DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1483; Project Identifier MCAI-2023-01094-T]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2021-10-02, which applies to all Bombardier, Inc., Model BD-700-1A10
and BD-700-1A11 airplanes. AD 2021-10-02 requires repetitive general
visual inspections of the left- and right-hand elevator torque tube
bearings for any sand, dust, or corrosion; repetitive functional tests
of the elevator control system; and replacement of the elevator torque
tube bearings if necessary. Since the FAA issued AD 2021-10-02, the FAA
has determined that a new airworthiness limitation is necessary. This
proposed AD would continue to require certain actions in AD 2021-10-02
and require revising the existing maintenance or inspection program, as
applicable, to incorporate new airworthiness limitations. The FAA is
proposing this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this NPRM by July 29, 2024.

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 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 above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-1483; 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 mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
street address for Docket Operations is listed above.
Material Incorporated by Reference:
For Bombardier material, contact Bombardier Business
Aircraft Customer Response Center, 400 Cote-Vertu Road West,
Dorval, Quebec H4S 1Y9, Canada; telephone 514-855-2999; email
ac.yul@aero.bombardier.com; website bombardier.com.
You may view this material 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.

FOR FURTHER INFORMATION CONTACT: Gabriel Kim, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-
228-7300; email 9-avs-nyaco-cos@faa.gov.

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-2024-1483; Project Identifier
MCAI-2023-01094-T'' 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
the 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
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
Gabriel Kim, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite
410, Westbury, NY 11590; telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov.
Any commentary that the FAA receives that is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.

Background

The FAA issued AD 2021-10-02, Amendment 39-21535 (86 FR 33088, June
24, 2021) (AD 2021-10-02), for all Bombardier, Inc., Model BD-700-1A10
and BD-700-1A11 airplanes. AD 2021-10-02 was prompted by an MCAI
originated by Transport Canada, which is the aviation authority for
Canada. Transport Canada issued AD CF-2020-29, dated August 21, 2020
(Transport Canada AD CF-2020-29), to correct an unsafe condition.
AD 2021-10-02 requires repetitive general visual inspections of the
left- and right-hand elevator torque tube bearings for any sand, dust,
or corrosion; repetitive functional tests of the elevator control
system; and replacement of the elevator torque tube bearings if
necessary. The FAA issued AD 2021-10-02 to address sand contamination
and corrosion of the elevator torque tube bearings, which could lead to
binding or seizure of the bearings, and potentially lead to a
reduction in or loss of airplane pitch control.

Actions Since AD 2021-10-02 Was Issued

Since the FAA issued AD 2021-10-02, Transport Canada superseded
Transport Canada CF-2020-29, and issued Transport Canada AD CF-2020-
29R1, dated October 20, 2023 (Transport Canada AD CF-2020-29R1)
(referred to after this as the MCAI) to correct an unsafe condition on
certain Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11 airplanes.
The MCAI states that data collected from the reports mandated by
Transport Canada AD CF-2020-29 was used to validate inspection
intervals, which have been integrated into new certification
maintenance requirement (CMR) tasks. The MCAI also states that
Transport Canada AD CF-2020-29R1 mandates the new CMR tasks while
giving credit for initial and repetitive inspections already performed,
revises the applicability to exclude airplanes delivered with the new
CMRs, and removes the reporting requirement.
The FAA is proposing this AD to address sand contamination and
corrosion of the elevator torque tube bearings, which could lead to
binding or seizure of the bearings, and potentially lead to a reduction
in or loss of airplane pitch control.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2024-1483.

