Airworthiness Directives; Airbus Helicopters, 67303-67307 [2021-25703]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 86, Number 225 (Friday, November 26, 2021)]
[Rules and Regulations]
[Pages 67303-67307]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-25703]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0197; Project Identifier 2018-SW-107-AD; Amendment 
39-21789; AD 2021-22-16]
RIN 2120-AA64


Airworthiness Directives; Airbus 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 
Airbus Helicopters Model EC 155B and EC155B1 helicopters. This AD was 
prompted by the failure of a main gearbox (MGB) second stage planet 
gear. This AD requires replacing the MGB, or as an alternative, 
replacing the epicyclic reduction gear module for certain serial 
numbered planet gear assemblies installed on the MGB. This AD also 
requires inspecting the MGB magnetic plugs and MGB filter for 
particles, and for certain serial-numbered planet gear assemblies, 
inspecting the oil sump for particles. Depending on the outcome of 
these inspections, this AD requires further inspections and replacing 
certain parts. This AD also prohibits installing certain parts. The FAA 
is issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective January 3, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of certain documents listed in this AD as of January 3, 2022.

ADDRESSES: For service information identified in this final rule, 
contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 
75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; 
or at https://www.airbus.com/helicopters/services/technical-support.html. 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. For information on the 
availability of this material at the FAA, call (817) 222-5110. Service 
information

[[Page 67304]]

that is incorporated by reference is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0197.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0197; 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 
European Aviation Safety Agency (now European Union Aviation Safety 
Agency) (EASA) 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: Rao Edupuganti, Aerospace Engineer, 
Dynamic Systems Section, Technical Innovation Policy Branch, Policy & 
Innovation Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; 
telephone (817) 222-5110; email [email protected].

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 Airbus Helicopters 
Model EC 155B and EC155B1 helicopters. The NPRM published in the 
Federal Register on July 22, 2021 (86 FR 38608). In the NPRM, the FAA 
proposed to require for helicopters with at least one Type Y planet 
gear assembly with a certain serial number (S/N) installed, or at least 
one Type Z planet gear assembly with a certain S/N installed, within 10 
hours time-in-service (TIS) after the effective date of the AD and 
thereafter at intervals not to exceed 10 hours TIS, inspecting the MGB 
magnetic plugs for particles. If there are particles, the NPRM proposed 
to require further inspections and analyses and replacing the MGB, 
depending on the type and the size of the particles.
    The NPRM also proposed to require for helicopters with a Type Y 
planet gear assembly with a certain S/N installed, within 25 hours TIS 
after the effective date of the AD, inspecting the MGB filter for 
particles. If there are particles, the NPRM proposed to require further 
inspections and analyses and replacing the MGB, depending on the type 
and the size of the particles. The NPRM proposed to require for 
helicopters with at least one Type Y planet gear assembly with a 
certain S/N installed, within 50 hours TIS after the effective date of 
the AD, replacing the MGB. As an alternative to replacing the MGB, the 
NPRM would allow replacing the epicyclic reduction gear in the affected 
MGB.
    Additionally, the NPRM proposed to require, for helicopters without 
any Type Y planet gear assembly but at least one Type Z planet gear 
assembly with a certain S/N installed, replacing the MGB within 50 
hours TIS after the effective date of the AD or before any planet gear 
assembly accumulates 1,800 total hours TIS, whichever occurs later. As 
an alternative to replacing the MGB, the NPRM would allow replacing the 
epicyclic reduction gear in the affected MGB.
    The NPRM also proposed to require, for helicopters with at least 
one Type Z planet gear with a certain S/N installed, within certain 
compliance times specified in the figures in this AD, inspecting the 
MGB filter and inspecting the oil sump for particles. If there are 
particles, the NPRM proposed to require further inspections and 
analyses, and replacing the MGB, depending on the type and the size of 
the particles.
    The NPRM also proposed to prohibit installing an MGB with a certain 
serial numbered Type Y planet gear assembly and proposed to prohibit 
installing a Type Y planet gear assembly with a certain S/N on any 
helicopter.
    Additionally, the NPRM proposed to prohibit installing certain 
serial numbered Type Z planet gear assemblies that have accumulated 
1,800 or more total hours TIS and prohibit installing an MGB with 
certain serial numbered Type Z planet gear assemblies that have 
accumulated 1,800 or more total hours TIS.
    Finally, the NPRM proposed to prohibit installing an MGB if the 
type of the planet gear assembly cannot be determined and also prohibit 
installing any planet gear assembly if the type cannot be determined.
    The NPRM was prompted by EASA AD 2018-0263, dated December 7, 2018 
(EASA AD 2018-0263), issued by EASA, which is the Technical Agent for 
the Member States of the European Union, to correct an unsafe condition 
for Airbus Helicopters Model EC 155 B and EC 155 B1 helicopters. EASA 
advises that after an accident on a Model EC225 helicopter, an 
investigation revealed the failure of an MGB second stage planet gear. 
EASA states that one of the two types of planet gear used in the MGB 
epicyclic module is subject to higher outer race contact pressures and 
therefore is more susceptible to spalling and cracking. This condition, 
if not addressed, could result in failure of a MGB planet gear 
assembly, failure of the MGB, and subsequent loss of helicopter 
control.
    Accordingly, EASA AD 2018-0263 requires repetitive inspections of 
the MGB magnetic plugs, the MGB filer, and the oil sump for particles, 
and depending on the results of those inspections, removing or 
replacing certain parts. EASA AD 2018-0263 also requires reducing the 
life limit of Type Z planet gear assemblies. EASA AD 2018-0263 also 
requires, if certain gear assemblies are installed, either replacing 
the MGB or replacing the epicyclic reduction gear. Finally, EASA AD 
2018-0263 prohibits installing a Type Y planet gear assembly or an MGB 
with a Type Y planet gear assembly on any helicopter.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from one commenter. The following 
presents the comments received on the NPRM and the FAA's response.

