DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1710; Project Identifier MCAI-2023-00243-T]
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for certain Bombardier, Inc., Model CL-600-2B16 (601-3A, 601-3R, and
604 Variants) airplanes. This proposed AD was prompted by reports from
the supplier that sensing elements of the bleed air leak detection
system were manufactured with insufficient salt fill, which can result
in an inability to detect hot bleed air leaks. This proposed AD would
require testing of all affected overheat detection sensing elements of
the bleed air leak detection system, and replacement if necessary. This
proposed AD would also prohibit the installation of affected parts. The
FAA is proposing this AD to address the unsafe condition on these
DATES: The FAA must receive comments on this proposed AD by September
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
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-2023-1710; 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 service information identified in this
NPRM, contact Bombardier Business Aircraft Customer Response Center,
400 Cote-Vertu Road West, Dorval, Quebec H4S 1Y9, Canada;
telephone 514-855-2999; email firstname.lastname@example.org; website
For Kidde Aerospace & Defense service information
identified in this NPRM, contact Kidde Aerospace & Defense, 4200
Airport Drive NW, Building B, Wilson, NC 27896; telephone: 319-295-
5000; website: kiddetechnologies.com/aviation.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.
FOR FURTHER INFORMATION CONTACT: Chirayu Gupta, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
telephone 516-228-7300; email email@example.com.
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-2023-1710; Project Identifier
MCAI-2023-00243-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
Chirayu Gupta, Aviation Safety Engineer, FAA, 1600 Stewart Avenue,
Suite 410, Westbury, NY 11590; telephone 516-228-7300; email
firstname.lastname@example.org. Any commentary that the FAA receives which is
specifically designated as CBI will be placed in the public docket for
Transport Canada, which is the aviation authority for Canada, has
issued Transport Canada AD CF-2023-05, dated February 8, 2023
(Transport Canada AD CF-2023-05) (also referred to after this as the
MCAI), to correct an unsafe condition on certain Bombardier, Inc.,
Model CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes. The
MCAI states that Bombardier received reports from the supplier of the
overheat detection sensing elements of a manufacturing quality escape.
Some of the sensing elements of the bleed air leak detection system
were manufactured with insufficient salt fill, which can result in an
inability to detect hot bleed air leaks and cause damage to surrounding
structures and systems that can prevent continued safe flight and
The FAA is proposing this AD to address the unsafe condition on
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-1710.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Bombardier Service Bulletin 604-36-005, Bombardier
Service Bulletin 605-36-002, and Bombardier Service Bulletin 650-36-
001, all dated December 23, 2022. This service information specifies
procedures for testing affected bleed air leak detection system sensing
elements (i.e., those marked with a date code before ``A2105'' (which
corresponds to January 31, 2021) with a part number defined in this
service information) to determine if they are serviceable, and
replacing failed sensing elements with serviceable ones. These
documents are distinct since they apply to different airplane serial
The FAA reviewed Kidde Aerospace & Defense Service Bulletin CFD-26-
1, Revision 6, dated February 28, 2022. This service information
specifies affected continuous fire detector part numbers and testing
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.
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 AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the service information already described. This proposed AD would
also prohibit the installation of affected parts.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 694 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs for Required Actions
|Up to 37 work-hours x $85 per
hour = Up to $3,145
|Up to $3,145
||Up to $2,182,630
The 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 these on-condition actions.
Estimated Costs of On-Condition Actions
|37 work-hours x $85 per hour
* The FAA has received no definitive
data on which to base the cost
estimates for the parts specified in this proposed AD. This is the
estimated cost for replacement of 2 percent of the failed sensing
elements. If all sensing elements failed, the estimated parts cost
would be $40,000 for each airplane.
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.
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
(1) Is not a ``significant regulatory action'' under Executive
(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
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 adding the following new airworthiness