Related Service Information Under 1 CFR Part 51

The FAA reviewed the following Bombardier temporary revisions:
Bombardier Global Express, BD-700 Temporary Revision 5-2-
53, dated March 31, 2023 (for Model BD-700-1A10 airplanes);
Bombardier Global Express XRS, BD-700 Temporary Revision
5-2-15, dated March 31, 2023 (for Model BD-700-1A10 airplanes);
Bombardier Global 6000, GL 6000 Temporary Revision 5-2-20,
dated March 31, 2023 (for Model BD-700-1A10 airplanes);
[Bombardier] Global 6500, GL 6500 Temporary Revision 5-2-
3, dated March 31, 2023 (for Model BD-700-1A10 airplanes);
Bombardier Global 5000, BD-700 Temporary Revision 5-2-21,
dated March 31, 2023 (for Model BD-700-1A11 airplanes);
Bombardier Global 5000 GL 5000 Featuring Global Vision
Flight Deck Temporary Revision 5-2-20, dated March 31, 2023 (for Model
BD-700-1A11 airplanes); and
[Bombardier] Global 5500 GL 5500 Temporary Revision, 5-2-
3, dated March 31, 2023 (for Model BD-700-1A11 airplanes).
This service information specifies airworthiness limitations for
certification maintenance requirements. These documents are distinct
since they apply to different airplane models and configurations.
This proposed AD would also require the following service
information which the Director of the Federal Register approved for
incorporation by reference as of July 29, 2021 (86 FR 33088, June 24,
2021).
Bombardier Service Bulletin 700-1A11-27-041, Revision 1,
dated December 7, 2020.
Bombardier Service Bulletin 700-27-083, Revision 1, dated
December 7, 2020.
Bombardier Service Bulletin 700-27-5012, Revision 1, dated
December 7, 2020.
Bombardier Service Bulletin 700-27-5503, Revision 1, dated
December 7, 2020.
Bombardier Service Bulletin 700-27-6012, Revision 1, dated
December 7, 2020.
Bombardier Service Bulletin 700-27-6503, Revision 1, dated
December 7, 2020.
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.

FAA's Determination

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to the FAA's bilateral agreement with this State of Design Authority,
it has notified the FAA of the unsafe condition described in the MCAI
and service information referenced above. The FAA is issuing this NPRM
after determining that the unsafe condition described previously is
likely to exist or develop on other products of the same type design.

Proposed Requirements of This NPRM

This proposed AD would retain certain requirements of AD 2021-10-
02. This proposed AD would remove airplanes from the applicability,
remove the reporting requirement, and provide credit for certain
actions. This proposed AD would also require revising the existing
maintenance or inspection program, as applicable, to incorporate a new
airworthiness limitation.
This proposed AD would require revisions to certain operator
maintenance documents to include new actions (e.g., inspections).
Compliance with these actions is required by 14 CFR 91.403(c). For
airplanes that have been previously modified, altered, or repaired in
the areas addressed by this proposed AD, the operator may not be able
to accomplish the actions described in the revisions. In this
situation, to comply with 14 CFR 91.403(c), the operator must request
approval for an alternative method of compliance according to paragraph
(l)(1) of this proposed AD.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 461 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
The FAA has determined that revising the maintenance or inspection
program takes an average of 90 work-hours per operator, although the
agency recognizes that this number may vary from operator to operator.
Since operators incorporate maintenance or inspection program changes
for their affected fleet(s), the FAA has determined that a per-operator
estimate is more accurate than a per-airplane estimate. Therefore, the
agency estimates the average total cost per operator to be $7,650 (90
work-hours x $85 per work-hour).
The FAA estimates the total cost per operator for the new proposed
actions to be $7,650 (90 work-hours x $85 per work-hour).

Estimated Costs for Required Actions

* Parts cost include replacement parts where necessary.

The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of any
required actions. The FAA has no way of determining the number of
aircraft that might need this on-condition action:

Estimated Costs of On-Condition Actions

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this proposed AD may be covered under warranty, thereby reducing the
cost impact on affected operators.

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 above, I certify this proposed
regulation:
(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

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by:

a. Removing Airworthiness Directive 2021-10-02, Amendment 39-21535 (86
FR 33088, June 24, 2021); and

b. Adding the following new airworthiness directive: