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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2021-0787; Project Identifier MCAI-2021-00252-T]
RIN 2120-AA64
 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 CL-600-1A11 (600), CL-600-2A12 (601), and CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes. This proposed AD was prompted by a report of a wing stall (wing drop/un-commanded roll) during a landing flare. This proposed AD would require revising the existing airplane flight manual (AFM) to incorporate a limitation and procedure for the wing anti-ice (WAI) system in order to mitigate the risk of ice accumulation on the wing leading edges. 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 November 1, 2021.
 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 *https://www.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. For service information identified in this NPRM, contact Bombardier, Inc., 200 Côte-Vertu Road West, Dorval, Québec H4S 2A3, Canada; North America toll-free telephone 1-866-538-1247 or direct-dial telephone 1-514-855-2999; email *ac.yul@aero.bombardier.com;* internet *https://www.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. Examining the AD Docket You may examine the AD docket at *https://www.regulations.gov* by searching for and locating Docket No. FAA-2021-0787; 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, any comments received, and other information. The street address for Docket Operations is listed above.
 FOR FURTHER INFORMATION CONTACT: Chirayu Gupta, Aerospace Engineer, Mechanical Systems and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531; 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-2021-0787; Project Identifier MCAI-2021-00252-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 *https://www.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, Aerospace Engineer, Mechanical Systems and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531; 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 Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued TCCA AD CF-2021-06, dated February 26, 2021 (TCCA AD CF-2021-06) (also referred to after this as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for certain Bombardier, Inc., Model CL-600-1A11 (600), CL-600-2A12 (601), and CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes. You may examine the MCAI in the AD docket at *https://www.regulations.gov* by searching for and locating Docket No. FAA-2021-0787. This proposed AD was prompted by a report of a wing stall (wing drop/un-commanded roll) during a landing flare. Photographs after landing showed that the airplane had mixed ice on the leading edges of the wings; therefore, it was determined that during descent the ( print page 51280)WAI system had been OFF because the ice detector did not detect ice. Post-incident functional checks of the ice detectors revealed no faults with the ice detector units onboard the aircraft. After the investigation, it was revealed that the flightcrew had followed the AFM procedures, which did not require the WAI system to be selected ON. The FAA is proposing this AD to address ice accumulation on the wing leading edges, which could result in a wing stall during landing and consequent reduced controllability of the airplane. See the MCAI for additional background information. Related Service Information Under 1 CFR Part 51 Bombardier has issued the following service information, which specifies a revised AFM limitation and procedure for the WAI system in order to mitigate the risk of ice accumulation on the wing leading edge. These documents are distinct since they apply to different airplane configurations. Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 3., OPERATION LIMITATIONS, of the LIMITATIONS section; and sub-section C., Icing Conditions During Flight, of Chapter 3., SYSTEMS OPERATIONS—ANTI-ICE, and sub-section I., Before Landing, of Chapter 42., CONSOLIDATED CHECK LIST, of NORMAL PROCEDURES section; of Canadair Challenger CL-600-1A11 AFM, Product Publication 600, Revision 114, dated April 16, 2020.
        Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 4., OPERATION LIMITATIONS, of the LIMITATIONS section; and sub-section C., Icing Conditions During Flight, of Chapter 4., SYSTEMS OPERATIONS—ANTI-ICE, and sub-section I., Before Landing, of Chapter 23., CONSOLIDATED CHECK LIST, of the NORMAL PROCEDURES section; of Canadair Challenger CL-600-1A11 AFM, Product Support Publication (PSP) 600-1, Revision 106, dated April 16, 2020.
        Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 3., OPERATING LIMITATIONS, of the LIMITATIONS section; and sub-section E., Icing Conditions During Flight, of Chapter 4., SYSTEMS OPERATIONS—ANTI-ICE, of the NORMAL PROCEDURES section; of Canadair Challenger CL-600-2A12 AFM, PSP 601-1A, Revision 123, dated April 16, 2020.
        Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 3., OPERATING LIMITATIONS, of the LIMITATIONS section; and sub-section E., Icing Conditions During Flight, of Chapter 4., SYSTEMS OPERATIONS—ANTI-ICE, of the NORMAL PROCEDURES section; of Canadair Challenger CL-600-2A12 AFM, PSP 601-1A-1, Revision 82, dated April 16, 2020.
        Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 3., OPERATING LIMITATIONS, of the LIMITATIONS section; and sub-section E., Icing Conditions During Flight, of Chapter 4., SYSTEMS OPERATIONS—ANTI-ICE, of the NORMAL PROCEDURES section; of Canadair Challenger CL-600-2A12 AFM, PSP 601-1B, Revision 86, dated April 16, 2020.
        Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 3., OPERATING LIMITATIONS, of the LIMITATIONS section; and sub-section E., Icing Conditions During Flight, of Chapter 4., SYSTEMS OPERATIONS—ANTI-ICE, of the NORMAL PROCEDURES section; of Canadair Challenger CL-600-2A12 AFM, PSP 601-1B-1, Revision 84, dated April 16, 2020.
        Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 3., OPERATING LIMITATIONS, of the LIMITATIONS section; and sub-section E., Icing Conditions During Flight, of Chapter 4., SYSTEMS OPERATIONS—ANTI-ICE, of the NORMAL PROCEDURES section; of Canadair Challenger CL-600-2B16 AFM, PSP 601A-1, Revision 106, dated April 16, 2020.
        Sub-sub section (2), Wing Anti-ice System, of sub-section I., Operation in Icing Conditions, of Chapter 3., OPERATING LIMITATIONS, of the LIMITATIONS section; and sub-section E., Icing Conditions During Flight, of Chapter 4., SYSTEMS OPERATIONS—ANTI-ICE, of the NORMAL PROCEDURES section; of Canadair Challenger CL-600-2B16 AFM, PSP 601A-1-1, Revision 95, dated April 16, 2020.
        Sub-sub section B., Wing Anti-ice System, of sub-section 4., Operation in Icing Conditions, of Section 02-04, Operating Limitations, of Chapter 2—LIMITATIONS; and sub-section M., Icing Conditions During Flight, of Section 04-14, Ice and Rain Protection, of Chapter 4—NORMAL PROCEDURES; of Bombardier Challenger 604 CL-600-2B16 AFM, PSP 604-1, Revision 116, dated December 18, 2019.
        Sub-sub section B., Wing Anti-ice System, of sub-section 4., Operation in Icing Conditions, of Section 02-04, Operating Limitations, of Chapter 2—LIMITATIONS; and sub-section M., Icing Conditions During Flight, of Section 04-14, Ice and Rain Protection, of Chapter 4—NORMAL PROCEDURES; of Bombardier Challenger 605 CL-600-2B16 AFM, PSP 605-1, Revision 54, dated December 18, 2019.
        Sub-sub section B., Wing Anti-ice System, of sub-section 4., Operation in Icing Conditions, of Section 02-04, Operating Limitations, of Chapter 2—LIMITATIONS; and sub-section M., Icing Conditions During Flight, of Section 04-14, Ice and Rain Protection, of Chapter 4—NORMAL PROCEDURES; of Bombardier Challenger 650 CL-600-2B16 AFM, PSP 650-1, Revision 19, dated December 18, 2019. 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 the State of Design Authority, the FAA has been notified of the unsafe condition described in the MCAI and service information referenced above. The FAA is proposing this AD because the FAA evaluated all the relevant information and determined 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 revising the existing AFM to incorporate the limitations and procedures for the WAI system described previously, in order to mitigate the risk of ice accumulation on the wing leading edges, except as discussed under “Differences Between this Proposed AD and the MCAI.” Differences Between This Proposed AD and the MCAI This NPRM updates certain AFM revision levels identified in TCCA AD CF-2021-06, and therefore identifies the complete, most recent service information that will be incorporated by reference in the final rule.( print page 51281) Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 619 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. operators1 work-hour × $85 per hour = $85
$0
$85
$52,615
 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
 2.The FAA amends § 39.13 by adding the following new airworthiness directive: **Bombardier, Inc.:** Docket No. FAA-2021-0787; Project Identifier MCAI-2021-00252-T. (a) Comments Due Date The FAA must receive comments on this airworthiness directive (AD) by November 1, 2021. (b) Affected ADs None. (c) Applicability This AD applies to Bombardier, Inc., airplanes, certificated in any category, as identified in paragraphs (c)(1) through (3) of this AD. (1) Model CL-600-1A11 (600) airplanes having serial numbers (S/Ns) 1001 through 1085 inclusive. (2) Model CL-600-2A12 (601) airplanes having S/Ns 3001 through 3066 inclusive. (3) Model CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes having S/Ns 5001 through 5194 inclusive; 5301 through 5665 inclusive; 5701 through 5988 inclusive; and 6050 through 6153 inclusive. (d) Subject Air Transport Association (ATA) of America Code 30, Ice and Rain Protection. (e) Unsafe Condition This AD was prompted by a report of a wing stall during a landing flare. Photographs after landing showed that the airplane had mixed ice on the leading edges of the wings; therefore, it was determined that during descent the wing anti-ice (WAI) system had been OFF because the ice detector did not detect ice. The FAA is issuing this AD to address ice accumulation on the wing leading edges, which could result in a wing stall during landing and consequent reduced controllability of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Airplane Flight Manual (AFM) Revision Within 60 days after the effective date of this AD: Revise the existing AFM to incorporate the specified sections of the Bombardier or Canadair Challenger AFM revision limitations and procedures for the WAI system specified in figure 1 to paragraph (g) of this AD. 
 