Request to Revise the Required Actions Section of the NPRM

    Airbus Helicopters Inc., requested that the FAA revise the Required 
Actions section of this AD dealing with the 25 hours TIS inspection for 
the oil sump (also referred to as inspecting the bottom housing of the 
MGB) by removing that repetitive inspection and explained that some of 
the proposed actions are unclear and not in line with the original 
equipment manufacturer's (OEM) service information. The commenter also 
provided an example of a similar AD, AD 2021-12-06, Amendment 39-21593 
(86 FR 31612, June 15, 2021) (AD 2021-12-06), stating that AD 2021-12-
06 is clear in explaining both the required repetitive actions and the 
limits provided by the OEM for the MGB oil filter inspection after 
finding particle(s) on the chip detector. The commenter stated that, as 
written, the proposed actions would create extra work, which could lead 
to an unwanted condition exposing the dynamic component to possible 
contamination and possibly foreign object debris.
    The FAA agrees that the repetitive 25 hours TIS oil sump inspection 
for Type Y planet gears is not necessary and has revised paragraph 
(g)(1) of the Required Actions section in this final rule by deleting 
this inspection.

Conclusion

    The FAA reviewed the relevant data, considered the comments 
received, and

[[Page 67305]]

determined that air safety and the public interest require adopting 
this AD as proposed, except for the change described previously, 
updating the service information for the optional replacement of the 
epicyclic reduction gear module in paragraphs (g)(3) and (4) of this 
AD, and for clarity, deleting the corrective actions when there are no 
16NCD13 particles. The FAA has determined that these changes will not 
increase the economic burden on any operator or increase the scope of 
this final rule.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Airbus Helicopters Alert Service Bulletin ASB No. 
EC155-05A034, Revision 5, dated December 4, 2018 (ASB EC155-05A34 Rev 
5) for Model EC 155 helicopters, which specifies periodic inspections 
of the MGB magnetic plugs, the MGB filter, and the oil sump for 
particles. ASB EC155-05A34 Rev 5 also specifies identifying the type of 
gear assembly installed in the MGB and replacing any Type Y planet gear 
assembly within 50 hours TIS. For Type Z gear assemblies that have 
logged less than 1,800 hours TIS since new, this service information 
specifies replacing the gear assembly before exceeding 1,800 total 
hours TIS, and for Type Z gear assemblies that have logged 1,800 or 
more total hours TIS, replacing the gear assembly within 600 hours TIS.
    The FAA also reviewed Airbus Helicopters Service Bulletin SB No. 
EC155-63-016, Revision 5, dated March 6, 2019, for Model EC 155 
helicopters. This service information specifies procedures for 
replacing the MGB epicyclic reduction gear without removing the MGB.
    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.

