[Federal Register Volume 85, Number 247 (Wednesday, December 23, 2020)]
[Rules and Regulations]
[Pages 83759-83761]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-28282]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0458; Product Identifier 2020-NM-029-AD; Amendment 
39-21348; AD 2020-25-06]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Bombardier, Inc., Model BD-100-1A10 airplanes. This AD was 
prompted by a report that corrosion was found on the shock strut 
cylinders during unscheduled maintenance of the nose landing gear 
(NLG). This AD requires a modification of the NLG shock strut cylinder. 
The FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective January 27, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of January 27, 
2021.

ADDRESSES: For service information identified in this final rule, 
contact Bombardier, Inc., 200 C[ocirc]te-Vertu Road West, Dorval, 
Qu[eacute]bec H4S 2A3, Canada; North America toll-free telephone 1-866-
538-1247 or direct-dial telephone 1-514-855-2999; email 
ac.yul@aero.bombardier.com; internet http://www.bombardier.com. You may 
view this service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 2200 South 216th St., Des Moines, 
WA. For information on the availability of this material at the FAA, 
call 206-231-3195. It is also available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0458.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0458; 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.

FOR FURTHER INFORMATION CONTACT: Darren Gassetto, Aerospace Engineer, 
Mechanical Systems and Administrative Services Section, FAA, New York 
ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
telephone 516-228-7323; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian AD CF-2019-43, dated November 
8, 2019 (``AD CF-2019-43'') (also referred to as the Mandatory 
Continuing Airworthiness Information, or ``the MCAI''), to correct an 
unsafe condition for certain Bombardier, Inc., Model BD-100-1A10 
airplanes. You may examine the MCAI in the AD docket on the internet at 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2020-0458.
    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain Bombardier, 
Inc., Model BD-100-1A10 airplanes. The NPRM published in the Federal 
Register on June 3, 2020 (85 FR 34141). The NPRM was prompted by a 
report that corrosion was found on the shock strut cylinders during 
unscheduled maintenance of the NLG. The NPRM proposed to require a 
modification of the NLG shock strut cylinder. The FAA is issuing this 
AD to address corrosion of the NLG, which could result in structural 
failure of the NLG. See the MCAI for additional background information.

Comments

    The FAA gave the public the opportunity to participate in 
developing this final rule. The following presents the comment received 
on the NPRM and the FAA's response to that comment.

Request To Revise Certain Compliance Language in the Proposed AD

    Flexjet stated that where the compliance section of Bombardier 
Service Bulletin 100-32-33, Revision 02, dated September 30, 2019, and 
Figure 1 to paragraph (g) of the proposed AD, specify the compliance 
time for NLG assemblies with more than 96 months time since new (TSN), 
the compliance time does not take into account that the NLG cylinders 
with part number (P/N) 40640-3 and P/N 40640-5 serialized (next higher 
assembly P/N 40640-105 and subcomponents) are life-limited items with a 
7,500 flight cycle discard interval. Flexjet commented that during the 
first 96 month inspection, if the operator has high flight cycles, it 
may elect to replace the cylinder at that time. Flexjet also commented 
that the compliance section of Bombardier Service Bulletin 100-32-33, 
Revision 02, dated September 30, 2019, does not take into account that 
a new cylinder could be installed at the 96-month inspection and it 
also does not address if the cylinder was replaced for another reason 
after the 96-month inspection.
    Flexjet stated that the proposed AD needs to be specific on 
applying to the nose gear cylinder and sleeve part numbers and not the 
nose gear or nose gear strut assembly part numbers. Flexjet also stated 
that the nose gear cylinder and sleeve are the parts with corrosion and 
the primary reason for the service information. Flexjet pointed out 
that the sleeve is cut off for inspection of the cylinder and the same 
part number sleeve goes back on following the inspection. The FAA 
infers that Flexjet was requesting that the language in paragraphs 
(g)(1) and (2) of this AD specify that the actions apply to airplanes 
with NLG assemblies having NLG cylinder assemblies and sleeves with 
certain part numbers.
    The FAA disagrees with the comment. While NLG cylinder assemblies 
and their subcomponents can be replaced before or after the 96-month 
interval inspection, paragraphs 2.B. and 2.C. of the Accomplishment 
Instructions of Bombardier Service Bulletin 100-32-33, Revision 02, 
dated September 30, 2019, ensure the proper corrective actions are 
taken to prevent corrosion with those replaced components when 
reassembled on the NLG assembly. This is why the identification on the 
NLG assembly modplate is required. In addition, paragraph (f) of this 
AD specifies to, ``Comply with this AD within the compliance times 
specified, unless already done.'' Therefore, if some of the specified 
corrective actions are already

