[Federal Register Volume 89, Number 167 (Wednesday, August 28, 2024)]
[Proposed Rules]
[Pages 68837-68840]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-17318]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2009; Project Identifier AD-2023-01286-R]
RIN 2120-AA64


Airworthiness Directives; MD Helicopters, LLC, Helicopters

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 certain MD Helicopters, LLC, Model 369 (Army YOH-6A), 369A (Army 
OH-6A), 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 
600N helicopters. This proposed AD was prompted by multiple reports of 
cracked tail rotor (T/R) pedal support brackets. This proposed AD would 
require repetitively inspecting certain part-numbered T/R pedal support 
brackets and depending on the results, replacing the T/R pedal support 
bracket or refinishing any exposed areas. This proposed AD would also 
prohibit installing certain part-numbered T/R pedal support brackets. 
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 October 15, 
2024.

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-2024-2009; 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.
    Material Incorporated by Reference:

[[Page 68838]]

     For MD Helicopters material identified in this AD, contact 
MD Helicopters, LLC, 4555 East McDowell Road, Mesa, AZ 85215-9734; 
phone: (480) 346-6300; email: [email protected]; website: 
mdhelicopters.com/contact/.
     You may view this material at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, 
Fort Worth, TX 76177. For information on the availability of this 
material at the FAA, call (817) 222-5110.

FOR FURTHER INFORMATION CONTACT: Eduardo Orozco-Duran, Aviation Safety 
Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: 
(562) 627-5264; 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-2024-2009; 
Project Identifier AD-2023-01286-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 
Eduardo Orozco-Duran, Aviation Safety Engineer, FAA, 3960 Paramount 
Boulevard, Lakewood, CA 90712; phone: (562) 627-5264; email: 
[email protected]. 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 FAA received a report of a forced emergency landing involving 
an MD Helicopters, LLC, Model 369D helicopter in Canada in 2022 that 
was caused by a cracked magnesium cast T/R pedal support bracket having 
part number (P/N) 369A7505-8. There have been 16 other reports of 
cracked magnesium cast T/R pedal support brackets having P/Ns 369A7505-
7, 369A7505-8, 369A7505-14, or 369A7505-15 discovered during 
maintenance in the last 30 years. Material deficiencies associated with 
magnesium cast parts, as well as fatigue damage and successive in-
flight loading have been determined to cause the parts to fail. 
Additionally, magnesium cast parts are susceptible to corrosion where 
insufficient protective coatings have shown to wear and deteriorate. 
All reported failures of this part have been the magnesium cast 
369A7505 configuration. The aluminum cast T/R pedal support bracket P/N 
369N2640 have no reported failures but are still subject to the 
inspection requirements of this AD. The natural corrosion advantages of 
aluminum, as well as the coating requirements of its anodization offer 
greater mitigation of the risks of corrosion in comparison to the 
magnesium cast part. Although superior to the magnesium cast part, the 
alternate aluminum cast part could still be prone to these material 
deficiencies of cast parts.
    This proposed AD would require repetitively inspecting magnesium 
cast T/R pedal support brackets having P/N 369A7505-7, 369A7505-8, 
369A7505-14, or 369A7505-15, and aluminum cast T/R pedal support 
brackets having P/N 369N2640-1 or 369N2640-2. These T/R pedal support 
brackets may be installed on MD Helicopters, LLC, Model 369 (Army YOH-
6A), 369A (Army OH-6A), 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 
369HS, 500N, and 600N helicopters. This proposed AD would also prohibit 
installing magnesium cast T/R pedal support bracket P/N 369A7505-7, 
369A7505-8, 369A7505-14, or 369A7505-15 on any helicopter. This 
condition, if not addressed, could result in failure of the T/R pedal 
support bracket, reduced controllability of the helicopter, and 
subsequent loss of control of the helicopter.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of these same type designs.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed MD Helicopters Service Bulletin SB369D-231R2 for 
Model 369D helicopters, SB369E-131R2 for Model 369E helicopters, 
SB369F-122R2 for Model 369F and 369FF helicopters, SB369H-265R2 for 
Model 369H, 369HE, 369HM, and 369HS helicopters, SB500N-068R2 for Model 
500N helicopters, and SB600N-082R2 for Model 600N helicopters, each 
dated November 1, 2023 (co-published as one document). For magnesium 
cast T/R pedal support brackets P/N 369A7505-7, 369A7505-8, 369A7505-
14, and 369A7505-15, this material specifies procedures for visually 
inspecting each T/R pedal support bracket for a crack and corrosion and 
depending on the results, replacing the bracket with an aluminum cast 
T/R pedal support bracket having P/N 369N2640-1 or 369N2640-2, or 
refinishing any exposed areas. For magnesium cast T/R pedal support 
brackets P/N 369A7505-7, 369A7505-8, 369A7505-14, and 369A7505-15, this 
material also specifies procedures for fluorescent penetrant 
inspecting, eddy current inspecting, or dye penetrant inspecting each 
T/R pedal support bracket for a crack and depending on the results, 
replacing the bracket with an aluminum cast T/R pedal support bracket 
having P/N 369N2640-1 or 369N2640-2, or refinishing any exposed areas. 
For the purposes of this proposed AD, MD Helicopters, LLC, Model 369 
(Army YOH-6A) and 369A (Army OH-6A) helicopters would use MD 
Helicopters Service Bulletin SB369D-231R2, dated November 1, 2023, to 
accomplish certain actions required by this proposed AD.
    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.