Interim Action

    The FAA considers this AD to be an interim action. If final action 
is later identified, the FAA might consider further rulemaking then.

Differences Between This AD and EASA AD 2018-0263

    EASA AD 2018-0263 specifies compliance times based on flight hours 
and calendar dates. This AD sets compliance times based on hours TIS or 
before further flight. EASA AD 2018-0263 allows a pilot to inspect the 
MGB magnetic plugs for particles, while this AD does not. For 
helicopters with at least one affected Type Z planet gear assembly that 
has accumulated 1,800 or more total hours TIS installed, EASA AD 2018-
0263 requires replacing the MGB or epicyclic reduction gear within 600 
flight hours after March 16, 2018, whereas this AD requires either of 
those replacements within 50 hours TIS after the effective date of this 
AD instead. If 16NCD13 particles are present, EASA AD 2018-0263 
requires taking a 1 liter sample of oil and returning it to Airbus 
Helicopters and removing the MGB for depot-level inspection, whereas 
this AD requires replacing the MGB instead.

Costs of Compliance

    The FAA estimates that this AD affects 14 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.
    Inspecting the magnetic plugs for particle deposits takes about 1 
work-hour for an estimated cost of $85 per helicopter per inspection 
cycle.
    Inspecting the MGB filter or oil sump for particle deposits takes 
about 1 work-hour for an estimated cost of $85 per helicopter per 
inspection cycle.
    Replacing an MGB takes about 42 work-hours, and parts cost about 
$295,000 (overhauled) for an estimated total cost of $298,570 per 
helicopter.
    Replacing the epicyclic reduction gear takes about 56 work-hours 
and parts cost about $11,404 for an estimated total cost of $16,164 per 
helicopter.

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 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:

2021-22-16 Airbus Helicopters: Amendment 39-21789; Docket No. FAA-
2021-0197; Project Identifier 2018-SW-107-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective January 3, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Helicopters Model EC 155B and EC155B1 
helicopters, certificated in any category.

(d) Subject

    Joint Aircraft Service Component (JASC) Code: 6300, Main Rotor 
Drive System.

(e) Unsafe Condition

    This AD was prompted by the failure of a main gearbox (MGB) 
second stage planet gear. The FAA is issuing this AD to prevent 
failure of an MGB planet gear assembly. The unsafe condition, if not 
addressed, could result in failure of the MGB and subsequent loss of 
helicopter control.

(f) Compliance

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

[[Page 67306]]