[[Page 83760]]

complied with, only the remaining corrective actions in the AD need to 
be completed to comply with this AD. The FAA has not changed this AD in 
this regard.

Conclusion

    The FAA reviewed the relevant data, considered the comment 
received, and determined that air safety and the public interest 
require adopting this final rule as proposed, except for minor 
editorial changes. The FAA has determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

    Bombardier has issued Service Bulletin 100-32-33, Revision 02, 
dated September 30, 2019; and Service Bulletin 350-32-009, Revision 02, 
dated September 30, 2019. This service information describes procedures 
for modification of the NLG shock strut cylinder. These documents are 
distinct since they apply to different airplane serial numbers. 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.

Costs of Compliance

    The FAA estimates that this AD affects 560 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
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             Labor cost                 Parts cost       Cost per product           Cost on U.S. operators
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Up to 54 work-hours x $85 per hour =         $43,999  Up to $48,589.........  Up to $27,209,840
 Up to $4,590.
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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

    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.

Adoption of 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 (AD):

2020-25-06 Bombardier, Inc.: Amendment 39-21348; Docket No. FAA-
2020-0458; Product Identifier 2020-NM-029-AD.

(a) Effective Date

    This AD is effective January 27, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bombardier, Inc., Model BD-100-1A10 
airplanes, certificated in any category, serial numbers (S/Ns) 20003 
through 20767 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 32, Landing 
gear.

(e) Reason

    This AD was prompted by a report that corrosion was found on the 
shock strut cylinders during unscheduled maintenance of the nose 
landing gear (NLG). The FAA is issuing this AD to address corrosion 
of the NLG, which could result in structural failure of the NLG.

(f) Compliance

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

(g) Modification for Airplanes With S/N 20003 Through 20500 Inclusive

    For Bombardier, Inc., Model BD-100-1A10 airplanes with S/N 20003 
through 20500 inclusive: At the applicable compliance time specified 
in paragraph (g)(1) or (2) of this AD, do the modification in 
paragraph (g)(1) or (2) of this AD, as applicable.
    (1) For airplanes with NLG assemblies with 96 months or less 
time since new (TSN) as of the effective date of this AD: At the NLG 
96-month scheduled inspection, do a modification of the NLG shock 
strut cylinder, in accordance with paragraph 2.B. of the 
Accomplishment Instructions of Bombardier Service Bulletin 100-32-
33, Revision 02, dated September 30, 2019.
    (2) For airplanes with NLG assemblies with more than 96 months 
TSN as of the effective date of this AD: At the applicable 
compliance time specified in figure 1 to paragraph (g) of this AD, 
do a modification of the NLG shock strut cylinder, in accordance 
with paragraph 2.C. of the Accomplishment Instructions of Bombardier 
Service Bulletin 100-32-33, Revision 02, dated September 30, 2019.

[[Page 83761]]

[GRAPHIC] [TIFF OMITTED] TR23DE20.001

(h) Modification for Airplanes With S/N 20501 Through 20767 Inclusive

    For Bombardier, Inc., Model BD-100-1A10 airplanes with S/N 20501 
through 20767 inclusive: At the NLG 96-month scheduled inspection, 
do a modification of the NLG shock strut cylinder, in accordance 
with paragraph 2.B. of the Accomplishment Instructions of Bombardier 
Service Bulletin 350-32-009, Revision 02, dated September 30, 2019.

