2024-05962. 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 (AD) for certain Bombardier, Inc., Model BD–100–1A10 airplanes. This proposed AD was prompted by the discovery of a single-point failure within the left-hand and right-hand heater current monitor (HCM) units. This proposed AD would require installing a monitor circuit comprising relays external to the HCM units. This proposed AD would also require revising the normal and non-normal procedure sections of the existing airplane flight manual (AFM) to add new procedures associated with revised crew alerting system (CAS) messages. The FAA is proposing this AD to address the unsafe condition on these products.

DATES:

The FAA must receive comments on this proposed AD by May 9, 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: [phone].

• 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–2024–0758; 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 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone [phone]; email: [e-mail]; website: 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.

FOR FURTHER INFORMATION CONTACT:

Steven Dzierzynski, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

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–2024–0758; Project Identifier MCAI–2023–00671–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 Steven Dzierzynski, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail]. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

Transport Canada, which is the aviation authority for Canada, has issued Transport Canada AD CF–2023–33, dated May 10, 2023 (Transport Canada AD CF–2023–33) (also referred to after this as the MCAI), to correct an unsafe condition on certain Bombardier, Inc., Model BD–100–1A10 airplanes. The MCAI states that during a review of the air data system, Bombardier discovered that a single-point failure exists within the left-hand and right-hand HCM units. The HCM unit is designed with a single programmable logic device (PLD), which is responsible for the control and monitoring functions of the HCM unit. The PLD could fail in a way that it would erroneously energize the heater control relay and switch the heaters off. This failure could lead to un-annunciated loss of ice protection on the air data probes, resulting in the potential display of misleading airspeed, and erroneous indications to the flightcrew.

The FAA is proposing 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–2024–0758.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Bombardier Service Bulletin 100–30–06 and Bombardier Service Bulletin 350–30–001, both dated December 29, 2022. The service information specifies procedures to install a monitoring circuit comprising relays external to the HCM units, including reworking the plate assembly, installing relay bracket assemblies, installing relays and a rail terminal module, installing wires for the relays, and performing operational testing. These documents are distinct since they apply to different airplane serial numbers.

The FAA also reviewed the following service information, which specifies new normal procedures to follow after installation of the monitoring circuit. These documents are distinct since they apply to different airplane serial numbers.

• BEFORE STARTING ENGINES section, Subsection 04–02, Chapter 4, Normal Procedures, Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, Revision 72, dated May 11, 2023. (For obtaining the procedures for Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, use Document Identification No. CH 300 AFM–I.)

• BEFORE STARTING ENGINES section, Subsection 04–02, Chapter 4, Normal Procedures, Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, Revision 38, dated May 11, 2023. (For obtaining the procedures for Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, use Document Identification No. CH 350 AFM.)

The FAA reviewed the following service information, which specifies non-normal procedures to follow after installation of the monitoring circuit. These documents are distinct since they apply to different airplane serial numbers.

• Subsection 05–27, Ice & Rain Protection, Chapter 5, Non-Normal Procedures, Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, Revision 72, dated May 11, 2023. (For obtaining the procedures for Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, use Document Identification No. CH 300 AFM–I.)
• Subsection 05–27, Ice & Rain Protection, Chapter 5, Non-Normal Procedures, Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, Revision 38, dated May 11, 2023. (For obtaining the procedures for Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, use Document Identification No. CH 350 AFM.)

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 AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified in the service information already described. This AD also requires revising the existing AFM.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 343 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs for Required Actions

Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Up to 70 work-hours × $85 per hour = Up to $5,950.00	Up to $2,324	Up to $8,274	Up to $2,837,982.

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

Bombardier, Inc.: Docket No. FAA–2024–0758; Project Identifier MCAI–2023–00671–T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by May 9, 2024.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Bombardier, Inc., Model BD–100–1A10 airplanes, certificated in any category, serial numbers 20003 through 20936 inclusive.

(d) Subject

Air Transport Association (ATA) of America Code 30, Ice and Rain Protection.

(e) Unsafe Condition

This AD was prompted by a review of the air data system where Bombardier discovered that a single-point failure exists within the left-hand and right-hand heater current monitor (HCM) units. The FAA is issuing this AD to address the failure of the programmable logic device in the left-hand and right-hand HCM units. The unsafe condition, if not addressed, could lead to un-annunciated loss of ice protection on the air data probes, resulting in the potential display of misleading airspeed, and erroneous indications to the flightcrew.

