorcraft Unit, Airworthiness Products Section, 
Operational Safety Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 
76177; telephone 817-222-5110; email matthew.fuller@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to Bell Model 505 
helicopters with a truss assembly part number (P/N) SLS-030-056-015 
with a serial number (S/N) listed in Attachment A of Bell Alert Service 
Bulletin (ASB) 505-19-12, Revision A, dated July 11, 2019 (505-19-12 
Rev A). The NPRM published in the Federal Register on March 22, 2021 
(86 FR 15146). In the NPRM, the FAA proposed to require the following 
within 100 hours time-in-service (TIS):
     Accessing and cleaning the lower attachment hardware 
securing the restraint to the truss assembly, loosening the torque on 
each lower nut to measure the tare, and adding a torque value of 20 
inch-lbs to the measured tare of each nut and torqueing each nut to 
this new total value.
     Inspecting for a gap around the circumference between the 
nut and the washer and between the washer and the truss assembly clevis 
lower lug mounting surface of the right-hand (RH) and left-hand (LH) 
sides, and if there is a gap, measuring the gap.
     If there is a gap that is less than 0.003 inch (0.076 mm), 
installing the hardware using the original torque value of 40 to 58 
foot-pounds (55 to 78 Nm) plus tare and completing the installation of 
the attachment point.
     If there is a gap that is 0.003 inch (0.076 mm) to 0.020 
inch (0.508 mm) inclusive, installing the hardware with a decreased 
torque value limit of 20 to 60 inch-pounds (2.3 to 6.8 Nm) plus tare 
and completing the installation of the attachment point. The NPRM also 
proposed to require updating records for your helicopter to indicate 
the new torque limits on one or both sides. Thereafter, within 100 
hours TIS, and thereafter at intervals not to exceed 100 hours TIS, the 
NPRM proposed to

[[Page 31090]]

require inspecting the assembly for fretting between the washer and 
truss lower lug mounting surface, the security of the pitch restraint 
attachment hardware to make sure it does not turn freely, and the 
torque seal lacquer between the nut and the washer to make sure the 
torque seal is intact on the RH and LH sides. Depending on the 
inspection results, the NPRM proposed to require removing the cotter 
pin from service and removing the nut, washer, and bolt, and inspecting 
the bolt and the lower surface of the truss assembly clevis lower lug. 
Depending on these inspection results, the NPRM proposed to require 
removing the bolt from service; reworking and cleaning the lower 
surface of the clevis lower lug and inspecting for any cracks; removing 
the clevis lower lug from service; or applying primer and final paint. 
The NPRM then proposed to require installing the hardware with a 
decreased torque value limit of 20 to 60 inch-pounds (2.3 to 6.8 Nm) 
plus tare and completing the installation of the attachment point.
     If there is a gap that is more than more than 0.020 inch 
(0.508 mm), removing the nut, washer, and bolt from service and 
repairing or replacing the truss assembly clevis lower lug in 
accordance with FAA-approved procedures.
    The NPRM was prompted by Canadian AD CF-2019-35, dated October 2, 
2019 (Transport Canada AD CF-2019-35), issued by Transport Canada, 
which is the aviation authority for Canada, to correct an unsafe 
condition for Bell Model 505 helicopters, S/Ns 65011 and subsequent. 
Transport Canada advises of a gap between the transmission restraint 
assembly aft attachment hardware lower washer and the lower lug of the 
truss assembly clevis identified during quality control activity of a 
helicopter in final assembly. This gap can occur on the RH and LH sides 
of the truss assembly clevis. Subsequent investigation revealed that 
this condition may exist on in-service helicopters. Transport Canada 
advises that excessive gapping at either of these locations will result 
in increased stress when fasteners are installed and that the increased 
stress may result in cracking on the clevis lower lug and subsequent 
failure of one or both clevis lower lugs. Transport Canada further 
advises that this condition, if not corrected, could lead to loss of 
pylon pitch stiffness, excessive pylon pitch motions leading to unknown 
cyclic inputs to the main rotor, and consequent loss of control of the 
helicopter.
    Accordingly, Transport Canada AD CF-2019-35 requires identifying 
the S/N of the installed truss assembly, and for a helicopter with an 
affected truss assembly installed, performing an initial inspection of 
the transmission restraint aft attachment hardware installations for a 
gap. Depending on the inspection results, Transport Canada AD CF-2019-
35 requires reducing the torque to the attachment hardware, updating 
records, and repetitive inspections of the attachment hardware for wear 
and fretting because of the reduced friction between the mating 
surfaces; reporting findings to Bell and accomplishing corrective 
actions specified by Bell; or completing the installation of the 
attachment hardware and updating records.

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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed 505-19-12 Rev A. This service information 
specifies procedures for an inspection of the restraint hardware 
installation for the presence of a gap and if needed, reducing the 
torque to the affected attachment hardware, a repetitive 100-hour 
inspection of the pitch restraint attachment hardware, and repair of 
fretting damage on the truss assembly clevis lower lug.
    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.

