SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under ADDRESSES . Include “Docket No. FAA-2026-8802; Project Identifier MCAI-2025-01828-A” 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 this 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 Jesse Wulf, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2025-0284, dated December 16, 2025 (EASA AD 2025-0284) (also referred to as the MCAI), to correct an unsafe condition on all Airbus Defence and Space GmbH Bölkow Model BO 208 and BO 209 airplanes.

The MCAI states that corrosion damage has been reported on the rudder drive installed on Model BO 209 airplanes. It further states that due to the similarity of the rudder drive design, Model BO 208 airplanes may be subject to the same unsafe condition. This condition, if not detected and corrected, could reduce the structural integrity of the rudder drive, which could result in reduced control of the airplane. The MCAI requires repetitive inspections of the affected rudder drive, corrective actions if discrepancies are found, and the application of a corrosion inhibitor.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-8802. ( printed page 58391)

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Airbus Service Bulletin BO208-SB-002/2025, Issue 1, dated December 1, 2025, and Airbus Service Bulletin BO209-SB-002/2025, Issue 2, dated December 1, 2025. This material specifies procedures for repetitive inspections of the rudder drive (including for blockage of the drainage hole), corrective actions including replacement if corrosion is detected, and application of a corrosion inhibitor. These documents are distinct because they apply to different airplane models. 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.

FAA's Determination

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 and material 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 material already described, except as discussed under “Differences Between this Proposed AD and the MCAI/Material Incorporated by Reference.”

Differences Between This Proposed AD and the MCAI/Material Incorporated by Reference

The MCAI and material incorporated by reference apply to Model Bölkow BO 208C Junior and Bölkow Junior airplanes, however, this proposed AD would only apply to Model Bölkow Junior airplanes and not Model Bölkow BO 208C Junior airplanes because that model does not have an FAA type certificate. Additionally, the MCAI and material incorporated by reference apply to Model Bölkow BO 209 S airplanes; however, this proposed AD would not because that model does not have an FAA type certificate.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect five airplanes of U.S. registry.

The FAA estimates the following costs to comply with this proposed AD:

The FAA estimates the following costs to do any necessary replacement that would be required based on the results of the proposed inspection. The agency has no way of determining the number of airplanes that might need this replacement:

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.

The Proposed Amendment

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

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

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

Airbus Defence and Space GmbH: Docket No. FAA-2026-8802; Project Identifier MCAI-2025-01828-A.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by October 30, 2026.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all Airbus Defence and Space GmbH Model BO-209-150 FF, BO-209-150 FV, BO-209-150 RV, BO-209-160 FV, BO-209-160 RV, and Bölkow Jr. airplanes, certificated in any category.

(d) Subject

Joint Aircraft System Component (JASC) Code 2720, Rudder Control System.

(e) Unsafe Condition

This AD was prompted by reports of corrosion damage on the rudder drive. The FAA is issuing this AD to detect and correct corrosion damage in the rudder drive. The unsafe condition, if not addressed, could reduce the structural integrity of the rudder drive and result in reduced control of the airplane.

(f) Compliance

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

(g) Serviceable Part Definition

For the purpose of this AD, a serviceable part is an affected rudder drive that is either:

(1) A new part ( i.e., a part that has not been previously installed on any airplane); or

(2) A part that has accumulated less than 5 years since the last inspection, provided that no corrosion was found during that inspection and corrosion inhibitor was applied in accordance with step 5., section 7., of Airbus Service Bulletin BO208-SB-002/2025, Issue 1, dated December 1, 2025 (Airbus SB BO208-SB-002/2025, Issue 1); or Airbus Service Bulletin BO209-SB-002/2025, Issue 2, dated December 1, 2025 (Airbus SB BO209-SB-002/2025, Issue 2); as applicable.

(h) Required Actions

(1) Within 2 months after the effective date of this AD and thereafter at intervals not to exceed 5 years, remove the rudder and perform an inspection of the rudder drive torsion tube for corrosion using an endoscope and inspect the drainage hole for blockage in accordance with steps 1. and 2., section 7., of Airbus SB BO208-SB-002/2025, Issue 1; or Airbus SB BO209-SB-002/2025, Issue 2; as applicable.

(2) If any corrosion is found during any inspection required by paragraph (h)(1) of this AD, before further flight, replace the rudder drive with a serviceable part in accordance with step 3., section 7., of Airbus SB BO208-SB-002/2025, Issue 1; or Airbus SB BO209-SB-002/2025, Issue 2; as applicable.

(3) After each inspection required by paragraph (h)(1) of this AD and after any replacement required by paragraph (h)(2) of this AD, before further flight, apply corrosion inhibitor to the inside of the rudder drive in accordance with step 5., section 7., of Airbus SB BO208-SB-002/2025, Issue 1; or Airbus SB BO209-SB-002/2025, Issue 2; as applicable. Where step 5., section 7., of the applicable service bulletin specifies using LPS 3 corrosion inhibitor, an equivalent corrosion inhibitor may be used instead.

(4) Before further flight after accomplishing the actions required by paragraph (h)(3) of this AD, re-inspect the drainage hole for blockage and clean it if necessary and reinstall the rudder in accordance with steps 6. and 7. section 7., of Airbus SB BO208-SB-002/2025, Issue 1; or Airbus SB BO209-SB-002/2025, Issue 2; as applicable.

(i) Credit for Previous Actions

This paragraph provides credit for the actions required by paragraphs (h)(1) through (4) of this AD if those actions were performed before the effective date of this AD using Airbus Service Bulletin BO209-SB-002/2025, Issue 1, dated August 21, 2025.

(j) Parts Installation

As of the effective date of this AD, do not install an affected part on any airplane that is not a serviceable part, as defined in paragraph (g)(1) or (2) of this AD.

(k) 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 local Flight Standards District Office, as appropriate. If sending information directly to the manager of the International Validation Branch, send it to the attention of the person identified in paragraph (l) of this AD and email to: AMOC@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(l) Additional Information

For more information about this AD, contact Jesse Wulf, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (847) 294-7183; email: jesse.r.wulf@faa.gov.

(m) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(i) Airbus Service Bulletin BO208-SB-002/2025, Issue 1, dated December 1, 2025.

(ii) Airbus Service Bulletin BO209-SB-002/2025, Issue 2, dated December 1, 2025.

(3) For Airbus material identified in this AD, contact Airbus Defence and Space GmbH, Dr. Alexander Allen, Willy-Messerschmitt-Strasse 1, 82024 Taufkirchen, Germany; phone: +49 (8459) 81-7883; email: Lightweight-Aircraft@airbus.com.

(4) You may view this material at FAA, Airworthiness Products Section, Operational Safety Branch, 1100 Main, Kansas City, MO 64105. For information on the availability of this material at the FAA, call (817) 222-5110.

(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 fr.inspection@nara.gov.

91 FR 58390