[Federal Register Volume 89, Number 153 (Thursday, August 8, 2024)]
[Proposed Rules]
[Pages 64834-64837]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-17339]


 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 89, No. 153 / Thursday, August 8, 2024 / 
Proposed Rules  

[[Page 64834]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2011; Project Identifier AD-2023-01121-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 (MDHI), Model 369, 369A, 369D, 369E, 
369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. 
This proposed AD was prompted by a report of a seized and damaged 
roller bearing in the pilot interconnecting cyclic torque tube (torque 
tube) assembly. This proposed AD would require repetitively inspecting 
the torque tube assembly for corrosion and cracks and the roller 
bearings for corrosion and degradation. This proposed AD would also 
require repetitively inspecting the torque tube assembly for freedom-
of-movement. Depending on the results, this proposed AD would require 
replacing parts or accomplishing additional inspections. 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 September 
23, 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-2024-2011; 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.

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 ADDRESSES. Include ``Docket No. FAA-2024-2011; Project Identifier 
AD-2023-01121-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 seized and damaged roller bearing 
assembly in the torque tube assembly of an MDHI Model MD369E 
helicopter. This damage did not allow the torque tube to rotate as 
designed, which initiated a crack and resulted in an emergency landing. 
The seized roller bearings were due to rust compounded with dried 
grease residue and an aggressive chemical environment. Because the 
seized roller bearings did not allow the torque tube to rotate freely, 
additional torsional stresses occurred on the torque tube, causing a 
crack to initiate and eventually propagate until the part failed and 
longitudinal control was lost. Since MDHI Model 369, 369A, 369D, 369F, 
369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters have the 
same torque tube assembly installed, they are also affected by this 
unsafe condition.
    Accordingly, this proposed AD would require repetitively visually 
inspecting the torque tube for corrosion and cracks, repetitively 
visually inspecting the roller bearings for corrosion and degradation, 
performing a repetitive freedom-of-movement inspection of the torque 
tube assembly for binding or ratcheting, and corrective or additional 
action as necessary. This condition, if not addressed, could result in 
reduced controllability and subsequent loss of control of the 
helicopter.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition

[[Page 64835]]

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 repetitive visual inspections of the 
torque tube assembly for cracks and corrosion and the roller bearings 
for corrosion and degradation. This proposed AD would also require 
repetitively inspecting the freedom of movement of the torque tube 
assembly for binding and ratcheting. Depending on the results, this 
proposed AD would require replacing parts or accomplishing additional 
inspections.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 353 helicopters of U.S. registry. The FAA estimates the 
following costs to comply with this proposed AD. Labor costs are 
estimated at $85 per work-hour.
    Visually inspecting the torque tube and roller bearings would take 
approximately 1 work-hour for an estimated cost of $85 per helicopter 
and $30,005 for the U.S. fleet, per inspection cycle. Inspecting the 
torque tube assembly for freedom of movement would take approximately 
0.75 work-hour for an estimated cost of $64 per helicopter and $22,595 
for U.S fleet cost, per inspection cycle. If required, a more in-depth 
inspection of the roller bearings would take approximately 0.25 work-
hour for an estimated cost of $21 per helicopter, per instance.
    If required, replacing a torque tube would take approximately 6 
work-hours and parts would cost approximately $4,773 for an estimated 
cost of $5,283 per torque tube replacement. Replacing a roller bearing 
would take approximately 6 work-hours and parts would cost 
approximately $210 for an estimated cost of $720 per roller bearing 
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.

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-2024-2011; Project Identifier 
AD-2023-01121-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by September 23, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to MD Helicopters, LLC, Model 369, 369A, 369D, 
369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N 
helicopters, certificated in any category, with a pilot 
interconnecting cyclic torque tube (torque tube) part number 
369H7133-7 installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 6700, Rotorcraft 
Flight Control.

