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[Federal Register Volume 89, Number 223 (Tuesday, November 19, 2024)]
[Rules and Regulations]
[Pages 91248-91251]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-26919]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2011; Project Identifier AD-2023-01121-R; 
Amendment 39-22885; AD 2024-23-06]
RIN 2120-AA64

Airworthiness Directives; MD Helicopters, LLC, Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting 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 AD 
was prompted by a report of a seized and damaged roller bearing in the 
pilot interconnecting cyclic torque tube (torque tube) assembly. This 
AD requires repetitively inspecting the torque tube assembly and roller 
bearings, and depending on the results, replacing parts, or 
accomplishing additional inspections. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective December 24, 2024.

ADDRESSES: 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 final rule, any comments 
received, and other information. The address for Docket Operations is 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, 
Washington, DC 20590.

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:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to MDHI Model 369, 369A, 
369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N 
helicopters with a torque tube part number 369H7133-7 installed. The 
NPRM published in the Federal Register on August 8, 2024 (89 FR 64834). 
The NPRM was prompted by a report of a seized and damaged roller 
bearing assembly in the torque tube assembly of an MDHI Model MD369E 
helicopter. 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. In 
the NPRM, the FAA proposed to 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. The FAA is issuing this AD to address the unsafe 
condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    The FAA reviewed the relevant data and determined that air safety 
requires adopting this AD as proposed. Accordingly, the FAA is issuing 
this AD to address the unsafe condition on these products. Except for 
minor editorial changes and clarifying two paragraph cross-references 
in the Required Actions section of this AD, paragraphs (g)(2)(iii)(A) 
and (g)(2)(iv), by replacing the text ``paragraph (g)(2)(iii) of this 
AD'' with ``the introductory text of paragraph (g)(2)(iii) of this 
AD,'' this AD is adopted as proposed in the NPRM.

Costs of Compliance

    The FAA estimates that this AD affects 353 helicopters of U.S. 
registry. Labor costs are estimated at $85 per work-hour. Based on 
these numbers, the FAA estimates the following costs to comply with 
this AD.
    Visually inspecting the torque tube and roller bearings will take 1 
work-hour for an estimated cost of $85 per helicopter and $30,005 for 
the U.S. fleet,

[[Page 91249]]

per inspection cycle. Inspecting the torque tube assembly for freedom 
of movement will take 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 will take 
0.25 work-hour for an estimated cost of $21 per helicopter, per 
instance.
    If required, replacing a torque tube will take 6 work-hours and 
parts will cost $4,773 for an estimated cost of $5,283 per torque tube 
replacement. Replacing a roller bearing will take 6 work-hours and 
parts will cost $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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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:

2024-23-06 MD Helicopters, LLC: Amendment 39-22885; Docket No. FAA-
2024-2011; Project Identifier AD-2023-01121-R.

(a) Effective Date

    This airworthiness directive (AD) is effective December 24, 
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.
BILLING CODE 4910-13-P

[[Page 91250]]

Figure 1 to Paragraph (g)(1)--Torque Tube Assembly
[GRAPHIC] [TIFF OMITTED] TR19NO24.001

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 the introductory text of paragraph (g)(2)(iii) of

[[Page 91251]]

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 the introductory text of 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 November 12, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-26919 Filed 11-18-24; 8:45 am]
BILLING CODE 4910-13-P
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