(i) Parts Installation Limitation

    As of the effective date of this AD, no person may install, on 
any airplane, an NLG shock strut assembly with part number (P/N) 
40630-111, P/N 40630-113, or P/N 44630-101, unless it has been 
modified in accordance with paragraphs 2.B. or 2.C. of the 
Accomplishment Instructions of Bombardier Service Bulletin 100-32-
33, Revision 02, dated September 30, 2019; or paragraph 2.B. of the 
Accomplishment Instructions of Bombardier Service Bulletin 350-32-
009, Revision 02, dated September 30, 2019; as applicable.

(j) Credit for Previous Actions

    (1) This paragraph provides credit for actions required by 
paragraph (g) of this AD, if those actions were performed before the 
effective date of this AD using paragraph 2.B. or 2.C., as 
applicable, of Bombardier Service Bulletin 100-32-33, dated October 
31, 2018; or Bombardier Service Bulletin 100-32-33, Revision 01, 
July 31, 2019.
    (2) This paragraph provides credit for actions required by 
paragraph (h) of this AD, if those actions were performed before the 
effective date of this AD using paragraph 2.B. of Bombardier Service 
Bulletin 350-32-009, dated October 31, 2018; or Bombardier Service 
Bulletin 350-32-009, Revision 01 dated July 31, 2019; provided that 
the NLG shock strut assembly with P/N 44630-101 was removed in lieu 
of P/N 44610-101, as specified in paragraph 2.B.(1) of the 
Accomplishment Instructions of Bombardier Service Bulletin 350-32-
009, dated October 31, 2018; or Bombardier Service Bulletin 350-32-
009, Revision 01 dated July 31, 2019.

(k) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York ACO 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 certification 
office, send it to ATTN: Program Manager, Continuing Operational 
Safety, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531. 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.
    (2) Contacting the Manufacturer: For any requirement in this AD 
to obtain instructions from a manufacturer, the instructions must be 
accomplished using a method approved by the Manager, New York ACO 
Branch, FAA; or Transport Canada Civil Aviation (TCCA); or 
Bombardier's TCCA Design Approval Organization (DAO). If approved by 
the DAO, the approval must include the DAO-authorized signature.

(l) Related Information

    (1) Refer to Mandatory Continuing Airworthiness Information 
(MCAI) Canadian AD CF-2019-43, dated November 8, 2019, for related 
information. This MCAI may be found in the AD docket on the internet 
at https://www.regulations.gov by searching for and locating Docket 
No. FAA-2020-0458.
    (2) For more information about this AD, contact Darren Gassetto, 
Aerospace Engineer, Mechanical Systems and Administrative Services 
Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone 516-228-7323; fax 516-794-5531; email 
9-avs-nyaco-cos@faa.gov.
    (3) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (m)(3) and (4) of this AD.

(m) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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 this AD specifies otherwise.
    (i) Bombardier Service Bulletin 100-32-33, Revision 02, dated 
September 30, 2019.
    (ii) Bombardier Service Bulletin 350-32-009, Revision 02, dated 
September 30, 2019.
    (3) For service information identified in this AD, contact 
Bombardier, Inc., 200 C[ocirc]te-Vertu Road West, Dorval, 
Qu[eacute]bec H4S 2A3, Canada; North America toll-free telephone 1-
866-538-1247 or direct-dial telephone 1-514-855-2999; email 
ac.yul@aero.bombardier.com; internet http://www.bombardier.com.
    (4) You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 2200 
South 216th St., Des Moines, WA. For information on the availability 
of this material at the FAA, call 206-231-3195.
    (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 December 1, 2020.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2020-28282 Filed 12-22-20; 8:45 am]
BILLING CODE 4910-13-P