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

[[Page 68839]]

this Proposed AD and the Referenced Material.''

Differences Between This Proposed AD and the Referenced Material

    The related material applies to magnesium cast T/R pedal support 
brackets having P/N 369A7505-7, 369A7505-8, 369A7505-14, or 369A7505-
15, whereas this proposed AD would apply to those part-numbered 
magnesium cast T/R pedal support brackets and aluminum cast T/R pedal 
support brackets having P/N 369N2640-1 or 369N2640-2. This proposed AD 
would prohibit installing magnesium cast T/R pedal support brackets 
having P/N 369A7505-7, 369A7505-8, 369A7505-14, or 369A7505-15, whereas 
the related material does not.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 353 helicopters of U.S. registry. Labor rates are estimated at 
$85 per work-hour. Based on these numbers, the FAA estimates the 
following costs to comply with this proposed AD.
    Visually inspecting the T/R pedal support brackets (up to two T/R 
pedal support brackets per helicopter) would take approximately 0.5 
work-hour for an estimated cost of up to $43 per helicopter and $15,179 
for the U.S. fleet per inspection cycle. Non-destructive inspection of 
the T/R pedal support brackets would take approximately 2 work-hours 
for an estimated cost of up to $170 per helicopter and $60,010 for the 
U.S. fleet per inspection cycle.
    If required, replacing a T/R pedal support bracket would take 
approximately 8 work-hours and parts would cost approximately $2,075 
for an estimated cost of $2,755 per T/R pedal support bracket. 
Refinishing any exposed areas could vary significantly from helicopter 
to helicopter. The FAA has no data to determine the costs to accomplish 
this action or the number of helicopters that may require this action.

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:

MD Helicopters, LLC: Docket No. FAA-2024-2009; Project Identifier 
AD-2023-01286-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by October 15, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to MD Helicopters, LLC, Model 369 (Army YOH-6A), 
369A (Army OH-6A), 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 
369HS, 500N, and 600N helicopters, certificated in any category, 
with a tail rotor (T/R) pedal support bracket part number (P/N) 
369A7505-7, 369A7505-8, 369A7505-14, 369A7505-15, 369N2640-1, or 
369N2640-2, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code: 6720, tail rotor 
control system.

(e) Unsafe Condition

    This AD was prompted by multiple reports of cracked T/R pedal 
support brackets. The FAA is issuing this AD to detect a cracked T/R 
pedal support bracket. The unsafe condition, if not addressed, could 
result in failure of the T/R pedal support bracket, reduced 
controllability of the helicopter, and subsequent loss of control of 
the helicopter.