Other Related Service Information

    The FAA also reviewed Bell ASB 505-19-12, dated June 27, 2019. This 
original version of the service information contains the same 
procedures as 505-19-12 Rev A, except 505-19-12 Rev A corrects a torque 
value.

Differences Between This AD and the Transport Canada AD

    The applicability of the Transport Canada AD is by helicopter S/N 
and requires identifying the S/N of the installed truss assembly P/N 
SLS-030-056-015 to determine if the helicopter is affected by the 
unsafe condition, whereas the applicability of this AD is by 
helicopters with certain serial-numbered truss assembly P/N SLS-030-
056-015 installed instead. The compliance time of the initial 
inspections required by the Transport Canada AD is within 100 hours air 
time or 6 months, whichever occurs first, whereas the compliance time 
in this AD is within 100 hours TIS. The Transport Canada AD requires 
reporting information to Bell to obtain certain corrective action, 
while this AD requires repairing or removing affected parts from 
service instead.

Costs of Compliance

    The FAA estimates that this AD affects 87 helicopters of U.S. 
registry. Labor costs are estimated at $85 per work-hour. Based on 
these numbers, the FAA estimates the following costs to comply with 
this AD.
    Measuring tare and inspecting for a gap between the transmission 
restraint assembly aft attachment hardware lower washer and the truss 
assembly will take about 1 work-hour for an estimated cost of $85 per 
helicopter and $7,395 for the U.S. fleet. If required, inspecting a 
pitch restraint attachment point will take about 1 work-hour for an 
estimated cost of $85 per attachment point per inspection cycle.
    The FAA estimates the following costs to do any necessary repairs 
or replacements based on the results of the inspections:
     Updating records to indicate the new torque limits will 
take about 0.25 work-hour for an estimated cost of $21.
     Replacing a bolt will take a minimal additional amount of 
time after inspecting and the part will cost about $50.
     Reworking the lower surface of the clevis lower lug will 
take about 1 work-hour for an estimated cost of $85.

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

[[Page 31091]]

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 helicopters identified in this rulemaking action.

Regulatory Findings

    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

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:

2021-11-19 Bell Textron Canada Limited (Type Certificate Previously 
Held by Bell Helicopter Textron Canada Limited): Amendment 39-21581; 
Docket No. FAA-2021-0185; Project Identifier MCAI-2020-00265-R.

(a) Effective Date

    This airworthiness directive (AD) is effective July 16, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bell Textron Canada Limited (type certificate 
previously held by Bell Helicopter Textron Canada Limited) Model 505 
helicopters, certificated in any category, with a truss assembly 
part number (P/N) SLS-030-056-015 with a serial number listed in 
Attachment A of Bell Alert Service Bulletin (ASB) 505-19-12, 
Revision A, dated July 11, 2019 (ASB 505-19-12 Rev A).

(d) Subject

    Joint Aircraft System Component (JASC) Code 5310, Fuselage Main, 
Structure.

(e) Unsafe Condition

    The FAA is issuing this AD to address a gap between the 
transmission restraint assembly aft attachment hardware lower washer 
and the right-hand (RH) and left-hand (LH) mating airframe truss 
assembly (truss assembly) clevis lower lug. The unsafe condition, if 
not addressed, could result in increased stress, cracking and 
failure of one or both of the clevis lower lugs, and subsequent loss 
of pylon pitch stiffness, excessive pylon pitch motions leading to 
unknown cyclic inputs to the main rotor, and loss of control of the 
helicopter.