(g) Required Actions

    (1) For helicopters with at least one Type Y planet gear 
assembly with a serial number (S/N) listed in Appendix 4.A. of 
Airbus Helicopters Alert Service Bulletin ASB No. EC155-05A034, 
Revision 5, dated December 4, 2018 (ASB EC155-05A034 Rev 5) or with 
at least one Type Z planet gear assembly with an S/N listed in 
Appendix 4.B. of ASB EC155-05A034 Rev 5 installed, within 10 hours 
time-in-service (TIS) after the effective date of this AD, and 
thereafter at intervals not to exceed 10 hours TIS, inspect the MGB 
magnetic plugs for particles. If there are any particles that 
consist of any scale, flake, splinter, or other particle other than 
cotter pin fragments, pieces of lock wire, swarf, abrasion, or 
miscellaneous non-metallic waste, and any of the planet gears have 
accumulated less than 50 total hours TIS, before further flight, 
inspect the MGB filter for particles. Thereafter, for 25 hours TIS, 
continue to inspect the MGB plugs for particles before each flight, 
inspect the MGB filter for particles at intervals not to exceed 25 
hours TIS, and inspect the cumulative surface area of the particles 
collected from the magnetic plugs, the MGB filter, since last MGB 
overhaul, or since new if no overhaul has been performed.
    Note 1 to the introductory text of paragraph (g)(1): Airbus 
Helicopters service information refers to an MGB filter as an oil 
filter.
    (i) If the total surface area of the particles is less than 3 
mm\2\, examine the particles with the largest surface area (S), 
greatest length (L), and greatest thickness (e).
    (A) If any (S) of all of the particles is less than or equal to 
1 mm\2\, the (L) is less than or equal to 1.5 mm, and the (e) is 
less than or equal to 0.2 mm, inspect the MGB plugs for particles 
before further flight, and inspect the MGB filter for particles 
within 25 hours TIS. Thereafter:
    (1) For 25 hours TIS, continue to inspect the MGB plugs for 
particles before each flight and perform the actions required by 
paragraphs (g)(1)(i) and (ii) of this AD.
    (2) Inspect the MGB filter for particles at intervals not to 
exceed 25 hours TIS and perform the actions required by paragraphs 
(g)(1)(i) and (ii) of this AD.
    (B) If any (S) is greater than 1 mm\2\, (L) is greater than 1.5 
mm, or (e) is greater than 0.2 mm, perform a metallurgical analysis 
for any 16NCD13 particles, using a method in accordance with FAA-
approved procedures.
    (C) If there are any 16NCD13 particles, before further flight, 
replace the MGB with an airworthy MGB.
    (ii) If the total surface area of collected particles is greater 
than or equal to 3 mm\2\, before further flight, perform a 
metallurgical analysis for any 16NCD13 particles using a method in 
accordance with FAA-approved procedures. If there are any 16NCD13 
particles, before further flight, replace the MGB with an airworthy 
MGB.
    (2) For helicopters with at least one Type Y planet gear 
assembly with an S/N listed in Appendix 4.A. of ASB EC155-05A034 Rev 
5 installed, within 25 hours TIS after the effective date of this 
AD, inspect the MGB filter for particles. If there are any particles 
that consist of any scale, flake, splinter, or particle other than 
cotter pin fragments, pieces of lock wire, swarf, abrasion, or 
miscellaneous non-metallic waste, and any of the planet gears have 
accumulated more than 50 total hours TIS, before further flight, 
perform the actions required by paragraphs (g)(1)(i) and (ii) of 
this AD.
    (3) For helicopters with at least one Type Y planet gear 
assembly with an S/N listed in Appendix 4.A. of ASB EC155-05A034 Rev 
5 installed, within 50 hours TIS after the effective date of this 
AD, replace the MGB or as an alternative to replacing an affected 
MGB, replace the epicyclic reduction gear module in the affected MGB 
in accordance with paragraph 3.B.2. of the Accomplishment 
Instructions of Airbus Helicopters Service Bulletin SB No. EC155-63-
016, Revision 5, dated March 6, 2019 (SB EC155-63-016 Rev 5), except 
you are not required to contact Airbus Helicopters.
    (4) For helicopters without any Type Y planet gear assembly 
installed but with at least one Type Z planet gear assembly with an 
S/N listed in Appendix 4.B. of ASB EC155-05A034 Rev 5 installed, 
within 50 hours TIS after the effective date of this AD, or before 
any gear accumulates 1,800 total hours TIS, whichever occurs later, 
replace the MGB or as an alternative to replacing an affected MGB, 
replace the epicyclic reduction gear module in the affected MGB in 
accordance with paragraph 3.B.2. of the Accomplishment Instructions 
of SB EC155-63-016 Rev 5, except you are not required to contact 
Airbus Helicopters.
    (5) For helicopters with at least one Type Z planet gear 
assembly with an S/N listed in Appendix 4.B. of ASB EC155-05A034 Rev 
5 installed, inspect the MGB filter for particles within the 
compliance times specified in Figure 1 to paragraph (g)(5) of this 
AD and inspect the oil sump for particles within the compliance 
times specified in Figure 2 to paragraph (g)(5) of this AD, based on 
the total hours TIS accumulated by the Type Z planet gear with the 
most total hours TIS accumulated since first installation in an MGB. 
If there are particles, before further flight, perform the actions 
required by paragraphs (g)(1)(i) and (ii) of this AD.

