Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes

[Federal Register Volume 90, Number 30 (Friday, February 14, 2025)]
[Rules and Regulations]
[Pages 9602-9604]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-02646]



[[Page 9602]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1893; Project Identifier MCAI-2023-01050-T; 
Amendment 39-22953; AD 2025-03-05]
RIN 2120-AA64


Airworthiness Directives; Airbus Canada Limited Partnership (Type 
Certificate Previously Held by C Series Aircraft Limited Partnership 
(CSALP); Bombardier, Inc.) Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-
1A11 airplanes. This AD was prompted by reported events of annunciated 
horizontal stabilizer trim actuator (HSTA) jams occurring at the end of 
the cruise phase of flight. This AD requires lubricating the HSTA using 
an improved method, at a reduced interval, as specified in a Transport 
Canada AD, which is incorporated by reference. The FAA is issuing this 
AD to address the unsafe condition on these products.

DATES: This AD is effective March 21, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 21, 
2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-1893; 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 mandatory continuing airworthiness 
information (MCAI), 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.
    Material Incorporated by Reference:
    <bullet> For Transport Canada material identified in this AD, 
contact Transport Canada, Transport Canada National Aircraft 
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; 
telephone 888-663-3639; email [email protected]; website at tc.canada.ca/en/
aviation.
    <bullet> 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. It is also available at regulations.gov under 
Docket No. FAA-2024-1893.

FOR FURTHER INFORMATION CONTACT: Mark Taylor, Aviation Safety Engineer, 
FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 781-238-
7229; 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 certain Airbus Canada 
Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. The 
NPRM published in the Federal Register on July 24, 2024 (89 FR 59851). 
The NPRM was prompted by AD CF-2023-68R1, dated April 30, 2024, issued 
by Transport Canada, which is the aviation authority for Canada 
(Transport Canada AD CF-2023-68R1) (also referred to as the MCAI). The 
MCAI states that there have been reported events of annunciated HSTA 
jams occurring at the end of the cruise phase of flight. Investigation 
revealed water intrusion in the primary ball nut and/or secondary nut 
housing of the HSTA ballscrew assembly. Water intrusion and subsequent 
freezing has caused jamming of the HSTA, resulting in the loss of pitch 
trim capability. Loss of pitch trim capability could result in loss of 
control of the airplane.
    In the NPRM, the FAA proposed to require lubricating the HSTA using 
an improved method, at a reduced interval, as specified in Transport 
Canada AD CF-2023-68R1. The FAA is issuing this AD to address water 
intrusion and subsequent freezing, which causes jamming of the HSTA, 
resulting in the loss of pitch trim capability.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2024-1893.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from the Air Line Pilots Association, 
International (ALPA), and an individual, who supported the NPRM without 
change.
    The FAA received additional comments from Delta Air Lines. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request for Airworthiness Limitations (AWL) Manual To Be Used as an 
Alternative Method of Compliance

    Delta requested that the FAA issue an AD to mandate an AWL in lieu 
of mandating the actions specified in Airbus Canada Limited Partnership 
Service Bulletin BD500-274006, Issue 001, dated June 29, 2023 (Airbus 
Canada Limited Partnership Service Bulletin BD500-274006). As an 
alternative, Delta requested that the FAA revise the proposed AD to 
allow the AWL as another acceptable means of compliance. Delta stated 
that Airbus Canada released A220 AWL Issue 018.00 on June 20, 2024, 
which adds CMR task C27-41-00-02 to perform the lubrication of the HSTA 
ballscrew assembly within intervals of 1,000 flight hours or 12 months. 
Delta noted that Airbus Canada Limited Partnership Service Bulletin 
BD500-274006 has a note that states it is not necessary to do the 
service bulletin after the HSTA lubrication interval given in the AWL 
manual is revised. Delta concluded that A220 AWL Issue 018.00 would be 
an acceptable means of compliance and an equivalent level of safety to 
Service Bulletin BD500-274006.
    The FAA does not agree to include A220 AWL Issue 018.00 as an 
optional method of compliance. The AWL will not be mandated at this 
time. This AD corresponds to Transport Canada AD CF-2023-68R1, which 
mandates lubrication of the HSTA using Airbus Canada Limited 
Partnership Service Bulletin BD500-274006. By mandating the Transport 
Canada AD, the FAA minimizes differences between the FAA AD and the 
MCAI and MCAI-referenced service information. This FAA AD is consistent 
with FAA Order 8040.5, dated September 29, 2006, which covers the AD 
process for MCAIs. Furthermore, the FAA has not been provided any 
validation indicating equivalency of the requested change to the 
current MCAI requirement. Therefore, the FAA concurs with Transport 
Canada's requirement to mandate the service bulletin as specified in 
the Transport Canada AD. The FAA has not changed this AD in this 
regard.