(e) Unsafe Condition

    This AD was prompted by a report of a seized and damaged roller 
bearing in the torque tube assembly. The FAA is issuing this AD to 
prevent failure of the torque tube assembly. The unsafe condition, 
if not addressed, could result in reduced controllability 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 100 hours time-in-service (TIS) or within one year 
after the effective date of this AD, whichever occurs first, and 
thereafter at intervals not to exceed 100 hours TIS, accomplish the 
actions required by paragraphs (g)(1)(i) and (ii) of this AD.
    (i) Using a flashlight and mirror, visually inspect the torque 
tube for corrosion and cracks. If there is any corrosion or a crack, 
before further flight, remove the torque tube from service and 
install an airworthy torque tube.
    (ii) Visually inspect each roller bearing (number 5) as depicted 
in Figure 1 to paragraph (g)(1) of this AD for corrosion and 
degradation. If a roller bearing has any corrosion or degradation, 
before further flight, remove the roller bearing from service and 
install an airworthy roller bearing.
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[GRAPHIC] [TIFF OMITTED] TP08AU24.000

BILLING CODE 4910-13-C
    (2) Before the helicopter accumulates 3,000 total hours TIS or 
within 100 hours TIS after the effective date of this AD, whichever 
occurs later, and thereafter at intervals not to exceed 100 hours 
TIS, perform a freedom-of movement inspection on the torque tube 
assembly by accomplishing the actions required by paragraphs 
(g)(2)(i) through (v) of this AD.
    (i) Disconnect the one-way lock (number 6) of the torque tube by 
removing the cotter pin (number 7), nut (number 8), bolt (number 9), 
washers (number 10), and slotted bushing (number 11) from the torque 
tube assembly as depicted in Figure 1 to paragraph (g)(1) of this 
AD.
    (ii) Loosen the longitudinal cyclic friction knob (number 12 or 
13) of the torque tube assembly as depicted in Figure 1 to paragraph 
(g)(1) of this AD.
    (iii) While moving the cyclic control forward and aft to allow 
the torque tube assembly to rotate through its full range of motion, 
inspect the torque tube assembly for binding and ratcheting.
    (A) If there is any binding or ratcheting as a result of the 
action required by paragraph (g)(2)(iii) of this AD, before further 
flight, inspect each roller bearing (number 5) as depicted in Figure 
1 to paragraph (g)(1) of this AD for damage. For the purposes of 
this inspection, damage may be indicated by corrosion, lack of 
lubrication (dry exterior surface), or material degradation.
    (B) If any roller bearing (number 5) as depicted in Figure 1 to 
paragraph (g)(1) of this AD has any damage, before further flight, 
remove the roller bearing from service and install an airworthy 
roller bearing.
    (iv) If there is not any binding or ratcheting as a result of 
the action required by

[[Page 64837]]

paragraph (g)(2)(iii) of this AD or after accomplishing the action 
required by paragraph (g)(2)(iii)(B) of this AD, as applicable, 
tighten the cyclic friction knob (number 12 or 13) as depicted in 
Figure 1 to paragraph (g)(1) of this AD.
    (v) Connect the one-way lock (number 6) as depicted in Figure 1 
to paragraph (g)(1) of this AD by accomplishing the actions required 
by paragraphs (g)(2)(v)(A) and (B).
    (A) Install the slotted bushing (number 11), washers (number 
10), bolt (number 9), nut (number 8), and new (zero total hours TIS) 
cotter pin (number 7) as depicted in Figure 1 to paragraph (g)(1) of 
this AD.
    (B) Ensure the edge of the slotted bushing (number 11) protrudes 
0.010 to 0.080 inch (0.25 to 2.03 mm) above the surface of the 
cyclic torque tube after the nut is tightened.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, West 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 responsible Flight 
Standards Office, as appropriate. If sending information directly to 
the manager of the West 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

    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].

(j) Material Incorporated by Reference

    None.

    Issued on July 31, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-17339 Filed 8-7-24; 8:45 am]
BILLING CODE 4910-13-P