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 Bell Model 407 helicopters. The NPRM was published in the Federal Register on November 18, 2025 (90 FR 51602). The NPRM was prompted by AD CF-2024-18, dated May 29, 2024 (Transport Canada AD CF-2024-18) (also referred to as the MCAI), issued by Transport Canada, which is the aviation authority for Canada. The MCAI states that Bell received a report that a pilot cyclic stick tube assembly having part number (P/N) 206-001-342-101 fractured at the lower end of the tube near the upper slotted area where it is held in place in the pivot assembly. Examination of the fractured pilot cyclic stick tube and subsequent findings of other cracked pilot cyclic stick tubes revealed fatigue cracking. Further investigation identified the root cause of the pilot cyclic stick tube cracking as the application of excessive force to the cyclic stick during the freedom of movement of the controls and cyclic centering light operation check as part of the interior and prestart check, which resulted in elevated stress at the slotted area and was aggravated by the high stress concentration design feature of the upper slotted area.

In the NPRM, the FAA proposed to require repetitively inspecting the pilot cyclic stick tube assembly for cracking and, depending on the results, repairing or replacing the pilot cyclic stick tube assembly. The FAA is issuing this AD to detect and correct a crack in the pilot cyclic stick tube which, if not addressed, could lead to an in-flight failure of the pilot cyclic stick tube and consequent loss of control of the helicopter.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-3436.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from the Citizens Rulemaking Alliance. The following presents the comments received on the NPRM and the FAA's response to each comment.

Request To Issue an NPRM or Justify Forgoing Notice and Comment

The Citizens Rulemaking Alliance requested that the FAA either convert this action to an NPRM or provide its justification for finding good cause to bypass notice and comment procedures, extend the effective date to at least 30 days after publication, commit in the preamble to responding to comments, and adjust the AD accordingly within a defined short timeframe. Alternatively, the commenter requested that the AD record be supplemented to provide a more specific explanation tied to the particular failure mode why an NPRM was impracticable. The commenter asserted the FAA has not adequately justified use of the good cause exemption to bypass notice and comment and the 30-day delayed effective date.

The FAA notes the comment was submitted in response to an NPRM for which the FAA provided a 45-day comment period. This final rule is effective 35 days after its publication in the Federal Register . Therefore, no change to this AD is necessary.

Request To Comply With the Paperwork Reduction Act (PRA)

The Citizens Rulemaking Alliance requested that the FAA revise the proposed AD to comply with the PRA ( printed page 44736) if reporting is required or suspend any reporting provisions until PRA requirements are satisfied. If reporting is not required, the commenter requested the FAA clarify that in the AD.

The FAA notes paragraph (i) of this AD specifies that this AD does not require reporting. If an AD were to require reporting, the preamble of the final rule would include a paragraph titled “Paperwork Reduction Act” that would provide the applicable OMB control number, required PRA statements, and the estimated time to collect the required information (burden). Any costs associated with the reporting requirement would be included in the Costs of Compliance section in the preamble of the final rule. Therefore, the FAA did not change this AD as a result of this comment.

Request To Make Incorporation by Reference (IBR) Materials Reasonably Available

The Citizens Rulemaking Alliance stated that the FAA's current practices for IBR frequently fail to meet the legal and regulatory standards for reasonable availability. The commenter called on the FAA to guarantee that all IBR materials are easily and freely accessible to the public and affected parties for both commenting and compliance purposes. The commenter also requested that this access be documented in the rulemaking record.

The FAA notes that this AD incorporates by reference Transport Canada AD CF-2024-18, not the manufacturer service information referenced in that Transport Canada AD. The FAA posted Transport Canada AD CF-2024-18 to the AD docket when the NPRM was published in the Federal Register . The material referenced in Transport Canada AD CF-2024-18 may only be posted before the final rule's publication if it is already publicly available or if there is written consent from the owner of that material. Additionally, the FAA provided notice in the NPRM that the material referenced in Transport Canada AD CF-2024-18 will be available in the AD docket after this AD is published. Therefore, the FAA did not change this AD as a result of this comment.

Request To Consider Impact on Small Entities and Compliance Costs

The Citizens Rulemaking Alliance requested that the FAA expand the proposed economic analysis to consider the impacts on small-entities and to offer explicit alternatives where justified. The commenter argued that the FAA's standard labor rate of $85 per work-hour underestimates total labor costs and downtime experienced by operators and maintenance providers. The commenter instead suggested a labor rate between $110 and $140 per work-hour, in addition to accounting for costs related to ferry flights, lost revenue, and parts scarcity.

Compliance Costs

The FAA has determined that the current labor rate of $85 per hour remains accurate for this AD. The FAA evaluates this rate periodically, based on U.S. Bureau of Labor Statistic data found at data.bls.gov/oes, and will change the rate when appropriate. The FAA used a blended wage rate to estimate the labor rate for this AD, where the FAA assumes 60 percent weight for aircraft mechanics (at a fully burdened mean wage rate of $69.85 per hour) and 40 percent for general and operations managers (at a fully burdened mean wage rate of $108.15 per hour). To calculate the blended wage rate, the FAA multiplied each wage rate by its corresponding weight and added up the products to obtain a wage rate of $85.17, which the FAA rounded down to $85.

The FAA also recognizes that, in doing the actions required by an AD, operators might incur indirect or incidental costs in addition to the direct costs. The cost analysis in an AD typically describes only the direct costs of the specific actions required by an AD, which does not include indirect or incidental costs such as downtime, loss of revenue, planning, or time necessitated by other administrative actions since those costs might vary significantly among operators. In the Cost of Compliance section of the proposed AD, the FAA disclosed the estimated number of work hours, the number of helicopters affected on the U.S. registry (updated in this final rule), and an estimated parts cost. Since the FAA has assessed and disclosed the total known costs of the AD requirements in the Costs of Compliance section of the proposed AD, and the commenter did not provide additional cost data for the FAA to consider in its cost analysis, it is not necessary to provide additional cost information for this AD.

Small Entities to Which This AD Applies

The FAA has considered the AD's impact on small businesses and provides the following factual basis for its Regulatory Flexibility Act (RFA) certification.

The Regulatory Flexibility Act of 1980, Public Law 96-354, 94 Stat. 1164 (5 U.S.C. 601-612), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (Pub. L. 104-121, 110 Stat. 857, Mar. 29, 1996) and the Small Business Jobs Act of 2010 (Pub. L. 111-240, 124 Stat. 2504, Sept. 27, 2010), requires Federal agencies to consider the effects of the regulatory action on small business and other small entities and to minimize any significant economic impact. The term “small entities” comprises small businesses and not-for-profit organizations that are independently owned and operated and are not dominant in their fields, and governmental jurisdictions with populations of less than 50,000.

The FAA used the definition of small entities in the RFA for this analysis. The RFA defines small entities as small businesses, small governmental jurisdictions, or small organizations. In 5 U.S.C. 601(3), the RFA defines “small business” to have the same meaning as “small business concern” under section 3 of the Small Business Act. The Small Business Act authorizes the Small Business Administration (SBA) to define “small business” by issuing regulations.

The SBA (2023) has established size standards for various types of economic activities, or industries, under the North American Industry Classification System (NAICS). These size standards generally define small businesses based on the number of employees or annual receipts. Note that the SBA definition of a small business applies to the parent company and all affiliates as a single entity.

To identify small entities, the FAA first identified the primary NAICS of the entity or parent company, and then used data from different sources ( e.g., company annual reports, Bureau of Transportation Statistics) to determine whether the entity meets the applicable size standard. This AD will affect approximately 299 domestic entities, of which the FAA identified approximately 91 as small entities. The table below presents the industries of the small entities, the average annual revenue, and the AD's estimated low-case and high-case cost burden relative to that average annual revenue. ( printed page 44737)

( printed page 44738)

Small Entity Impacts

While the FAA has determined that this final rule affects a substantial number of small entities, the compliance costs of the AD relative to each small entity's annual revenue is minimal in both the low- and high-case scenarios. In the high-case scenario, the AD's cost as a percentage of annual revenue imposes a mean impact of 0.46 percent. Therefore, as provided in section 605(b), the FAA certifies that this AD will not result in a significant economic impact on a substantial number of small entities.

