DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1003; Project Identifier MCAI-2023-00712-T;
Amendment 39-22837; AD 2024-18-03]
RIN 2120-AA64
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2023-11-
01, which applied to certain Bombardier, Inc., Model BD-100-1A10
airplanes. AD 2023-11-01 required a records check and replacement of
affected left-hand (LH) direct current power center (DCPC) units. AD
2023-11-01 also provided optional terminating action for the records
check and replacement. This AD was prompted by multiple reports of
erratic electrical system status on the push button annunciators (PBAs)
and the engine instrument and crew alerting system (EICAS) while on-
ground and during flight, and by the determination that certain DCPC
units require additional modification or replacement. This AD requires
checking maintenance records of certain airplanes, replacing certain
DCPC units, and modifying certain DCPC units. This AD also expands the
applicability of AD 2023-11-01 and prohibits the installation of
affected parts. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective November 12, 2024.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of November 12, 2024.
The Director of the Federal Register approved the incorporation by
reference of certain other publications listed in this AD as of August
15, 2023 (88 FR 44042, July 11, 2023).
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-1003; 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:
For Bombardier material identified in this AD, contact
Bombardier Business Aircraft Customer Response Center, 400 C[ocirc]te-
Vertu Road West, Dorval, Qu[eacute]bec H4S 1Y9, Canada; telephone 514-
855-2999; email bombardier.com">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. It is also available at regulations.gov under
Docket No. FAA-2024-1003.
FOR FURTHER INFORMATION CONTACT: Steven Dzierzynski, 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:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2023-11-01, Amendment 39-22446 (88 FR
44042, July 11, 2023) (AD 2023-11-01). AD 2023-11-01 applied to certain
Bombardier, Inc., Model BD-100-1A10 airplanes. AD 2023-11-01 required a
records check and replacement of affected LH DCPC units, and provided
optional terminating action for those actions. The FAA issued AD 2023-
11-01 to address erratic indications, which could cause the flight crew
to turn off fully-operational electrical power sources, leading to
partial or complete loss of electrical power resulting in loss of
flight displays and reduced controllability of the airplane.
The NPRM published in the Federal Register on April 26, 2024 (89 FR
32380). The NPRM was prompted by AD CF-2023-35, dated May 26, 2023,
issued by Transport Canada, which is the aviation authority for Canada
(Transport Canada AD CF-2023-35) (also referred to as the MCAI). The
MCAI states that airplanes could experience misleading electrical
system status indications (PBA and EICAS) as a result of contamination
of electrical contacts in the LH DCPC internal communication data bus.
In the NPRM, the FAA proposed to continue to require checking the
airplane records and replacement of affected LH DCPC units. The NPRM
also proposed to require modification of certain LH DCPC units,
prohibit installation of affected parts, and expand the applicability
of AD 2023-11-01. The FAA is issuing this AD to address the unsafe
condition on these products.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2024-1003.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from Bombardier, Inc. (Bombardier), who
also stated its support for the NPRM. The following presents the
comment received on the NPRM and the FAA's response to that comment.
Request To Extend the Compliance Time
Bombardier requested that the proposed AD be revised to extend the
proposed compliance time to March 31, 2026. Bombardier asserted that,
due to changes made in the airplane flight manual (AFM), which
introduced the "Unexpected Electrical Indications" procedure
instructing pilots not to act on erratic indications related to the
electrical power generation and distribution system, the medium risk
was mitigated and the severity of a misleading indication event was
lowered from potentially catastrophic to major. Even if such events
still occur after the implementation of Bombardier Service Bulletins
100-24-30 and 350-24-005, following implementation of the AFM revision,
Bombardier considers these events a reliability issue and stated its
commitment to work with the supplier to correct the effects of such
events. Bombardier further asserted that, when analyzed in conjunction
with the probability of occurrence, the risk becomes low. Additionally,
Bombardier attested that, based on its provisions, a shorter compliance
time will create additional pressure on the U.S. operators, exposing
them to a potential grounding scenario, necessitating the need for
Bombardier to apply for an alternative method of compliance (AMOC) to
support this AD.