Request for AD To Include AMP of Any Revision

    Delta requested that the FAA add an exception to Airbus Canada 
Limited Partnership Service Bulletin BD500-274006 paragraph 3.2 to 
allow the use of Aircraft Maintenance Program (AMP) BD500-A-J12-20-27-
12AAA-240B-A without referencing a revision level. Delta stated that 
per Airbus Canada Technical Request Case Number

[[Page 9603]]

00129773, the changes made to AMP issue 11 were minor and do not affect 
the intent of the task. Delta added that performing the AMP at any 
revision level would still accomplish the intended lubrication task.
    The FAA disagrees with the request. In general, being in control of 
all aspects of an AD to minimize variability is critically important 
when addressing a safety issue. Limiting the allowable issues/revisions 
of service information is an important element of this process as the 
summation of numerous incremental changes over several issues/revisions 
can be significant. Therefore, the FAA is in full agreement with the 
Transport Canada AD and the reference to AMP BD500-A-J12-20-27-12AAA-
240B-A at Issue 012 or later. The FAA has not changed this AD in this 
regard.

Request for Elimination of Grace Period for Compliance

    Delta requested that the FAA remove the 5-day ``grace period'' from 
the exceptions paragraphs (h)(3)(ii) and (h)(4)(ii) of the proposed AD. 
Delta stated that the previous versions of the Airbus A220 
Airworthiness Limitations Issue 017.00 CCMR Section and MRB already 
included task 27-41-00-02 for the lubrication of the HSTA ballscrew 
assembly. Delta noted that in A220 AWL Issue 018.00, the task was 
transferred to the CMR section task C27-41-00-02; that task had a 12-
month and 3,000-flight-hour limit. By including these requirements in 
the A220 AWL, MRBR, and MPD, the task already requires operators to 
perform the lubrication task within 12 months. Therefore, Delta 
concluded that no operator should be beyond the 12-month and 3,000-
flight-hour limit, and thus there is no need to allow up to 5 days 
after the effective date requirement.
    The FAA disagrees with the request. The allowance of a ``grace 
period'' (in this case 5 days) in a non-emergency AD is provided in 
order to avoid inadvertently and unnecessarily grounding any airplanes. 
The FAA has determined that providing a 5-day ``grace period'' will not 
adversely affect safety. The FAA notes that the commenter did not 
contend that the 5-day ``grace period'' is a problem or risk. The 
commenter is only contending that it ``should'' not be needed. If it is 
not needed, then it simply will not be utilized. However, if the 5-day 
``grace period'' is needed, then it prevents inadvertent and 
unnecessary grounding of an airplane and provides operators with time 
after the effective date of the AD to accomplish the new lubrication 
task. The FAA has not revised this AD in this regard.

Additional Change in This AD

    Paragraph (h)(1) of the proposed AD erroneously referred to the 
effective date of Transport Canada AD CF-2023-68R1, and should have 
referred to the effective date of AD CF-2023-68 (October 18, 2023). 
Paragraph (h)(1) of this AD has been revised accordingly.

Conclusion

    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 
referenced above. The FAA reviewed the relevant data, considered the 
comments received, and determined that air safety requires adopting 
this AD as proposed. Accordingly, the FAA is issuing this AD to address 
the unsafe condition on this product. Except for minor editorial 
changes, this AD is adopted as proposed in the NPRM. None of the 
changes will increase the economic burden on any operator.

Material Incorporated by Reference Under 1 CFR Part 51

    Transport Canada AD CF-2023-68R1 specifies improved procedures for 
lubricating the HSTA and repeating the lubrication at a reduced 
interval. This material 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 100 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
----------------------------------------------------------------------------------------------------------------
Up to 2 work-hours x $85 per hour = $170              $0  Up to $170................  Up to $17,000.
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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.

