[Federal Register Volume 90, Number 116 (Wednesday, June 18, 2025)]
[Proposed Rules]
[Pages 25911-25914]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-11213]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-1106; Project Identifier MCAI-2023-01052-R]
RIN 2120-AA64


Airworthiness Directives; Airbus Helicopters Deutschland GmbH

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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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

[[Page 25912]]

proposing this AD to address the unsafe condition on these products.

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

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: (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.
    AD Docket: You may examine the AD docket at regulations.gov 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.
    Material Incorporated by Reference:
     For EASA material identified in this proposed AD, contact 
EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 
8999 000; email: [email protected]; website: easa.europa.eu. You may 
find this material on the EASA website at ad.easa.europa.eu.
     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 
regulations.gov under Docket No. FAA-2025-1106.

FOR FURTHER INFORMATION CONTACT: Aryanna Sanchez, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (817) 222-4058; email: [email protected].

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 the ADDRESSES 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 
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 
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.

Background

    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 regulations.gov under 
Docket No. FAA-2025-1106.

Material Incorporated by Reference Under 1 CFR Part 51

    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 ADDRESSES section.

FAA's Determination

    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.

Proposed AD Requirements in This NPRM

    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

[[Page 25913]]

inserting pages, which is not considered a maintenance action.

Explanation of Required Compliance Information

    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 regulations.gov under Docket No. FAA-2025-1106 after the 
FAA final rule is published.

Differences Between This Proposed AD and the MCAI

    EASA AD 2023-0175 applies to Model MBB-BK117 D-2m and MBB-BK117 D-
3m helicopters, whereas this AD would not because those models do not 
have an FAA type certificate.
    EASA AD 2023-0175 requires operators to ``inform all flight crews'' 
of the revisions to the RFMS, and thereafter to ``operate the 
helicopter accordingly.'' However, this proposed AD would not require 
those actions as those actions are already required by FAA regulations. 
FAA regulations require operators furnish to pilots any changes to the 
RFM (for example, 14 CFR 135.21) and that pilots are familiar with the 
RFM (for example, 14 CFR 91.505). As with any other flight crew 
training requirement, training on the updated RFM content is tracked by 
the operators and recorded in each pilot's training record, which is 
available for the FAA to review. FAA regulations also require pilots to 
follow the procedures in the existing RFM including all updates. 
Section 91.9 requires that any person operating a civil aircraft must 
comply with the operating limitations specified in the RFM. Therefore, 
including a requirement in this proposed AD to operate the helicopter 
according to the revised RFM would be redundant and unnecessary.
    EASA AD 2023-0175 does not have any flight restrictions, whereas 
this proposed AD would require a revision to the RFMS restricting 
helicopters to operation under visual flight rules (VFR) until the 
helicopter is modified with ACS condenser outlet covers.
    EASA AD 2023-0175 specifies amending the applicable RFMS, whereas 
this proposed AD would specifically require amending the Limitations 
Section of the applicable RFMS.

Interim Action

    The FAA considers that this proposed AD would be an interim action. 
The manufacturer is currently developing a modification that will 
address the unsafe condition identified in this AD. Once this 
modification is developed, approved, and available, the FAA might 
consider additional rulemaking.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 71 helicopters of U.S. registry. Labor costs are estimated at 
$85 per hour. Based on these numbers, the FAA estimates the following 
costs to comply with this proposed AD.
    Replacing the ACS condenser outlet grids would take 20 work-hours 
and parts would cost $970, for an estimated cost of $2,670 per 
helicopter and $189,570 for the U.S. fleet. Revising the existing RFM 
for the helicopter would take 1 work-hour for an estimated cost of $85 
per helicopter and $6,035 for the U.S. fleet.

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

0
1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

Airbus Helicopters Deutschland GmbH: Docket No. FAA-2025-1106; 
Project Identifier MCAI-2023-01052-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by August 4, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Helicopters Deutschland GmbH Model 
MBB-BK 117 D-2 and MBB-BK 117 D-3 helicopters, certificated in any 
category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 2100, Air 
Conditioning System.

[[Page 25914]]

(e) Unsafe Condition

    This AD was prompted by reports of airspeed and altitude 
indication errors. The FAA is issuing this AD to address airspeed 
and altitude indication errors. The unsafe condition, if not 
addressed, could result in significant increase in crew workload and 
reduced situational awareness.

(f) Compliance

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

(g) Requirements

    (1) Except as specified in paragraphs (h) and (i) of this AD: 
Comply with all required actions and compliance times specified in, 
and in accordance with, European Union Aviation Safety Agency AD 
2023-0175, dated October 5, 2023 (EASA AD 2023-0175).
    (2) The owner/operator (pilot) holding at least a private pilot 
certificate may revise the existing Rotorcraft Flight Manual for the 
helicopter and must enter compliance with this requirement into the 
helicopter maintenance records in accordance with 14 CFR 43.9(a) and 
14 CFR 91.417(a)(2)(v). The record must be maintained as required by 
14 CFR 91.417, 121.380, or 135.439.

(h) Exceptions to EASA AD 2023-0175

    (1) Where EASA AD 2023-0175 refers to its effective date, this 
AD requires using the effective date of this AD.
    (2) Where EASA AD 2023-0175 requires compliance in terms of 
flight hours, this AD requires using hours time-in-service.
    (3) Where paragraph (1) of EASA AD 2023-0175 states ``by 
incorporating the ACS RFMS altitude correction procedure, as defined 
in appendix 1 of this AD,'' this AD requires replacing that text 
with ``by incorporating the ACS RFMS altitude correction procedure, 
as defined in appendix 1 of this AD, into the Limitations section 
and by adding a visual flight rules (VFR) only restriction to the 
procedure''.
    (4) Where paragraph (1) of EASA AD 2023-0175 specifies to inform 
all flight crews and, thereafter, operate the helicopter 
accordingly, this AD does not require those actions.
    (5) Where paragraph (2) of EASA AD 2023-0175 states ``which 
includes the same content as the ACS RFMS altitude correction 
procedure,'' this AD requires replacing that text with ``which 
includes information identical to the information in the ACS RFMS 
altitude correction procedure, as defined in appendix 1 of this 
AD''.
    (6) Where the material referenced in EASA AD 2023-0175 
recommends complying with its instructions again after replacing the 
left-hand or right-hand exhaust cowling assembly, this AD does not 
require that action.
    (7) This AD does not adopt the Remarks section of EASA AD 2023-
0175.

(i) No Reporting Requirement

    Although the material referenced in EASA AD 2023-0175 specifies 
to submit certain information to the manufacturer, this AD does not 
include that requirement.

(j) Alternative Methods of Compliance (AMOCs)

    (1) 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 (k) of 
this AD and email to: [email protected].
    (2) 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.

(k) Additional Information

    For more information about this AD, contact Aryanna Sanchez, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone (817) 222-4058; email: 
[email protected].

(l) 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) European Union Aviation Safety Agency (EASA) AD 2023-0175, 
dated October 5, 2023.
    (ii) [Reserved]
    (3) For EASA material identified in this AD, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 
000; email: [email protected]; website: easa.europa.eu. You may 
find this EASA material on the EASA website at ad.easa.europa.eu.
    (4) 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.
    (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 [email protected].

    Issued on June 13, 2025.
Christopher R. Parker,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-11213 Filed 6-17-25; 8:45 am]
BILLING CODE 4910-13-P