                      Figure 1 to Paragraph (g)(5)
------------------------------------------------------------------------
                                    Compliance time     Compliance time
   Total hours TIS accumulated       for  initial       for repetitive
                                      inspection          inspections
------------------------------------------------------------------------
Less than 400 total hours TIS...  Within 55 hours     Within 55 hours
                                   TIS after the       TIS.
                                   effective date of
                                   this AD.
400 or more total hours TIS.....  Within 25 hours     Within 25 hours
                                   TIS after the       TIS.
                                   effective date of
                                   this AD.
------------------------------------------------------------------------


                      Figure 2 to Paragraph (g)(5)
------------------------------------------------------------------------
                                    Compliance time     Compliance time
   Total hours TIS accumulated       for  initial       for repetitive
                                      inspection          inspections
------------------------------------------------------------------------
Less than 400 total hours TIS...  Before exceeding    Within 55 hours
                                   400 hours TIS       TIS.
                                   after the
                                   effective date of
                                   this AD.
400 or more total hours TIS.....  Within 55 hours     Within 55 hours
                                   TIS after the       TIS.
                                   effective date of
                                   this AD.
------------------------------------------------------------------------

    (6) As of the effective date of this AD, do not install a type Y 
planet gear assembly with an S/N listed in Appendix 4.A. of ASB 
EC155-05A034 Rev 5 on any helicopter, and do not install an MGB with 
a Type Y planet gear assembly with an S/N listed in Appendix 4.A. of 
ASB EC155-05A034 Rev 5 on any helicopter.
    (7) As of the effective date of this AD, do not install a Type Z 
planet gear assembly with an S/N listed in Appendix 4.B. of ASB 
EC155-05A034 Rev 5 that has accumulated 1,800 or more total hours 
TIS on any helicopter, and do not install an MGB with at least one 
Type Z planet gear assembly with an S/N listed in Appendix 4.B. of 
ASB EC155-05A034 Rev 5 that has accumulated 1,800 or more total 
hours TIS on any helicopter.
    (8) As of the effective date of this AD, do not install any 
planet gear on any helicopter if the planet gear assembly type 
cannot be determined, and do not install any MGB on any helicopter 
if any of the planet gear assembly types cannot be determined.

[[Page 67307]]

(h) 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 (i)(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.

(i) Related Information

    (1) For more information about this AD, contact Rao Edupuganti, 
Aerospace Engineer, Dynamic Systems Section, Technical Innovation 
Policy Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; 
telephone (817) 222-5110; email [email protected].
    (2) The subject of this AD is addressed in European Aviation 
Safety Agency (now European Union Aviation Safety Agency) (EASA) AD 
2018-0263, dated December 7, 2018. You may view the EASA AD at 
https://www.regulations.gov in Docket No. FAA-2021-0197.

(j) 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) Airbus Helicopters Alert Service Bulletin ASB No. EC155-
05A034, Revision 5, dated December 4, 2018.
    (ii) Airbus Helicopters Service Bulletin SB No. EC155-63-016, 
Revision 5, dated March 6, 2019.
    (3) For service information identified in this AD, contact 
Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; 
telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or 
at https://www.airbus.com/helicopters/services/technical-support.html.
    (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: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on October 19, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-25703 Filed 11-24-21; 8:45 am]
BILLING CODE 4910-13-P