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Proposed Rule

Airworthiness Directives; Airbus Helicopters Deutschland GmbH

Notice of proposed rulemaking (NPRM).

📖 Research Context From Federal Register API

Summary:

The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH Model MBB-BK 117 D-2 and MBB-BK 117 D-3 helicopters. This proposed AD was prompted by reports of airspeed and altitude indication errors. This proposed AD would require revising the existing rotorcraft flight manual supplement (RFMS) for the helicopter and replacing the air conditioning system (ACS) condenser outlet grids with ACS condenser outlet covers, and would prohibit installing ACS condenser outlet grids. The FAA is proposing this AD to address the unsafe condition on these products.

Key Dates
Citation: 90 FR 25911
The FAA must receive comments on this NPRM by August 4, 2025.
Comments closed: August 4, 2025
Public Participation
0 comments 1 supporting doc
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Topics:
Air transportation Aircraft Aviation safety Incorporation by reference Safety

In Plain English

What is this Federal Register notice?

This is a proposed rule published in the Federal Register by Transportation Department, Federal Aviation Administration. Proposed rules invite public comment before becoming final, legally binding regulations.

Is this rule final?

No. This is a proposed rule. It has not yet been finalized and is subject to revision based on public comments.

Who does this apply to?

Notice of proposed rulemaking (NPRM).

When does it take effect?

The FAA must receive comments on this NPRM by August 4, 2025.

📋 Rulemaking Status

This is a proposed rule. A final rule may be issued after the comment period and agency review.

Document Details

Document Number2025-11213
FR Citation90 FR 25911
TypeProposed Rule
PublishedJun 18, 2025
Effective Date-
RIN2120-AA64
Docket IDDocket No. FAA-2025-1106
Pages25911–25914 (4 pages)
Text FetchedYes

Agencies & CFR References

CFR References:

Linked CFR Parts

PartNameAgency
14 CFR 39 Airworthiness Directives... Federal Aviation Administration

Paired Documents

TypeProposedFinalMethodConf
No paired documents

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Full Document Text (3,001 words · ~16 min read)

Text Preserved
DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-1106; Project Identifier MCAI-2023-01052-R]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Airbus Helicopters Deutschland GmbH</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Notice of proposed rulemaking (NPRM). <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH Model MBB-BK 117 D-2 and MBB-BK 117 D-3 helicopters. This proposed AD was prompted by reports of airspeed and altitude indication errors. This proposed AD would require revising the existing rotorcraft flight manual supplement (RFMS) for the helicopter and replacing the air conditioning system (ACS) condenser outlet grids with ACS condenser outlet covers, and would prohibit installing ACS condenser outlet grids. The FAA is proposing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> The FAA must receive comments on this NPRM by August 4, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • <E T="03">Federal eRulemaking Portal:</E> Go to <E T="03">regulations.gov</E> . Follow the instructions for submitting comments. • <E T="03">Fax:</E> (202) 493-2251. • <E T="03">Mail:</E> U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. • <E T="03">Hand Delivery:</E> Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1106; 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. <E T="03">Material Incorporated by Reference:</E> • For EASA material identified in this proposed AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: <E T="03">ADs@easa.europa.eu;</E> website: <E T="03">easa.europa.eu.</E> You may find this material on the EASA website at <E T="03">ad.easa.europa.eu.</E> • You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1106. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Aryanna Sanchez, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-4058; email: <E T="03">aryanna.t.sanchez@faa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Comments Invited</HD> The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-1106; Project Identifier MCAI-2023-01052-R” 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 <E T="03">regulations.gov</E> , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. <HD SOURCE="HD1">Confidential Business Information</HD> 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 Aryanna Sanchez, 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. <HD SOURCE="HD1">Background</HD> EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2023-0175, dated October 5, 2023 (EASA AD 2023-0175) (also referred to as “the MCAI”), to correct an unsafe condition on Airbus Helicopters Deutschland GmbH Model MBB-BK 117 D-2, MBB-BK 117 D-2m, MBB-BK 117 D-3, and MBB-BK 117 D-3m helicopters. The MCAI states that there have been reports of airspeed and altitude indication errors. Subsequent investigation revealed that the ACS condenser outlets are in close proximity to the static ports, and air from the outlets affects the static ports during flight. The static ports and pitot tubes measure different pressures, which are then used to calculate airspeed, altitude, and vertical speed. Incorrect readings can then occur. This condition, if not corrected, could result in a significant increase in crew workload and reduced situational awareness. The FAA is proposing this AD to address the unsafe condition on these products. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1106. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> The FAA reviewed EASA AD 2023-0175, which specifies procedures for amending the applicable RFMS by incorporating new altitude corrections if the helicopter has ACS condenser outlet grids, and not covers, installed. EASA AD 2023-0175 also specifies procedures for replacing the ACS condenser outlet grid part number (P/N) D211M1821302 or P/N D211M1822302 with ACS condenser outlet cover P/N D211M1821402 or P/N D211M1822402 and prohibits installing ACS condenser outlet grids on any helicopter. 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 <E T="02">ADDRESSES</E> section. <HD SOURCE="HD1">FAA's Determination</HD> These products have been approved by the 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, it has notified the FAA of the unsafe condition described in the MCAI 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. <HD SOURCE="HD1">Proposed AD Requirements in This NPRM</HD> This proposed AD would require accomplishing the actions specified in the material already described, except for any differences identified as exceptions in the regulatory text of this AD. See “Differences Between this Proposed AD and the MCAI” for a discussion of those differences. This proposed AD would require revising the RFMS for the helicopter. This proposed action may be performed by the owner/operator (pilot) holding at least a private pilot certificate and compliance with the applicable paragraphs of this proposed AD must be entered into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The pilot may perform this action because it only involves revising the existing RFMS by inserting pages, which is not considered a maintenance action. <HD SOURCE="HD1">Explanation of Required Compliance Information</HD> In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate EASA AD 2023-0175 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2023-0175 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2023-0175 does not mean that operators need comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2023-0175. Material referenced in EASA AD 2023-0175 for compliance will be available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1106 after the FAA final rule is published. <HD SOURCE="HD1">Differences Between This ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 21k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
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