(f) Compliance

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

(g) Required Actions

    (1) Within 25 hours time-in-service (TIS) and thereafter at 
intervals not to exceed 100 hours TIS, using a 10X power 
magnification glass, mirror, and flashlight, visually inspect each 
T/R pedal support bracket for cracks and corrosion by following the 
Accomplishment Instructions, paragraph 2.A.(2)., of MD Helicopters 
Service Bulletin SB369D-231R2, SB369E-131R2, SB369F-122R2, SB369H-
265R2, SB500N-068R2, or SB600N-082R2, each dated November 1, 2023 
(collectively referred to as ``the service bulletins''), as 
applicable to your helicopter model; you may use a borescope as 
specified in the note in paragraph 2.A.(2) of the service bulletins. 
For the purposes of this AD, for MD Helicopters, LLC, Model 369 
(Army YOH-6A) and 369A (Army OH-6A) helicopters, use MD Helicopters 
Service Bulletin SB369D-231R2, dated November 1, 2023, to accomplish 
the actions required by this AD.
    (i) If there is a crack or any corrosion as a result of the 
inspections required by the introductory text of paragraph (g)(1) of 
this AD, before further flight, remove the T/R pedal support bracket 
from service and replace it with an airworthy T/R pedal support 
bracket P/N 369N2640-1 or 369N2640-2.
    (ii) If there is not a crack and there is no corrosion as a 
result of the inspections required by the introductory text of 
paragraph (g)(1) of this AD, before further flight, refinish any 
exposed areas.
    (2) Within 50 hours TIS and thereafter at intervals not to 
exceed 300 hours TIS, eddy current, dye penetrant, or fluorescent 
penetrant inspect each T/R pedal support bracket for a crack by 
following the Accomplishment Instructions, paragraph 2.B.(2)., of 
the service bulletins, as applicable to your helicopter model. The 
inspections required by this paragraph must be performed by a Level 
II or Level III inspector certified in the FAA-acceptable standards 
for nondestructive inspection personnel.
    Note 1 to the introductory text of paragraph (g)(2): Advisory 
Circular 65-31B contains examples of FAA-acceptable Level II and 
Level III qualification standards criteria

[[Page 68840]]

for inspection personnel doing nondestructive test inspections.
    (i) If there is a crack as a result of the actions required by 
the introductory text of paragraph (g)(2) of this AD, before further 
flight, remove the T/R pedal support bracket from service and 
replace it with an airworthy T/R pedal support bracket P/N 369N2640-
1 or 369N2640-2.
    (ii) If there is not a crack as a result of the actions required 
by the introductory text of paragraph (g)(2) of this AD, before 
further flight, refinish any exposed areas.
    (3) As of the effective date of this AD, do not install 
magnesium cast T/R pedal support bracket P/N 369A7505-7, 369A7505-8, 
369A7505-14, or 369A7505-15 on any helicopter.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Western Certification 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 Western Certification Branch, send it 
to the attention of the person identified in paragraph (i) of this 
AD. Information may be emailed 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.

(i) Additional Information

    (1) For more information about this AD, contact Eduardo Orozco-
Duran, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, 
Lakewood, CA 90712; phone: (562) 627-5264; email: [email protected].
    (2) For advisory circular material identified in this AD that is 
not incorporated by reference, go to faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/1023552.

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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) MD Helicopters Service Bulletin SB369D-231R2, dated November 
1, 2023.
    (ii) MD Helicopters Service Bulletin SB369E-131R2, dated 
November 1, 2023.
    (iii) MD Helicopters Service Bulletin SB369F-122R2, dated 
November 1, 2023.
    (iv) MD Helicopters Service Bulletin SB369H-265R2, dated 
November 1, 2023.
    (v) MD Helicopters Service Bulletin SB500N-068R2, dated November 
1, 2023.
    (vi) MD Helicopters Service Bulletin SB600N-082R2, dated 
November 1, 2023.
    Note 2 to paragraph (j)(2): The service bulletins identified in 
paragraphs (j)(2)(i) through (vi) of this AD are co-published as one 
document.
    (3) For MD Helicopters material identified in this AD, contact 
MD Helicopters, LLC, 4555 East McDowell Road, Mesa, AZ 85215-9734; 
phone: (480) 346-6300; email: [email protected]; website: 
mdhelicopters.com/contact/.
    (4) You may view this material at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., 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 July 31, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-17318 Filed 8-27-24; 8:45 am]
BILLING CODE 4910-13-P