  
 
  
 
  (h) Other FAA AD Provisions The following provisions also apply to this AD: (1) *Alternative Methods of Compliance (AMOCs):* The Manager, New York ACO 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 certification office, send it to ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531. 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, New York ACO Branch, FAA; or Transport Canada Civil Aviation (TCCA); or Bombardier, Inc.'s TCCA Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature. (i) Related Information (1) Refer to Mandatory Continuing Airworthiness Information (MCAI) TCCA AD CF-2021-06, dated February 26, 2021, for related information. This MCAI may be found in the AD docket at *https://www.regulations.gov* by searching for and locating Docket No. FAA-2021-0787. (2) For more information about this AD, contact Chirayu Gupta, Aerospace Engineer, Mechanical Systems and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531; email *9-avs-nyaco-cos@faa.gov.* (3) For service information identified in this AD, contact Bombardier, Inc., 200 Côte-Vertu Road West, Dorval, Québec H4S 2A3, Canada; North America toll-free telephone 1-866-538-1247 or direct-dial telephone 1-514-855-2999; email *ac.yul@aero.bombardier.com;* internet *https://www.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. Issued on September 9, 2021. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service.


BILLING CODE 4910-13-P [FR Doc. 2021-19814 Filed 9-14-21; 8:45 am] BILLING CODE 4910-13-C