(f) Compliance

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

(g) Required Actions

    Within 100 hours time-in-service (TIS) after the effective date 
of this AD, access the transmission restraint assembly and:
    (1) Remove the safety pin at each lower nut location of the aft 
bolts securing the restraint to the truss assembly. Use solvent (C-
304) to remove the corrosion preventive compound on each nut and 
washer located under the RH and LH truss assembly clevis lower lug.
    (2) Loosen the torque on each lower nut while holding the bolt 
with a wrench until the washer turns freely while sitting on top of 
the nut.
    (3) Measure and record the tare of each nut. For purposes of 
this AD, tare is the torque required to overcome the internal 
friction between a self-locking nut and bolt as the nut is being 
turned on the bolt, but before the nut contacts the washer. Add a 
torque value of 20 inch-lbs to the measured tare of each nut and 
torque each nut to this new total value.
    (4) Inspect for a gap around the circumference between the nut 
and the washer and between the washer and the truss assembly clevis 
lower lug mounting surface of the RH and LH sides as illustrated in 
Figure 1 of ASB 505-19-12 Rev A (2 sheets). If there is a gap, 
measure the gap.
    (i) If there is a gap that is less than 0.003 inch (0.076 mm), 
before further flight, install the hardware using the original 
torque value of 40 to 58 foot-pounds (55 to 78 Nm) plus tare. Do not 
exceed the limit specified in this paragraph plus tare. Install a 
cotter pin and apply corrosion preventive compound (C-101) and 
torque seal lacquer (C-049) between the nut, washer, and lower 
surface of the truss assembly clevis.
    (ii) If there is a gap that is 0.003 inch (0.076 mm) to 0.020 
inch (0.508 mm) inclusive, before further flight, install the 
hardware with a decreased torque value limit of 20 to 60 inch-pounds 
(2.3 to 6.8 Nm) plus tare. Do not exceed the limit specified in this 
paragraph plus tare. Install a cotter pin. You may install an 
additional washer P/N NAS1149E0863P before torqueing and installing 
the cotter pin while not exceeding the maximum limit of 60 inch-lbs 
plus tare. Apply corrosion preventive compound (C-101) and torque 
seal lacquer (C-049) between the nut, washer, and lower surface of 
the truss assembly clevis. Update records for your helicopter to 
indicate the new torque limits on one or both sides.
    (A) Within 100 hours TIS after performing paragraph (g)(4)(ii) 
of this AD, and thereafter at intervals not to exceed 100 hours TIS, 
inspect the assembly for fretting between the washer and truss lower 
lug mounting surface, inspect the security of the pitch restraint 
attachment hardware to make sure it does not turn freely, and 
inspect the torque seal lacquer between the nut and the washer to 
make sure the torque seal is intact on the RH and LH sides.
    (B) If there is any fretting, the pitch restraint attachment 
hardware turns freely, or a torque seal is broken, remove the cotter 
pin from service and remove the nut, washer, and bolt. Inspect the 
bolt for damage and the lower surface of the truss assembly clevis 
lower lug for fretting damage.
    (1) If the bolt has damage, remove the bolt from service.
    (2) If the lower surface of the truss assembly clevis lower lug 
has fretting damage within allowable repair limits, use 400 grit 
sandpaper (C-423) and rework fretting damage smooth with adjacent 
surfaces, while removing minimum material. Do not exceed .010 inch 
(0.254 mm) deep total cumulative amount of material to be removed 
from the clevis's lower lugs compared to adjacent original surfaces 
after rework. Clean with acetone (C-316) and let dry. With the 
acetone dry, visually inspect the clevis lower lug for any cracks.
    (i) If there is a crack within allowable repair limits, repair 
in accordance with FAA-approved procedures. If there is a crack that 
meets or exceeds allowable repair limits, remove the truss assembly 
clevis lower lug from service.
    (ii) If there is not a crack, apply primer (C-204) to the 
reworked surface and let dry. With the primer dry, apply final paint 
(polyurethane topcoat color No. 16492) to the reworked surface.
    (3) If the lower surface of the truss assembly clevis lower lug 
has fretting damage that exceeds allowable repair limits, before 
further flight, remove the truss assembly clevis lower lug from 
service.
    (C) Install a nut, washer, and bolt with a decreased torque 
value limit of 20 to 60 inch-pounds (2.3 to 6.8 Nm) plus tare. Do 
not exceed the limit specified in this paragraph plus tare. Install 
a cotter pin. You may install an additional washer P/N NAS1149E0863P 
before torqueing and installing the cotter pin while not exceeding 
the maximum limit of 60 inch-lbs plus tare. Apply corrosion 
preventive compound (C-101) and torque seal lacquer (C-049) between 
the nut, washer, and lower surface of the truss assembly clevis.

[[Page 31092]]

    (iii) If there is a gap that is more than 0.020 inch (0.508 mm), 
before further flight, remove the nut, washer, and bolt from service 
and repair or replace the truss assembly clevis lower lug in 
accordance with FAA-approved procedures.

(h) Credit for Previous Actions

    You may take credit for the first instance of the actions that 
are required by paragraphs (g)(1) through (4) of this AD, except not 
paragraphs (g)(4)(i), (g)(4)(ii)(A) through (C), or (g)(4)(iii) of 
this AD if you completed the Accomplishment Instructions, Part I of 
Bell ASB 505-19-12, dated June 27, 2019, before the effective date 
of this AD.

(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: 9-AVS-AIR-730-AMOC@faa.gov.
    (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 Matt Fuller, AD 
Program Manager, General Aviation & Rotorcraft Unit, Airworthiness 
Products Section, Operational Safety Branch, FAA, 10101 Hillwood 
Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email 
matthew.fuller@faa.gov.
    (2) Bell Alert Service Bulletin 505-19-12, dated June 27, 2019, 
which is not incorporated by reference, contains additional 
information about the subject of this AD. This service information 
is available at the contact information specified in paragraphs 
(k)(3) and (4) of this AD.
    (3) The subject of this AD is addressed in Transport Canada AD 
CF-2019-35, dated October 2, 2019. You may view the Transport Canada 
AD at https://www.regulations.gov in Docket No. FAA-2021-0185.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the service information listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Bell Alert Service Bulletin 505-19-12, Revision A, dated 
July 11, 2019.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact Bell 
Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec 
J7J1R4; telephone 450-437-2862 or 800-363-8023; fax 450-433-0272; or 
at https://www.bellcustomer.com.
    (4) 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: fedreg.legal@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on May 20, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-12229 Filed 6-10-21; 8:45 am]
BILLING CODE 4910-13-P