(f) Compliance

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

(g) Monitoring Circuit Installation and Tests

Within 60 months from the effective date of this AD, install a monitoring circuit comprising relays external to the HCM units, in accordance with sections 2.B. and 2.C. of the Accomplishment Instructions of the applicable service information specified in paragraph (g)(1) or (2) of this AD.

(1) Bombardier Service Bulletin 100–30–06, dated December 29, 2022 (for airplane serial numbers 20003 through 20500 inclusive).

(2) Bombardier Service Bulletin 350–30–001, dated December 29, 2022 (for airplane serial numbers 20501 through 20936 inclusive); as applicable.

(h) Revision of Existing Airplane Flight Manual (AFM)

Within 60 months from the effective date of this AD, and after the completion of the actions required by paragraph (g) of this AD, revise the existing AFM as specified in paragraphs (h)(1) through (4) of this AD, as applicable.

(1) For airplane serial numbers 20003 through 20500 inclusive: Revise Chapter 4, Normal Procedures, to include the information in BEFORE STARTING ENGINES section, Subsection 04–02, Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, Revision 72, dated May 11, 2023.

Note 1 to paragraph (h)(1): For obtaining the procedures specified in paragraphs (h)(1) and (2) of this AD for Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, use Document Identification No. CH 300 AFM–I.

(2) For airplane serial numbers 20003 through 20500 inclusive: Revise Chapter 5, Non-Normal Procedures, to include the information in Subsection 05–27, Ice & Rain Protection, Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, Revision 72, dated May 11, 2023.

(3) For airplane serial numbers 20501 through 20936 inclusive: Revise Chapter 4, Normal Procedures, to include the information in BEFORE STARTING ENGINES section, Subsection 04–02, Bombardier Challenger 350, Publication No. CH 350 AFM, Revision 38, dated May 11, 2023.

Note 2 to paragraph (h)(3): For obtaining the procedures specified in paragraphs (h)(3) and (4) of this AD for Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, use Document Identification No. CH 350 AFM.

(4) For airplane serial numbers 20501 through 20936 inclusive: Revise Chapter 5, Non-Normal Procedures, to include the information in Subsection 05–27, Ice & Rain Protection, Bombardier Challenger 350, Publication No. CH 350 AFM, Revision 38, dated May 11, 2023.

(i) Additional AD Provisions

The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Validation 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 International Validation Branch, mail it to the address identified in paragraph (j)(2) of this AD. Information may be emailed to: [e-mail]. 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, International Validation Branch, FAA; or Transport Canada; or Bombardier, Inc.'s Transport Canada Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature.

(j) Additional Information

(1) Refer to Transport Canada AD CF–2023–33, dated May 10, 2023, for related information. This Transport Canada AD may be found in the AD docket at regulations.gov under Docket No. FAA–2024–0758.

(2) For more information about this AD, contact Steven Dzierzynski, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

(k) 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) BEFORE STARTING ENGINES section, Subsection 04–02, Chapter 4, Normal Procedures, Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, Revision 72, dated May 11, 2023.

Note 3 to paragraph (k)(2)(i): For obtaining the procedures specified in paragraphs (k)(2)(i) and (ii) of this AD for Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, use Document Identification No. CH 300 AFM–I.

(ii) Subsection 05–27, Ice & Rain Protection, Chapter 5, Non-Normal Procedures, Bombardier Challenger 300 AFM (Imperial Version), Publication No. CSP 100–1, Revision 72, dated May 11, 2023.

(iii) BEFORE STARTING ENGINES section, Subsection 04–02, Chapter 4, Normal Procedures, Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, Revision 38, dated May 11, 2023.

Note 4 to paragraph (k)(2)(iii): For obtaining the procedures specified in paragraphs (k)(2)(iii) and (iv) of this AD for Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, use Document Identification No. CH 350 AFM.

(iv) Subsection 05–27, Ice & Rain Protection, Chapter 5, Non-Normal Procedures, Bombardier Challenger 350 AFM, Publication No. CH 350 AFM, Revision 38, dated May 11, 2023.

(v) Bombardier Service Bulletin 100–30–06, dated December 29, 2022.

(vi) Bombardier Service Bulletin 350–30–001, dated December 29, 2022.

(3) For service information identified in this AD, contact Bombardier Business Aircraft Customer Response Center, 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone [phone]; email [e-mail]; website 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 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 [e-mail].

Issued on March 15, 2024.

Victor Wicklund,

Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.