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:


[[Page 9604]]


    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:

2025-03-05 Airbus Canada Limited Partnership (Type Certificate 
Previously Held by C Series Aircraft Limited Partnership (CSALP); 
Bombardier, Inc.): Amendment 39-22953; Docket No. FAA-2024-1893; 
Project Identifier MCAI-2023-01050-T.

(a) Effective Date

    This airworthiness directive (AD) is effective March 21, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Canada Limited Partnership (Type 
Certificate previously held by C Series Aircraft Limited Partnership 
(CSALP); Bombardier, Inc.) Model BD-500-1A10 and BD-500-1A11 
airplanes, certificated in any category, as identified in Transport 
Canada AD CF-2023-68R1, dated April 30, 2024 (Transport Canada AD 
CF-2023-68R1).

(d) Subject

    Air Transport Association (ATA) of America Code 55, Stabilizers.

(e) Unsafe Condition

    This AD was prompted by reported events of annunciated 
horizontal stabilizer trim actuator (HSTA) jams occurring at the end 
of the cruise phase of flight. Investigation revealed water 
intrusion in the primary ball nut and/or secondary nut housing of 
the HSTA ballscrew assembly. The FAA is issuing this AD to address 
water intrusion and subsequent freezing, which causes jamming of the 
HSTA, resulting in the loss of pitch trim capability. The unsafe 
condition, if not addressed, could result in loss of control of the 
airplane.

(f) Compliance

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

(g) Requirements

    Except as specified in paragraph (h) of this AD: Comply with all 
required actions and compliance times specified in, and in 
accordance with, Transport Canada AD CF-2023-68R1.

(h) Exceptions to Transport Canada AD CF-2023-68R1

    (1) Where Transport Canada AD CF-2023-68R1 refers to ``the 
effective date of AD CF-2023-68 (18 October 2023),'' this AD 
requires using the effective date of this AD.
    (2) Where Transport Canada AD CF-2023-68R1 refers to hours air 
time, this AD requires using flight hours.
    (3) Where paragraph A of Part I of Transport Canada AD CF-2023-
68R1 specifies an initial compliance time for performing the 
lubrication of the HSTA, for this AD, the initial compliance time is 
at the earlier of the times specified in paragraphs (h)(3)(i) and 
(ii) of this AD.
    (i) Within 1,100 flight hours after the effective date of this 
AD.
    (ii) Within 12 months after the date of the most recent HSTA 
lubrication task, or within 5 days after the effective date of this 
AD, whichever occurs later.
    (4) Where paragraph B of Part I of Transport Canada AD CF-2023-
68R1 specifies an initial compliance time for performing the 
lubrication of the HSTA, for this AD, the initial compliance time is 
at the later of the times specified in paragraphs (h)(4)(i) and (ii) 
of this AD.
    (i) Within 1,100 flight hours or 12 months, whichever occurs 
first, since the date of issuance of the original airworthiness 
certificate or the original export certificate of airworthiness.
    (ii) Within 5 days after the effective date of this AD.

(i) Additional AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, AIR-
520, Continued Operational Safety 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 responsible Flight Standards Office, 
as appropriate. If sending information directly to the manager of 
the Continued Operational Safety Branch, mail it to the address 
identified in paragraph (j) of this AD. Information may be emailed 
to: [email protected]. Before using any approved AMOC, notify your 
appropriate principal inspector, or lacking a principal inspector, 
the manager of the responsible Flight Standards 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, AIR-520, 
Continued Operational Safety Branch, FAA; or Transport Canada; or 
Airbus Canada Limited Partnership's Transport Canada Design Approval 
Organization (DAO). If approved by the DAO, the approval must 
include the DAO-authorized signature.

(j) Additional Information

    For more information about this AD, contact Mark Taylor, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; telephone 781-238-7229; email [email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the material listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless this AD specifies otherwise.
    (i) Transport Canada AD CF-2023-68R1, dated April 30, 2024.
    (ii) [Reserved]
    (3) For Transport Canada AD CF-2023-68R1, contact Transport 
Canada, Transport Canada National Aircraft Certification, 159 
Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888-663-
3639; email [email protected]. You may find this Transport 
Canada AD on the Transport Canada website at tc.canada.ca/en/
aviation.
    (4) 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.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations, or email [email protected].

    Issued on January 29, 2025.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-02646 Filed 2-13-25; 8:45 am]
BILLING CODE 4910-13-P

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