The FAA disagrees with the request. Bombardier provided no
substantiating data to support the need for an extension of the
proposed compliance time. In developing an appropriate compliance time
for this action, the FAA considered the safety implications, the time
necessary to accomplish the required actions, the availability of
required parts, and normal maintenance schedules for timely
accomplishment of the required actions. Considering these items, the
FAA has determined that the specified compliance time, as proposed, is
appropriate to ensure an acceptable level of safety. The FAA has not
changed this AD because of this comment. However, under the provisions
of paragraph (m)(1) of this AD, the FAA will consider requests for
approval of alternative compliance times if sufficient data are
submitted to substantiate that the change would provide an acceptable
level of safety.
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
comment 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
The FAA reviewed Bombardier Service Bulletins 100-24-29 and 350-24-
004, both Revision 01, both dated July 27, 2023. This material
specifies procedures for a records check to determine the total flight
hours and replacement of affected LH DCPC units (part numbers
975GC02Y04, 975GC0Y05, 975GC02Y06, and 975GC02Y07). These documents are
distinct since they apply to different airplane configurations.
The FAA also reviewed Subject 24-61-01 DC Power Center (DCPC)--
Removal/Installation, Chapter 24--Electrical Power, Bombardier
Challenger 300 Aircraft Maintenance Manual, Part Two, Publication No.
CH 300 AMM, Revision 82, dated November 9, 2023, which specifies:
procedures for removing DCPC units in Task 24-61-01-000-801
Removal of the DC Power Center (DCPC);
procedures for installing DCPC units in Task 24-61-01-400-801
Installation of the DC Power Center (DCPC); and
procedures for testing DCPC units in Task 24-61-01-720-801
Functional Test of the DC Power Center (DCPC).
For obtaining these tasks for the Bombardier Challenger 300
Aircraft Maintenance Manual, Part Two, Publication
No. CH 300 AMM, use Document Identification No. CH 300 AMM.
The FAA also reviewed Subject 24-61-01 DC Power Center (DCPC)--
Removal/Installation, Chapter 24--Electrical Power, Bombardier
Challenger 350 Aircraft Maintenance Manual, Part Two, Publication No.
CH 300 AMM, Revision 38, dated November 9, 2023, which specifies:
procedures for removing DCPC units in Task 24-61-01-000-
801 Removal of the DC Power Center (DCPC);
procedures for installing DCPC units in Task 24-61-01-400-801
Installation of the DC Power Center (DCPC); and
procedures for testing DCPC units in Task 24-61-01-720-801
Functional Test of the DC Power Center (DCPC).
For obtaining these tasks for the Bombardier Challenger 350
Aircraft Maintenance Manual, Part Two, Publication No. CH 350 AMM, use
Document Identification No. CH 350 AMM.
This AD would also require the following material, which the
Director of the Federal Register approved for incorporation by
reference as of August 15, 2023 (88 FR 44042, July 11, 2023).
Bombardier Service Bulletin 100-24-29, dated April 9, 2021.
Bombardier Service Bulletin 100-24-30, dated November 29, 2022.
Bombardier Service Bulletin 350-24-004, dated April 9, 2021.
Bombardier Service Bulletin 350-24-005, dated November 29, 2022.
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 356 airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
ACTION
|
LABOR COST
|
PARTS COST
|
COST PER PRODUCT
|
COST ON U.S. OPERATORS
|
Records check |
1 work-hours x $85 per hour = $85 |
$0
|
$85
|
$30,260
|
New actions (modification) |
2 work-hours x $85 per hour = $170 |
0
|
170
|
60,520
|
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
LABOR COST |
PARTS COST |
COST PER PRODUCT |
7 work-hours x $85 per hour = $595 |
Up to $35,000 |
Up to $35,595 |
According to the manufacturer, some or all of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected operators. The FAA does not control warranty coverage for
affected operators. As a result, the FAA has included all known costs
in the cost estimate.
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
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 (AD) 2023-11-01, Amendment 39-22446
(88 FR 44042, July 11, 2023); and
b. Adding the following new AD:
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