The FAA did not change this AD as a result of this comment.

Conclusion

These products have been approved by the civil aviation authority of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, that authority has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data, considered any 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 these products. 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 Transport Canada AD CF-2024-18, which specifies procedures for revising the applicable Bell 407 rotorcraft flight manual (RFM) Normal Procedures section to limit the allowable freedom of movement during interior and prestart checks for certain serial-numbered helicopters (Group 1 helicopters). Transport Canada AD CF-2024-18 also specifies procedures for inspecting the pilot cyclic stick tube assembly for cracks and replacing or repairing and reidentifying any cracked pilot cyclic stick tube assembly for certain other serial-numbered helicopters (Group 2 helicopters). If, as a result of an inspection, a pilot cyclic stick tube assembly is repaired rather than replaced, Transport Canada AD CF-2024-18 further specifies procedures for repetitive inspections of the repaired pilot cyclic stick tube assembly and replacement within 24 months after the repair. 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.

Differences Between This AD and the MCAI

The MCAI only applies to helicopter serial numbers 53000 through 53900, 53911 through 53999, 54000 through 54166, 54300 through 54800, 54805 through 54999, 56300 through 56305, and 56311 through 56315, whereas this AD applies to all serial numbered Model 407 helicopters with cyclic stick tube assembly P/N 206-001-342-101 or P/N 206-001-342-101FM installed.

The MCAI specifies procedures for revising the applicable Bell 407 RFM Normal Procedures section for certain serial-numbered helicopters to limit the allowable freedom of movement during interior and prestart checks, whereas this AD does not because the full sweep for freedom of movement is necessary to clear icing and detect any jamming or binding during the pre-start check.

This AD also adds a repetitive inspection for pilot cyclic stick tube assemblies that have accumulated 3,600 or more hours time-in-service, at intervals not to exceed every 300 hours time-in-service or 6 months, whichever occurs first. This is from a determination that a pilot cyclic control stick could experience high loading during hydraulic-off training and other emergency procedure situations. This inspection is not part of the MCAI.

Interim Action

The FAA considers that this AD is to be an interim action. If final action is later identified, the FAA might consider further rulemaking.

Costs of Compliance

The FAA estimates that this AD affects 972 helicopters of U.S. registry, of which 651 helicopters would have or will accumulate 3,600 hours time-in-service within the 2-year analysis period. The FAA estimates the following costs to comply with this AD.

The FAA estimates operators of all helicopters will incur an initial inspection cost of $340, and operators of a helicopter with over 3,600 hours time-in-service will also incur a recurrent inspection cost of $340. Repetitive inspections will occur once per inspection cycle, which is either every 6 months or every 300 hours time-in-service. The FAA assumes that the inspection cycle is 6 months for each helicopter. Based upon the results of an inspection, operators could incur three conditional repair costs. The FAA cannot estimate the number of conditional repairs each operator would need to undertake. The table below presents the estimated costs for required inspections and any conditional repair and replacement costs.

The FAA used a 2-year analysis period for estimating the costs of this AD. Because the FAA cannot estimate the number of helicopters which would need repair or replacement, the FAA has created a low-case and high-case cost scenario. In the low-case scenario, helicopters would only incur inspections costs. In the high-case scenario, all helicopters would have to replace their pilot cyclic sticks based upon the results of their initial inspection.

In the low-case scenario, all 972 helicopters would incur an initial inspection cost of $340, and all helicopters with over 3,600 hours time-in-service (651 helicopters) would undergo 3 repetitive inspections of $340 each. In the high-case scenario, all 972 ( printed page 44739) helicopters would incur an initial inspection cost of $340 and an initial pilot cyclic repair cost of $510. All 972 helicopters would then undergo 3 repetitive inspections of $510 (the sum of the required $340 inspection cost and $170 conditional inspection cost). In year 2 of the analysis period, all helicopters would incur a $1,714 cost to replace their pilot cyclic tube. The tables below present the costs associated with the low- and high-case scenarios and a summary of the total costs of this AD.

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.

The Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

91 FR 44735